64 results on '"Bucher, AM"'
Search Results
2. A survey on the integration and cooperation of various NUM projects within CODEX+
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Schmidt, M, Bartholmes, A, Kadioglu, D, Bucher, AM, Majeed, RW, Triefenbach, L, Boor, P, Röhrig, R, Storf, H, Schmidt, M, Bartholmes, A, Kadioglu, D, Bucher, AM, Majeed, RW, Triefenbach, L, Boor, P, Röhrig, R, and Storf, H
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- 2023
3. Carboplatin pharmacokinetics following a single-dose infusion in sulphur-crested cockatoos (Cacatua galerita)
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FILIPPICH, LJ, primary, CHARLES, BG, additional, SUTTON, RH, additional, and BUCHER, AM, additional
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- 2004
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4. Platinum pharmacokinetics in sulphur-crested cockatoos (Cacatua galerita) following single-dose cisplatin infusion
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FILIPPICH, LJ, primary, BUCHER, AM, additional, and CHARLES, BG, additional
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- 2000
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5. The prognostic relevance of pleural effusion in patients with COVID-19 - A German multicenter study.
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Bucher AM, Dietz J, Ehrengut C, Müller L, Schramm D, Akinina A, Drechsel M, Kloeckner R, Sieren M, Isfort P, Sähn MJ, Fink MA, Móré D, Melekh B, Meinel FG, Schön H, May MS, Siegler L, Münzfeld H, Ruppel R, Penzkofer T, Kim MS, Balzer M, Borggrefe J, Meyer HJ, and Surov A
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- Humans, Female, Male, Germany epidemiology, Prognosis, Retrospective Studies, Aged, Middle Aged, Respiration, Artificial statistics & numerical data, Aged, 80 and over, SARS-CoV-2, Adult, COVID-19 mortality, COVID-19 complications, COVID-19 diagnostic imaging, Pleural Effusion diagnostic imaging, Pleural Effusion mortality, Tomography, X-Ray Computed methods
- Abstract
Purpose: This study evaluates the prognostic significance of pleural effusion (PE) in COVID-19 patients across thirteen centers in Germany, aiming to clarify its role in predicting clinical outcomes., Methods: In this retrospective analysis within the RACOON project (Radiological Cooperative Network of the COVID-19 pandemic), 1183 patients (29.3 % women, 70.7 % men) underwent chest CT to assess PE. We investigated PE's association with 30-day mortality, ICU admission, and the need for mechanical ventilation., Results: PE was detected in 31.5 % of patients, showing a significant correlation with 30-day mortality (47.5 % in non-survivors vs. 27.3 % in survivors, p < 0.001), with a hazard ratio of 2.22 (95 % CI 1.65-2.99, p < 0.001). No significant association was found between PE volume or density and mortality. ICU admissions were noted in 46.8 % of patients, while mechanical ventilation was required for 26.7 %., Conclusion: Pleural effusion is present in a significant portion of COVID-19 patients and independently predicts increased 30-day mortality, underscoring its value as a prognostic marker. Its identification, irrespective of volume or density, should be a priority in radiological reports to guide clinical decision-making., Competing Interests: Declaration of competing interest The authors have no competing interests to declare that are relevant to the content of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2025
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6. Evaluating Medical Image Segmentation Models Using Augmentation.
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Sayed M, Saba-Sadiya S, Wichtlhuber B, Dietz J, Neitzel M, Keller L, Roig G, and Bucher AM
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- Humans, Algorithms, Reproducibility of Results, Tomography, X-Ray Computed methods, Image Processing, Computer-Assisted methods
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Background: Medical imagesegmentation is an essential step in both clinical and research applications, and automated segmentation models-such as TotalSegmentator-have become ubiquitous. However, robust methods for validating the accuracy of these models remain limited, and manual inspection is often necessary before the segmentation masks produced by these models can be used., Methods: To address this gap, we have developed a novel validation framework for segmentation models, leveraging data augmentation to assess model consistency. We produced segmentation masks for both the original and augmented scans, and we calculated the alignment metrics between these segmentation masks., Results: Our results demonstrate strong correlation between the segmentation quality of the original scan and the average alignment between the masks of the original and augmented CT scans. These results were further validated by supporting metrics, including the coefficient of variance and the average symmetric surface distance, indicating that agreement with augmented-scan segmentation masks is a valid proxy for segmentation quality., Conclusions: Overall, our framework offers a pipeline for evaluating segmentation performance without relying on manually labeled ground truth data, establishing a foundation for future advancements in automated medical image analysis.
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- 2024
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7. CT-Defined Pectoralis Muscle Density Predicts 30-Day Mortality in Hospitalized Patients with COVID-19: A Nationwide Multicenter Study.
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Bucher AM, Behrend J, Ehrengut C, Müller L, Emrich T, Schramm D, Akinina A, Kloeckner R, Sieren M, Berkel L, Kuhl C, Sähn MJ, Fink MA, Móré D, Melekh B, Kardas H, Meinel FG, Schön H, Kornemann N, Renz DM, Lubina N, Wollny C, Both M, Watkinson J, Stöcklein S, Mittermeier A, Abaci G, May M, Siegler L, Penzkofer T, Lindholz M, Balzer M, Kim MS, Römer C, Wrede N, Götz S, Breckow J, Borggrefe J, Meyer HJ, and Surov A
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Rationale and Objectives: The prognostic role of computed tomography (CT)-defined skeletal muscle features in COVID-19 is still under investigation. The aim of the present study was to evaluate the prognostic role of CT-defined skeletal muscle area and density in patients with COVID-19 in a multicenter setting., Materials and Methods: This retrospective study is a part of the German multicenter project RACOON (Radiological Cooperative Network of the COVID-19 pandemic). The acquired sample included 1379 patients, 389 (28.2%) women and 990 (71.8%) men. In each case, chest CT was analyzed and pectoralis muscle area and density were calculated. Data were analyzed by means of descriptive statistics. Group differences were calculated using the Mann-Whitney-U test and Fisher's exact test. Univariable and multivariable logistic regression analyses were performed., Results: The 30-day mortality was 17.9%. Using median values as thresholds, low pectoralis muscle density (LPMD) was a strong and independent predictor of 30-day mortality, HR=2.97, 95%-CI: 1.52-5.80, p=0.001. Also in male patients, LPMD predicted independently 30-day mortality, HR=2.96, 95%-CI: 1.42-6.18, p=0.004. In female patients, the analyzed pectoralis muscle parameters did not predict 30-day mortality. For patients under 60 years of age, LPMD was strongly associated with 30-day mortality, HR=2.72, 95%-CI: 1.17;6.30, p=0.019. For patients over 60 years of age, pectoralis muscle parameters could not predict 30-day mortality., Conclusion: In male patients with COVID-19, low pectoralis muscle density is strongly associated with 30-day mortality and can be used for risk stratification. In female patients with COVID-19, pectoralis muscle parameters cannot predict 30-day mortality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
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- 2024
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8. Current State of Community-Driven Radiological AI Deployment in Medical Imaging.
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Gupta V, Erdal B, Ramirez C, Floca R, Genereaux B, Bryson S, Bridge C, Kleesiek J, Nensa F, Braren R, Younis K, Penzkofer T, Bucher AM, Qin MM, Bae G, Lee H, Cardoso MJ, Ourselin S, Kerfoot E, Choudhury R, White RD, Cook T, Bericat D, Lungren M, Haukioja R, and Shuaib H
- Abstract
Artificial intelligence (AI) has become commonplace in solving routine everyday tasks. Because of the exponential growth in medical imaging data volume and complexity, the workload on radiologists is steadily increasing. AI has been shown to improve efficiency in medical image generation, processing, and interpretation, and various such AI models have been developed across research laboratories worldwide. However, very few of these, if any, find their way into routine clinical use, a discrepancy that reflects the divide between AI research and successful AI translation. The goal of this paper is to give an overview of the intersection of AI and medical imaging landscapes. We also want to inform the readers about the importance of using standards in their radiology workflow and the challenges associated with deploying AI models in the clinical workflow. The main focus of this paper is to examine the existing condition of radiology workflow and identify the challenges hindering the implementation of AI in hospital settings. This report reflects extensive weekly discussions and practical problem-solving expertise accumulated over multiple years by industry experts, imaging informatics professionals, research scientists, and clinicians. To gain a deeper understanding of the requirements for deploying AI models, we introduce a taxonomy of AI use cases, supplemented by real-world instances of AI model integration within hospitals. We will also explain how the need for AI integration in radiology can be addressed using the Medical Open Network for AI (MONAI). MONAI is an open-source consortium for providing reproducible deep learning solutions and integration tools for radiology practice in hospitals., (©Vikash Gupta, Barbaros Erdal, Carolina Ramirez, Ralf Floca, Bradley Genereaux, Sidney Bryson, Christopher Bridge, Jens Kleesiek, Felix Nensa, Rickmer Braren, Khaled Younis, Tobias Penzkofer, Andreas Michael Bucher, Ming Melvin Qin, Gigon Bae, Hyeonhoon Lee, M Jorge Cardoso, Sebastien Ourselin, Eric Kerfoot, Rahul Choudhury, Richard D White, Tessa Cook, David Bericat, Matthew Lungren, Risto Haukioja, Haris Shuaib. Originally published in JMIR AI (https://ai.jmir.org), 09.12.2024.)
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- 2024
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9. The influence of pretreatment respiratory sinus arrhythmia dimensions on trauma-focused cognitive behavioral therapy outcomes: Findings from a randomized controlled feasibility trial.
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Brown MP, Shenk CE, Allen B, Dunning ED, Lombera MA, Bucher AM, and Dreschel NA
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- Humans, Female, Male, Child, Adolescent, Emotional Regulation, Child Abuse psychology, Treatment Outcome, Cognitive Behavioral Therapy methods, Stress Disorders, Post-Traumatic therapy, Feasibility Studies, Respiratory Sinus Arrhythmia physiology
- Abstract
Child maltreatment is associated with respiratory sinus arrhythmia (RSA) dysregulation, a physiological indicator of emotion regulation that predicts elevated posttraumatic stress disorder (PTSD) symptoms and may be a mechanism of action for exposure-based therapies, such as trauma-focused cognitive behavioral therapy (TF-CBT). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT for improving emotion regulation following maltreatment. The current study reports findings from a randomized controlled feasibility trial (N = 33; M
age = 11.79 years, SD = 3.08; 63.6% White; 66.7% female) that measured youths' resting RSA, RSA reactivity, and RSA recovery in response to a pretreatment laboratory challenge. We tested whether (a) lower pretreatment resting RSA was associated with blunted RSA during the challenge; (b) either of the pretreatment RSA dimensions predicted more severe pretreatment PTSD symptoms; and (c) either of the pretreatment RSA dimensions predicted less severe posttreatment PTSD symptoms and, as an exploratory aim, whether this was moderated by treatment group (i.e., TF-CBT vs. TF-CBT + AAT). Results from multiple linear regression indicated that, after controlling for pretreatment symptom severity, there was a large effect size for higher resting RSA predicting less severe caregiver-reported posttreatment PTSD symptoms, β = -.52, p = .058, and higher RSA during recovery predicting less severe child-reported posttreatment PTSD symptoms, β = -.70, p = .056, although these findings were not significant. These preliminary results offer important insights for future studies to investigate how the ability to regulate RSA informs which children need additional support to benefit from psychotherapeutic treatment., (© 2024 The Authors. Journal of Traumatic Stress published by Wiley Periodicals LLC on behalf of International Society for Traumatic Stress Studies.)- Published
- 2024
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10. Value of MRI - T2 Mapping to Differentiate Clinically Significant Prostate Cancer.
