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230 results on '"Grosse Hokamp, N."'

4. Long-Term Follow-Up and Clinical Relevance of Incidental Findings of Fibrin Sheath and Thrombosis on Computed Tomography Scans of Cancer Patients with Port Catheters

Author

Lichtenstein T, Mammadov K, Rau K, Große Hokamp N, Do TD, Maintz D, and Chang DH

Subjects
catheter-related complications, central venous catheters, port-a-cath, imaging, staging, Therapeutics. Pharmacology, RM1-950
Abstract

Thorsten Lichtenstein,1 Kamal Mammadov,2 Karin Rau,1 Nils Große Hokamp,1 Thuy D Do,3 David Maintz,1 De-Hua Chang1,3 1Department of Radiology, University Hospital of Cologne, Cologne, Germany; 2Department of Radiology, Klinikum Aschaffenburg, Aschaffenburg, Germany; 3Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg, GermanyCorrespondence: Thorsten LichtensteinInstitut für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Köln (AöR), Kerpener Str. 62, Cologne 50937, GermanyTel +49 221 478-82035Email thorsten.lichtenstein@uk-koeln.dePurpose: This retrospective study examined the incidence, progression, and clinical relevance of catheter-related thrombosis (CRT) and/or fibrin sheaths presenting as incidental findings on routine staging computed tomography (CT) scans performed in cancer patients.Patients and Methods: Patients who underwent central venous port catheter (CVC) placement in a tertiary care hospital between September 2010 and August 2013 were followed up for up to five years. Two radiologists assessed the presence of fibrin sheath and thrombosis in consensus in staging CT scan. Patient demographics, type of cancer, preoperative comorbidities, date of CVC placement and CTs, preexisting anticoagulation, as well as the type and treatment of catheter-related complications were determined from the electronic medical record.Results: A total of 194 patients with 530 CT scans and a mean follow-up time of 394 days were included. Fibrin sheaths and thromboses were seen on 46 scans (8.7%) in 30 patients and 80 scans (15.1%) in 35 patients. The incidence of fibrin sheaths and thromboses was found to be 15.5% and 18%, respectively. The comparison to initial CT reports results indicated that fibrin sheaths or thromboses were missed in 106 examinations (20%). Catheter-associated complications were reported in 14 patients (21.5%) without specific therapy.Conclusion: Fibrin sheaths and CRTs are often overlooked on routine CT scans when patients are asymptomatic. The subsequent high complication rate demonstrates the clinical relevance of the initial incidental finding on CT scan. Further studies should elucidate the effect of thrombolytic agents and interventional radiologic treatment in asymptomatic patients.Keywords: catheter-related complications, central venous catheters, port-a-cath, imaging, staging

Published
2021

5. Low-dose computed tomography of urolithiasis in obese patients: a feasibility study to evaluate image reconstruction algorithms

Author

Chang DH, Slebocki K, Khristenko E, Herden J, Salem J, Große Hokamp N, Mammadov K, Hellmich M, and Kabbasch C

Subjects
Low-dose computed tomography, Model-based iterative reconstruction, Statistical iterative, Urolithiasis, Obesity, Specialties of internal medicine, RC581-951
Abstract

De-Hua Chang,1 Karin Slebocki,2 Ekaterina Khristenko,1 Jan Herden,3 Johannes Salem,3 Nils Große Hokamp,2 Kamal Mammadov,2 Martin Hellmich,4 Christoph Kabbasch21Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg, Germany; 2Department of Diagnostic and Interventional Radiology, University Hospital of Cologne, Cologne, Germany; 3Department of Urology, University Hospital of Cologne, Cologne, Germany; 4Institute of Medical Statistics and Computational Biology (IMSB), Medical Faculty, University of Cologne, Cologne, GermanyPurpose: Retrospective evaluation and comparison of image quality generated by low-dose computed tomography (LDCT) from obese patients with urolithiasis using alternative reconstruction algorithms.Materials and methods: Twenty-five obese patients (body mass index [BMI]>25 kg/m2,) underwent LDCT scans for suspected urolithiasis. The scans were recompiled using filtered-back projection (FBP), statistical iterative reconstruction (iDose) and iterative model-based reconstruction (IMR). Dose-length product (DLP) and patient details were obtained from the CT dose report and clinical charts, respectively. Objective image noise was assessed by measuring the SD of Hounsfield units (HUs) in defined locations. Additionally, subjective image evaluation was independently performed by two radiologists using a 3-point Likert scale. The inter-reviewer agreement of image quality was calculated.Results: Ureteral concretions were observed in all CT scans, two of which revealed bilateral stones. The assessed patients’ mean BMI was 29.29±3.74 kg/m,2 and the DLP of the CT scans was 100.04±10.00 mGy*cm. All scans were rated diagnostic with the iDose and iterative model-based reconstructions, whereas 41% of the scans performed with FBP reconstruction were nondiagnostic. With respect to image quality, IMR was superior to iDose and FBP, both in the objective (P

Published
2019

24. Automated Color-Coding of Lesion Changes in Contrast-Enhanced 3D T1-Weighted Sequences for MRI Follow-up of Brain Metastases

Author

Zopfs, D., Laukamp, K., Reimer, R., Grosse Hokamp, N., Kabbasch, C., Borggrefe, J., Pennig, L., Bunck, A. C., Schlamann, M., Lennartz, S., Zopfs, D., Laukamp, K., Reimer, R., Grosse Hokamp, N., Kabbasch, C., Borggrefe, J., Pennig, L., Bunck, A. C., Schlamann, M., and Lennartz, S.

