180 results on '"Ahmed E Othman"'
Search Results
2. Pre-treatment 18F-FDG-PET/CT parameters as biomarkers for progression free survival, best overall response and overall survival in metastatic melanoma patients undergoing first-line immunotherapy.
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Felix Peisen, Annika Gerken, Isabel Dahm, Konstantin Nikolaou, Thomas Eigentler, Teresa Amaral, Jan H Moltz, Ahmed E Othman, and Sergios Gatidis
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Medicine ,Science - Abstract
BackgroundCheckpoint inhibitors have drastically improved the therapy of patients with advanced melanoma. 18F-FDG-PET/CT parameters might act as biomarkers for response and survival and thus can identify patients that do not benefit from immunotherapy. However, little literature exists on the association of baseline 18F-FDG-PET/CT parameters with progression free survival (PFS), best overall response (BOR), and overall survival (OS).Materials and methodsUsing a whole tumor volume segmentation approach, we investigated in a retrospective registry study (n = 50) whether pre-treatment 18F-FDG-PET/CT parameters of three subgroups (tumor burden, tumor glucose uptake and non-tumoral hematopoietic tissue metabolism), can act as biomarkers for the primary endpoints PFS and BOR as well as for the secondary endpoint OS.ResultsCompared to the sole use of clinical parameters, baseline 18F-FDG-PET/CT parameters did not significantly improve a Cox proportional-hazard model for PFS (C-index/AIC: 0.70/225.17 and 0.68/223.54, respectively; p = 0.14). A binomial logistic regression analysis for BOR was not statistically significant (χ2(15) = 16.44, p = 0.35), with a low amount of explained variance (Nagelkerke's R2 = 0.38). Mean FDG uptake of the spleen contributed significantly to a Cox proportional-hazard model for OS (HR 3.55, p = 0.04).ConclusionsThe present study could not confirm the capability of the pre-treatment 18F-FDG-PET/CT parameters tumor burden, tumor glucose uptake and non-tumoral hematopoietic tissue metabolism to act as biomarkers for PFS and BOR in metastatic melanoma patients receiving first-line immunotherapy. The documented potential of 18F-FDG uptake by immune-mediating tissues such as the spleen to act as a biomarker for OS has been reproduced.
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- 2024
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3. Feasibility of Ultra-High Resolution Supra-Aortic CT Angiography: An Assessment of Diagnostic Image Quality and Radiation Dose
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Felix Anton Ucar, Marius Frenzel, Mario Alberto Abello Mercado, Sebastian Altmann, Sebastian Reder, Carolin Brockmann, Marc A Brockmann, and Ahmed E Othman
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computed tomography ,computed tomography angiography ,cerebral arteries ,stroke ,contrast media ,image enhancement ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
(1) Background: To evaluate diagnostic image quality and radiation exposure of ultra-high resolution cerebral Computed-Tomography (CT) angiography (CTA) obtained on an ultra-high resolution computed tomography scanner (UHR-CT). (2) Methods: Fifty consecutive patients with UHR-CTA were enrolled. Image reconstruction was processed with a 1024 × 1024 matrix and a slice thickness of 0.25 mm. Quantitative analyses comprising CT values, contrast–noise ratio (CNR) and signal-to-noise ratio (SNR) were performed. Subjective assessment of image quality, vessel contrast, noise, artefacts and delineation of different sized vessels were assessed by two readers on a 4-point scale. Radiation exposure was determined. (3) Results: Hounsfield values (ACI: 461.8 ± 16.8 HU; MCA: 406.1 ± 24.2 HU; BA: 412.2 ± 22.3 HU), SNR (ACI: 35.4 ± 13.1; MCA: 20.8 ± 12.4; BA: 23.7 ± 12.9) and CNR (ACI: 48.7 ± 21; MCA: 63.9 ± 26.9; BA: 48.1 ± 21.4) were remarkably high in all segments. Subjective analysis by two raters (fair agreement, k = 0.26) indicated excellent image qualities (image quality = 4; contrast = 4; noise = 3; artefacts = 4).Our analysis revealed a notably high traceability of the cerebral perforators (3 Points). Radiation exposure was at moderate dose levels (effective dose = 2.5 ± 0.6mSv). (4) Conclusions: UHR-CTA generates highly valuable image qualities that allow the depiction of vessels including cerebral perforators at acceptable dose levels. The UHR-CTA may therefore enhance the detection of small cerebral pathologies and may improve interpretability, especially in settings where high image qualities are crucial for the diagnostic accuracy.
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- 2021
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4. A Machine learning model trained on dual-energy CT radiomics significantly improves immunotherapy response prediction for patients with stage IV melanoma
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Konstantin Nikolaou, Thomas Eigentler, Ahmed E Othman, Andreas Stefan Brendlin, Felix Peisen, Haidara Almansour, Saif Afat, Sebastian Faby, and Adria Font Calvarons
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Published
- 2021
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5. Effect of reduced z-axis scan coverage on diagnostic performance and radiation dose of neck computed tomography in patients with suspected cervical abscess.
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Jakob Weiss, Michael Maurer, Dominik Ketelsen, Mike Notohamiprodjo, Dominik Zinsser, Julian L Wichmann, Konstantin Nikolaou, Fabian Bamberg, and Ahmed E Othman
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Medicine ,Science - Abstract
To evaluate the effect of reduced z-axis scan coverage on diagnostic performance and radiation dose of neck CT in patients with suspected cervical abscess.Fifty-one patients with suspected cervical abscess were included and underwent contrast-enhanced neck CT on a 2nd or 3rd generation dual-source CT system. Image acquisition ranged from the aortic arch to the upper roof of the frontal sinuses (CTstd). Subsequently, series with reduced z-axis coverage (CTred) were reconstructed starting at the aortic arch up to the orbital floor. CTstd and CTred were independently assessed by two radiologists for the presence/absence of cervical abscesses and for incidental and alternative findings. In addition, diagnostic accuracy for the depiction of the cervical abscesses was calculated for both readers. Furthermore, DLP (dose-length-product), effective dose (ED) and organ doses were calculated and compared for CTred and CTstd, using a commercially available dose management platform.A total of 41 abscesses and 3 incidental/alternative findings were identified in CTstd. All abscesses and incidental/alternative findings could also be detected on CTred resulting in a sensitivity and specificity of 1.0 for both readers. DLP, ED and organ doses of the brain, the eye lenses, the red bone marrow and the salivary glands of CTred were significantly lower than for CTstd (p
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- 2017
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6. Continual atlas-based segmentation of prostate MRI.
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Amin Ranem, Camila González, Daniel Pinto dos Santos, Andreas M. Bucher, Ahmed E. Othman, and Anirban Mukhopadhyay 0003
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- 2024
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7. Improving assessment of lesions in longitudinal CT scans: a bi-institutional reader study on an AI-assisted registration and volumetric segmentation workflow.
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Alessa Hering, Max Westphal, Annika Gerken, Haidara Almansour, Michael Maurer, Benjamin P. Geisler, Temke Kohlbrandt, Thomas Eigentler, Teresa Amaral, Nikolas Lessmann, Sergios Gatidis, Horst K. Hahn, Konstantin Nikolaou, Ahmed E. Othman, Jan Hendrik Moltz, and Felix Peisen
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- 2024
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8. Detection of Intracranial Hemorrhage for Trauma Patients.
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Antoine P. Sanner, Nils F. Grauhan, Marc A. Brockmann, Ahmed E. Othman, and Anirban Mukhopadhyay 0003
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- 2024
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9. Voxel Scene Graph for Intracranial Hemorrhage.
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Antoine P. Sanner, Nils F. Grauhan, Marc A. Brockmann, Ahmed E. Othman, and Anirban Mukhopadhyay 0003
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- 2024
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10. Task-Agnostic Continual Hippocampus Segmentation for Smooth Population Shifts.
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Camila González, Amin Ranem, Ahmed E. Othman, and Anirban Mukhopadhyay 0003
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- 2022
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11. Clinical feasibility and validation of the accelerated T2 mapping sequence GRAPPATINI in brain imaging
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Natascha Gruenebach, Mario Alberto Abello Mercado, Nils F. Grauhan, Antoine Sanner, Andrea Kronfeld, Sergiu Groppa, Vanessa Ines Schoeffling, Tom Hilbert, Marc A. Brockmann, and Ahmed E. Othman
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quantitative Brain mapping ,Prospective ,Synthetic images ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Rationale and objectives: To prospectively evaluate feasibility and robustness of an accelerated T2 mapping sequence (GRAPPATINI) in brain imaging and to assess its synthetic T2-weighted images (sT2w) in comparison with a standard T2-weighted sequence (T2 TSE). Material and methods: Volunteers were included to evaluate the robustness and consecutive patients for morphological evaluation. They were scanned on a 3 T MR-scanner. Healthy volunteers underwent GRAPPATINI of the brain three times (day 1: scan/rescan; day 2: follow-up). Patients between the ages of 18 and 85 years who were able to provide written informed consent and who had no MRI contraindications were included. For morphological comparison two radiologists with 5 and 7 years of experience in brain MRI evaluated image quality using a Likert scale (1 being poor, 4 being excellent) in a blinded and randomized fashion. Results: Images were successfully acquired in ten volunteers with a mean age of 25 years (ranging from 22 to 31 years) and 52 patients (23 men/29 women) with a mean age of 55 years (range of 22–83 years). Most brain regions showed repeatable and reproducible T2 values (rescan: CoV 0.75%–2.06%, ICC 69%–92.3%; follow-up: CoV 0.41%–1.59%, ICC 79.4%–95.8%), except for the caudate nucleus (rescan: CoV 7.25%, ICC 66.3%; follow-up: CoV 4.78%, ICC 80.9%). Image quality of sT2w was rated inferior to T2 TSE (median for T2 TSE: 3; sT2w: 1–2), but measurements revealed good interrater reliability of sT2w (lesion counting: ICC 0.85; diameter measure: ICC 0.68 and 0.67). Conclusion: GRAPPATINI is a feasible and robust T2 mapping sequence of the brain on intra- and intersubject level. The resulting sT2w depict brain lesions comparable to T2 TSE despite its inferior image quality.
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- 2023
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12. Continual atlas-based segmentation of prostate MRI.
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Amin Ranem, Camila González, Daniel Pinto dos Santos, Andreas M. Bucher, Ahmed E. Othman, and Anirban Mukhopadhyay 0003
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- 2023
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13. The state-of-the-art 3D anisotropic intracranial hemorrhage segmentation on non-contrast head CT: The INSTANCE challenge.
