Publications by authors named "Gerald Antoch"

296 Publications

Prospective comparison of the diagnostic accuracy of 18F-FDG PET/MRI, MRI, CT, and bone scintigraphy for the detection of bone metastases in the initial staging of primary breast cancer patients.

Eur Radiol 2021 Apr 28. Epub 2021 Apr 28.

Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Moorenstrasse 5, D-40225, Dusseldorf, Germany.

Objectives: To compare the diagnostic performance of [F]FDG PET/MRI, MRI, CT, and bone scintigraphy for the detection of bone metastases in the initial staging of primary breast cancer patients.

Material And Methods: A cohort of 154 therapy-naive patients with newly diagnosed, histopathologically proven breast cancer was enrolled in this study prospectively. All patients underwent a whole-body [F]FDG PET/MRI, computed tomography (CT) scan, and a bone scintigraphy prior to therapy. All datasets were evaluated regarding the presence of bone metastases. McNemar χ test was performed to compare sensitivity and specificity between the modalities.

Results: Forty-one bone metastases were present in 7/154 patients (4.5%). Both [F]FDG PET/MRI and MRI alone were able to detect all of the patients with histopathologically proven bone metastases (sensitivity 100%; specificity 100%) and did not miss any of the 41 malignant lesions (sensitivity 100%). CT detected 5/7 patients (sensitivity 71.4%; specificity 98.6%) and 23/41 lesions (sensitivity 56.1%). Bone scintigraphy detected only 2/7 patients (sensitivity 28.6%) and 15/41 lesions (sensitivity 36.6%). Furthermore, CT and scintigraphy led to false-positive findings of bone metastases in 2 patients and in 1 patient, respectively. The sensitivity of PET/MRI and MRI alone was significantly better compared with CT (p < 0.01, difference 43.9%) and bone scintigraphy (p < 0.01, difference 63.4%).

Conclusion: [F]FDG PET/MRI and MRI are significantly better than CT or bone scintigraphy for the detection of bone metastases in patients with newly diagnosed breast cancer. Both CT and bone scintigraphy show a substantially limited sensitivity in detection of bone metastases.

Key Points: • [F]FDG PET/MRI and MRI alone are significantly superior to CT and bone scintigraphy for the detection of bone metastases in patients with newly diagnosed breast cancer. • Radiation-free whole-body MRI might serve as modality of choice in detection of bone metastases in breast cancer patients.
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http://dx.doi.org/10.1007/s00330-021-07956-0DOI Listing
April 2021

Statement of the German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists on Requirements for the Performance and Reporting of MR Imaging Examinations Outside of Radiology.

Rofo 2021 Apr 8. Epub 2021 Apr 8.

Heinrich-Heine-Universität Düsseldorf, Medizinische Fakultät, Institut für Diagnostische und Interventionelle Radiologie, Düsseldorf.

Background:  Magnetic Resonance Imaging (MRI) is a very innovative, but at the same time complex and technically demanding diagnostic method in radiology. It plays an increasing role in high-quality and efficient patient management. Quality assurance in MRI is of utmost importance to avoid patient risks due to errors before and during the examination and when reporting the results. Therefore, MRI requires higher physician qualification and expertise than any other diagnostic imaging technique in medicine. This holds true for indication, performance of the examination itself, and in particular for image evaluation and writing of the report. In Germany, the radiologist is the only specialist who is systematically educated in all aspects of MRI during medical specialty training and who must document a specified, high number of examinations during this training. However, also non-radiologist physicians are increasingly endeavoring to conduct and bill MRI examinations on their own.

Method:  In this position statement, the following aspects of quality assurance for MRI examinations and billing by radiologists and non-radiologist physician specialists are examined scientifically: Requirements for specialist physician training, MRI risks and contraindications, radiation protection in the case of non-ionizing radiation, application of MR contrast agents, requirements regarding image quality, significance of image artifacts and incidental findings, image evaluation and reporting, interdisciplinary communication and multiple-eyes principle, and impact on healthcare system costs.