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Bucher AM, Egger J, Dietz J, Strecker R, Hilbert T, Frodl E, Wenzel M, Penzkofer T, Hamm B, Chun FK, Vogl T, Kleesiek J, and Beeres M
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- Humans, Male, Middle Aged, Retrospective Studies, Aged, Prostate diagnostic imaging, Prostate pathology, Diagnosis, Differential, Image Interpretation, Computer-Assisted methods, Multiparametric Magnetic Resonance Imaging methods, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms pathology, Magnetic Resonance Imaging methods, Magnetic Resonance Imaging standards
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Standardized reporting of multiparametric prostate MRI (mpMRI) is widespread and follows international standards (Pi-RADS). However, quantitative measurements from mpMRI are not widely comparable. Although T2 mapping sequences can provide repeatable quantitative image measurements and extract reliable imaging biomarkers from mpMRI, they are often time-consuming. We therefore investigated the value of quantitative measurements on a highly accelerated T2 mapping sequence, in order to establish a threshold to differentiate benign from malignant lesions. For this purpose, we evaluated a novel, highly accelerated T2 mapping research sequence that enables high-resolution image acquisition with short acquisition times in everyday clinical practice. In this retrospective single-center study, we included 54 patients with clinically indicated MRI of the prostate and biopsy-confirmed carcinoma (n = 37) or exclusion of carcinoma (n = 17). All patients had received a standard of care biopsy of the prostate, results of which were used to confirm or exclude presence of malignant lesions. We used the linear mixed-effects model-fit by REML to determine the difference between mean values of cancerous tissue and healthy tissue. We found good differentiation between malignant lesions and normal appearing tissue in the peripheral zone based on the mean T2 value. Specifically, the mean T2 value for tissue without malignant lesions was (151.7 ms [95% CI: 146.9-156.5 ms] compared to 80.9 ms for malignant lesions [95% CI: 67.9-79.1 ms]; p < 0.001). Based on this assessment, a limit of 109.2 ms is suggested. Aditionally, a significant correlation was observed between T2 values of the peripheral zone and PI-RADS scores (p = 0.0194). However, no correlation was found between the Gleason Score and the T2 relaxation time. Using REML, we found a difference of -82.7 ms in mean values between cancerous tissue and healthy tissue. We established a cut-off-value of 109.2 ms to accurately differentiate between malignant and non-malignant prostate regions. The addition of T2 mapping sequences to routine imaging could benefit automated lesion detection and facilitate contrast-free multiparametric MRI of the prostate., Competing Interests: Declarations. Ethics Approval: For this IRB approved (No. 19-299), retrospective case-control study, the hospital's PACS was searched by an independent investigator for prostate MRIs between 08/2018 and 07/2019. Consent to Participate: For the retrospective case-control study, no consent to participate was needed. Consent to Publish: For the anonymized data, no consent to publish is needed. Competing Interests: R.S. and T.H. are employed by Siemens Healthineers. T.P. receives funding from Berlin Institute of Health (Advanced Clinician Scientist Grant, Platform Grant), Ministry of Education and Research (BMBF, 01KX2021 (RACOON), 01KX2121 („NUM 2.0“, RACOON), 68GX21001A, 01ZZ2315D), German Research Foundation (DFG, SFB 1340/2), European Union (H2020, CHAIMELEON: 952172, DIGITAL, EUCAIM:101100633) and reports research agreements (no personal payments, outside of submitted work) with AGO, Aprea AB, ARCAGY-GINECO, Astellas Pharma Global Inc. (APGD), Astra Zeneca, Clovis Oncology, Inc., Holaira, Incyte Corporation, Karyopharm, Lion Biotechnologies, Inc., MedImmune, Merck Sharp & Dohme Corp, Millennium Pharmaceuticals, Inc., Morphotec Inc., NovoCure Ltd., PharmaMar S.A. and PharmaMar USA, Inc., Roche, Siemens Healthineers, and TESARO Inc., and fees for a book translation (Elsevier B.V.). A.M.B.: Bayer, Guebert, Siemens Healthineers (Consulting fees and travel Support)., (© 2024. The Author(s).)
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- 2024
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11. Malignancy predictors and treatment strategies for adult intestinal intussusception.
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Reschke P, Le Hong QA, Gruenewald LD, Gotta J, Koch V, Höhne E, Mahmoudi S, Juergens LJ, Hescheler DA, Bucher AM, Biciusca T, Schreckenbach T, Martin SS, Booz C, Hammerstingl R, Yel I, Mader C, Scholtz JE, Pinto Dos Santos D, Eichler K, Vogl TJ, and Gruber-Rouh T
- Abstract
Intussusception in adult patients is a rare medical finding, which is accompanied by an underlying tumor in some cases. However, no accepted method has been established to identify patients at risk for tumor-related intussusception. This study aimed to identify imaging features as predictors for tumor-related intussusception.CT images of patients with confirmed intussusception were retrospectively acquired between 01/2008 and 12/2022. Available follow-up images and medical health records were evaluated to identify various imaging features, the cause of intussusception, and treatment strategies. Imaging interpretation was conducted by two blinded radiologists. A third radiologist was consulted in cases of disagreement.A total of 71 consecutive patients were included in this study (42 males, 29 females) with a median age of 56 years (interquartile range: 40.5-73.8 years). Enteroenteric intussusceptions in the small bowel were the most common type observed in adult patients. In contrast, colocolic intussusception was more frequently associated with malignancy, and this association was statistically significant (p < 0.05). Among the malignant tumors, adenocarcinoma was the most common, followed by metastases and lymphoma. Additionally, bowel obstruction and wall thickening were significantly correlated with malignancy (p < 0.05). The high negative predictive values (NPVs) and high specificities for ileus (NPV 88.5%, specificity 82.1%), bowel wall thickening (NPV 90.9%, specificity 71.4%), and acute abdomen (NPV 84.6%, specificity 78.8%) suggest that the absence of these features strongly predicts a low probability of malignancy in cases of adult intussusception.Active surveillance with follow-up exams is suitable for asymptomatic and transient intussusception when imaging features suggest a low likelihood of a neoplasm. Additionally, malignancy predictors such as ileus and thickening of the bowel wall in the affected segment could guide tailored treatment. Surgical interventions are essential for symptomatic cases, with adenocarcinoma being the most common malignancy found in colocolic intussusceptions.Intussusception in adults is rare and is often associated with underlying tumors, particularly in colocolic intussusceptions. Key imaging predictors for malignancy include bowel obstruction, wall thickening in the affected segment, and the presence of acute abdomen, with high NPVs and specificities indicating low malignancy risk when these features are absent. Active surveillance is recommended for asymptomatic cases with low neoplasm probability, while surgical intervention is the method of choice for symptomatic patients. · Reschke P, Le Hong QA, Gruenewald LD et al. Malignancy predictors and treatment strategies for adult intestinal intussusception. Fortschr Röntgenstr 2024; DOI 10.1055/a-2434-7932., Competing Interests: C.B. received speaking fees from Siemens Healthineers. I.Y. received a speaking fee from Siemens Healthineers., (Thieme. All rights reserved.)
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- 2024
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12. Assessment of Different Castration Resistance Definitions and Staging Modalities in Metastatic Castration-Resistant Prostate Cancer.
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Wenzel M, Hoeh B, Humke C, Siech C, Cano Garcia C, Salomon G, Maurer T, Graefen M, Bernatz S, Bucher AM, Kluth L, Chun FKH, and Mandel P
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Background/Objectives : Progression to metastatic castration-resistant prostate cancer (mCRPC) is defined either biochemically, radiographically or both. Moreover, staging for mCRPC can be performed either conventionally or with molecular imaging such as prostate-specific membrane antigen computer tomography (PSMA-PET/CT). Methods : We relied on the Frankfurt Metastatic Cancer Database of the Prostate (FRAMCAP) database to compare progression-free (PFS) and overall survival (OS) outcomes regarding the cause of castration resistance and the staging modality used. Results : Overall, 35% progressed to mCRPC biochemically vs. 23% radiographically vs. 42% biochemically + radiographically. The PSA nadir in mHSPC (1.4 vs. 0.4 vs. 0.8 ng/mL) and PSA level at mCRPC progression (15 vs. 2 vs. 21 ng/mL, both p ≤ 0.01) were significantly higher for biochemical vs. radiographic vs. both progressed patients. In PFS and OS analyses, no significant differences were observed among all three compared groups. In the comparison of the staging used for progression to mCRPC, 67% received conventional vs. 33% PSMA-PET/CT, with higher metastatic burden in mHSPC and osseous lesions in mCRPC for conventionally staged patients (both p < 0.01). In PFS (15.3 vs. 10.1 months, hazard ratio [HR]: 0.75) and OS analyses (52.6 vs. 34.3 months, HR: 0.61, both p < 0.05), PSMA-PET/CT harbored better prognosis; however, this did not hold after multivariable adjustment. Similar results were observed for further analyses in second- and third-line mCRPC or patients with a PSA level of ≥2 ng/mL. Conclusions : The cause of progression to mCRPC seems not to influence cancer-control outcomes, despite important baseline tumor characteristic differences. The PSMA-PET/CT staging modality might be associated with better PFS and OS outcomes, possibly due to its more sensitive detection of progression or new metastatic lesions.
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- 2024
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13. Enhancing Forensic Diagnostics: Structured Reporting of Post-Mortem CT versus Autopsy for Laryngohyoid Complex Fractures in Strangulation.
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Bucher AM, Koppold A, Kettner M, Kölzer S, Dietz J, Frodl E, Surov A, Pinto Dos Santos D, Vogl TJ, Verhoff MA, Beeres M, Lux C, and Heinbuch S
- Abstract
Background: The purpose of this study was to establish a standardized structured workflow to compare findings from high-resolution, optimized reconstructions from post-mortem computed tomography (pmCT) with autopsy results in the detection of fractures of the laryngohyoid complex in strangulation victims., Method: Forty-two strangulation cases were selected, and pmCT scans of the laryngohyoid complex were obtained. Both pmCT scans and autopsy reports were analyzed using a structured template and compared using Cohen's kappa coefficient (κ) and the McNemar test. The study also compared the prevalence of ossa sesamoidea and non-fusion of the major and minor horns of the hyoid bone between both diagnostic methods., Results: The detection of fractures showed a very good correlation between autopsy and pmCT results (κ = 0.905), with the McNemar test showing no statistically significant difference between the two methods. PmCT identified 28 sesamoid bones, 45 non-fusions of the major horns, and 47 non-fusions of the minor horns of the hyoid bone, compared to four, six, and zero, respectively, identified by autopsy ( p < 0.0001)., Conclusions: Autopsy and pmCT findings correlate well and can be used in a complementary manner. PmCT is superior to autopsy in identifying dislocations and detecting anatomical variations in the laryngohyoid complex, which can lead to misinterpretations during autopsy. Therefore, we do not advocate replacing autopsy with pmCT but propose using a structured workflow, including our standardized reporting template, for evaluating lesions in the laryngohyoid complex.
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- 2024
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14. Prevalence and prognostic role of thoracic lymphadenopathy in Covid-19.
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Bucher AM, Sieren MM, Meinel FG, Kloeckner R, Fink MA, Sähn MJ, Wienke A, Meyer HJ, Penzkofer T, Dietz J, Vogl TJ, Borggrefe J, and Surov A
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Purpose: The prevalent coronavirus disease 2019 (COVID-19) pandemic has spread throughout the world and is considered a serious threat to global health. The prognostic role of thoracic lymphadenopathy in COVID-19 is unclear. The aim of the present meta-analysis was to analyze the prognostic role of thoracic lymphadenopathy for the prediction of 30-day mortality in patients with COVID-19., Materials and Methods: The MEDLINE library, Cochrane, and SCOPUS databases were screened for associations between CT-defined features and mortality in COVID-19 patients up to June 2021. In total, 21 studies were included in the present analysis. The quality of the included studies was assessed by the Newcastle-Ottawa Scale. The meta-analysis was performed using RevMan 5.3. Heterogeneity was calculated by means of the inconsistency index I2. DerSimonian and Laird random-effect models with inverse variance weights were performed without any further correction., Results: The included studies comprised 4621 patients. The prevalence of thoracic lymphadenopathy varied between 1 % and 73.4 %. The pooled prevalence was 16.7 %, 95 % CI = (15.6 %; 17.8 %). The hospital mortality was higher in patients with thoracic lymphadenopathy (34.7 %) than in patients without (20.0 %). The pooled odds ratio for the influence of thoracic lymphadenopathy on mortality was 2.13 (95 % CI = [1.80-2.52], p < 0.001)., Conclusion: The prevalence of thoracic lymphadenopathy in COVID-19 is 16.7 %. The presence of thoracic lymphadenopathy is associated with an approximately twofold increase in the risk for hospital mortality in COVID-19., Key Points: · The prevalence of lymphadenopathy in COVID-19 is 16.7 %.. · Patients with lymphadenopathy in COVID-19 have a higher risk of mortality during hospitalization.. · Lymphadenopathy nearly doubles mortality and plays an important prognostic role.., Citation Format: · Bucher AM, Sieren M, Meinel F et al. Prevalence and prognostic role of thoracic lymphadenopathy in Covid-19. Fortschr Röntgenstr 2024; DOI: 10.1055/a-2293-8132., Competing Interests: R. K.: Consulting fees from Boston Scientific, Bristol Myers Squibb, Guerbet, Roche, and Sirtex; payment for lectures from BTG, Eisai, Guerbet, Ipsen, Roche, Siemens, Sirtex, and MSD Sharp & Dohme; chair of the European Society of Radiology Audit and Standards Subcommittee.A.M.B.: Bayer, Guebert, Siemens Healthineers (Consulting fees and travel Support) T.P.: Fördermittel vom Berlin Institute of Health (Advanced Clinician Scientist Grant, Platform Grant), Bundesministerium für Bildung und Forschung (BMBF, 01KX2021 (RACOON), 01KX2121 (“NUM 2. 0” RACOON), 68GX21001A, 01ZZ2315D), Deutsche Forschungsgemeinschaft (DFG, SFB 1340/2), Europäische Union (H2020, CHAIMELEON: 952172, DIGITAL, EUCAIM:101100633) und berichtet über Forschungsvereinbarungen (keine persönlichen Zuwendungen, außerhalb der eingereichten Arbeit) mit AGO, Aprea AB, ARCAGY-GINECO, Astellas Pharma Global Inc. (APGD), Astra Zeneca, Clovis Oncology, Inc, Holaira, Incyte Corporation, Karyopharm, Lion Biotechnologies, Inc, MedImmune, Merck Sharp & Dohme Corp, Millennium Pharmaceuticals, Inc, Morphotec Inc, NovoCure Ltd, PharmaMar S.A. und PharmaMar USA, Inc, Roche, Siemens Healthineers und TESARO Inc, sowie Honorare für eine Buchübersetzung (Elsevier B.V.)., (Thieme. All rights reserved.)