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Xiangyu Li 0004, Gongning Luo, Kuanquan Wang, Hongyu Wang, Jun Liu, Xinjie Liang, Jie Jiang, Zhenghao Song, Chunyue Zheng, Haokai Chi, Mingwang Xu, Yingte He, Xinghua Ma, Jingwen Guo, Yifan Liu, Chuanpu Li, Zeli Chen, Md Mahfuzur Rahman Siddiquee, Andriy Myronenko, Antoine P. Sanner, Anirban Mukhopadhyay 0003, Ahmed E. Othman, Xingyu Zhao, Weiping Liu, Jinhuang Zhang, Xiangyuan Ma, Qinghui Liu, Bradley J. MacIntosh, Wei Liang, Moona Mazher, Abdul Qayyum, Valeriia Abramova, Xavier Lladó, and Shuo Li 0001
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- 2023
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14. Can Whole-Body Baseline CT Radiomics Add Information to the Prediction of Best Response, Progression-Free Survival, and Overall Survival of Stage IV Melanoma Patients Receiving First-Line Targeted Therapy: A Retrospective Register Study
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Felix Peisen, Annika Gerken, Alessa Hering, Isabel Dahm, Konstantin Nikolaou, Sergios Gatidis, Thomas K. Eigentler, Teresa Amaral, Jan H. Moltz, and Ahmed E. Othman
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melanoma ,imaging biomarkers ,prognostic biomarkers ,artificial intelligence and machine learning ,targeted therapy ,biomarkers for targeted therapy ,Medicine (General) ,R5-920 - Abstract
Background: The aim of this study was to investigate whether the combination of radiomics and clinical parameters in a machine-learning model offers additive information compared with the use of only clinical parameters in predicting the best response, progression-free survival after six months, as well as overall survival after six and twelve months in patients with stage IV malignant melanoma undergoing first-line targeted therapy. Methods: A baseline machine-learning model using clinical variables (demographic parameters and tumor markers) was compared with an extended model using clinical variables and radiomic features of the whole tumor burden, utilizing repeated five-fold cross-validation. Baseline CTs of 91 stage IV malignant melanoma patients, all treated in the same university hospital, were identified in the Central Malignant Melanoma Registry and all metastases were volumetrically segmented (n = 4727). Results: Compared with the baseline model, the extended radiomics model did not add significantly more information to the best-response prediction (AUC [95% CI] 0.548 (0.188, 0.808) vs. 0.487 (0.139, 0.743)), the prediction of PFS after six months (AUC [95% CI] 0.699 (0.436, 0.958) vs. 0.604 (0.373, 0.867)), or the overall survival prediction after six and twelve months (AUC [95% CI] 0.685 (0.188, 0.967) vs. 0.766 (0.433, 1.000) and AUC [95% CI] 0.554 (0.163, 0.781) vs. 0.616 (0.271, 1.000), respectively). Conclusions: The results showed no additional value of baseline whole-body CT radiomics for best-response prediction, progression-free survival prediction for six months, or six-month and twelve-month overall survival prediction for stage IV melanoma patients receiving first-line targeted therapy. These results need to be validated in a larger cohort.
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- 2023
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15. Enhanced Image Processing Using Complex Averaging in Diffusion-Weighted Imaging of the Prostate: The Impact on Image Quality and Lesion Detectability
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Sebastian Werner, Dominik Zinsser, Michael Esser, Dominik Nickel, Konstantin Nikolaou, and Ahmed E. Othman
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image quality ,multiparametric MRI ,prostate cancer ,diffusion-weighted imaging ,high b-value ,complex averaging ,Medicine (General) ,R5-920 - Abstract
Diffusion-weighted images of the prostate can suffer from a “hazy” background in low signal-intensity areas. We hypothesize that enhanced image processing (EIP) using complex averaging reduces artifacts, noise, and distortion in conventionally acquired diffusion-weighted images and synthesized high b-value images, thus leading to higher image quality and better detection of potentially malignant lesions. Conventional DWI trace images with a b-value of 1000 s/mm2 (b1000), calculated images with a b-value of 2000 s/mm2 (cb2000), and ADC maps of 3T multiparametric prostate MRIs in 53 patients (age 68.8 ± 10 years) were retrospectively evaluated. Standard images were compared to images using EIP. In the standard images, 36 lesions were detected in the peripheral zone and 20 in the transition zone. In 13 patients, EIP led to the detection of 8 additional lesions and the upgrading of 6 lesions; 6 of these patients were diagnosed with prostate carcinoma Gleason 7 or 8. EIP improved qualitative ratings for overall image quality and lesion detectability. Artifacts were significantly reduced in the cb2000 images. Quantitative measurements for lesion detectability expressed as an SI ratio were significantly improved. EIP using complex averaging led to image quality improvements in acquired and synthesized DWI, potentially resulting in elevated diagnostic accuracy and management changes.
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- 2023
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16. Virtual Monoenergetic Imaging of Lower Extremities Using Dual-Energy CT Angiography in Patients with Diabetes Mellitus
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Giuseppe Mauro Bucolo, Tommaso D’Angelo, Ibrahim Yel, Vitali Koch, Leon D. Gruenewald, Ahmed E. Othman, Leona Soraja Alizadeh, Daniel P. Overhoff, Stephan Waldeck, Simon S. Martin, Silvio Mazziotti, Giorgio Ascenti, Alfredo Blandino, Thomas J. Vogl, and Christian Booz
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virtual monoenergetic imaging ,dual energy ,CT angiography ,lower extremities ,Medicine (General) ,R5-920 - Abstract
Background: Type 2 diabetes mellitus (DM) is the most common metabolic disorder in the world and an important risk factor for peripheral arterial disease (PAD). CT angiography represents the method of choice for the diagnosis, pre-operative planning, and follow-up of vascular disease. Low-energy dual-energy CT (DECT) virtual mono-energetic imaging (VMI) has been shown to improve image contrast, iodine signal, and may also lead to a reduction in contrast medium dose. In recent years, VMI has been improved with the use of a new algorithm called VMI+, able to obtain the best image contrast with the least possible image noise in low-keV reconstructions. Purpose: To evaluate the impact of VMI+ DECT reconstructions on quantitative and qualitative image quality in the evaluation of the lower extremity runoff. Materials and Methods: We evaluated DECT angiography of lower extremities in patients suffering from diabetes who had undergone clinically indicated DECT examinations between January 2018 and January 2023. Images were reconstructed with standard linear blending (F_0.5) and low VMI+ series were generated from 40 to 100 keV, in an interval of 15 keV. Vascular attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for objective analysis. Subjective analysis was performed using five-point scales to evaluate image quality, image noise, and diagnostic assessability of vessel contrast. Results: Our final study cohort consisted of 77 patients (41 males). Attenuation values, CNR, and SNR were higher in 40-keV VMI+ reconstructions compared to the remaining VMI+ and standard F_0.5 series (HU: 1180.41 ± 45.09; SNR: 29.91 ± 0.99; CNR: 28.60 ± 1.03 vs. HU 251.32 ± 7.13; SNR: 13.22 ± 0.44; CNR: 10.57 ± 0.39 in standard F_0.5 series) (p < 0.0001). Subjective image rating was significantly higher in 55-keV VMI+ images compared to the other VMI+ and standard F_0.5 series in terms of image quality (mean score: 4.77), image noise (mean score: 4.39), and assessability of vessel contrast (mean value: 4.57) (p < 0.001). Conclusions: DECT 40-keV and 55-keV VMI+ showed the highest objective and subjective parameters of image quality, respectively. These specific energy levels for VMI+ reconstructions could be recommended in clinical practice, providing high-quality images with greater diagnostic suitability for the evaluation of lower extremity runoff, and potentially needing a lower amount of contrast medium, which is particularly advantageous for diabetic patients.
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- 2023
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17. Ultra-High-Resolution CT of the Head and Neck with Deep Learning Reconstruction—Assessment of Image Quality and Radiation Exposure and Intraindividual Comparison with Normal-Resolution CT
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Sebastian Altmann, Mario A. Abello Mercado, Felix A. Ucar, Andrea Kronfeld, Bilal Al-Nawas, Anirban Mukhopadhyay, Christian Booz, Marc A. Brockmann, and Ahmed E. Othman
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computed tomography ,head and neck neoplasms ,ultra-high resolution ,image quality ,radiation dose ,deep learning ,Medicine (General) ,R5-920 - Abstract
Objectives: To assess the benefits of ultra-high-resolution CT (UHR-CT) with deep learning–based image reconstruction engine (AiCE) regarding image quality and radiation dose and intraindividually compare it to normal-resolution CT (NR-CT). Methods: Forty consecutive patients with head and neck UHR-CT with AiCE for diagnosed head and neck malignancies and available prior NR-CT of a different scanner were retrospectively evaluated. Two readers evaluated subjective image quality using a 5-point Likert scale regarding image noise, image sharpness, artifacts, diagnostic acceptability, and assessability of various anatomic regions. For reproducibility, inter-reader agreement was analyzed. Furthermore, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and slope of the gray-value transition between different tissues were calculated. Radiation dose was evaluated by comparing CTDIvol, DLP, and mean effective dose values. Results: UHR-CT with AiCE reconstruction led to significant improvement in subjective (image noise and diagnostic acceptability: p < 0.000; ICC ≥ 0.91) and objective image quality (SNR: p < 0.000; CNR: p < 0.025) at significantly lower radiation doses (NR-CT 2.03 ± 0.14 mSv; UHR-CT 1.45 ± 0.11 mSv; p < 0.0001) compared to NR-CT. Conclusions: Compared to NR-CT, UHR-CT combined with AiCE provides superior image quality at a markedly lower radiation dose. With improved soft tissue assessment and potentially improved tumor detection, UHR-CT may add further value to the role of CT in the assessment of head and neck pathologies.