Conclusion:  The German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists are critical with regard to MRI performance by non-radiologists in the interest of quality standards, patient welfare, and healthcare payers. The 24-month additional qualification in MRI as defined by the physician specialization regulations (Weiterbildungsordnung) through the German state medical associations (Landesärztekammern) is the only competence-based and quality-assured training program for board-certified specialist physicians outside radiology. This has to be required as the minimum standard for performance and reporting of MRI exams. Exclusively unstructured MRI training outside the physician specialization regulations has to be strictly rejected for reasons of patient safety. The performance and reporting of MRI examinations must be reserved for adequately trained and continuously educated specialist physicians.

Key Points: · MR imaging plays an increasing role due to its high diagnostic value and serves as the reference standard in many indications.. · MRI is a complex technique that implies patient risks in case of inappropriare application or lack of expertise.. · In Germany, the radiologist is the only specialist physician that has been systematically trained in all aspects of MRI such as indication, performance, and reporting of examinations in specified, high numbers.. · The only competence-based and quality-assured MRI training program for specialist physicians outside radiology is the 24-month additional qualification as defined by the regulations through the German state medical associations.. · In view of quality-assurance and patient safety, a finalized training program following the physician specialization regulations has to be required for the performance and reporting of MRI examinations..

Citation Format: · Hunold P, Bucher AM, Sandstede J et al. Statement of the German Roentgen Society, German Society of Neuroradiology, and Society of German-speaking Pediatric Radiologists on Requirements for the Performance and Reporting of MR Imaging Examinations Outside of Radiology. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1463-3626.
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http://dx.doi.org/10.1055/a-1463-3626DOI Listing
April 2021

Impact of qualitative, semi-quantitative, and quantitative analyses of dynamic contrast-enhanced magnet resonance imaging on prostate cancer detection.

PLoS One 2021 5;16(4):e0249532. Epub 2021 Apr 5.

Medical Faculty, Department of Diagnostic and Interventional Radiology, Univ Dusseldorf, Dusseldorf, Germany.

Dynamic contrast enhanced imaging (DCE) as an integral part of multiparametric prostate magnet resonance imaging (mpMRI) can be evaluated using qualitative, semi-quantitative, or quantitative assessment methods. Aim of this study is to analyze the clinical benefits of these evaluations of DCE regarding clinically significant prostate cancer (csPCa) detection and grading. 209 DCE data sets of 103 consecutive patients with mpMRI (T2, DWI, and DCE) and subsequent MRI-(in-bore)-biopsy were retrospectively analyzed. Qualitative DCE evaluation according to PI-RADS v2.1, semi-quantitative (curve type; DCE score according to PI-RADS v1), and quantitative Tofts analyses (Ktrans, kep, and ve) as well as PI-RADS v1 and v2.1 overall classification of 209 lesions (92 PCa, 117 benign lesions) were performed. Of each DCE assessment method, cancer detection, discrimination of csPCa, and localization were assessed and compared to histopathology findings. All DCE analyses (p<0.01-0.05), except ve (p = 0.02), showed significantly different results for PCa and benign lesions in the peripheral zone (PZ) with area under the curve (AUC) values of up to 0.92 for PI-RADS v2.1 overall classification. In the transition zone (TZ) only the qualitative DCE evalulation within PI-RADS (v1 and v2.1) could distinguish between PCa and benign lesions (p<0.01; AUC = 0.95). None of the DCE parameters could differentiate csPCa from non-significant (ns) PCa (p ≥ 0.1). Qualitative analysis of DCE within mpMRI according to PI-RADS version 2.1 showed excellent results regarding (cs)PCa detection. Semi-quantitative and quantitative parameters provided no additional improvements. DCE alone wasn't able to discriminate csPCa from nsPCa.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0249532PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8021163PMC
April 2021

Progressive Sarcopenia Correlates with Poor Response and Outcome to Immune Checkpoint Inhibitor Therapy.

J Clin Med 2021 Mar 25;10(7). Epub 2021 Mar 25.

Clinic for Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Medical Faculty of Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.

Background: Immune checkpoint inhibitors (ICIs) represent a new therapeutic standard for an increasing number of tumor entities. Nevertheless, individual response and outcome to ICI is very heterogeneous, and the identification of the ideal ICI candidate has remained one of the major issues. Sarcopenia and the progressive loss of muscle mass and strength, as well as muscular fat deposition, have been established as negative prognostic factors for a variety of diseases, but their role in the context of ICI therapy is not fully understood. Here, we have evaluated skeletal muscle composition as a novel prognostic marker in patients undergoing ICI therapy for solid malignancies.