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- 2024
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15. Cooperative AI training for cardiothoracic segmentation in computed tomography: An iterative multi-center annotation approach.
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Lassen-Schmidt B, Baessler B, Gutberlet M, Berger J, Brendel JM, Bucher AM, Emrich T, Fervers P, Kottlors J, Kuhl P, May MS, Penzkofer T, Persigehl T, Renz D, Sähn MJ, Siegler L, Kohlmann P, Köhn A, Link F, Meine H, Thiemann MT, Hahn HK, and Sieren MM
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- Humans, Radiographic Image Interpretation, Computer-Assisted methods, Radiography, Thoracic methods, Artificial Intelligence, Mediastinum diagnostic imaging, Heart diagnostic imaging, Tomography, X-Ray Computed methods
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Purpose: Radiological reporting is transitioning to quantitative analysis, requiring large-scale multi-center validation of biomarkers. A major prerequisite and bottleneck for this task is the voxelwise annotation of image data, which is time-consuming for large cohorts. In this study, we propose an iterative training workflow to support and facilitate such segmentation tasks, specifically for high-resolution thoracic CT data., Methods: Our study included 132 thoracic CT scans from clinical practice, annotated by 13 radiologists. In three iterative training experiments, we aimed to improve and accelerate segmentation of the heart and mediastinum. Each experiment started with manual segmentation of 5-25 CT scans, which served as training data for a nnU-Net. Further iterations incorporated AI pre-segmentation and human correction to improve accuracy, accelerate the annotation process, and reduce human involvement over time., Results: Results showed consistent improvement in AI model quality with each iteration. Resampled datasets improved the Dice similarity coefficients for both the heart (DCS 0.91 [0.88; 0.92]) and the mediastinum (DCS 0.95 [0.94; 0.95]). Our AI models reduced human interaction time by 50 % for heart and 70 % for mediastinum segmentation in the most potent iteration. A model trained on only five datasets achieved satisfactory results (DCS > 0.90)., Conclusions: The iterative training workflow provides an efficient method for training AI-based segmentation models in multi-center studies, improving accuracy over time and simultaneously reducing human intervention. Future work will explore the use of fewer initial datasets and additional pre-processing methods to enhance model quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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16. Multiparametric Cardiovascular MRI Assessment of Post-COVID Syndrome in Children in Comparison to Matched Healthy Individuals.
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Eckstein J, Skeries V, Pöhler G, Babazade N, Kaireit T, Gutberlet M, Kornemann N, Hellms S, Pfeil A, Bucher AM, Hansmann G, Beerbaum P, Hansen G, Wacker F, Vogel-Claussen J, Wetzke M, and Renz DM
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- Humans, Male, Female, Adolescent, Prospective Studies, Child, SARS-CoV-2, Case-Control Studies, Post-Acute COVID-19 Syndrome, Heart diagnostic imaging, COVID-19 diagnostic imaging, COVID-19 complications, Magnetic Resonance Imaging methods
- Abstract
Background: Post-COVID syndrome (PCS) can adversely affect the quality of life of patients and their families. In particular, the degree of cardiac impairment in children with PCS is unknown., Objective: The aim of this study was to identify potential cardiac inflammatory sequelae in children with PCS compared with healthy controls., Methods: This single-center, prospective, intraindividual, observational study assesses cardiac function, global and segment-based strains, and tissue characterization in 29 age- and sex-matched children with PCS and healthy children using a 3 T magnetic resonance imaging (MRI)., Results: Cardiac MRI was carried out over 36.4 ± 24.9 weeks post-COVID infection. The study cohort has an average age of 14.0 ± 2.8 years, for which the majority of individuals experience from fatigue, concentration disorders, dyspnea, dizziness, and muscle ache. Children with PSC in contrast to the control group exhibited elevated heart rate (83.7 ± 18.1 beats per minute vs 75.2 ± 11.2 beats per minute, P = 0.019), increased indexed right ventricular end-diastolic volume (95.2 ± 19.2 mlm -2 vs 82.0 ± 21.5 mlm -2 , P = 0.018) and end-systolic volume (40.3 ± 7.9 mlm -2 vs 34.8 ± 6.2 mlm -2 , P = 0.005), and elevated basal and midventricular T1 and T2 relaxation times ( P < 0.001 to P = 0.013). Based on the updated Lake Louise Criteria, myocardial inflammation is present in 20 (69%) children with PCS. No statistically significant difference was observed for global strains., Conclusions: Cardiac MRI revealed altered right ventricular volumetrics and elevated T1 and T2 mapping values in children with PCS, suggestive for a diffuse myocardial inflammation, which may be useful for the diagnostic workup of PCS in children., Competing Interests: Conflicts of interest and sources of funding: Ministry for Science and Culture of Lower Saxony in Germany (grant number: ZN3894); Radiological Cooperative Network (RACOON) of the Network University Medicine (NUM) under the BMBF grant numbers 01KX2021 and 01KX2121., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)
- Published
- 2024
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17. Editorial for "Magnetic Resonance Imaging-Based Classification Systems for Informing Better Outcomes of Adenomyosis After Ultrasound-Guided High-Intensity Focused Ultrasound Ablating Surgery".
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Bucher AM, Penzkofer T, and May MS
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- Female, Humans, Treatment Outcome, Magnetic Resonance Imaging, Ultrasonography, Interventional, Adenomyosis diagnostic imaging, Adenomyosis surgery, High-Intensity Focused Ultrasound Ablation
- Published
- 2024
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18. Pericardial Effusion Predicts Clinical Outcomes in Patients with COVID-19: A Nationwide Multicenter Study.
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Bucher AM, Henzel K, Meyer HJ, Ehrengut C, Müller L, Schramm D, Akinina A, Drechsel M, Kloeckner R, Isfort P, Sähn MJ, Fink M, More D, Melekh B, Meinel FG, Dreger F, May M, Siegler L, Münzfeld H, Ruppel R, Penzkofer T, Kim MS, Balzer M, Borggrefe J, and Surov A
- Subjects
- Humans, Male, Female, Retrospective Studies, Aged, Middle Aged, Prognosis, Germany epidemiology, Respiration, Artificial statistics & numerical data, SARS-CoV-2, Intensive Care Units, Aged, 80 and over, COVID-19 mortality, COVID-19 epidemiology, COVID-19 diagnostic imaging, COVID-19 complications, Pericardial Effusion diagnostic imaging, Pericardial Effusion epidemiology, Tomography, X-Ray Computed
- Abstract
Rationale and Objectives: The prognostic role of pericardial effusion (PE) in Covid 19 is unclear. The aim of the present study was to estimate the prognostic role of PE in patients with Covid 19 in a large multicentre setting., Materials and Methods: This retrospective study is a part of the German multicenter project RACOON (Radiological Cooperative Network of the Covid 19 pandemic). The acquired sample comprises 1197 patients, 363 (30.3%) women and 834 (69.7%) men. In every case, chest computed tomography was analyzed for PE. Data about 30-day mortality, need for mechanical ventilation and need for intensive care unit (ICU) admission were collected. Data were evaluated by means of descriptive statistics. Group differences were calculated with Mann-Whitney test and Fisher exact test. Uni-and multivariable regression analyses were performed., Results: Overall, 46.4% of the patients were admitted to ICU, mechanical lung ventilation was performed in 26.6% and 30-day mortality was 24%. PE was identified in 159 patients (13.3%). The presence of PE was associated with 30-day mortality: HR= 1.54, CI 95% (1.05; 2.23), p = 0.02 (univariable analysis), and HR= 1.60, CI 95% (1.03; 2.48), p = 0.03 (multivariable analysis). Furthermore, density of PE was associated with the need for intubation (OR=1.02, CI 95% (1.003; 1.05), p = 0.03) and the need for ICU admission (OR=1.03, CI 95% (1.005; 1.05), p = 0.01) in univariable regression analysis. The presence of PE was associated with 30-day mortality in male patients, HR= 1.56, CI 95%(1.01-2.43), p = 0.04 (multivariable analysis). In female patients, none of PE values predicted clinical outcomes., Conclusion: The prevalence of PE in Covid 19 is 13.3%. PE is an independent predictor of 30-day mortality in male patients with Covid 19. In female patients, PE plays no predictive role., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
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- 2024
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19. Lightweight Techniques to Improve Generalization and Robustness of U-Net Based Networks for Pulmonary Lobe Segmentation.
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Dadras AA, Jaziri A, Frodl E, Vogl TJ, Dietz J, and Bucher AM
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Lung lobe segmentation in chest CT is relevant to a wide range of clinical applications. However, existing segmentation pipelines often exhibit vulnerabilities and performance degradations when applied to external datasets. This is usually attributed to the size of the available dataset or model. We show that it is possible to enhance generalizability without huge resources by carefully curating the dataset and combining machine learning with medical expertise. Multiple machine learning techniques (self-supervision (SSL), attention (A), and data augmentation (DA)) are used to train a fast and fully-automated lung lobe segmentation model based on 2D U-Net. Our study involved evaluating these techniques on a diverse dataset collected under the RACOON project, encompassing 100 CT chest scans from patients with bacterial, viral, or SARS-CoV2 infections. We compare our model to a baseline U-Net trained on the same dataset. Our approach significantly improved segmentation accuracy (Dice score of 92.8% vs. 82.3%, p < 0.001). Moreover, our model achieved state-of-the-art performance (Dice score of 92.8% vs. 90.8% for the literature's state-of-the-art, p = 0.102) with reduced training examples (69 vs. 231 CT Scans). Among the techniques, data augmentation with expert knowledge displayed the most significant impact, enhancing the Dice score by +0.056. Notably, these enhancements are not limited to lobe segmentation but can be seamlessly integrated into various medical imaging segmentation tasks, demonstrating their versatility and potential for broader applications.
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- 2023
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20. Challenges in Implementing the Local Node Infrastructure for a National Federated Machine Learning Network in Radiology.
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Jacobs PP, Ehrengut C, Bucher AM, Penzkofer T, Lukas M, Kleesiek J, and Denecke T
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Data-driven machine learning in medical research and diagnostics needs large-scale datasets curated by clinical experts. The generation of large datasets can be challenging in terms of resource consumption and time effort, while generalizability and validation of the developed models significantly benefit from variety in data sources. Training algorithms on smaller decentralized datasets through federated learning can reduce effort, but require the implementation of a specific and ambitious infrastructure to share data, algorithms and computing time. Additionally, it offers the opportunity of maintaining and keeping the data locally. Thus, data safety issues can be avoided because patient data must not be shared. Machine learning models are trained on local data by sharing the model and through an established network. In addition to commercial applications, there are also numerous academic and customized implementations of network infrastructures available. The configuration of these networks primarily differs, yet adheres to a standard framework composed of fundamental components. In this technical note, we propose basic infrastructure requirements for data governance, data science workflows, and local node set-up, and report on the advantages and experienced pitfalls in implementing the local infrastructure with the German Radiological Cooperative Network initiative as the use case example. We show how the infrastructure can be built upon some base components to reflect the needs of a federated learning network and how they can be implemented considering both local and global network requirements. After analyzing the deployment process in different settings and scenarios, we recommend integrating the local node into an existing clinical IT infrastructure. This approach offers benefits in terms of maintenance and deployment effort compared to external integration in a separate environment (e.g., the radiology department). This proposed groundwork can be taken as an exemplary development guideline for future applications of federated learning networks in clinical and scientific environments.
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- 2023
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21. Work expectations, their fulfillment, and exhaustion among radiologists of all career levels: what can be learned from the example of Germany.