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- 2023
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18. Single-Energy Metal Artifact Reduction (SEMAR) in Ultra-High-Resolution CT Angiography of Patients with Intracranial Implants
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Abdullah Jabas, Mario Alberto Abello Mercado, Sebastian Altmann, Florian Ringel, Christian Booz, Andrea Kronfeld, Antoine P. Sanner, Marc A. Brockmann, and Ahmed E. Othman
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metal artifact reduction ,artifacts ,computed tomography angiography ,ultra-high-resolution computed tomography ,intracranial aneurysm ,Medicine (General) ,R5-920 - Abstract
Purpose: To evaluate the effects of single-energy metal artifact reduction (SEMAR) on image quality of ultra-high-resolution CT-angiography (UHR-CTA) with intracranial implants after aneurysm treatment. Methods: Image quality of standard and SEMAR-reconstructed UHR-CT-angiography images of 54 patients who underwent coiling or clipping was retrospectively evaluated. Image noise (i.e., index for metal-artifact strength) was analyzed in close proximity to and more distally from the metal implant. Frequencies and intensities of metal artifacts were additionally measured and intensity-differences between both reconstructions were compared in different frequencies and distances. Qualitative analysis was performed by two radiologists using a four-point Likert-scale. All measured results from both quantitative and qualitative analysis were then compared between coils and clips. Results: Metal artifact index (MAI) and the intensity of coil-artifacts were significantly lower in SEMAR than in standard CTA in close vicinity to and more distally from the coil-package (p p = 0.036; p p = 0.007; p p p < 0.05) for SEMAR. Conclusion: SEMAR significantly reduces metal artifacts in UHR-CT-angiography images with intracranial implants and improves image quality and diagnostic confidence. SEMAR effects were strongest in patients with coils, whereas the effects were minor in patients with titanium-clips due to the absent of or minimal artifacts.
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- 2023
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19. Diagnosis of an Acute Anterior Wall Infarction in Dual-Energy CT
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Aynur Gökduman, Ibrahim Yel, Thomas J. Vogl, Mirela Dimitrova, Leon D. Grünewald, Vitali Koch, Leona S. Alizadeh, Andreas S. Brendlin, Ahmed E. Othman, Simon S. Martin, Tommaso D’Angelo, Alfredo Blandino, Silvio Mazziotti, and Christian Booz
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dual-energy CT ,myocardial infarct ,acute chest pain ,cardiovascular diseases ,triple-rule-out ,virtual monoenergetic images ,Medicine (General) ,R5-920 - Abstract
Due to its high morbidity and mortality, myocardial infarction is the leading cause of death worldwide. Against this background, rapid diagnosis is of immense importance. Especially in case of an atypical course, the correct diagnosis may be delayed and thus lead to increased mortality rates. In this report, we present a complex case of acute coronary syndrome. A triple-rule-out CT examination was performed in dual-energy CT (DECT) mode. While pulmonary artery embolism and aortic dissection could be ruled out with conventional CT series, the presence of anterior wall infarction was only detectable on DECT reconstructions. Subsequently, adequate and rapid therapy was then initiated leading to survival of the patient.
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- 2023
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20. Application of a Deep Learning Algorithm for Combined Super-Resolution and Partial Fourier Reconstruction Including Time Reduction in T1-Weighted Precontrast and Postcontrast Gradient Echo Imaging of Abdominopelvic MR Imaging
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Daniel Wessling, Judith Herrmann, Saif Afat, Dominik Nickel, Haidara Almansour, Gabriel Keller, Ahmed E. Othman, Andreas S. Brendlin, and Sebastian Gassenmaier
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MRI ,deep learning ,abdominal ,pelvic ,Medicine (General) ,R5-920 - Abstract
Purpose: The purpose of this study was to test the technical feasibility and the impact on the image quality of a deep learning-based super-resolution reconstruction algorithm in 1.5 T abdominopelvic MR imaging. Methods: 44 patients who underwent abdominopelvic MRI were retrospectively included, of which 4 had to be subsequently excluded. After the acquisition of the conventional volume interpolated breath-hold examination (VIBEStd), images underwent postprocessing, using a deep learning-based iterative denoising super-resolution reconstruction algorithm for partial Fourier acquisitions (VIBESR). Image analysis of 40 patients with a mean age of 56 years (range 18–84 years) was performed qualitatively by two radiologists independently using a Likert scale ranging from 1 to 5, where 5 was considered the best rating. Results: Image analysis showed an improvement of image quality, noise, sharpness of the organs and lymph nodes, and sharpness of the intestine for pre- and postcontrast images in VIBESR compared to VIBEStd (each p < 0.001). Lesion detectability was better for VIBESR (p < 0.001), while there were no differences concerning the number of lesions. Average acquisition time was 16 s (±1) for the upper abdomen and 15 s (±1) for the pelvis for VIBEStd, and 15 s (±1) for the upper abdomen and 14 s (±1) for the pelvis for VIBESR. Conclusion: This study demonstrated the technical feasibility of a deep learning-based super-resolution algorithm including partial Fourier technique in abdominopelvic MR images and illustrated a significant improvement of image quality, noise, and sharpness while reducing TA.
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- 2022
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21. Reduced scan range abdominopelvic CT in patients with suspected acute appendicitis - impact on diagnostic accuracy and effective radiation dose.
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Dominik Zinsser, Michael Maurer, Phuong-Linh Do, Jakob Weiß, Mike Notohamiprodjo, Fabian Bamberg, and Ahmed E. Othman
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- 2019
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22. Prospective intraindividual comparison of a standard 2D TSE MRI protocol for ankle imaging and a deep learning-based 2D TSE MRI protocol with a scan time reduction of 48%
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Gabriel Keller, Arne Estler, Judith Herrmann, Saif Afat, Ahmed E. Othman, Dominik Nickel, Gregor Koerzdoerfer, and Fabian Springer
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Radiology, Nuclear Medicine and imaging ,General Medicine - Abstract
Purpose Magnetic resonance imaging (MRI) scan time remains a limited and valuable resource. This study evaluates the diagnostic performance of a deep learning (DL)-based accelerated TSE study protocol compared to a standard TSE study protocol in ankle MRI. Material and methods Between October 2020 and July 2021 forty-seven patients were enrolled in this study for an intraindividual comparison of a standard TSE study protocol and a DL TSE study protocol either on a 1.5 T or a 3 T scanner. Two radiologists evaluated the examinations regarding structural pathologies and image quality categories (5-point-Likert-scale; 1 = “non diagnostic”, 5 = “excellent”). Results Both readers showed almost perfect/perfect agreement of DL TSE with standard TSE in all analyzed structural pathologies (0.81–1.00) with a median “good” or “excellent” rating (4–5/5) in all image quality categories in both 1.5 T and 3 T MRI. The reduction of total acquisition time of DL TSE compared to standard TSE was 49% in 1.5 T and 48% in 3 T MRI to a total acquisition time of 5 min 41 s and 5 min 46 s. Conclusion In ankle MRI the new DL-based accelerated TSE study protocol delivers high agreement with standard TSE and high image quality, while reducing the acquisition time by 48%.
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- 2023
23. Deep learning-based super-resolution gradient echo imaging of the pancreas: Improvement of image quality and reduction of acquisition time
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Maryanna Chaika, Saif Afat, Daniel Wessling, Carmen Afat, Dominik Nickel, Stephan Kannengiesser, Judith Herrmann, Haidara Almansour, Simon Männlin, Ahmed E. Othman, and Sebastian Gassenmaier
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Radiological and Ultrasound Technology ,Radiology, Nuclear Medicine and imaging ,General Medicine - Abstract
The purpose of this study was to evaluate the impact of a deep learning-based super-resolution technique on T1-weighted gradient-echo acquisitions (volumetric interpolated breath-hold examination; VIBE) on the assessment of pancreatic MRI at 1.5 T compared to standard VIBE imaging (VIBEThis retrospective single-center study was conducted between April 2021 and October 2021. Fifty patients with a total of 50 detectable pancreatic lesion entities were included in this study. There were 27 men and 23 women, with a mean age of 69 ± 13 (standard deviation [SD]) years (age range: 33-89 years). VIBEVIBEOur results indicate that the newly developed deep learning-based super-resolution algorithm adapted to partial Fourier acquisitions has a positive influence not only on shortening the examination time but also on improvement of image quality in pancreatic MRI.
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- 2023
24. DSA-Based 2D Perfusion Measurements in Delayed Cerebral Ischemia to Estimate the Clinical Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage: A Technical Feasibility Study
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Kronfeld, Sebastian R. Reder, Steffen Lückerath, Axel Neulen, Katja U. Beiser, Nils F. Grauhan, Ahmed E. Othman, Marc A. Brockmann, Carolin Brockmann, and Andrea
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digital subtraction angiography ,aneurysmal subarachnoid hemorrhage ,delayed cerebral ischemia ,vasospasm ,perfusion ,outcome prediction - Abstract
(1) Background: To predict clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH) and delayed cerebral ischemia (DCI) by assessment of the cerebral perfusion using a 2D perfusion angiography (2DPA) time–contrast agent (CA) concentration model. (2) Methods: Digital subtraction angiography (DSA) data sets of n = 26 subjects were acquired and post-processed focusing on changes in contrast density using a time–concentration model at three time points: (i) initial presentation with SAH (T0); (ii) vasospasm-associated acute clinical impairment (T1); and (iii) directly after endovascular treatment (T2) of SAH-associated large vessel vasospasm (LVV), which resulted in n = 78 data sets. Maximum slope (MS in SI/ms), time-to-peak (TTP in ms), and maximum amplitude of a CA bolus (dSI) were measured in brain parenchyma using regions of interest (ROIs). First, acquired parameters were standardized to the arterial input function (AIF) and then statistically analyzed as mean values. Additionally, data were clustered into two subsets consisting of patients with regredient or with stable/progredient symptoms (or Doppler signals) after endovascular treatment (n = 10 vs. n = 16). (3) Results: Perfusion parameters (MS, TTP, and dSI) differed significantly between T0 and T1 (p = 0.003 each). Significant changes between T1 and T2 were only detectable for MS (0.041 ± 0.016 vs. 0.059 ± 0.026; p = 0.011) in patients with regredient symptoms at T2 (0.04 ± 0.012 vs. 0.066 ± 0.031; p = 0.004). For dSI, there were significant differences between T0 and T2 (5095.8 ± 2541.9 vs. 3012.3 ± 968.3; p = 0.001), especially for those with stable symptoms at T2 (5685.4 ± 2967.2 vs. 3102.8 ± 1033.2; p = 0.02). Multiple linear regression analysis revealed that a) the difference in MS between T1 and T2 and b) patient’s age (R = 0.6; R2 = 0.34; p = 0.009) strongly predict the modified Rankin Scale (mRS) at discharge. (4) Conclusions: 2DPA allows the direct measurement of treatment effects in SAH associated DCI and may be used to predict outcomes in these critically ill patients.