Methods: We analyzed patients with metastasized cancers receiving ICI therapy according to the recommendation of the specific tumor board. Routine CT scans before treatment initialization and during ICI therapy were used to assess the skeletal muscle index (L3SMI) as well as the mean skeletal muscle attenuation (MMA) in = 88 patients receiving ICI therapy.

Results: While baseline L3SMI and MMA values were unsuitable for predicting the individual response and outcome to ICI therapy, longitudinal changes of the L3SMI and MMA (∆L3SMI, ∆MMA) during ICI therapy turned out to be a relevant marker of therapy response and overall survival. Patients who responded to ICI therapy at three months had a significantly higher ∆L3SMI compared to non-responders (-3.20 mm/cm vs. 1.73 mm/cm, = 0.002). Moreover, overall survival (OS) was significantly lower in patients who had a strongly decreasing ∆L3SMI (<-6.18 mm/cm) or a strongly decreasing ∆MMA (<-0.4 mm/cm) during the first three month of ICI therapy. Median OS was only 127 days in patients with a ∆L3SMI of below -6.18 mm/cm, compared to 547 days in patients with only mildly decreasing or even increasing ∆L3SMI values ( < 0.001).

Conclusion: Both progressive sarcopenia and an increasing skeletal muscle fat deposition are associated with poor response and outcome to ICI therapy, which might help to guide treatment decisions during ICI therapy.
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http://dx.doi.org/10.3390/jcm10071361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036296PMC
March 2021

Non-Specific Low Back Pain and Lumbar Radiculopathy: Comparison of Morphologic and Compositional MRI as Assessed by gagCEST Imaging at 3T.

Diagnostics (Basel) 2021 Feb 26;11(3). Epub 2021 Feb 26.

Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany.

Using glycosaminoglycan Chemical Exchange Saturation Transfer (gagCEST) magnetic resonance imaging (MRI), this study comparatively evaluated the GAG contents of lumbar intervertebral disks (IVDs) of patients with non-specific low back pain (nsLBP), radiculopathy, and asymptomatic volunteers to elucidate the association of clinical manifestation and compositional correlate. A total of 18 patients (mean age 57.5 ± 22.5 years) with radiculopathy, 16 age-matched patients with chronic nsLBP and 20 age-matched volunteers underwent standard morphologic and compositional gagCEST MRI on a 3T scanner. In all cohorts, GAG contents of lumbar IVDs were determined using gagCEST MRI. An assessment of morphologic IVD degeneration based on the Pfirrmann classification and T2-weighted sequences served as a reference. A linear mixed model adjusted for multiple confounders was used for statistical evaluation. IVDs of patients with nsLBP showed lower gagCEST values than those of volunteers (nsLBP: 1.3% [99% confidence intervals (CI): 1.0; 1.6] vs. volunteers: 1.9% [99% CI: 1.6; 2.2]). Yet, IVDs of patients with radiculopathy (1.8% [99% CI: 1.4; 2.1]) were not different from patients with nsLBP or volunteers. In patients with radiculopathy, IVDs directly adjacent to IVD extrusions demonstrated lower gagCEST values than distant IVDs (adjacent: 0.9% [99% CI: 0.3; 1.5], distant: 2.1% [99% CI: 1.7; 2.5]). Advanced GAG depletion in nsLBP and directly adjacent to IVD extrusions in radiculopathy indicates close interrelatedness of clinical pathology and compositional degeneration.
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http://dx.doi.org/10.3390/diagnostics11030402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7996864PMC
February 2021

Correlation between contrast enhancement, standardized uptake value (SUV), and diffusion restriction (ADC) with tumor grading in patients with therapy-naive neuroendocrine neoplasms using hybrid Ga-DOTATOC PET/MRI.

Eur J Radiol 2021 Apr 19;137:109588. Epub 2021 Feb 19.

University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.

Objectives: To investigate a correlation between Ga-DOTATOC PET/MR imaging parameters such as arterial and venous contrast enhancement, diffusion restriction, and maximum standardized uptake value (SUVmax) with histopathological tumor grading in patients with neuroendocrine neoplasms (NEN).