Abstract

BACKGROUND AND PURPOSE: MR imaging is the technique of choice for follow-up of patients with brain metastases, yet the radiologic assessment is often tedious and error-prone, especially in examinations with multiple metastases or subtle changes. This study aimed to determine whether using automated color-coding improves the radiologic assessment of brain metastases compared with conventional reading. MATERIALS AND METHODS: One hundred twenty-one pairs of follow-up examinations of patients with brain metastases were assessed. Two radiologists determined the presence of progression, regression, mixed changes, or stable disease between the follow-up examinations and indicated subjective diagnostic certainty regarding their decisions in a conventional reading and a second reading using automated color-coding after an interval of 8 weeks. RESULTS: The rate of correctly classified diagnoses was higher (91.3%, 221/242, versus 74.0%, 179/242, P?

Published
2022

26. Feasibility of artificial intelligence-supported assessment of bone marrow infiltration using dual-energy computed tomography in patients with evidence of monoclonal protein - a retrospective observational study

Author

Fervers, P., Fervers, Florian, Lohneis, P., Pollman-Schweckhors, P., Zaytoun, H., Rinneburger, M., Maintz, D., Große Hokamp, N., and Publica

Subjects
multiple myeloma, x-ray computed, monoclonal gammopathy of undetermined signifcance
Abstract

Objectives To demonstrate the feasibility of an automated, non-invasive approach to estimate bone marrow (BM) infiltration of multiple myeloma (MM) by dual-energy computed tomography (DECT) after virtual non-calcium (VNCa) post-processing. Methods Individuals with MM and monoclonal gammopathy of unknown significance (MGUS) with concurrent DECT and BM biopsy between May 2018 and July 2020 were included in this retrospective observational study. Two pathologists and three radiologists reported BM infiltration and presence of osteolytic bone lesions, respectively. Bone mineral density (BMD) was quantified CT-based by a CE-certified software. Automated spine segmentation was implemented by a pre-trained convolutional neural network. The non-fatty portion of BM was defined as voxels > 0 HU in VNCa. For statistical assessment, multivariate regression and receiver operating characteristic (ROC) were conducted. Results Thirty-five patients (mean age 65 ± 12 years; 18 female) were evaluated. The non-fatty portion of BM significantly predicted BM infiltration after adjusting for the covariable BMD (p = 0.007, r = 0.46). A non-fatty portion of BM > 0.93% could anticipate osteolytic lesions and the clinical diagnosis of MM with an area under the ROC curve of 0.70 [0.49-0.90] and 0.71 [0.54-0.89], respectively. Our approach identified MM-patients without osteolytic lesions on conventional CT with a sensitivity and specificity of 0.63 and 0.71, respectively. Conclusions Automated, AI-supported attenuation assessment of the spine in DECT VNCa is feasible to predict BM infiltration in MM. Further, the proposed method might allow for pre-selecting patients with higher pre-test probability of osteolytic bone lesions and support the clinical diagnosis of MM without pathognomonic lesions on conventional CT.

Published
2022

47. Improved visualization of hypodense liver lesions in virtual monoenergetic images from spectral detector CT: Proof of concept in a 3D-printed phantom and evaluation in 74 patients

Author

Große Hokamp, N, Obmann, Verena Carola, Kessner, R, Laukamp, K R, Persigehl, T, Haneder, S, and Ramaiya, N

Subjects
610 Medicine & health
Abstract

OBJECTIVES The well-known boost of iodine associated-attenuation in low-keV virtual monoenergetic images (VMI_low) is frequently used to improve visualization of lesions and structures taking up contrast media. This study aimed to evaluate this concept in reverse. Hence to investigate if increased attenuation within the liver allows for improved visualization of little or not-enhancing lesions. METHODS A 3D-printed phantom mimicking the shape of a human liver exhibiting a lesion in its center was designed and printed. Both, parenchyma- and lesion-mimic were filled with different solutions exhibiting 80/100/120HU and 0/15/40/60HU, respectively. Further, a total of 74 contrast-enhanced studies performed on a spectral detector CT scanner (SDCT) were included in this retrospective study. Patients had MRI or follow-up proven cysts and/or hypodense metastases. VMI of 40-200 keV as well as conventional images (CI) were reconstructed. ROI were placed in lesion and parenchyma(-mimics) on CI and transferred to VMI. Signal- and contrast-to-noise ratio were calculated (S-/CNR). Further, two radiologists independently evaluated image quality. Data was statistically assessed using ANOVA or Wilcoxon-test. RESULTS In phantoms, S/CNR was significantly higher in VMI_low. The cyst-mimic in highly attenuating parenchyma-mimic on CI yielded a CNR of 6.4 ± 0.8; using VMI_40 keV, mildly hypodense lesion-mimic in poorly attenuating parenchyma-mimic exhibited a similar CNR (5.8 ± 0.9; p ≤ 0.05). The same tendency was observed in patients (cyst in CI/metastasis in VMI_40 keV: 4.4 ± 1.2/3.9 ± 1.8; p ≤ 0.05). Qualitative analysis indicated a benefit of VMI_40 keV (p ≤ 0.05). CONCLUSIONS VMI_low from SDCT allow for an improved visualization of hypodense focal liver lesions exploiting the concept of contrast blooming in reverse.

Published
2018
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