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- 2023
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25. Free-breathing Arterial Spin Labeling MRI for the Detection of Pulmonary Embolism
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Ahmed E. Othman, Cecilia Liang, Yasmin Komma, Max Munz, Manuel Kolb, Dominik Rath, Brigitte Gückel, Rolf Pohmann, Konstantin Nikolaou, Martin Schwartz, Thomas Küstner, Petros Martirosian, and Ferdinand Seith
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Radiology, Nuclear Medicine and imaging - Abstract
Background Arterial spin labeling (ASL) MRI can be used to assess organ perfusion but has yet to be implemented for perfusion evaluation of the lung. Purpose To evaluate pseudo-continuous ASL (PCASL) MRI for the detection of acute pulmonary embolism (PE) and its potential as an alternative to CT pulmonary angiography (CTPA). Materials and Methods Between November 2020 and November 2021, 97 patients (median age, 61 years; 48 women) with suspected PE were enrolled in this prospective study. PCASL MRI was performed within a 72-hour period following CTPA under free-breathing conditions and included three orthogonal planes. The pulmonary trunk was labeled during systole, and the image was acquired during diastole of the subsequent cardiac cycle. Additionally, multisection, coronal, balanced, steady-state free-precession imaging was carried out. Two radiologists blindly assessed overall image quality, artifacts, and diagnostic confidence (five-point Likert scale, 5 = best). Patients were categorized as positive or negative for PE, and a lobe-wise assessment in PCASL MRI and CTPA was conducted. Sensitivity and specificity were calculated on a patient level with the final clinical diagnosis serving as the reference standard. Interchangeability between MRI and CTPA was also tested with use of an individual equivalence index (IEI). Results PCASL MRI was performed successfully in all patients with high scores for image quality, artifact, and diagnostic confidence (κ ≥ .74). Of the 97 patients, 38 were positive for PE. PCASL MRI depicted PE correctly in 35 of 38 patients with three false-positive and three false-negative findings, resulting in a sensitivity of 35 of 38 patients (92% [95% CI: 79, 98]) and a specificity of 56 of 59 patients (95% [95% CI: 86, 99]). Interchangeability analysis revealed an IEI of 2.6% (95% CI: 1.2, 3.8). Conclusion Free-breathing pseudo-continuous arterial spin labeling MRI depicted abnormal lung perfusion caused by acute pulmonary embolism and may be useful as a contrast material-free alternative to CT pulmonary angiography for selected patients. German Clinical Trials Register no. DRKS00023599
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- 2023
26. Ultrafast Brain MRI Protocol at 1.5 T Using Deep Learning and Multi-shot EPI
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Sebastian Altmann, Mario Alberto Abello Mercado, Lavinia Brockstedt, Andrea Kronfeld, Bryan Clifford, Thorsten Feiweier, Timo Uphaus, Sergiu Groppa, Marc A. Brockmann, and Ahmed E. Othman
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Radiology, Nuclear Medicine and imaging - Published
- 2023
27. Fellowship Training: Navigating the Decision to Be a Generalist or a Subspecialist—Radiology In Training
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Haidara Almansour, Aileen O’Shea, Ryan W. England, Saif Afat, Konstantin Nikolaou, and Ahmed E. Othman
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Radiology, Nuclear Medicine and imaging - Published
- 2022
28. Editorial for 'Deep Learning With an Attention Mechanism for Differentiating the Origin of Brain Metastasis Using <scp>MR</scp> Images: A Multicenter Study'
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Antoine Sanner and Ahmed E. Othman
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Radiology, Nuclear Medicine and imaging - Published
- 2023
29. Deep Learning Reconstruction for Accelerated Spine MRI: Prospective Analysis of Interchangeability
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Haidara Almansour, Judith Herrmann, Sebastian Gassenmaier, Saif Afat, Johann Jacoby, Gregor Koerzdoerfer, Dominik Nickel, Mahmoud Mostapha, Mariappan Nadar, and Ahmed E. Othman
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Radiology, Nuclear Medicine and imaging - Abstract
Background Deep learning (DL)-based MRI reconstructions can reduce examination times for turbo spin-echo (TSE) acquisitions. Studies that prospectively employ DL-based reconstructions of rapidly acquired, undersampled spine MRI are needed. Purpose To investigate the diagnostic interchangeability of an unrolled DL-reconstructed TSE (hereafter, TSE
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- 2023
30. Early Tumor Size Reduction of at least 10% at the First Follow-Up Computed Tomography Can Predict Survival in the Setting of Advanced Melanoma and Immunotherapy
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Thomas Eigentler, Ferdinand Seith, Amadeus Schraag, Saif Afat, Felix Peisen, Teresa Amaral, Haidara Almansour, Andreas Brendlin, Bernhard Klumpp, Lina María Serna-Higuita, and Ahmed E. Othman
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Oncology ,medicine.medical_specialty ,Context (language use) ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Progression-free survival ,Prospective cohort study ,Melanoma ,Retrospective Studies ,business.industry ,fungi ,Retrospective cohort study ,medicine.disease ,Clinical trial ,Treatment Outcome ,030220 oncology & carcinogenesis ,Biomarker (medicine) ,Immunotherapy ,Tomography, X-Ray Computed ,business ,Progressive disease ,Follow-Up Studies - Abstract
Early tumor size reduction (TSR) has been explored as a prognostic factor for survival in patients with advanced melanoma in clinical trials. The purpose of this analysis is to validate, in a routine clinical milieu, the predictive capacity of TSR by 10% for overall survival (OS) and progression-free survival (PFS) and to compare its predictive performance with the RECIST 1.1 criteria.This retrospective study was approved by the local ethics committee. A total of 152 patients with both CT before immunotherapy initiation and at first response evaluation after immunotherapy initiation were included. Prior to statistical analysis, treatment response was trichotomized as follows: Complete response and/or partial response, stable disease and progressive disease. Furthermore, response was dichotomized regarding TSR (TSR ≥ 10% and TSR10%). Kaplan-Meier survival estimates, Cox regression and Harrel's concordance index (C-index) were computed for prediction of overall survival and progression-free survival.Tumor size reduction by at least 10% significantly differentiated between patients with increased survival from the ones with decreased survival (median OS: TSR ≥ 10%: 2137 days vs. TSR10%: 263 days) (p0.001) (median PFS: TSR ≥ 10%: 590 days vs. TSR10%: 11 days) (p0.001). RECIST 1.1. criteria had a slightly higher C-index for overall survival reflecting a slight superior predictive capacity (RECIST: 0.69 vs TSR: 0.64) but a similar predictive capacity regarding progression-free survival (both: 0. 63).Early tumor size reduction serves as a simple-to-use metric which can be implemented on the first follow-up CT. Tumor size reduction by at least 10% can be considered an additional biomarker predictive of overall survival and progression-free survival in routine clinical care and not only in the context of clinical trials in patients with advanced melanoma undergoing immunotherapy. Nevertheless, RECIST-based criteria should remain the main tool of treatment response assessment until results of prospective studies validating the TSR method are available.
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- 2022
31. Lockpicking using Ultra-High Resolution Multi- Slice and Cone Beam Computed Tomography
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Hamzah Adwan, Ahmed E. Othman, Marc A. Brockmann, and Sebastian Steinmetz
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(1) Purpose: Combination locks are frequently being used to protect personal property. Since hitherto not described in the literature, we evaluated whether locks can be picked using computed tomography imaging. (2) Materials and methods: Three different combination locks (1296-42875 possible combinations) were scanned using an ultra-high resolution multi slice CT-Scanner (UHR-MSCT) and cone beam computed tomography (CBCT). Image quality was rated by two radiologists using a 4-point Likert scale (1: Poor, 2: Moderate, 3: Good, 4: Very good) and both radiologists were asked to pick the lock using the acquired CT images. The time until picking each of the lock was measured. (3) Results: All three locks were successfully picked by both radiologists using the UHR-MSCT und CBCT images. Overall, the image quality of CBCT (median=3.5) was superior to MSCT (median=3). The interrater reliability showed a moderate agreement for image quality of CBCT (k=0.4) and MSCT (k=0.5) between both radiologists. The median overall time required by both radiologists for picking all locks was 10.5 minutes (Range: 6-16 minutes). The median lockpicking time required by radiologist 1 was 10 minutes (Range: 7-15 minutes), and by radiologist 2 was 11 minutes (Range: 6-16 minutes). (4) Conclusion: UHR-MSCT and CBCT can be successfully applied for picking different kinds of combination locks.
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- 2023
32. How Real Are Computed Tomography Low Dose Simulations? An Investigational In-Vivo Large Animal Study
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Andreas S. Brendlin, Robin Wrazidlo, Haidara Almansour, Arne Estler, David Plajer, Salvador Guillermo Castaneda Vega, Wilfried Klingert, Elisa Bertolani, Ahmed E. Othman, Martin Schenk, and Saif Afat
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Radiology, Nuclear Medicine and imaging - Published
- 2023
33. A Rapid Late Enhancement MRI Protocol Improves Differentiation between Brain Tumor Recurrence and Treatment-Related Contrast Enhancement of Brain Parenchyma
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Neda Satvat, Oliver Korczynski, Matthias Müller-Eschner, Ahmed E. Othman, Vanessa Schöffling, Naureen Keric, Florian Ringel, Clemens Sommer, Marc A. Brockmann, and Sebastian Reder
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Cancer Research ,Oncology ,late enhancement ,pseudo progression ,radiation necrosis ,glioblastoma ,delayed-contrast-MRI - Abstract
Purpose: Differentiation between tumor recurrence and treatment-related contrast enhancement in MRI can be difficult. Late enhancement MRI up to 75 min after contrast agent application has been shown to improve differentiation between tumor recurrence and treatment-related changes. We investigated the diagnostic performance of late enhancement using a rapid MRI protocol optimized for clinical workflow. Methods: Twenty-three patients with 28 lesions suspected for glioma recurrence underwent MRI including T1-MPRAGE-series acquired 2 and 20 min after contrast agent administration. Early contrast series were subtracted from late contrast series using motion correction. Contrast enhancing lesions were retrospectively and independently evaluated by two readers blinded to the patients’ later clinical course and histology with or without the use of late enhancement series. Sensitivity, specificity, NPV, and PPV were calculated for both readers by comparing results of MRI with histological samples. Results: Using standard MR sequences, sensitivity, specificity, PPV, and NPV were 0.84, 0, 0.875, and 0 (reader 1) and 0.92, 0, 0.885, and 0 (reader 2), respectively. Early late enhancement increased sensitivity, specificity, PPV, and NPV to 1 for each value and for both readers. Inter-reader reliability increased from 0.632 (standard MRI sequences) to 1.0 (with early late enhancement). Conclusion: The described rapid late enhancement MRI protocol improves MRI-based discrimination between tumor tissue and treatment-related changes of the brain parenchyma.