Material And Methods: A total of 26 patients with newly diagnosed, therapy-naive neuroendocrine neoplasms (NEN) were enrolled in this prospective study and underwent Ga-DOTATOC PET/MRI. Images were evaluated regarding NEN lesion number and location, predominant tumor signal intensity on precontrast T1w and T2w images and on postcontrast arterial and portal venous phase T1w images, apparent diffusion coefficient (ADC) and SUVmax. Histopathological tumor grading was assessed and related to PET/MRI features using Pearson's correlation coefficient and Fisher's exact t-test. A binary logistic regression analysis was performed to evaluate a potential relation with an aggressive tumor biology and odds ratios (OR) were calculated.

Results: There was a moderate negative correlation between arterial contrast enhancement and tumor grading (r=-0.35, p = 0.005), while portal venous enhancement showed a weak positive correlation with the Ki-67 index (r = 0.28, p = 0.008) and a non-significant positive correlation with tumor grading (r = 0.19, p = 0.063). Features that were significantly associated with an aggressive tumor biology were the presence of liver metastases (OR 2.6, p = 0.042), T1w hyperintensity in comparison to muscle (OR 12.7, p = 0.0001), arterial phase hyperenhancement (OR 1.4, p = 0.001), diffusion restriction (OR 2.8, p = 0.02) and SUVmax above the hepatic level (OR 7.0, p = 0.001).

Conclusion: The study reveals that PET/MRI features might be useful for prediction of NEN grading and thus provide a preliminary assessment of tumor aggressiveness.
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http://dx.doi.org/10.1016/j.ejrad.2021.109588DOI Listing
April 2021

Impact of increasing levels of adaptive statistical iterative reconstruction on image quality in oil-based postmortem CT angiography in coronary arteries.

Int J Legal Med 2021 Feb 24. Epub 2021 Feb 24.

Medical Faculty, Department of Diagnostic and Interventional Radiology, University Dusseldorf, D-40225, Dusseldorf, Germany.

Introduction: Postmortem multi-detector computed tomography (PMCT) has become an important part in forensic imaging. Modern reconstruction techniques such as iterative reconstruction (IR) are frequently used in postmortem CT angiography (PMCTA). The image quality of PMCTA depends on the strength of IR. For this purpose, we aimed to investigate the impact of different advanced IR levels on the objective and subjective PMCTA image quality.

Material And Methods: We retrospectively analyzed the coronary arteries of 27 human cadavers undergoing whole-body postmortem CT angiography between July 2017 and March 2018 in a single center. Iterative reconstructions of the coronary arteries were processed in five different level settings (0%; 30%; 50%; 70%; 100%) by using an adaptive statistical IR method. We evaluated the objective (contrast-to-noise ratio (CNR)) and subjective image quality in several anatomical locations.

Results: Our results demonstrate that the increasing levels of an IR technique have relevant impact on the image quality in PMCTA scans in forensic postmortem examinations. Higher levels of IR have led to a significant reduction of image noise and therefore to a significant improvement of objective image quality (+ 70%). However, subjective image quality is inferior at higher levels of IR due to plasticized image appearance.

Conclusion: Objective image quality in PMCTA progressively improves with increasing level of IR with the best CNR at the highest IR level. However, subjective image quality is best at low to medium levels of IR. To obtain a "classic" image appearance with optimal image quality, PMCTAs should be reconstructed at medium levels of IR.
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http://dx.doi.org/10.1007/s00414-021-02530-1DOI Listing
February 2021

Comparing lesion detection efficacy and image quality across different PET system generations to optimize the iodine-124 PET protocol for recurrent thyroid cancer.

EJNMMI Phys 2021 Feb 15;8(1):14. Epub 2021 Feb 15.

Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.

Background: In recurrent differentiated thyroid cancer patients, detectability in I PET is limited for lesions with low radioiodine uptake. We assess the improvements in lesion detectability and image quality between three generations of PET scanners with different detector technologies. The results are used to suggest an optimized protocol.

Methods: Datasets of 10 patients with low increasing thyroglobulin or thyroglobulin antibody levels after total thyroidectomy and radioiodine therapies were included. PET data were acquired and reconstructed on a Biograph mCT PET/CT (whole-body, 4-min acquisition time per bed position; OSEM, OSEM-TOF, OSEM-TOF+PSF), a non-TOF Biograph mMR PET/MR (neck region, 4 min and 20 min; OSEM), and a new generation Biograph Vision PET/CT (whole-body, 4 min; OSEM, OSEM-TOF, OSEM-TOF+PSF). The 20-min image on the mMR was used as reference to calculate the detection efficacy in the neck region. Image quality was rated on a 5-point scale.