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Molwitz I, Kemper C, Stahlmann K, Oechtering TH, Sieren MM, Afat S, Gerwing M, Bucher AM, Storz C, Langenbach MC, Reim M, Lotz J, Zagrosek-Regitz V, Can E, Köhler D, Yamamura J, Adam G, Hamm B, and Keller S
- Subjects
- Humans, Motivation, Radiologists psychology, Surveys and Questionnaires, Physicians psychology, Burnout, Professional epidemiology, Burnout, Professional psychology, Internship and Residency
- Abstract
Objectives: To evaluate work expectations of radiologists at different career levels, their fulfillment, prevalence of exhaustion, and exhaustion-associated factors., Methods: A standardized digital questionnaire was distributed internationally to radiologists of all career levels in the hospital and in ambulatory care via radiological societies and sent manually to 4500 radiologists of the largest German hospitals between December 2020 and April 2021. Statistics were based on age- and gender-adjusted regression analyses of respondents working in Germany (510 out of 594 total respondents)., Results: The most frequent expectations were "joy at work" (97%) and a "good working atmosphere" (97%), which were considered fulfilled by at least 78%. The expectation of a "structured residency within the regular time interval" (79%) was more frequently judged fulfilled by senior physicians (83%, odds ratio (OR) 4.31 [95% confidence interval (95% CI) 1.95-9.52]), chief physicians (85%, 6.81 [95% CI 1.91-24.29]), and radiologists outside the hospital (88%, 7.59 [95% CI 2.40-24.03]) than by residents (68%). Exhaustion was most common among residents (physical exhaustion: 38%; emotional exhaustion: 36%), in-hospital specialists (29%; 38%), and senior physicians (30%; 29%). In contrast to paid extra hours, unpaid extra hours were associated with physical exhaustion (5-10 extra hours: OR 2.54 [95% CI 1.54-4.19]). Fewer opportunities to shape the work environment were related to a higher probability of physical (2.03 [95% CI 1.32-3.13]) and emotional (2.15 [95% CI 1.39-3.33]) exhaustion., Conclusions: While most radiologists enjoy their work, residents wish for more training structure. Ensuring payment of extra hours and employee empowerment may help preventing burnout in high-risk groups., Key Points: • Most important work expectations of radiologists who work in Germany are "joy at work," a "good working atmosphere," "support for further qualification," and a "structured residency within the regular time interval," with the latter containing potential for improvement according to residents. • Physical and emotional exhaustion are common at all career levels except for chief physicians and for radiologists who work outside the hospital in ambulatory care. • Exhaustion as a major burnout criterion is associated with unpaid extra hours and reduced opportunities to shape the work environment., (© 2023. The Author(s).)
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- 2023
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22. Work and Training Conditions of German Residents and Young Radiologists in Interventional Radiology - A Nationwide Survey.
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Sieren M, Katoh M, Mahnken AH, Reimer P, Westphalen K, Hoffmann RT, Paprottka P, Rohde S, Wacker FK, Minko P, Molwitz I, Oechtering TH, Afat S, Bucher AM, Gerwing M, Storz C, Ziegler HR, Barkhausen J, and Frisch A
- Subjects
- Male, Female, Humans, Germany, Surveys and Questionnaires, Curriculum, Radiology, Interventional education, Radiologists
- Abstract
With the increasing need for minimally invasive procedures based on lower complication rates, higher patient acceptance, and technical developments, there is a growing focus on the sound interventional training of young radiologists. This survey aimed to analyze the current situation in interventional radiology (IR) training in Germany to detect shortcomings and identify areas for improvement.From November 1-30, 2020, an online questionnaire was distributed to representative radiological associations and societies with the request to forward it to radiology residents and radiologists < 40 years. The 44 questions covered six distinct areas from personal working conditions to the characterization of the IR department, training conditions, role of women in IR, and attendance at congresses/external training.A total of 330 participants completed the questionnaire. 77 % of participants expressed a high interest in IR, and 47 % could even imagine subspecializing in interventional radiology. Most institutions provided the necessary learning conditions and infrastructure. The rate of overall satisfaction with IR training conditions was 45 % (vs. a dissatisfaction rate of 39 %). However, females showed a lower satisfaction rate with their training environment than male participants (28 % vs. 51 %; P = 0.06). Positive correlations with work satisfaction were found for the presence and duration of the IR rotation, the number of partly independently/mentored performed interventions, and structured feedback. Moreover, the need for a structured training curriculum was expressed by 67 % of participants.Radiological residents and young radiologists expressed a high interest in interventional radiology, and they rate the infrastructure of German hospitals regarding IR as sufficient. However, they expressed the need for consistent IR rotations and better-structured resident and postgraduate education (curricula & interviews).Interest in interventional radiology among radiological residents and young radiologists in Germany is high, but satisfaction with interventional radiology training leaves room for improvement. The most frequently mentioned aspects that can improve IR training were · organized rotations of at least 6 months. · structured curriculums with face-to-face feedback. · structured guidance by senior interventionists during procedures. CITATION FORMAT: · Sieren M, Katoh M, Mahnken AH et al. Work and Training Conditions of German Residents and Young Radiologists in Interventional Radiology - A Nationwide Survey. Fortschr Röntgenstr 2022; 194: 1346 - 1357., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)
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- 2022
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23. Respiratory Sinus Arrhythmia Change during Trauma-Focused Cognitive-Behavioral Therapy: Results from a Randomized Controlled Feasibility Trial.
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Shenk CE, Allen B, Dreschel NA, Wang M, Felt JM, Brown MP, Bucher AM, Chen MJ, and Olson AE
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- Humans, Female, Male, Feasibility Studies, Arrhythmia, Sinus, Respiratory Sinus Arrhythmia physiology, Animal Assisted Therapy, Cognitive Behavioral Therapy methods, Stress Disorders, Post-Traumatic therapy
- Abstract
Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) is a well-established treatment for pediatric posttraumatic stress disorder (PTSD). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT that may improve treatment effects through enhanced targeting of affect regulation, as indexed by specific changes in the respiratory sinus arrhythmia (RSA). The current study reports results from a randomized controlled feasibility trial (N = 33; M
age = 11.79 [SD = 3.08]; 64% White; 67% female) that measured RSA during Sessions 1, 4, 8, and 12 of a twelve-session TF-CBT protocol and tested whether: 1) TF-CBT + AAT achieved higher average RSA amplitudes relative to TF-CBT alone, and 2) RSA regulation, defined as less variability around person-specific RSA slopes during treatment, explained variation in post-treatment PTSD symptoms. Multilevel modeling failed to support an effect for TF-CBT + AAT on RSA amplitudes (δ001 = 0.08, p = 0.844). However, regardless of treatment condition, greater RSA withdrawal was observed within Sessions 4 (γ11 = -.01, p < .001) and 12 (γ13 = -.01, p = .015) relative to the Session 1 baseline. The average level of RSA amplitude in Session 8 was also significantly lower compared to Session 1 (γ02 = -0.70, p = .046). Intraindividual regression models demonstrated that greater RSA regulation predicted improved PTSD symptoms at post-treatment after adjusting for pre-treatment levels (b3 = 20.00, p = .012). These preliminary results offer support for future confirmatory trials testing whether affect regulation, as indexed by changes in RSA, is a mechanism of action for TF-CBT in the treatment of pediatric PTSD., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)- Published
- 2022
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24. CODEX Meets RACOON - A Concept for Collaborative Documentation of Clinical and Radiological COVID-19 Data.
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Schmidt M, Gebauer S, Bartholmes A, Kadioglu D, Kleesiek J, Hamm B, Vogl TJ, Penzkofer T, Bucher AM, and Storf H
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- Animals, Documentation, Humans, Raccoons, Radiography, Workflow, COVID-19
- Abstract
Within the scope of the two NUM projects CODEX and RACOON we developed a preliminary technical concept for documenting clinical and radiological COVID-19 data in a collaborative approach and its preceding findings of a requirement analysis. At first, we provide an overview of NUM and its two projects CODEX and RACOON including the GECCO data set. Furthermore, we demonstrate the foundation for the increased collaboration of both projects, which was additionally supported by a survey conducted at University Hospital Frankfurt. Based on the survey results mint Lesion™, developed by Mint Medical and used at all project sites within RACOON, was selected as the "Electronic Data Capture" (EDC) system for CODEX. Moreover, to avoid duplicate entry of GECCO data into both EDC systems, an early effort was made to consider a collaborative and efficient technical approach to reduce the workload for the medical documentalists. As a first effort we present a preliminary technical concept representing the current and possible future data workflow of CODEX and RACOON. This concept includes a software component to synchronize GECCO data sets between the two EDC systems using the HL7 FHIR standard. Our first approach of a collaborative use of an EDC system and its medical documentalists could be beneficial in combination with the presented synchronization component for all participating project sites of CODEX and RACOON with regard to an overall reduced documentation workload.
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- 2022
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25. Vision, Development, and Structure of the First German Specialist Training Curriculum for Radiology.
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Molwitz I, Frisch A, Adam G, Afat S, Ammon J, Antoch G, Baeßler B, Balks F, Barkhausen J, Bayerl N, Brendlin A, Bucher AM, Dammann E, Ellmann S, Faron A, Gerwing M, Kaiser D, Nikolaou K, Özden C, Platz Batista da Silva N, Paulus C, Sieren M, Storz C, Vollbrecht T, Wegner F, Ziegler HR, and Oechtering TH
- Subjects
- Curriculum, Specialization, Internship and Residency, Radiology education
- Abstract
Competing Interests: The authors declare that they have no conflict of interest.
- Published
- 2022
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26. Integrating Animal-Assisted Therapy Into TF-CBT for Abused Youth With PTSD: A Randomized Controlled Feasibility Trial.
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Allen B, Shenk CE, Dreschel NE, Wang M, Bucher AM, Desir MP, Chen MJ, and Grabowski SR
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- Adolescent, Animals, Dogs, Feasibility Studies, Humans, Treatment Outcome, Animal Assisted Therapy, Cognitive Behavioral Therapy methods, Stress Disorders, Post-Traumatic diagnosis, Stress Disorders, Post-Traumatic therapy, Substance-Related Disorders
- Abstract
This clinical trial examined animal-assisted therapy (AAT) as an adjunct to Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) for abused youth with posttraumatic stress disorder (PTSD). Youth between the ages of 6 and 17 ( M = 11.79, SD = 3.08) were randomized to receive standard TF-CBT or TF-CBT with adjunctive AAT (TF-CBT+AAT) employing retired service dogs. Feasibility metrics evaluating the addition of AAT were collected in addition to common clinical outcomes evaluated in TF-CBT trials. The inclusion of AAT increased the number of potential participants who declined participation and there were no noted benefits for treatment retention or satisfaction with services. Analyses showed that the inclusion of AAT did not enhance improvement of PTSD symptom severity (β = .90, t = .94, p = .351) or a number of other outcomes. On the contrary, there were indications from analyses and clinician feedback that AAT may have attenuated improvement in many cases. This study identified a number of important feasibility considerations in the design of studies testing AAT. However, the results examining clinical outcomes suggest that the inclusion of AAT with TF-CBT in the treatment of maltreated youth with PTSD is not warranted at this time.
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- 2022
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27. Impact of the COVID-19 Pandemic on Radiology in Inpatient and Outpatient Care in Germany: A Nationwide Survey Regarding the First and Second Wave.
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Bernatz S, Afat S, Othman AE, Nikolaou K, Sieren M, Sähn MJ, Pinto Dos Santos D, Penzkofer T, Bucher AM, Hamm B, Vogl TJ, and Bodelle B
- Subjects
- Ambulatory Care, Germany, Humans, Inpatients, Pandemics, SARS-CoV-2, COVID-19, Radiology
- Abstract
Objectives: To find out the opinion of radiological inpatient and outpatient medical staff regarding the measures taken in relation to the COVID-19 pandemic during the first and second waves and to identify the measures that are still perceived as needing improvement., Materials and Methods: We conducted an anonymous online survey among more than 10 000 radiologists/technicians in Germany from January 5 to January 31, 2021. A total of 862 responses (head physicians, n = 225 [inpatient doctors, n = 138; outpatient doctors, n = 84; N/A, n = 3]; radiologic personnel, n = 637 [inpatient doctor, n = 303; outpatient doctor, n = 50; inpatient technician, n = 217; outpatient technician, n = 26; N/A, n = 41]) were received. Questions of approximation, yes/no questions, and Likert scales were used., Results: During the first/second wave, 70 % (86/123)/43 % (45/104) of inpatient and 26 % (17/66)/10 % (5/52) of outpatient head physicians agreed that they received financial support from the authorities but the majority rated the financial support as insufficient. During the first and second wave, 33 % (8/24) and 80 % (16/20) of outpatient technicians agreed that they were adequately provided with personal protective equipment. The perceived lack of personal protective equipment improved for all participants during the second wave. Inpatient [outpatient] technicians perceived an increased workload in the first and second wave: 72 % (142/198) [79 % (19/24)] and 84 % (146/174) [80 % (16/20)]., Conclusion: Technicians seem increasingly negatively affected by the COVID-19 pandemic in Germany. Financial support by the competent authorities seems to be in need of improvement., Key Points: · The accessibility of personal protective equipment resources improved in the second wave.. · In particular, radiology technicians seem increasingly negatively affected by the COVID-19 pandemic.. · Financial and consulting support from the government could be improved.., Citation Format: · Bernatz S, Afat S, Othman AE et al. Impact of the COVID-19 Pandemic on Radiology in Inpatient and Outpatient Care in Germany: A Nationwide Survey Regarding the First and Second Wave. Fortschr Röntgenstr 2022; 194: 70 - 82., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)
- Published
- 2022
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28. Association of levonorgestrel intrauterine devices with stress reactivity, mental health, quality of life and sexual functioning: A systematic review.