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- 2022
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34. 1.5 vs 3 Tesla Magnetic Resonance Imaging
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Judith Herrmann, Alexander Isaak, Daniel Paech, Jürgen F. Schäfer, Konstantin Nikolaou, Sebastian Gassenmaier, Alexander Radbruch, Julian A. Luetkens, and Ahmed E. Othman
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Male ,3 Tesla Magnetic Resonance Imaging ,Musculoskeletal imaging ,2019-20 coronavirus outbreak ,medicine.medical_specialty ,Magnetic Resonance Spectroscopy ,medicine.diagnostic_test ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Image quality ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Magnetic resonance imaging ,General Medicine ,Magnetic Resonance Imaging ,medicine ,Humans ,Whole Body Imaging ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Child ,business ,Cardiac imaging - Abstract
The second part of this review deals with experiences in neuroradiological and pediatric examinations using modern magnetic resonance imaging systems with 1.5 T and 3 T, with special attention paid to experiences in pediatric cardiac imaging. In addition, whole-body examinations, which are widely used for diagnostic purposes in systemic diseases, are compared with respect to the image quality obtained in different body parts at both field strengths. A systematic overview of the technical differences at 1.5 T and 3 T has been presented in part 1 of this review, as well as several organ-based magnetic resonance imaging applications including musculoskeletal imaging, abdominal imaging, and prostate diagnostics.
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- 2021
35. Application of a Deep Learning Algorithm for Combined Super-Resolution and Partial Fourier Reconstruction Including Time Reduction in T1-Weighted Precontrast and Postcontrast Gradient Echo Imaging of Abdominopelvic MR Imaging
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Gassenmaier, Daniel Wessling, Judith Herrmann, Saif Afat, Dominik Nickel, Haidara Almansour, Gabriel Keller, Ahmed E. Othman, Andreas S. Brendlin, and Sebastian
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MRI ,deep learning ,abdominal ,pelvic - Abstract
Purpose: The purpose of this study was to test the technical feasibility and the impact on the image quality of a deep learning-based super-resolution reconstruction algorithm in 1.5 T abdominopelvic MR imaging. Methods: 44 patients who underwent abdominopelvic MRI were retrospectively included, of which 4 had to be subsequently excluded. After the acquisition of the conventional volume interpolated breath-hold examination (VIBEStd), images underwent postprocessing, using a deep learning-based iterative denoising super-resolution reconstruction algorithm for partial Fourier acquisitions (VIBESR). Image analysis of 40 patients with a mean age of 56 years (range 18–84 years) was performed qualitatively by two radiologists independently using a Likert scale ranging from 1 to 5, where 5 was considered the best rating. Results: Image analysis showed an improvement of image quality, noise, sharpness of the organs and lymph nodes, and sharpness of the intestine for pre- and postcontrast images in VIBESR compared to VIBEStd (each p < 0.001). Lesion detectability was better for VIBESR (p < 0.001), while there were no differences concerning the number of lesions. Average acquisition time was 16 s (±1) for the upper abdomen and 15 s (±1) for the pelvis for VIBEStd, and 15 s (±1) for the upper abdomen and 14 s (±1) for the pelvis for VIBESR. Conclusion: This study demonstrated the technical feasibility of a deep learning-based super-resolution algorithm including partial Fourier technique in abdominopelvic MR images and illustrated a significant improvement of image quality, noise, and sharpness while reducing TA.
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- 2022
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36. Monitoring Pulmonary Thrombectomy: What Information Can Be Gained with Arterial Spin Labeling MRI?
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Cecilia Zhang, Gerd Groezinger, Klaus-Peter Kreißelmeier, Ahmed E. Othman, Petros Martirosian, Rolf Pohmann, and Ferdinand Seith
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Cerebrovascular Circulation ,Humans ,Radiology, Nuclear Medicine and imaging ,Spin Labels ,Magnetic Resonance Imaging ,Thrombectomy - Abstract
Acute pulmonary embolism (PE) can be a life-threatening event that requires immediate care to maintain cardiovascular circulation. In addition to systemic thrombolytic therapy, mechanical thrombectomy may be indicated in cases with a high or intermediate risk of mortality, to directly remove obstructive emboli for rapid patient improvement [1]. Several devices for catheter-directed thrombolysis and mechanical thrombectomy are available, and data regarding the efficacy of these procedures are inconsistent. Non-invasive imaging of pulmonary blood flow might help evaluate treatment success and support the acceptance of revascularization procedures. Arterial spin labeling (ASL)-MRI is a well-established technique in brain imaging to measure organ perfusion without the need for contrast agents, using blood as an endogenous tracer. Perfusion imaging with ASL has already been implemented in routine clinical diagnosis of cerebrovascular pathologies, including arterio-occlusive disease, vascular shunts, and neuro-degenerative diseases [2]. In the lung, the complex vessel anatomy, highly pulsatile nature of blood flow, respiratory movements, and low proton density are challenging conditions for ASL-MRI, hindering its translation to routine clinical use. We recently presented electrocardiogram-triggered pseudo-continuous ASL (PCASL) imaging with balanced steady-state free precession readout at 1.5T as a promising approach to enable the imaging of pulmonary blood flow even under free-breathing conditions [3]. We aimed to demonstrate the first use of PCASL-MRI in patients to monitor the treatment success of catheter-directed mechanical thrombectomy. A 79-year-old female patient was brought to our emergency unit with clinical signs of PE. A contrast-enhanced CT-scan was performed showing a massive occlusion of the right and left pulmonary arteries with signs of right ventricular dysfunction (Fig. 1A-C). Right ventricular strain was diagnosed on echocardiography and electrocardiogram (Fig. 1D). In accordance with the European Society of Cardiology (ESC) guidelines and after interdisciplinary discussion, the patient was brought to the angiography suite in our radiology department for mechanical thrombectomy.
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- 2022
37. Stellenwert des 1,5-T-MR-Linearbeschleunigers für die primäre Therapie des Prostatakarzinoms
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Arndt-Christian Müller, D. Wegener, Haidara Almansour, Frank Paulsen, Cihan Gani, Konstantin Nikolaou, S. Boeke, Daniel Zips, and Ahmed E. Othman
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Magnetic resonance imaging ,Interventional radiology ,medicine.disease ,Radiosurgery ,030218 nuclear medicine & medical imaging ,Radiation therapy ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Soft tissue contrast ,030220 oncology & carcinogenesis ,medicine ,Radiology, Nuclear Medicine and imaging ,Radiology ,business ,Cardiac imaging ,Neuroradiology - Abstract
Zusammenfassung Hintergrund Der potenzielle Nutzen des verbesserten Weichteilkontrastes von MR-Sequenzen gegenüber der Computertomographie (CT) für die Radiotherapie des Prostatakarzinoms ist bekannt und führt zu konsistenteren und kleineren Zielvolumina sowie verbesserter Risikoorganschonung. Hybridgeräte aus Magnetresonanztomographie (MRT) und Linearbeschleuniger (MR-Linac) stellen eine neue vielversprechende Erweiterung der radioonkologischen Therapieoptionen dar. Material und Methoden Dieser Artikel gibt eine Übersicht über bisherige Erfahrungen, Indikationen, Vorteile und Herausforderungen für die Radiotherapie des primären Prostatakarzinoms mit dem 1,5-T-MR-Linac. Ergebnisse Alle strahlentherapeutischen Therapieindikationen für das primäre Prostatakarzinom können mit dem 1,5-T-MR-Linac abgedeckt werden. Die potenziellen Vorteile umfassen die tägliche MR-basierte Lagekontrolle in Bestrahlungsposition und die Möglichkeit der täglichen Echtzeitanpassung des Bestrahlungsplans an die aktuelle Anatomie der Beckenorgane (adaptive Strahlentherapie). Zusätzlich werden am 1,5-T-MR-Linac funktionelle MRT-Sequenzen für individuelles Response-Assessment für die Therapieanpassung untersucht. Dadurch soll das therapeutische Fenster weiter optimiert werden. Herausforderungen stellen u. a. die technische Komplexität und die Dauer der Behandlungssitzung dar. Schlussfolgerung Der 1,5-T-MR-Linac erweitert das radioonkologische Spektrum in der Therapie des Prostatakarzinoms und bietet Vorteile durch tagesaktuelle MRT-basierte Zielvolumendefinition und Planadaptation. Weitere klinische Untersuchungen sind notwendig, um die Patienten zu identifizieren, die von der Behandlung am MR-Linac gegenüber anderen strahlentherapeutischen Methoden besonders profitieren.
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- 2021
38. Development and Evaluation of Deep Learning-Accelerated Single-Breath-Hold Abdominal HASTE at 3 T Using Variable Refocusing Flip Angles
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Dominik Nickel, Konstantin Nikolaou, Sebastian Gassenmaier, Simon Arberet, Judith Herrmann, Saif Afat, Ahmed E. Othman, and John P. Mugler
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medicine.diagnostic_test ,Image quality ,Computer science ,business.industry ,media_common.quotation_subject ,Deep learning ,Specific absorption rate ,Magnetic resonance imaging ,Ranging ,General Medicine ,Magnetic Resonance Imaging ,Noise ,Deep Learning ,Flip angle ,Abdomen ,medicine ,Humans ,Contrast (vision) ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Artificial intelligence ,Artifacts ,Nuclear medicine ,business ,media_common - Abstract
Objective Deep learning (DL) reconstruction enables substantial acceleration of image acquisition while maintaining diagnostic image quality. The aims of this study were to overcome the drawback of specific absorption rate (SAR)-related limitations at 3 T and to develop a DL-accelerated single-breath-hold half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence for 2-dimesional T2-weighted fat-suppressed magnetic resonance imaging of the abdomen at 3 T using a variable flip angle (FA) evolution for the refocusing radiofrequency pulses, as well as to evaluate its feasibility and image quality in comparison to state-of-the-art T2-weighted fat-suppressed imaging technique (BLADE). Materials and methods First, a suitable FA evolution with low cardiac motion-related signal loss (CRSL) and low SAR was determined through a prospective volunteer study with 11 participants. Image quality and diagnostic confidence with 5 different FA evolutions of a HASTEDL were assessed to identify the most suitable FA evolution. Second, the identified FA evolution was implemented clinically and evaluated in 51 patients undergoing a clinically indicated liver magnetic resonance imaging at 3 T. Two radiologists assessed the HASTEDL and standard sequences regarding overall image quality, noise, contrast, sharpness, artifacts, CRSL, and diagnostic confidence using a Likert scale ranging from 1 to 4, with 4 being the best. Comparative analyses were conducted to assess the differences between HASTEDL (acquisition time, 21 seconds; single breath-hold) and the routinely used T2-weighted BLADE sequence (acquisition time, 4 minutes; respiratory triggering). Results From the volunteer study, the FA evolution characterized by the control points 130-90-110-130 degrees (HASTEDL) was identified as optimal among the 5 evolutions evaluated and was implemented in our clinical protocol. In all 51 patients, HASTEDL was successfully acquired at 3 T and showed excellent image quality (median, 4; interquartile range, 3-4). Although BLADE was rated significantly higher for overall image quality, noise, contrast, sharpness, artifacts, CRSL, and diagnostic confidence than HASTEDL, no differences were found concerning the number (n = 102) and measured diameter of the detected hepatic lesions between the 2 sequences BLADE and HASTEDL. Conclusions The proposed single-breath-hold abdominal HASTEDL with variable refocusing FAs is feasible at 3 T within SAR limits and yields high image quality and diagnostic confidence as compared with a standard T2-weighted acquisition technique, at a 10th of the acquisition time.
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- 2021
39. Reduction in Acquisition Time and Improvement in Image Quality in T2-Weighted MR Imaging of Musculoskeletal Tumors of the Extremities Using a Novel Deep Learning-Based Reconstruction Technique in a Turbo Spin Echo (TSE) Sequence
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Gassenmaier, Daniel Wessling, Judith Herrmann, Saif Afat, Dominik Nickel, Ahmed E. Othman, Haidara Almansour, and Sebastian
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deep learning ,accelerated turbo spin echo MRI ,musculoskeletal imaging ,musculoskeletal tumors ,artificial intelligence - Abstract
Background: The aim of this study was to assess the technical feasibility and the impact on image quality and acquisition time of a deep learning-accelerated fat-saturated T2-weighted turbo spin echo sequence in musculoskeletal imaging of the extremities. Methods: Twenty-three patients who underwent MRI of the extremities were prospectively included. Standard T2w turbo inversion recovery magnitude (TIRMStd) imaging was compared to a deep learning-accelerated T2w TSE (TSEDL) sequence. Image analysis of 23 patients with a mean age of 60 years (range 30–86) was performed regarding image quality, noise, sharpness, contrast, artifacts, lesion detectability and diagnostic confidence. Pathological findings were documented measuring the maximum diameter. Results: The analysis showed a significant improvement for the T2 TSEDL with regard to image quality, noise, contrast, sharpness, lesion detectability, and diagnostic confidence, as compared to T2 TIRMStd (each p < 0.001). There were no differences in the number of detected lesions. The time of acquisition (TA) could be reduced by 52–59%. Interrater agreement was almost perfect (κ = 0.886). Conclusion: Accelerated T2 TSEDL was technically feasible and superior to conventionally applied T2 TIRMStd. Concurrently, TA could be reduced by 52–59%. Therefore, deep learning-accelerated MR imaging is a promising and applicable method in musculoskeletal imaging.
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- 2022
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40. Dose Reduction and Image Quality in Photon-counting Detector High-resolution Computed Tomography of the Chest: Routine Clinical Data
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Dirk Graafen, Tilman Emrich, Moritz C. Halfmann, Peter Mildenberger, Christoph Düber, Yang Yang, Ahmed E. Othman, Jim O’ Doherty, Lukas Müller, and Roman Kloeckner
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Pulmonary and Respiratory Medicine ,Photons ,Drug Tapering ,Phantoms, Imaging ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Tomography, X-Ray Computed - Abstract
Photon-counting detector computed tomography (PCD-CT) has the potential to significantly improve CT imaging in many ways including, but not limited to, low-dose high-resolution CT (HRCT) of the lung. The aim of this study was to perform an intrapatient comparison of the radiation dose and image quality of PCD-CT compared with conventional energy-integrating detector CT (EID-CT).A total of 32 consecutive patients with available PCD-CT and EID-CT HRCT scans were included in the final analysis. The CT dose index (CTDI vol ) was extracted from patient dose reports. Qualitative image analysis comprised the lung parenchyma and mediastinal structures and was assessed by 3 readers using a 5-point Likert scale. Quantitative image analysis included assessment of noise and signal-to-noise ratio in the lung parenchyma, trachea, aorta, muscle, and background.The mean CTDI vol was 2.0 times higher in the conventional EID-CT scans (1.8±0.5 mGy) compared with PCD-CT (0.9±0.5 mGy, P0.001). The overall image quality was rated significantly better by all 3 raters ( P0.001) in the PCD-CT relative to the EID-CT. Quantitative analysis showed no significant differences in noise and signal-to-noise ratio in the lung parenchyma between PCD-CT and EID-CT.Compared with conventional EID-CT scans, PCD-CT demonstrated similar or better objective and subjective image quality at significantly reduced dose levels in an intrapatient comparison. These results and their effect on clinical decision-making should be further investigated in prospective studies.
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- 2022
41. Combination of Whole-Body Baseline CT Radiomics and Clinical Parameters to Predict Response and Survival in a Stage-IV Melanoma Cohort Undergoing Immunotherapy
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Felix, Peisen, Annika, Hänsch, Alessa, Hering, Andreas S, Brendlin, Saif, Afat, Konstantin, Nikolaou, Sergios, Gatidis, Thomas, Eigentler, Teresa, Amaral, Jan H, Moltz, and Ahmed E, Othman
- Abstract
This study investigated whether a machine-learning-based combination of radiomics and clinical parameters was superior to the use of clinical parameters alone in predicting therapy response after three months, and overall survival after six and twelve months, in stage-IV malignant melanoma patients undergoing immunotherapy with PD-1 checkpoint inhibitors and CTLA-4 checkpoint inhibitors.A random forest model using clinical parameters (demographic variables and tumor markers = baseline model) was compared to a random forest model using clinical parameters and radiomics (extended model) via repeated 5-fold cross-validation. For this purpose, the baseline computed tomographies of 262 stage-IV malignant melanoma patients treated at a tertiary referral center were identified in the Central Malignant Melanoma Registry, and all visible metastases were three-dimensionally segmented (The extended model was not significantly superior compared to the baseline model for survival prediction after six and twelve months (AUC (95% CI): 0.664 (0.598, 0.729) vs. 0.620 (0.545, 0.692) and AUC (95% CI): 0.600 (0.526, 0.667) vs. 0.588 (0.481, 0.629), respectively). The extended model was not significantly superior compared to the baseline model for response prediction after three months (AUC (95% CI): 0.641 (0.581, 0.700) vs. 0.656 (0.587, 0.719)).The study indicated a potential, but non-significant, added value of radiomics for six-month and twelve-month survival prediction of stage-IV melanoma patients undergoing immunotherapy.
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- 2022
42. Reduction in Acquisition Time and Improvement in Image Quality in T2-Weighted MR Imaging of Musculoskeletal Tumors of the Extremities Using a Novel Deep Learning-Based Reconstruction Technique in a Turbo Spin Echo (TSE) Sequence
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Daniel, Wessling, Judith, Herrmann, Saif, Afat, Dominik, Nickel, Ahmed E, Othman, Haidara, Almansour, and Sebastian, Gassenmaier
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Adult ,Aged, 80 and over ,Deep Learning ,Neoplasms ,Humans ,Extremities ,Musculoskeletal Diseases ,Middle Aged ,Artifacts ,Magnetic Resonance Imaging ,Aged - Abstract
The aim of this study was to assess the technical feasibility and the impact on image quality and acquisition time of a deep learning-accelerated fat-saturated T2-weighted turbo spin echo sequence in musculoskeletal imaging of the extremities.Twenty-three patients who underwent MRI of the extremities were prospectively included. Standard T2w turbo inversion recovery magnitude (TIRMStd) imaging was compared to a deep learning-accelerated T2w TSE (TSEDL) sequence. Image analysis of 23 patients with a mean age of 60 years (range 30-86) was performed regarding image quality, noise, sharpness, contrast, artifacts, lesion detectability and diagnostic confidence. Pathological findings were documented measuring the maximum diameter.The analysis showed a significant improvement for the T2 TSEDL with regard to image quality, noise, contrast, sharpness, lesion detectability, and diagnostic confidence, as compared to T2 TIRMStd (eachAccelerated T2 TSEDL was technically feasible and superior to conventionally applied T2 TIRMStd. Concurrently, TA could be reduced by 52-59%. Therefore, deep learning-accelerated MR imaging is a promising and applicable method in musculoskeletal imaging.
- Published
- 2022
43. Application of a Novel Iterative Denoising and Image Enhancement Technique in T1-Weighted Precontrast and Postcontrast Gradient Echo Imaging of the Abdomen
- Author
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Ahmed E. Othman, Sebastian Gassenmaier, Saif Afat, Rüdiger Hoffmann, Dominik Nickel, Stephan Kannengiesser, and Judith Herrmann
- Subjects
Image quality ,Noise reduction ,Contrast Media ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Precontrast ,Interquartile range ,Abdomen ,medicine ,T1 weighted ,Humans ,Radiology, Nuclear Medicine and imaging ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,General Medicine ,Image enhancement ,Image Enhancement ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Artifacts ,Nuclear medicine ,business ,030217 neurology & neurosurgery - Abstract
OBJECTIVES The aim of this study was to investigate the impact of a novel iterative denoising and image enhancement technique in T1-weighted precontrast and postcontrast volume-interpolated breath-hold examination (VIBE) of the abdomen on image quality, noise levels, and diagnostic confidence without change of acquisition parameters. MATERIALS AND METHODS Fifty patients were included in this retrospective, monocentric, institutional review board-approved study after clinically indicated magnetic resonance imaging of the abdomen including T1-weighted precontrast and postcontrast imaging. After acquisition of the standard VIBE (VIBES), images were processed with a novel reconstruction algorithm using the same raw data as for VIBES, resulting in a denoised and enhanced dataset (VIBEDE). Two different radiologists evaluated both datasets in a randomized order regarding sharpness of organs as well as vessels, noise levels, artifacts, overall image quality, and diagnostic confidence using a Likert scale ranging from 1 to 4 with 4 being the best. Furthermore, in the presence of focal liver lesions, the largest lesion was measured in the postcontrast dataset, and lesion detectability was analyzed using a Likert scale (1-4). RESULTS Precontrast and postcontrast sharpness of organs and sharpness of vessels were rated significantly superior by both readers in VIBEDE with a median of 4 (interquartile range, 0) compared with VIBES with a median of 3 (1) (all P's < 0.0001). Precontrast and postcontrast noise levels were also rated superior by both readers in VIBEDE with a median of 4 (0) compared with VIBES with a median of 3 (1) for precontrast and a median of 3 (0) (median of 3 [1] for reader 2) for postcontrast imaging (all P's < 0.0001).Overall image quality was also rated higher with a median of 4 (0) in VIBEDE versus 3 (1) in VIBES (P < 0.0001). Twenty-seven imaging studies contained liver lesions. There was no difference regarding the number and localization between the readers and between VIBES and VIBEDE. Lesion detectability was rated by both readers significantly better in VIBEDE with a median of 4 (0) compared with a median of 4 (1) for reader 1 and a median of 3 (1) for reader 2 (P = 0.001 for reader 1; P < 0.001 for reader 2). Consequently, diagnostic confidence was also significantly superior in VIBEDE versus VIBES with a median of 4 (0) for both (P = 0.001). Interreader agreement resulted in a Cohen κ of 0.76 for precontrast analysis as well as of 0.76 for postcontrast analysis. CONCLUSIONS Application of a novel iterative denoising and image enhancement technique in T1-weighted VIBE precontrast and postcontrast imaging of the abdomen is feasible, providing superior image quality, noise levels, and diagnostic confidence.