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Bürger Z, Bucher AM, Comasco E, Henes M, Hübner S, Kogler L, and Derntl B
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- Female, Humans, Mental Health, Quality of Life, Intrauterine Devices, Medicated, Levonorgestrel adverse effects
- Abstract
Levonorgestrel-intrauterine-devices (LNG-IUD) are one of the most used contraceptive methods worldwide. While several reviews exist on how LNG-IUDs impact physiology and gynaecological functions, this systematic review focuses on stress, mental health, quality of life, sexual functioning, and effects on brain architecture. While data on stress is scarce, results on mental health are ambiguous. More consistently, LNG-IUD use seems to improve quality of life and sexual functioning. No studies highlighting the consequences of LNG-IUD use on the brain were found. The reviewed studies are characterized by a substantial variation in approaches, participant groups, and study quality. More high-quality research assessing the effects of LNG-IUD on mental health, including response to stressors and brain function and structure, is needed to identify women vulnerable to adverse effects of LNG-IUD, also in comparison to oral contraceptives, and to empower women to make more informed choices concerning hormonal contraception., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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29. Statement of the German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists on Requirements for the Performance and Reporting of MR Imaging Examinations Outside of Radiology.
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Hunold P, Bucher AM, Sandstede J, Janka R, Fritz LB, Regier M, Loose R, Barkhausen J, Mentzel HJ, Zimmer C, and Antoch G
- Subjects
- Child, Germany, Humans, Magnetic Resonance Imaging, Radiography, Radiologists, Radiology
- Abstract
Background: Magnetic Resonance Imaging (MRI) is a very innovative, but at the same time complex and technically demanding diagnostic method in radiology. It plays an increasing role in high-quality and efficient patient management. Quality assurance in MRI is of utmost importance to avoid patient risks due to errors before and during the examination and when reporting the results. Therefore, MRI requires higher physician qualification and expertise than any other diagnostic imaging technique in medicine. This holds true for indication, performance of the examination itself, and in particular for image evaluation and writing of the report. In Germany, the radiologist is the only specialist who is systematically educated in all aspects of MRI during medical specialty training and who must document a specified, high number of examinations during this training. However, also non-radiologist physicians are increasingly endeavoring to conduct and bill MRI examinations on their own., Method: In this position statement, the following aspects of quality assurance for MRI examinations and billing by radiologists and non-radiologist physician specialists are examined scientifically: Requirements for specialist physician training, MRI risks and contraindications, radiation protection in the case of non-ionizing radiation, application of MR contrast agents, requirements regarding image quality, significance of image artifacts and incidental findings, image evaluation and reporting, interdisciplinary communication and multiple-eyes principle, and impact on healthcare system costs., Conclusion: The German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists are critical with regard to MRI performance by non-radiologists in the interest of quality standards, patient welfare, and healthcare payers. The 24-month additional qualification in MRI as defined by the physician specialization regulations (Weiterbildungsordnung) through the German state medical associations (Landesärztekammern) is the only competence-based and quality-assured training program for board-certified specialist physicians outside radiology. This has to be required as the minimum standard for performance and reporting of MRI exams. Exclusively unstructured MRI training outside the physician specialization regulations has to be strictly rejected for reasons of patient safety. The performance and reporting of MRI examinations must be reserved for adequately trained and continuously educated specialist physicians., Key Points: · MR imaging plays an increasing role due to its high diagnostic value and serves as the reference standard in many indications.. · MRI is a complex technique that implies patient risks in case of inappropriare application or lack of expertise.. · In Germany, the radiologist is the only specialist physician that has been systematically trained in all aspects of MRI such as indication, performance, and reporting of examinations in specified, high numbers.. · The only competence-based and quality-assured MRI training program for specialist physicians outside radiology is the 24-month additional qualification as defined by the regulations through the German state medical associations.. · In view of quality-assurance and patient safety, a finalized training program following the physician specialization regulations has to be required for the performance and reporting of MRI examinations.., Citation Format: · Hunold P, Bucher AM, Sandstede J et al. Statement of the German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists on Requirements for the Performance and Reporting of MR Imaging Examinations Outside of Radiology. Fortschr Röntgenstr 2021; 193: 1050 - 1060., Competing Interests: Hunold: Mitglied Deutsche Röntgengesellschaft, Vorstandsmitglied AG Herz- und Gefäßdiagnostik der DRG, Mitglied Bundesverband Deutscher Radiologen, Mitglied European Society of Radiology; Vortragshonorare Fa. Bayer VitalBucher: Mitglied Deutsche Röntgengesellschaft, Vorstandsmitglied der AGs Muskuloskelettale Radiologie, Gesundheitspolitische Verantwortung, Uroradiologie und Urogenitaldiagnostik und Forensisch-Radiologische Bildgebung der DRG, Mitglied European Society of Radiology; Travel support Fa. Bayer und GuerbetSandstede: Aufsichtsratsvorsitzender der Radiologengruppe 2020 (RG20) e.G. i. Gr., Stellv. Vorsitzender des Landesverbands Hamburg des Berufsverbands der Radiologen (BDR), Stellv. Vorsitzender des Forums Niedergelassene Radiologen (FuNRAD) der Deutschen Röntgengesellschaft (DRG), Stellv. Mitglied der Vertreterversammlung der KV HamburgJanka: Mitglied Deutsche Röntgengesellschaft, Vorstandsmitglied AG Muskuloskelettale Radiologie der DRG, Mitglied Bayerische Röntgengesellschaft, Mitglied European Society of Radiology; Vortragshonorare Fa. Siemens Healthineers und BraccoFritz: Mitglied Deutsche Röntgengesellschaft, Vorstandsvorsitzender der AG Gesundheitspolitische Verantwortung der DRGRegier: Mitglied Deutsche Röntgengesellschaft, Vorstandsvorsitzender AG Muskuloskelettale Radiologie der DRG, Mitglied Bundesverband Deutscher RadiologenLoose: Mitglied Deutsche RöntgengesellschaftBarkhausen: President elect und Mitglied Deutsche RöntgengesellschaftMentzel: Präsident und Mitglied Gesellschaft für Pädiatrische Radiologie, Mitglied Deutsche RöntgengesellschaftZimmer: Präsident und Mitglied Deutsche Gesellschaft für NeuroradiologieAntoch: Präsident und Mitglied Deutsche Röntgengesellschaft, (Thieme. All rights reserved.)
- Published
- 2021
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30. Generative Adversarial Networks: A Primer for Radiologists.
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Wolterink JM, Mukhopadhyay A, Leiner T, Vogl TJ, Bucher AM, and Išgum I
- Subjects
- Humans, Image Processing, Computer-Assisted, Radiologists, Artificial Intelligence, Neural Networks, Computer
- Abstract
Artificial intelligence techniques involving the use of artificial neural networks-that is, deep learning techniques-are expected to have a major effect on radiology. Some of the most exciting applications of deep learning in radiology make use of generative adversarial networks (GANs). GANs consist of two artificial neural networks that are jointly optimized but with opposing goals. One neural network, the generator, aims to synthesize images that cannot be distinguished from real images. The second neural network, the discriminator, aims to distinguish these synthetic images from real images. These deep learning models allow, among other applications, the synthesis of new images, acceleration of image acquisitions, reduction of imaging artifacts, efficient and accurate conversion between medical images acquired with different modalities, and identification of abnormalities depicted on images. The authors provide an introduction to GANs and adversarial deep learning methods. In addition, the different ways in which GANs can be used for image synthesis and image-to-image translation tasks, as well as the principles underlying conditional GANs and cycle-consistent GANs, are described. Illustrated examples of GAN applications in radiologic image analysis for different imaging modalities and different tasks are provided. The clinical potential of GANs, future clinical GAN applications, and potential pitfalls and caveats that radiologists should be aware of also are discussed in this review. The online slide presentation from the RSNA Annual Meeting is available for this article.
© RSNA, 2021.- Published
- 2021
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31. A reporting and analysis framework for structured evaluation of COVID-19 clinical and imaging data.
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Salg GA, Ganten MK, Bucher AM, Kenngott HG, Fink MA, Seibold C, Fischbach RE, Schlamp K, Velandia CA, Fervers P, Doellinger F, Luger A, Afat S, Merle U, Diener MK, Pereira PL, Penzkofer T, Persigehl T, Othman A, Heußel CP, Baumhauer M, Widmann G, Stathopoulos K, Hamm B, Vogl TJ, Nikolaou K, Kauczor HU, and Kleesiek J
- Abstract
The COVID-19 pandemic has worldwide individual and socioeconomic consequences. Chest computed tomography has been found to support diagnostics and disease monitoring. A standardized approach to generate, collect, analyze, and share clinical and imaging information in the highest quality possible is urgently needed. We developed systematic, computer-assisted and context-guided electronic data capture on the FDA-approved mint Lesion
TM software platform to enable cloud-based data collection and real-time analysis. The acquisition and annotation include radiological findings and radiomics performed directly on primary imaging data together with information from the patient history and clinical data. As proof of concept, anonymized data of 283 patients with either suspected or confirmed SARS-CoV-2 infection from eight European medical centers were aggregated in data analysis dashboards. Aggregated data were compared to key findings of landmark research literature. This concept has been chosen for use in the national COVID-19 response of the radiological departments of all university hospitals in Germany.- Published
- 2021
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32. Value of minimum intensity projections for chest CT in COVID-19 patients.
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Booz C, Vogl TJ, Joseph Schoepf U, Caruso D, Inserra MC, Yel I, Martin SS, Bucher AM, Lenga L, Caudo D, Schreckenbach T, Schoell N, Huegel C, Stratmann J, Vasa-Nicotera M, Rachovitsky-Duarte DE, Laghi A, De Santis D, Mazziotti S, D'Angelo T, and Albrecht MH
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Female, Humans, Internationality, Male, Middle Aged, Reproducibility of Results, Retrospective Studies, SARS-CoV-2, Sensitivity and Specificity, Young Adult, COVID-19 diagnostic imaging, Lung diagnostic imaging, Radiographic Image Interpretation, Computer-Assisted methods, Tomography, X-Ray Computed methods
- Abstract
Purpose: To investigate whether minimum intensity projection (MinIP) reconstructions enable more accurate depiction of pulmonary ground-glass opacity (GGO) compared to standard transverse sections and multiplanar reformat (MPR) series in patients with suspected coronavirus disease 2019 (COVID-19)., Method: In this multinational study, chest CT scans of 185 patients were retrospectively analyzed. Diagnostic accuracy, diagnostic confidence, image quality regarding the assessment of GGO, as well as subjective time-efficiency of MinIP and standard MPR series were analyzed based on the assessment of six radiologists. In addition, the suitability for COVID-19 evaluation, image quality regarding GGO and subjective time-efficiency in clinical routine was assessed by five clinicians., Results: The reference standard revealed a total of 149 CT scans with pulmonary GGO. MinIP reconstructions yielded significantly higher sensitivity (99.9 % vs 95.6 %), specificity (95.8 % vs 86.1 %) and accuracy (99.1 % vs 93.8 %) for assessing of GGO compared with standard MPR series. MinIP reconstructions achieved significantly higher ratings by radiologists concerning diagnostic confidence (medians, 5.00 vs 4.00), image quality (medians, 4.00 vs 4.00), contrast between GGO and unaffected lung parenchyma (medians, 5.00 vs 4.00) as well as subjective time-efficiency (medians, 5.00 vs 4.00) compared with MPR-series (all P < .001). Clinicians preferred MinIP reconstructions for COVID-19 assessment (medians, 5.00 vs 3.00), image quality regarding GGO (medians, 5.00 vs 3.00) and subjective time-efficiency in clinical routine (medians, 5.00 vs 3.00)., Conclusions: MinIP reconstructions improve the assessment of COVID-19 in chest CT compared to standard images and may be suitable for routine application., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
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33. DIALAPP: a prospective validation of a new diagnostic algorithm for acute appendicitis.
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Malkomes P, Edmaier F, Liese J, Reinisch-Liese A, El Youzouri H, Schreckenbach T, Bucher AM, Bechstein WO, and Schnitzbauer AA
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- Acute Disease, Algorithms, Appendectomy, Female, Humans, Infant, Newborn, Prospective Studies, Sensitivity and Specificity, Ultrasonography, Appendicitis diagnostic imaging, Appendicitis surgery
- Abstract
Purpose: The management of patients with suspected appendicitis remains a challenge in daily clinical practice, and the optimal management algorithm is still being debated. Negative appendectomy rates (NAR) continue to range between 10 and 15%. This prospective study evaluated the accuracy of a diagnostic pathway in acute appendicitis using clinical risk stratification (Alvarado score), routine ultrasonography, gynecology consult for females, and selected CT after clinical reassessment., Methods: Patients presenting with suspected appendicitis between November 2015 and September 2017 from age 18 years and above were included. Decision-making followed a clear management pathway. Patients were followed up for 6 months after discharge. The hypothesis was that the algorithm can reduce the NAR to a value of under 10%., Results: A total of 183 patients were included. In 65 of 69 appendectomies, acute appendicitis was confirmed by histopathology, corresponding to a NAR of 5.8%. Notably, all 4 NAR appendectomies had other pathologies of the appendix. The perforation rate was 24.6%. Only 36 patients (19.7%) received a CT scan. The follow-up rate after 30 days achieved 69%, including no patients with missed appendicitis. The sensitivity and specificity of the diagnostic pathway was 100% and 96.6%, respectively. The potential saving in costs can be as much as 19.8 million €/100,000 cases presenting with the suspicion of appendicitis., Conclusion: The risk-stratified diagnostic algorithm yields a high diagnostic accuracy for patients with suspicion of appendicitis. Its implementation can safely reduce the NAR, simultaneously minimizing the use of CT scans and optimizing healthcare-related costs in the treatment of acute appendicitis., Trial Registration: ClinicalTrials.gov Identifier: NCT02627781 (December 2015).