- Published
- 2020
44. Diagnostic Confidence and Feasibility of a Deep Learning Accelerated HASTE Sequence of the Abdomen in a Single Breath-Hold
- Author
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Matthias Kündel, Dominik Nickel, Judith Herrmann, Andreas Lingg, Saif Afat, Sebastian Gassenmaier, Simon Arberet, and Ahmed E. Othman
- Subjects
Image quality ,Fat suppression ,Time saving ,030218 nuclear medicine & medical imaging ,Lesion ,03 medical and health sciences ,Deep Learning ,0302 clinical medicine ,Interquartile range ,Abdomen ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,General Medicine ,Single breath ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Feasibility Studies ,medicine.symptom ,Artifacts ,business ,Nuclear medicine ,030217 neurology & neurosurgery - Abstract
OBJECTIVE The aim of this study was to evaluate the feasibility of a single breath-hold fast half-Fourier single-shot turbo spin echo (HASTE) sequence using a deep learning reconstruction (HASTEDL) for T2-weighted magnetic resonance imaging of the abdomen as compared with 2 standard T2-weighted imaging sequences (HASTE and BLADE). MATERIALS AND METHODS Sixty-six patients who underwent 1.5-T liver magnetic resonance imaging were included in this monocentric, retrospective study. The following T2-weighted sequences in axial orientation and using spectral fat suppression were compared: a conventional respiratory-triggered BLADE sequence (time of acquisition [TA] = 4:00 minutes), a conventional multiple breath-hold HASTE sequence (HASTES) (TA = 1:30 minutes), as well as a single breath-hold HASTE with deep learning reconstruction (HASTEDL) (TA = 0:16 minutes). Two radiologists assessed the 3 sequences regarding overall image quality, noise, sharpness, diagnostic confidence, and lesion detectability as well as lesion characterization using a Likert scale ranging from 1 to 4 with 4 being the best. Comparative analyses were conducted to assess the differences between the 3 sequences. RESULTS HASTEDL was successfully acquired in all patients. Overall image quality for HASTEDL was rated as good (median, 3; interquartile range, 3-4) and was significantly superior to HASTEs (P < 0.001) and inferior to BLADE (P = 0.001). Noise, sharpness, and artifacts for HASTEDL reached similar levels to BLADE (P ≤ 0.176) and were significantly superior to HASTEs (P < 0.001). Diagnostic confidence for HASTEDL was rated excellent by both readers and significantly superior to HASTEs (P < 0.001) and inferior to BLADE (P = 0.044). Lesion detectability and lesion characterization for HASTEDL reached similar levels to those of BLADE (P ≤ 0.523) and were significantly superior to HASTEs (P < 0.001). Concerning the number of detected lesions and the measured diameter of the largest lesion, no significant differences were found comparing BLADE, HASTES, and HASTEDL (P ≤ 0.912). CONCLUSIONS The single breath-hold HASTEDL is feasible and yields comparable image quality and diagnostic confidence to standard T2-weighted TSE BLADE and may therefore allow for a remarkable time saving in abdominal imaging.
- Published
- 2020
45. CoRad-19 - Modular Digital Teaching during the SARS-CoV-2 Pandemic
- Author
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Andreas Stefan Brendlin, Isabel Molwitz, Thekla Helene Oechtering, Jörg Barkhausen, Alex Frydrychowicz, Tanja Sulkowski, Maren Friederike Balks, Michael Buchholz, Stefan Lohwasser, Martin Völker, Olaf Goldschmidt, Anja Johenning, Sabine Schlender, Christian Paulus, Gerald Antoch, Sabine Dettmer, Bettina Baeßler, David Maintz, Daniel Pinto dos Santos, Thomas J. Vogl, Elke Hattingen, Dietrich Stoevesandt, Sebastian Reinartz, Corinna Storz, Katharina Müller-Peltzer, Fabian Bamberg, Fabian Rengier, Meike Weis, Anne Frisch, Nienke Lynn Hansen, Manuel Kolb, Michael Maurer, Konstantin Nikolaou, Saif Afat, and Ahmed E. Othman
- Subjects
Students, Medical ,SARS-CoV-2 ,Teaching ,COVID-19 ,Humans ,Radiology, Nuclear Medicine and imaging ,Curriculum ,Pandemics - Abstract
During the SARS-CoV-2 pandemic, higher education worldwide had to switch to digital formats. The purpose of this study was to evaluate CoRad-19, a digital teaching tool created by the German Radiological Society for medical students during the COVID-19 pandemic.A total of 13 German-speaking universities implemented CoRad-19 in their curriculum and partially or completely replaced their classes with the online courses. Previous experience and contact with radiology and the participants' opinions regarding the medium of e-learning were surveyed using a custom questionnaire. The subjective level of knowledge regarding the individual modules was also surveyed before and after participation to measure learning effects. The data of 994 medical students from the participating sites were analyzed and compared intraindividually using the Friedman test.From 4/1/2020-10/1/2020, 451 complete data sets from a total of 994 surveys were included. E-learning was rated "very useful" both before and after course participation (4 [IQR 3-4], p = 0.527, r = 0.16). E-learning as a method was also rated as a "very good" medium both before and after participation (4 [IQR 3-4], p = 0.414, r = 0.17). After participation, participants rated radiology as particularly suitable for digital teaching (before: 3 [IQR 3-4] vs. after 4 [IQR 3-4], p = 0.005, r = 0.6). Significant learning gains were measurable in all course modules (p ≤ 0.009). Post-hoc analysis showed interest in radiology to increase significantly after course participation (p = 0.02).In the representative survey, significant learning effects were observed in all course modules. In addition, it should be particularly emphasized that the students' interest in radiology was increased by course participation. Thus, the German Radiological Society provided significant support to German-speaking medical faculties with respect to maintaining excellent education using CoRad-19.· Co-Rad-19 course participation results in measurable subjective learning effects and increases student interest in radiology..· Brendlin AS, Molwitz I, Oechtering TH et al. CoRad-19 - Modular Digital Teaching during the SARS-CoV-2 Pandemic. Fortschr Röntgenstr 2022; 194: 644 - 651.ZIEL: Während der SARS-CoV-2-Pandemie musste die Hochschullehre weltweit auf digitale Formate umstellen. In dieser Studie sollte CoRad-19, ein im Rahmen der COVID-19-Pandemie erstelltes digitales Lehrangebot der Deutschen Röntgengesellschaft (DRG) für Medizinstudierende, evaluiert werden.Insgesamt 13 deutschsprachige Hochschulstandorte haben CoRad-19 in ihr Curriculum implementiert sowie ihre Lehrangebote teilweise oder sogar vollständig durch die Online-Kurse ersetzt. Mithilfe eines eigens entworfenen Fragebogens wurden Vorerfahrungen in und bisherige Kontakte zur Radiologie erfragt sowie die Meinung der Teilnehmenden gegenüber dem Medium E-Learning erhoben. Als Maßstab für den Lernerfolg wurde der subjektive Kenntnisstand bezüglich der einzelnen Module jeweils vor und nach der Teilnahme erhoben. Die Angaben 994 Medizinstudierender aus den beteiligten Standorten wurden analysiert und mittels Friedman-Test intraindividuell verglichen.Vom 01.04.2020–01.10.2020 wurden aus insgesamt 994 Erhebungen 451 vollständige Datensätze inkludiert. E-Learning wurde sowohl vor als auch nach der Teilnahme an den Kursen als „sehr sinnvoll“ eingeschätzt (4 [IQR 3–4], p = 0,527, r = 0,16). Auch E-Learning als Methode wurde sowohl vor als auch nach der Teilnahme als „sehr gutes“ Medium bewertet (4 [IQR 3–4], p = 0,414, r = 0,17). Nach Teilnahme an den Kursen schätzten die Teilnehmenden die Radiologie als besonders geeignet für digitale Lehre ein (vorher: 3 [IQR 3–4] vs. nachher 4 [IQR 3–4], p = 0,005, r = 0,6). In allen Kursmodulen waren signifikante Lernerfolge messbar (p ≤ 0,009). Eine Post-hoc-Analyse zeigte, dass das Interesse an der Radiologie nach Teilnahme an den Kursen signifikant zunahm (p = 0,02).In der repräsentativen Umfrage wurden signifikante Lerneffekte in allen Kursmodulen beobachtet. Zudem ist besonders hervorzuheben, dass das Interesse der Studierenden an der Radiologie durch die Kursteilnahme gesteigert werden konnte. Die DRG konnte den deutschsprachigen medizinischen Fakultäten durch CoRad-19 also wichtige Unterstützung bei der Aufrechterhaltung exzellenter Lehre bieten.· Die Kursteilnahme an CoRad-19 führt zu messbaren subjektiven Lerneffekten und steigert das Interesse Studierender an der Radiologie..· Brendlin AS, Molwitz I, Oechtering TH et al. CoRad-19 – Modular Digital Teaching during the SARS-CoV-2 Pandemic. Fortschr Röntgenstr 2022; 194: 644 – 651.
- Published
- 2022
46. Combined Deep Learning-based Super-Resolution and Partial Fourier Reconstruction for Gradient Echo Sequences in Abdominal MRI at 3 Tesla: Shortening Breath-Hold Time and Improving Image Sharpness and Lesion Conspicuity
- Author
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Haidara Almansour, Judith Herrmann, Sebastian Gassenmaier, Andreas Lingg, Marcel Dominik Nickel, Stephan Kannengiesser, Simon Arberet, Ahmed E. Othman, and Saif Afat
- Subjects
Radiology, Nuclear Medicine and imaging - Abstract
To investigate the impact of a prototypical deep learning-based super-resolution reconstruction algorithm tailored to partial Fourier acquisitions on acquisition time and image quality for abdominal T1-weighted volume-interpolated breath-hold examination (VIBEPatients with diverse abdominal pathologies, who underwent a clinically indicated contrast-enhanced abdominal VIBE magnetic resonance imaging at 3T between March and June 2021 were retrospectively included. Following the acquisition of the standard VIBEA total of 32 patients aged 59 ± 16 years (23 men (72%), 9 women (28%)) were included. For VIBEThe deep learning-based super-resolution reconstruction with partial Fourier in the slice phase-encoding direction enabled a reduction of breath-hold time and improved image sharpness and lesion conspicuity in T1-weighted gradient echo sequences in abdominal magnetic resonance imaging at 3 Tesla. Faster acquisition time without compromising image quality or diagnostic confidence was possible by using this deep learning-based reconstruction technique.
- Published
- 2022
47. Performance of an Automated Workflow for Magnetic Resonance Imaging of the Prostate
- Author
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Elisabeth Weiland, Andreas Lingg, Dominik Zinsser, Michael Esser, Berthold Kiefer, Matthias Kündel, Konstantin Nikolaou, and Ahmed E. Othman
- Subjects
Adult ,Male ,Image quality ,030218 nuclear medicine & medical imaging ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Prostate ,Interquartile range ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Multiparametric Magnetic Resonance Imaging ,Aged ,Retrospective Studies ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Ethics committee ,Prostatic Neoplasms ,Magnetic resonance imaging ,General Medicine ,Middle Aged ,Workflow ,medicine.anatomical_structure ,Artifacts ,Nuclear medicine ,business ,030217 neurology & neurosurgery ,Kappa - Abstract
OBJECTIVES The aim of this study was to evaluate the performance of an automated workflow for multiparametric magnetic resonance imaging (mpMRI) of the prostate compared with a manual mpMRI workflow. MATERIALS AND METHODS This retrospective study was approved by the local ethics committee. Two MR technicians scanned 2 healthy volunteers with a prototypical highly automated workflow (Siemens Healthineers GmbH, Erlangen, Germany) and with a manually adjusted scan protocol each. Thirty patients (mean age ± standard deviation, 68 ± 11 years; range, 41-93 years) with suspected prostate cancer underwent mpMRI on a 3 T MRI scanner. Fifteen patients were examined with the automated workflow and 15 patients with a conventional manual workflow. Two readers assessed image quality (contrast, zone distinction, organ margins, seminal vesicles, lymph nodes), organ coverage, orientation (T2w sequences), and artifacts (motion, susceptibility, noise) on a 5-point scale (1, poor; 5, excellent). Examination time and MR technicians' acceptance were compared between both groups. Interreader agreement was evaluated with Cohen's kappa (κ). RESULTS The automated workflow proved consistent for sequence orientation and image quality in the intraindividual comparisons. There were no significant differences in examination time (automated vs manual; median 26 vs 28 minutes; interquartile range [IQR], 25-28 minutes each; P = 0.57), study volume coverage, artifacts, or scores for T2w sequence orientation (5 vs 4 each; P > 0.3). Overall image quality was superior for automated MRI (4.6 vs 3.8; IQR, 3.9-4.8 vs 3.2-4.3; P = 0.002), especially concerning organ delineation and seminal vesicles (P = 0.045 and P = 0.013). The acceptance score was higher for the manual workflow (median, 10 vs 8; IQR, 10 vs 7-10; P = 0.002). General interreader agreement was excellent (κ = 0.832; P < 0.001). CONCLUSIONS The automated workflow for prostate MRI ensures accurate sequence orientation and maintains high image quality, whereas examination time remained unaffected compared with the manual procedure in our institution.
- Published
- 2020
48. The scaffold protein p62 regulates adaptive thermogenesis through ATF2 nuclear target activation
- Author
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Jens C. Brüning, Susanne Keipert, Bernd J. Pichler, Julia Zorn, Martin Klingenspor, Ines Pramme-Steinwachs, Siegfried Ussar, Martin Jastroch, Maria T. Diaz-Meco, Anna Fedl, Florian C. Maier, Markus Brielmeier, Jianfeng Huang, Stephan Sachs, Ahmed E. Othman, Henriette Uhlenhaut, Anna Fenzl, Jorge Moscat, M. H. Tschöp, Wolfgang M. Thaiss, Brian Finan, Maximilian Kleinert, Timo D. Müller, Kenneth A. Dyar, Manfred Kneilling, Stephen C. Woods, Angelika Scheideler, Dianxin Liu, Kerstin Stemmer, Christoffer Clemmensen, Katrin Fischer, Sheila Collins, and André Gessner
- Subjects
0301 basic medicine ,Scaffold protein ,Male ,Transcriptional regulatory elements ,Metabolic disorders ,General Physics and Astronomy ,Adipose tissue ,p38 Mitogen-Activated Protein Kinases ,Mice ,0302 clinical medicine ,Adipose Tissue, Brown ,Positron Emission Tomography Computed Tomography ,Brown adipose tissue ,Sequestosome-1 Protein ,lcsh:Science ,Uncoupling Protein 1 ,Mice, Knockout ,Multidisciplinary ,Adipogenesis ,biology ,Chemistry ,Magnetic Resonance Imaging ,Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ,Activating transcription factor 2 ,Cell biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Phosphorylation ,Protein Binding ,Adipose Tissue, White ,Science ,Alpha (ethology) ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,ddc:570 ,medicine ,Animals ,ddc:610 ,Obesity ,Enhancer ,Cell Nucleus ,Activating Transcription Factor 2 ,General Chemistry ,Mice, Inbred C57BL ,030104 developmental biology ,biology.protein ,lcsh:Q ,Thermogenesis - Abstract
During β-adrenergic stimulation of brown adipose tissue (BAT), p38 phosphorylates the activating transcription factor 2 (ATF2) which then translocates to the nucleus to activate the expression of Ucp1 and Pgc-1α. The mechanisms underlying ATF2 target activation are unknown. Here we demonstrate that p62 (Sqstm1) binds to ATF2 to orchestrate activation of the Ucp1 enhancer and Pgc-1α promoter. P62Δ69-251 mice show reduced expression of Ucp1 and Pgc-1α with impaired ATF2 genomic binding. Modulation of Ucp1 and Pgc-1α expression through p62 regulation of ATF2 signaling is demonstrated in vitro and in vivo in p62Δ69-251 mice, global p62−/− and Ucp1-Cre p62flx/flx mice. BAT dysfunction resulting from p62 deficiency is manifest after birth and obesity subsequently develops despite normal food intake, intestinal nutrient absorption and locomotor activity. In summary, our data identify p62 as a master regulator of BAT function in that it controls the Ucp1 pathway through regulation of ATF2 genomic binding., Beta-adrenergic stimulation of brown adipose tissue leads to thermogenesis via the activating transcription factor 2 (ATF2) mediated expression of the thermogenic genes Ucp1 and Pgc-1α. Here, the authors show that the scaffold protein p62 regulates brown adipose tissue function through modifying ATF2 genomic binding and subsequent Ucp1 and Pgc-1α induction.
- Published
- 2020
49. Comprehensive Clinical Evaluation of a Deep Learning-Accelerated, Single-Breath-Hold Abdominal HASTE at 1.5 T and 3 T
- Author
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Judith Herrmann, Daniel Wessling, Dominik Nickel, Simon Arberet, Haidara Almansour, Carmen Afat, Saif Afat, Sebastian Gassenmaier, and Ahmed E. Othman
- Subjects
Deep Learning ,Abdomen ,Liver Neoplasms ,Humans ,Radiology, Nuclear Medicine and imaging ,Artifacts ,Magnetic Resonance Imaging ,Retrospective Studies - Abstract
To evaluate the clinical performance of a deep learning-accelerated single-breath-hold half-Fourier acquisition single-shot turbo spin echo (HASTE
- Published
- 2022
50. Validation of Mct8/Oatp1c1 dKO mice as a model organism for the Allan-Herndon-Dudley Syndrome
- Author
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Gandhari Maity-Kumar, Lisa Ständer, Meri DeAngelis, Sooyeon Lee, Anna Molenaar, Lore Becker, Lillian Garrett, Oana V. Amerie, Sabine M. Hoelter, Wolfgang Wurst, Helmut Fuchs, Annette Feuchtinger, Valerie Gailus-Durner, Cristina Garcia-Caceres, Ahmed E. Othman, Caroline Brockmann, Vanessa I. Schöffling, Katja Beiser, Heiko Krude, Piotr A. Mroz, Susanna Hofmann, Jan Tuckermann, Richard D. DiMarchi, Martin Hrabe de Angelis, Matthias H. Tschöp, Paul T. Pfluger, and Timo D. Müller
- Subjects
Thyroid Hormones ,genetics [Mental Retardation, X-Linked] ,Cell Biology ,Energy metabolism ,genetics [Symporters] ,Allan-herndon Dudley Syndrome ,Energy Metabolism ,Mct8 ,Motor Coordination ,Myelination ,Oatp1c1 ,Thyroid Hormone ,Thyroid hormone ,Mice ,genetics [Monocarboxylic Acid Transporters] ,Animals ,Motor coordination ,ddc:610 ,Molecular Biology ,Allan-Herndon Dudley Syndrome - Abstract
OBJECTIVE: The Allan-Herndon-Dudley syndrome (AHDS) is a severe disease caused by dysfunctional central thyroid hormone transport due to functional loss of the monocarboxylate transporter 8 (MCT8). In this study, we assessed whether mice with concomitant deletion of the thyroid hormone transporters Mct8 and the organic anion transporting polypeptide (Oatp1c1) represent a valid preclinical model organism for the AHDS. METHODS: We generated and metabolically characterized a new CRISPR/Cas9 generated Mct8/Oatp1c1 double-knockout (dKO) mouse line for the clinical features observed in patients with AHDS. RESULTS: We show that Mct8/Oatp1c1 dKO mice mimic key hallmarks of the AHDS, including decreased life expectancy, central hypothyroidism, peripheral hyperthyroidism, impaired neuronal myelination, impaired motor abilities and enhanced peripheral thyroid hormone action in the liver, adipose tissue, skeletal muscle and bone. CONCLUSIONS: We conclude that Mct8/Oatp1c1 dKO mice are a valuable model organism for the preclinical evaluation of drugs designed to treat the AHDS.
- Published
- 2022
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