- Published
- 2021
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34. [Artificial intelligence in oncological radiology : A (p)review].
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Bucher AM and Kleesiek J
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- Algorithms, Humans, Radiography, Workflow, Artificial Intelligence, Radiology
- Abstract
Background: Artificial intelligence (AI) has the potential to fundamentally change medicine within the coming decades. Radiological imaging is one of the primary fields of its clinical application., Objectives: In this article, we summarize previous AI developments with a focus on oncological radiology. Based on selected examples, we derive scenarios for developments in the next 10 years., Materials and Methods: This work is based on a review of various literature and product databases, publications by regulatory authorities, reports, and press releases., Conclusions: The clinical use of AI applications is still in an early stage of development. The large number of research publications shows the potential of the field. Several certified products have already become available to users. However, for a widespread adoption of AI applications in clinical routine, several fundamental prerequisites are still awaited. These include the generation of evidence justifying the use of algorithms through representative clinical studies, adjustments to the framework for approval processes and dedicated education and teaching resources for its users. It is expected that use of AI methods will increase, thus, creating new opportunities for improved diagnostics, therapy, and more efficient workflows.
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- 2021
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35. Joint Imaging Platform for Federated Clinical Data Analytics.
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Scherer J, Nolden M, Kleesiek J, Metzger J, Kades K, Schneider V, Bach M, Sedlaczek O, Bucher AM, Vogl TJ, Grünwald F, Kühn JP, Hoffmann RT, Kotzerke J, Bethge O, Schimmöller L, Antoch G, Müller HW, Daul A, Nikolaou K, la Fougère C, Kunz WG, Ingrisch M, Schachtner B, Ricke J, Bartenstein P, Nensa F, Radbruch A, Umutlu L, Forsting M, Seifert R, Herrmann K, Mayer P, Kauczor HU, Penzkofer T, Hamm B, Brenner W, Kloeckner R, Düber C, Schreckenberger M, Braren R, Kaissis G, Makowski M, Eiber M, Gafita A, Trager R, Weber WA, Neubauer J, Reisert M, Bock M, Bamberg F, Hennig J, Meyer PT, Ruf J, Haberkorn U, Schoenberg SO, Kuder T, Neher P, Floca R, Schlemmer HP, and Maier-Hein K
- Subjects
- Data Science, Delivery of Health Care, Germany, Humans, Artificial Intelligence, Radiology
- Abstract
Purpose: Image analysis is one of the most promising applications of artificial intelligence (AI) in health care, potentially improving prediction, diagnosis, and treatment of diseases. Although scientific advances in this area critically depend on the accessibility of large-volume and high-quality data, sharing data between institutions faces various ethical and legal constraints as well as organizational and technical obstacles., Methods: The Joint Imaging Platform (JIP) of the German Cancer Consortium (DKTK) addresses these issues by providing federated data analysis technology in a secure and compliant way. Using the JIP, medical image data remain in the originator institutions, but analysis and AI algorithms are shared and jointly used. Common standards and interfaces to local systems ensure permanent data sovereignty of participating institutions., Results: The JIP is established in the radiology and nuclear medicine departments of 10 university hospitals in Germany (DKTK partner sites). In multiple complementary use cases, we show that the platform fulfills all relevant requirements to serve as a foundation for multicenter medical imaging trials and research on large cohorts, including the harmonization and integration of data, interactive analysis, automatic analysis, federated machine learning, and extensibility and maintenance processes, which are elementary for the sustainability of such a platform., Conclusion: The results demonstrate the feasibility of using the JIP as a federated data analytics platform in heterogeneous clinical information technology and software landscapes, solving an important bottleneck for the application of AI to large-scale clinical imaging data.
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- 2020
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36. Carotid and cerebrovascular dual-energy computed tomography angiography: Optimization of window settings for virtual monoenergetic imaging reconstruction.
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D'Angelo T, Lenga L, Arendt CT, Bucher AM, Peterke JL, Caruso D, Mazziotti S, Ascenti G, Blandino A, Othman AE, Martin SS, Albrecht MH, Bodelle B, Vogl TJ, and Wichmann JL
- Subjects
- Aged, Carotid Arteries diagnostic imaging, Cerebrovascular Disorders diagnostic imaging, Female, Humans, Male, Middle Aged, Reproducibility of Results, Retrospective Studies, Signal-To-Noise Ratio, Carotid Artery Diseases diagnostic imaging, Computed Tomography Angiography methods, Radiographic Image Interpretation, Computer-Assisted methods, Radiography, Dual-Energy Scanned Projection methods
- Abstract
Purpose: Dedicated post-processing of dual-energy computed tomography angiography (DE-CTA) datasets has been shown to allow for increased vascular contrast. The goal of our study was to define optimal window settings for displaying virtual monoenergetic images (VMI) reconstructed from dual-energy carotid and cerebrovascular DE-CTA., Methods: Fifty-seven patients who underwent clinically-indicated carotid and cerebrovascular third-generation dual-source DE-CTA were retrospectively evaluated. Standard linearly-blended (M_0.6), 70-keV traditional VMI (M70), and 40-keV noise-optimized VMI (M40+) reconstructions were analyzed. For M70 and M40+ datasets, the subjectively best window setting (width and level, B-W/L) was independently determined by two observers and subsequently related with aortic arch attenuation to calculate optimized values (O-W/L) using linear regression. Subjective evaluation of image quality (IQ) between W/L settings were assessed by two additional readers. Repeated measures analysis of variance were performed to compare W/L settings and IQ indices between M_0.6, M70, and M40 + ., Results: B-W/L and O-W/L for M70 were 580/210 and 560/200, and for M40+ were 1630/570 and 1560/550, respectively, higher than standard DE-CTA W/L settings (450/100). Highest subjective scores were observed for M40+ regarding overall IQ (all p < 0.001)., Conclusion: Application of O-W/L settings is mandatory to optimize subjective IQ of VMI reconstructions of DE-CTA., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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37. Diagnostic accuracy of color-coded virtual noncalcium dual-energy CT for the assessment of bone marrow edema in sacral insufficiency fracture in comparison to MRI.
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Booz C, Nöske J, Albrecht MH, Lenga L, Martin SS, Bucher AM, Huizinga NA, Wichmann JL, Vogl TJ, and Yel I
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- Aged, Edema diagnostic imaging, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Retrospective Studies, Sensitivity and Specificity, Tomography, X-Ray Computed, Bone Marrow diagnostic imaging, Fractures, Stress
- Abstract
Purpose: To evaluate the diagnostic accuracy of color-coded dual-energy CT virtual noncalcium (VNCa) reconstructions for the assessment of traumatic bone marrow edema in sacral insufficiency fracture (SIF)., Method: Data from 52 consecutive patients (28 women, 24 men; mean age, 61 ± 13 years; range, 49-94 years) who had undergone third-generation dual-source CT and 3-Tesla (T) MRI due to low back pain without adequate trauma were retrospectively evaluated. Five radiologists, blinded to MRI and clinical information, independently analyzed conventional grayscale dual-energy CT series for sacral fractures according to the Denis classification. Eight weeks later, readers re-assessed all scans using color-coded VNCa reconstructions for sacral bone marrow edema. CT numbers on VNCa reconstructions were measured by a sixth radiologist. One experienced radiologist (33 years of experience in musculoskeletal [MSK] imaging), blinded to CT and clinical information, defined the reference standard by analyzing the MRI scans. The primary indices for diagnostic accuracy were sensitivity, specificity, and the area under the curve (AUC)., Results: MRI revealed a total of 39 zones with SIF-associated bone marrow edema in 27 patients. In the qualitative analysis, VNCa showed high overall sensitivity (93 %) and specificity (95 %) for assessing SIF-associated bone marrow edema. The quantitative analysis of color-coded VNCa reconstructions revealed an overall AUC of 0.976. A cut-off value of -43 Hounsfield units provided a sensitivity of 85 % and a specificity of 95 % for differentiating bone marrow edema., Conclusions: Color-coded dual-energy CT VNCa reconstructions yield excellent diagnostic accuracy in the analysis of SIF-associated bone marrow edema compared to MRI., Competing Interests: Declaration of Competing Interest The other authors have no potential conflict of interest to disclose., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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38. Three-Dimensional Magnetic Resonance Imaging Volumetry of Radial Forearm Flap Reconstructions After Craniomaxillofacial Tumor Resection.
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Thoenissen P, Heselich A, Sader R, Vogl TJ, Ghanaati S, and Bucher AM
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- Aged, Female, Forearm surgery, Humans, Imaging, Three-Dimensional, Magnetic Resonance Imaging, Male, Middle Aged, Mouth Neoplasms diagnostic imaging, Quality of Life, Plastic Surgery Procedures, Surgical Flaps surgery, Forearm diagnostic imaging, Mouth Neoplasms surgery
- Abstract
Background: Oral cancer is a common and life threatening disease that requires interdisciplinary treatment and often necessitates complex facial reconstruction. Standard care includes tumor resection, while reconstruction is routinely performed with free radial forearm flaps. As esthetic results are crucial for quality of life, flap size, flap volume, and flap composition have to be considered. To date no standardized measurement of flap volume and shrinkage has been established for routine use. The purpose of this study was therefore to evaluate the transplant volume of radial forearm flaps in craniomaxillofacial reconstruction using magnetic resonance imaging (MRI) volumetry., Material and Methods: Ten postoperative MR sequences of 5 patients were included. All patients had received transplantation of radial forearm flaps after tumor resection and radiation therapy. Evaluated parameters were: sex, age, type of flap, flap volume. Two different observers (1 surgeon and 1 radiologist) segmented transplant volume at three different time points in a postoperative MRI independently and in consensus, using both axial and coronal slices. A nonfat saturated T1 spin echo sequence was used. Mean transplant volume was calculated., Results: A total of 90 volumetric measurements were included. Overall Tvolm was 24.83 cm from axial sections and 27.25 cm from coronal sections. Measurements for axial and coronal orientations differed significantly. Results showed excellent intra- and inter-rater correlation, coefficient for rater A and rater B were 0.91 (axial) and 0.96 (coronal)., Conclusion: MRI volumetry is a noninvasive reproducible method to quantify volume of free radial forearm flaps in situ but should follow specific considerations for best results.
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- 2020
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39. Evaluation of Radiation Dose and Image Quality using High-Pitch 70-kV Chest CT in Immunosuppressed Patients.
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Yel I, Martin SS, Wichmann JL, Lenga L, Albrecht MH, Bucher AM, Kaltenbach B, Polkowski C, Booz C, Vogl TJ, and Hammerstingl RM
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- Adult, Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Immunologic Deficiency Syndromes immunology, Male, Middle Aged, Opportunistic Infections immunology, Pneumonia immunology, Sensitivity and Specificity, Young Adult, Image Enhancement, Immunologic Deficiency Syndromes diagnostic imaging, Opportunistic Infections diagnostic imaging, Pneumonia diagnostic imaging, Radiation Dosage, Tomography, X-Ray Computed
- Abstract
Purpose: The aim of the study was to evaluate high-pitch 70-kV CT examinations of the thorax in immunosuppressed patients regarding radiation dose and image quality in comparison with 120-kV acquisition., Materials and Methods: The image data from 40 patients (14 women and 26 men; mean age: 40.9 ± 15.4 years) who received high-pitch 70-kV CT chest examinations were retrospectively included in this study. A control group (n = 40), matched by age, gender, BMI, and clinical inclusion criteria, had undergone standard 120-kV chest CT imaging. All CT scans were performed on a third-generation dual-source CT unit. For an evaluation of the radiation dose, the CT dose index (CTDIvol), dose-length product (DLP), effective dose (ED), and size-specific dose estimates (SSDE) were analyzed in each group. The objective image quality was evaluated using signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Three blinded and independent radiologists evaluated subjective image quality and diagnostic confidence using 5-point Likert scales., Results: The mean dose parameters were significantly lower for high-pitch 70-kV CT examinations (CTDIvol, 2.9 ± 0.9 mGy; DLP, 99.9 ± 31.0 mGyxcm; ED, 1.5 ± 0.6 mSv; SSDE, 3.8 ± 1.2 mGy) compared to standard 120-kV CT imaging (CTDIvol, 8.8 ± 3.7mGy; DLP, 296.6 ± 119.3 mGyxcm; ED, 4.4 ± 2.1 mSv; SSDE, 11.6 ± 4.4 mGy) (P≤ 0.001). The objective image parameters (SNR: 7.8 ± 2.1 vs. 8.4 ± 1.8; CNR: 7.7 ± 2.4 vs. 8.3 ± 2.8) (P≥ 0.065) and the cumulative subjective image quality (4.5 ± 0.4 vs. 4.7 ± 0.3) (p = 0.052) showed no significant differences between the two protocols., Conclusion: High-pitch 70-kV thoracic CT examinations in immunosuppressed patients resulted in a significantly reduced radiation exposure compared to standard 120-kV CT acquisition without a decrease in image quality., Key Points: · Third-generation dual-source CT units enable high-pitch 70-kV CT examinations of the chest.. · High-pitch 70-kV CT examinations show a significantly reduced radiation dose compared to standard 120-kV CT examinations.. · High-pitch 70-kV CT examinations of the chest show comparable objective and subjective image quality.. · Subjectively deteriorated image noise and sharpness of 70-kV CT did not impact diagnostic confidence.., Citation Format: · Yel I, Martin SS, Wichmann JL et al. Evaluation of Radiation Dose and Image Quality using High-Pitch 70-kV Chest CT in Immunosuppressed Patients . Fortschr Röntgenstr 2019; 191: 122 - 129., Competing Interests: Moritz H. Albrecht hat Referentenhonorare von Siemens erhalten.Julian L. Wichmann hat Referentenhonorare von Siemens und General Electric erhalten., (© Georg Thieme Verlag KG Stuttgart · New York.)
- Published
- 2019
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40. High-pitch Dual-source CT Angiography before TAVI - the Value of ECG Gating.
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Bucher AM, Albrecht MH, Scholtz JE, Herrmann E, Kaup M, Gruber-Rouh T, Jacobi V, Vogl TJ, and Beeres M
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- Adult, Aged, Aortic Valve diagnostic imaging, Female, Humans, Male, Middle Aged, Observer Variation, Patient Care Planning, Radiation Dosage, Aorta diagnostic imaging, Aortography methods, Cardiac-Gated Imaging Techniques methods, Computed Tomography Angiography methods, Electrocardiography methods, Transcatheter Aortic Valve Replacement methods
- Abstract
Purpose: To investigate image quality, and radiation dose between ECG-gated singlesource and dual-source CT Angiography (CTA) protocols for planning of Trans-catheter Aortic Valve Implantation (TAVI) with a reference non ECG-gated single-source protocol., Methods: A total of 120 patients were included in four groups: Non ECG-gated single-source (SS), ECG-gated single-source (SSECG), ECG-gated dual-source high-pitch (DSECG), or non-ECG-gated dual-source high-pitch mode (DS). Qualitative image quality of the aortic annulus, aortic valve, and coronary ostia as well as presence of motion or stair-step artefacts of the thoracic aorta were independently assessed by two readers. Quantitative image quality was assessed to calculate contrast to noise ratio., Results: Subjective and objective scoring of motion artefacts was significantly reduced in SSECG, DSECG and DS (p= 0.010). The imaging length was comparable between groups. Aortic annulus, aortic valve, and coronary ostia were reliably evaluable in all patients with SSECG, DSECG and DS protocols., Conclusion: High-pitch, dual-source CT angiography of the whole aorta with or without ECG gating is a dose-efficient and time-saving examination strategy before TAVI. However acquisition timing within the cardiac cycle needs to be taken into account., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
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- 2019
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41. A Randomized Controlled Trial of Strategies to Improve Family Members' Preparedness for Surrogate Decision-Making.
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Green MJ, Van Scoy LJ, Foy AJ, Stewart RR, Sampath R, Schubart JR, Lehman EB, Dimmock AEF, Bucher AM, Lehmann LS, Harlow AF, Yang C, and Levi BH
- Subjects
- Adult, Advance Directives psychology, Aged, Female, Humans, Internet, Male, Middle Aged, Self Efficacy, Socioeconomic Factors, Tertiary Care Centers, Advance Care Planning organization & administration, Decision Making, Family psychology
- Abstract
Objective: To evaluate 2 strategies for preparing family members for surrogate decision-making., Design: A 2 × 2 factorial, randomized controlled trial testing whether: (1) comprehensive online advance care planning (ACP) is superior to basic ACP, and (2) having patients engage in ACP together with family members is superior to ACP done by patients alone., Setting: Tertiary care centers in Hershey, Pennsylvania, and Boston, Massachusetts., Participants: Dyads of patients with advanced, severe illness (mean age 64; 46% female; 72% white) and family members who would be their surrogate decision-makers (mean age 56; 75% female; 75% white)., Interventions: Basic ACP: state-approved online advance directive plus brochure. Making Your Wishes Known (MYWK): Comprehensive ACP decision aid including education and values clarification., Measurements: Pre-post changes in family member self-efficacy (100-point scale) and postintervention concordance between patients and family members using clinical vignettes., Results: A total 285 dyads enrolled; 267 patients and 267 family members completed measures. Baseline self-efficacy in both MYWK and basic ACP groups was high (90.2 and 90.1, respectively), and increased postintervention to 92.1 for MYWK ( P = .13) and 93.3 for basic ACP ( P = .004), with no between-group difference. Baseline self-efficacy in alone and together groups was also high (90.2 and 90.1, respectively), and increased to 92.6 for alone ( P = .03) and 92.8 for together ( P = .03), with no between-group difference. Overall adjusted concordance was higher in MYWK compared to basic ACP (85.2% vs 79.7%; P = .032), with no between-group difference., Conclusion: The disconnect between confidence and performance raises questions about how to prepare family members to be surrogate decision-makers.
- Published
- 2018
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42. Optimisation of window settings for traditional and noise-optimised virtual monoenergetic imaging in dual-energy computed tomography pulmonary angiography.
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D'Angelo T, Bucher AM, Lenga L, Arendt CT, Peterke JL, Caruso D, Mazziotti S, Blandino A, Ascenti G, Othman AE, Martin SS, Leithner D, Vogl TJ, and Wichmann JL
- Subjects
- Female, Humans, Male, Middle Aged, Pulmonary Artery diagnostic imaging, Radiography, Dual-Energy Scanned Projection methods, Reproducibility of Results, Retrospective Studies, Signal-To-Noise Ratio, Computed Tomography Angiography methods, Image Processing, Computer-Assisted methods, Pulmonary Embolism diagnostic imaging
- Abstract
Objectives: To define optimal window settings for displaying virtual monoenergetic images (VMI) of dual-energy CT pulmonary angiography (DE-CTPA)., Methods: Forty-five patients who underwent clinically-indicated third-generation dual-source DE-CTPA were retrospectively evaluated. Standard linearly-blended (M_0.6), 70-keV traditional VMI (M70), and 40-keV noise-optimised VMI (M40+) reconstructions were analysed. For M70 and M40+ datasets, the subjectively best window setting (width and level, B-W/L) was independently determined by two observers and subsequently related with pulmonary artery attenuation to calculate separate optimised values (O-W/L) using linear regression. Subjective evaluation of image quality (IQ) between W/L settings were assessed by two additional readers. Repeated measures of variance were performed to compare W/L settings and IQ indices between M_0.6, M70, and M40+., Results: B-W/L and O-W/L for M70 were 460/140 and 450/140, and were 1100/380 and 1070/380 for M40+, respectively, differing from standard DE-CTPA W/L settings (450/100). Highest subjective scores were observed for M40+ regarding vascular contrast, embolism demarcation, and overall IQ (all p<0.001)., Conclusions: Application of O-W/L settings is beneficial to optimise subjective IQ of VMI reconstructions of DE-CTPA. A width slightly less than two times the pulmonary trunk attenuation and a level approximately of overall pulmonary vessel attenuation are recommended., Key Points: • Application of standard window settings for VMI results in inferior image perception. • No significant differences between B-W/L and O-W/L for M70/M40+ were observed. • O-W/L for M70 were 450/140 and were 1070/380 for M40+. • Improved subjective IQ characteristics were observed for VMI displayed with O-W/L.
- Published
- 2018
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43. Dynamic Liver Magnetic Resonance Imaging in Free-Breathing: Feasibility of a Cartesian T1-Weighted Acquisition Technique With Compressed Sensing and Additional Self-Navigation Signal for Hard-Gated and Motion-Resolved Reconstruction.
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Kaltenbach B, Bucher AM, Wichmann JL, Nickel D, Polkowski C, Hammerstingl R, Vogl TJ, and Bodelle B
- Subjects
- Aged, Artifacts, Breath Holding, Feasibility Studies, Female, Humans, Liver diagnostic imaging, Male, Respiration, Retrospective Studies, Colorectal Neoplasms pathology, Image Processing, Computer-Assisted methods, Liver Neoplasms diagnostic imaging, Liver Neoplasms secondary, Magnetic Resonance Imaging methods
- Abstract
Objectives: The aim of this study was to assess the feasibility of a free-breathing dynamic liver imaging technique using a prototype Cartesian T1-weighted volumetric interpolated breathhold examination (VIBE) sequence with compressed sensing and simultaneous acquisition of a navigation signal for hard-gated and motion state-resolved reconstruction., Materials and Methods: A total of 43 consecutive oncologic patients (mean age, 66 ± 11 years; 44% female) underwent free-breathing dynamic liver imaging for the evaluation of liver metastases from colorectal cancer using a prototype Cartesian VIBE sequence (field of view, 380 × 345 mm; image matrix, 320 × 218; echo time/repetition time, 1.8/3.76 milliseconds; flip angle, 10 degrees; slice thickness, 3.0 mm; acquisition time, 188 seconds) with continuous data sampling and additionally acquired self-navigation signal. Data were iteratively reconstructed using 2 different approaches: first, a hard-gated reconstruction only using data associated to the dominating motion state (CS VIBE, Compressed Sensing VIBE), and second, a motion-resolved reconstruction with 6 different motion states as additional image dimension (XD VIBE, eXtended dimension VIBE). Continuous acquired data were grouped in 16 subsequent time increments with 11.57 seconds each to resolve arterial and venous contrast phases. For image quality assessment, both CS VIBE and XD VIBE were compared with the patient's last staging dynamic liver magnetic resonance imaging including a breathhold (BH) VIBE as reference standard 4.5 ± 1.2 months before. Representative quality parameters including respiratory artifacts were evaluated for arterial and venous phase images independently, retrospectively and blindly by 3 experienced radiologists, with higher scores indicating better examination quality. To assess diagnostic accuracy, same readers evaluated the presence of metastatic lesions for XD VIBE and CS VIBE compared with reference BH examination in a second session., Results: Compared with CS VIBE, XD VIBE showed significantly higher overall image quality for both arterial phase (4.2 ± 0.6 vs 3.8 ± 0.7, P = 0.008) and venous phase (4.7 ± 0.4 vs 4.3 ± 0.7, P < 0.001) imaging. There was no significant difference between XD VIBE and BH VIBE for overall image quality in the venous phase (4.7 ± 0.4 vs 4.8 ± 0.4, P = 0.834), whereas arterial phase images were scored slightly lower for XD VIBE (4.5 ± 0.6 vs 4.2 ± 0.6, P = 0.024). Both XD VIBE and BH VIBE were characterized by a very low level of respiratory artifacts with no significant difference between BH and motion-resolved free-breathing strategy (P = 0.505 for arterial phase; P = 0.496 for venous phase). Compared with CS VIBE, obvious quality improvement could be achieved for the extended XD VIBE reconstruction with significantly reduced motion artifacts for venous phase images (P = 0.007). Generally, arterial phase images were scored slightly lower compared with venous phase images when using the free-breathing protocol. Overall, 98% of all metastatic lesions were identified on XD VIBE images and 92% of all metastases were found on CS VIBE., Conclusions: Dynamic liver imaging using the proposed free-breathing Cartesian strategy is feasible in oncologic patients with excellent image quality, high respiratory motion robustness, and accurate lesion detection. Overall, XD VIBE was superior to CS VIBE in our study.
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- 2017
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44. Automated Attenuation Based Tube Potential Selection of the Lower Extremity Runoff: A Comparison to Fixed Kilovolt with Automated Tube Current Modulation.
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Beeres M, Juhee K, Bucher AM, Frellesen C, Albrecht M, Wichmann JL, Park C, Kaup M, Scholtz JE, Vogl TJ, Gruber-Rouh T, and Bodelle B
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Signal-To-Noise Ratio, Computed Tomography Angiography instrumentation, Computed Tomography Angiography methods, Lower Extremity blood supply, Lower Extremity diagnostic imaging, Peripheral Arterial Disease diagnostic imaging, Radiation Dosage
- Abstract
Purpose: The aim of this study was to evaluate the impact of automated attenuation-based tube potential selection (ATPS) on image quality and radiation dose exposure parameters at a computed tomography angiography (CTA) lower-extremity runoff., Materials and Methods: Two hundred forty patients (156 men, 84 women) underwent CTA examinations of the lower-extremity runoff on a second-generation dual-source computed tomography system: 120 patients at a fixed tube potential of 120 kV and a tube current of 180 reference mAs, another 120 patients using automated ATPS. Volume computed tomography dose index (CTDIvol), dose-length-product (DLP), body diameters, noise, signal-to-noise ratio, and subjective image quality were compared., Results: In the ATPS group, 80 kV was automatically selected in 102 patients, 100 kV in 15 patients, and 120 kV in 3 patients; 140 kV was not chosen in any of the cases. The median CTDIvol of 4.81 mGy (2.2-10.6 mGy) and DLP of 568 mGy⋅cm (203-1324 mGy⋅cm) in the ATPS group were significantly lower compared with the CTDIvol of 8.1 mGy (4.4-14.4 mGy) and DLP of 1027.5 mGy⋅cm (509-1806 mGy⋅cm) in the fixed 120-kV group (P < 0.01). Image quality was comparable (P > 0.05)., Conclusion: Automated ATPS allows for significant dose savings in lower-extremity runoff CTA, whereas image quality remains constant at a high level.
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- 2017
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45. Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions.
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Albrecht MH, Bodelle B, Varga-Szemes A, Dewes P, Bucher AM, Ball BD, De Cecco CN, Schoepf UJ, Zhu X, Zangos S, Gruber-Rouh T, Wichmann JL, Lehnert T, and Vogl TJ
- Subjects
- Adult, Aged, Breath Holding, Contrast Media, Female, Hepatic Artery pathology, Humans, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Male, Middle Aged, Observer Variation, Portal Vein pathology, Reproducibility of Results, Liver Diseases diagnosis, Magnetic Resonance Angiography methods
- Abstract
Purpose: To evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach., Material and Methods: In this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1=definitely benign/not affected to 5=definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1=poor to 5=excellent)., Results: Reviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ=0.62 and 0.54, respectively, p<0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ=0.50 and 0.49, respectively, p<0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p<0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p<0.05)., Conclusion: Compared to the standard VIBE approach, CAIPIRINHA VIBE technique provides improved image quality and sharpness of intrahepatic veins, as well as higher diagnostic confidence. Additionally, this technique allows for higher inter-observer agreement when reporting focal liver lesions for both dignity and allocation., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
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- 2017
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46. Quantitative evaluation of beam-hardening artefact correction in dual-energy CT myocardial perfusion imaging.
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Bucher AM, Wichmann JL, Schoepf UJ, Wolla CD, Canstein C, McQuiston AD, Krazinski AW, De Cecco CN, Meinel FG, Vogl TJ, and Geyer LL
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- Aged, Algorithms, Artifacts, Female, Humans, Male, Middle Aged, Reproducibility of Results, Retrospective Studies, Sensitivity and Specificity, Tomography, Emission-Computed, Single-Photon, Heart diagnostic imaging, Radiographic Image Interpretation, Computer-Assisted methods, Tomography, X-Ray Computed methods
- Abstract
Objectives: To assess quantitatively the impact of a novel reconstruction algorithm ("kernel") with beam-hardening correction (BHC) on beam-hardening artefacts of the myocardium at dual-energy CT myocardial perfusion imaging (DE-CTMPI)., Methods: Rest-series of DE-CTMPI examinations from 14 patients were retrospectively analyzed. Six image series were reconstructed for each patient: a) 100 kV, b) 140 kV, and c) linearly blended MIX0.5, each with BHC (D33f kernel) and without (D30f kernel). Seven hundred and fifty-six myocardial regions were assessed. Seven equal regions of interest divided the myocardium in the axial section. Three subdivisions were created within these regions in areas prone to BHA. Reports of SPECT studies performed within 30 days of CT examination were used to confirm the presence and location of true perfusion defects. Paired student t-test was used for statistical evaluation., Results: Overall mean myocardial attenuation was lower using BHC (D30f: 87.3 ± 24.1 HU; D33f: 85.5 ± 21.5 HU; p = 0.009). Overall relative difference from average myocardial attenuation (RDMA) was more homogeneous using BHC (D30f: -0.3 ± 11.4 %; D33f: 0.1 ± 10.1 %; p < 0.001). Changes in RDMA were greatest in the posterobasal myocardium (D30f: -16.2 ± 10.0 %; D33f: 3.4 ± 10.7 %; p < 0.001)., Conclusions: A dedicated reconstruction algorithm with BHC can significantly reduce beam-hardening artefacts in DE-CTMPI., Key Points: • Beam-hardening artefacts (BHA) cause interference with attenuation-based CT myocardial perfusion assessment (CTMPI). • BHA occur mostly in the posterobasal left ventricular wall. • Beam-hardening correction homogenized and decreased mean myocardial attenuation. • BHC can help avoid false-positive findings and increase specificity of static CTMPI.
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- 2016
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47. Improved visual delineation of the intimal flap in Stanford type A and B dissections at 3rd generation dual-source high-pitch CT angiography.
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Beeres M, Bucher AM, Wichmann JL, Frellesen C, Scholtz JE, Albrecht M, Bodelle B, Nour-Eldin NE, Lee C, Kaup M, Vogl TJ, and Gruber-Rouh T
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- Adult, Aged, Aged, 80 and over, Cardiac-Gated Imaging Techniques, Contrast Media, Female, Humans, Iopamidol analogs & derivatives, Male, Middle Aged, Radiographic Image Interpretation, Computer-Assisted, Retrospective Studies, Aortic Dissection diagnostic imaging, Aortic Aneurysm diagnostic imaging, Computed Tomography Angiography, Tunica Intima diagnostic imaging
- Abstract
Objective: Evaluation of the intimal flap visibility comparing 2nd and 3rd generation dual-source high-pitch CT., Methods: Twenty-five consecutive patients with aortic dissection underwent CT angiography on a second and third generation dual-source CT scanner using prospective ECG-gated high-pitch dual-source CT acquisition mode. Contrast material, saline flush and flow rate were kept equal for optimum comparability. The visibility of the intimal flap as well as the delineation of the different vascular structures was evaluated., Results: In 3rd generation dual-source high-pitch CT we could show a significant improvement of intimal flap visibility in aortic dissection. Especially, the far end of the dissection membrane could be better evaluated in 3rd generation high-pitch CT, reaching statistical significance (P < 0.01)., Conclusion: 3rd Generation high-pitch CT angiography shows a better delineation of the aortic intimal flap in a small patient cohort, especially in the far ends of the dissection membrane. This might be due to higher tube power in this CT generation. However, to generalise these findings larger trials are needed.
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- 2016
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48. Advanced image-based virtual monoenergetic dual-energy CT angiography of the abdomen: optimization of kiloelectron volt settings to improve image contrast.
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Albrecht MH, Scholtz JE, Hüsers K, Beeres M, Bucher AM, Kaup M, Martin SS, Fischer S, Bodelle B, Bauer RW, Lehnert T, Vogl TJ, and Wichmann JL
- Subjects
- Female, Humans, Male, Middle Aged, Retrospective Studies, Signal-To-Noise Ratio, Abdominal Cavity diagnostic imaging, Algorithms, Computed Tomography Angiography methods, Radiography, Dual-Energy Scanned Projection methods
- Abstract
Objectives: To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA., Methods: Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M_0.6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured., Results: Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M_0.6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M_0.6 for CHA and SA (P < 0.009)., Conclusions: Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality., Key Points: • Mono+ combines increased attenuation with reduced image noise compared to standard DE-CTA. • Mono+ shows superior contrast-to-noise ratios at low keV compared to linearly-blended images. • Contrast-to-noise ratio in monoenergetic DE-CTA peaks at 40 keV. • Mono+ reconstructions significantly improve quantitative image quality at low keV levels.
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- 2016
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49. Systematic Comparison of Reduced Tube Current Protocols for High-pitch and Standard-pitch Pulmonary CT Angiography in a Large Single-center Population.
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Bucher AM, Kerl MJ, Albrecht MH, Beeres M, Ackermann H, Wichmann JL, Vogl TJ, Bauer RW, and Lehnert T
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- Adolescent, Adult, Aged, Aged, 80 and over, Algorithms, Artifacts, Computed Tomography Angiography instrumentation, Computed Tomography Angiography standards, Contrast Media administration & dosage, Female, Humans, Image Processing, Computer-Assisted standards, Injections, Intravenous, Iopamidol administration & dosage, Iopamidol analogs & derivatives, Male, Middle Aged, Observer Variation, Radiation Dosage, Radiographic Image Enhancement methods, Radiographic Image Enhancement standards, Retrospective Studies, Signal-To-Noise Ratio, Time Factors, Young Adult, Computed Tomography Angiography methods, Image Processing, Computer-Assisted methods, Pulmonary Artery diagnostic imaging
- Abstract
Rationale and Objectives: Benefits of iterative reconstruction (IR) algorithms combined with dose-reduction techniques have been shown at computed tomography pulmonary angiography (CTPA) in several medium to small patient collectives. In this study, we performed a systematic comparison of image quality to combinations of reduced tube current (RC) and IR for both standard-pitch (SP) single-source and high-pitch (HP) dual-source CTPA in a large, single-center population., Materials and Methods: Three hundred eighty-two consecutive patients (October 2010 through December 2012) received clinically indicated CTPA with one of four consecutively changed protocols: (1) HPSC: 180 mAs, weighted filtered back projection, pitch = 3; (2) HPRC: 90 mAs, IR, pitch = 3; (3) SPSC: 180 mAs, weighted filtered back projection, pitch = 1.2; and (4) HPRC: 90 mAs, IR, pitch = 1.2. Tube potential was 100 kV. Vascular attenuation and standardized signal-to-noise ratio (sSNR) were measured in the pulmonary trunk (sSNRPT) and on segmental artery level (sSNRS1, sSNRS10). Dose-length-product was recorded per series. Two independent investigators rated image quality. Kolmogorov-Smirnov test, Kruskal-Wallis test, and kappa statistics were used for statistical analysis. Median values are presented per group., Results: Image quality was consistent between all groups (observer 1: P = 0.118; observer 2: P = 0.122). Inter-reader consistency was very good (κ = 0.866, P < 0.001). Dose-length-product was significantly reduced in HP and RC groups (P < 0.001 for each; SPSC: 139.5 mGycm; HPRC: 92 mGycm; SPSC: 211 mGycm; HPRC: 137 mGycm). sSNR was comparable (sSNRPT overall: P = 0.052; sSNRS1 overall: P = 0.161; and sSNRS10 overall: P = 0.259)., Conclusions: Substantial dose reduction can be within a routine clinical setting without quantifiable loss of image quality either by HP pulmonary angiography or by a combination of IR and RC in either HP or SP acquisition., (Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.)
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- 2016
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50. ECG-gated Versus Non-ECG-gated High-pitch Dual-source CT for Whole Body CT Angiography (CTA).
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Beeres M, Wichmann JL, Frellesen C, Bucher AM, Albrecht M, Scholtz JE, Nour-Eldin NE, Gruber-Rouh T, Lee C, Vogl TJ, and Lehnert T
- Subjects
- Adult, Aged, Aged, 80 and over, Aorta, Thoracic diagnostic imaging, Aortic Valve diagnostic imaging, Contrast Media, Coronary Vessels diagnostic imaging, Female, Femoral Artery diagnostic imaging, Humans, Image Processing, Computer-Assisted methods, Iopamidol analogs & derivatives, Male, Middle Aged, Radiation Dosage, Radiographic Image Enhancement methods, Retrospective Studies, Signal-To-Noise Ratio, Single-Blind Method, Time Factors, Aortography methods, Artifacts, Computed Tomography Angiography methods, Electrocardiography methods, Whole Body Imaging methods
- Abstract
Rationale and Objectives: To investigate motion artifacts, image quality, and practical differences in electrocardiographic (ECG)-gated versus non-ECG-gated high-pitch dual-source computed tomography angiography (CTA) of the whole aorta., Materials and Methods: Two groups, each including 40 patients, underwent either ECG-gated or non-ECG-gated high-pitch dual-source CTA of the whole aorta. The aortic annulus, aortic valve, coronary ostia, and the presence of motion artifacts of the thoracic aorta as well as vascular contrast down to the femoral arteries were independently assessed by two readers. Additional objective parameters including image noise and signal-to-noise ratio were analyzed., Results: Subjective and objective scoring revealed no presence of motional artifacts regardless of whether the ECG-gated or the non-ECG-gated protocol was used (P > 0.1). Image acquisition parameters (examination length, examination duration, radiation dose) were comparable between the two groups without significant differences. The aortic annulus, aortic valve, and coronary ostia were reliably evaluable in all patients. Vascular contrast was rated excellent in both groups., Conclusions: High-pitch dual-source CTA of the whole aorta is a robust and dose-efficient examination strategy for the evaluation of aortic pathologies whether or not ECG gating is used., (Copyright © 2015 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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