Results: All detected lesions were in the neck region. Detection efficacy was 8/9 (Vision OSEM-TOF and OSEM-TOF+PSF), 4/9 (Vision OSEM), 3/9 (mMR OSEM and mCT OSEM-TOF+PSF), and 2/9 (mCT OSEM and OSEM-TOF). Median image quality was 4 (Vision OSEM-TOF and OSEM-TOF+PSF), 3 (Vision OSEM, mCT OSEM-TOF+PSF, and mMR OSEM 20-min), 2 (mCT OSEM-TOF), 1.5 (mCT OSEM), and 1 (mMR OSEM 4 min).

Conclusion: At a clinical standard acquisition time of 4 min per bed position, the new generation Biograph Vision using a TOF-based image reconstruction demonstrated the highest detectability and image quality and should, if available, be preferably used for imaging of low-uptake lesions. A prolonged acquisition time for the mostly affected neck region can be useful.
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http://dx.doi.org/10.1186/s40658-021-00361-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7884562PMC
February 2021

Machine learning-based differentiation between multiple sclerosis and glioma WHO II°-IV° using O-(2-[18F] fluoroethyl)-L-tyrosine positron emission tomography.

J Neurooncol 2021 Apr 27;152(2):325-332. Epub 2021 Jan 27.

Division of Clinical Neurooncology, Department of Neurology, University Hospital Essen, University Duisburg-Essen, Hufelandstrasse 55, 45147, Essen, Germany.

Introduction: This study aimed to test the diagnostic significance of FET-PET imaging combined with machine learning for the differentiation between multiple sclerosis (MS) and glioma II°-IV°.

Methods: Our database was screened for patients in whom FET-PET imaging was performed for the diagnostic workup of newly diagnosed lesions evident on MRI and suggestive of glioma. Among those, we identified patients with histologically confirmed glioma II°-IV°, and those who later turned out to have MS. For each group, tumor-to-brain ratio (TBR) derived features of FET were determined. A support vector machine (SVM) based machine learning algorithm was constructed to enhance classification ability, and Receiver Operating Characteristic (ROC) analysis with area under the curve (AUC) metric served to ascertain model performance.

Results: A total of 41 patients met selection criteria, including seven patients with MS and 34 patients with glioma. TBR values were significantly higher in the glioma group (TBRmax glioma vs. MS: p = 0.002; TBRmean glioma vs. MS: p = 0.014). In a subgroup analysis, TBR values significantly differentiated between MS and glioblastoma (TBRmax glioblastoma vs. MS: p = 0.0003, TBRmean glioblastoma vs. MS: p = 0.0003) and between MS and oligodendroglioma (ODG) (TBRmax ODG vs. MS: p = 0.003; TBRmean ODG vs. MS: p = 0.01). The ability to differentiate between MS and glioma II°-IV° increased from 0.79 using standard TBR analysis to 0.94 using a SVM based machine learning algorithm.

Conclusions: FET-PET imaging may help differentiate MS from glioma II°-IV° and SVM based machine learning approaches can enhance classification performance.
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http://dx.doi.org/10.1007/s11060-021-03701-1DOI Listing
April 2021

Spectral diffusion analysis of kidney intravoxel incoherent motion MRI in healthy volunteers and patients with renal pathologies.

Magn Reson Med 2021 Jun 18;85(6):3085-3095. Epub 2021 Jan 18.

Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Dusseldorf, Düsseldorf, Germany.

Purpose: To assess the feasibility of measuring tubular and vascular signal fractions in the human kidney using nonnegative least-square (NNLS) analysis of intravoxel incoherent motion data collected in healthy volunteers and patients with renal pathologies.

Methods: MR imaging was performed at 3 Tesla in 12 healthy subjects and 3 patients with various kidney pathologies (fibrotic kidney disease, failed renal graft, and renal masses). Relative signal fractions f and mean diffusivities of the diffusion components in the cortex, medulla, and renal lesions were obtained using the regularized NNLS fitting of the intravoxel incoherent motion data. Test-retest repeatability of the NNLS approach was tested in 5 volunteers scanned twice.

Results: In the healthy kidneys, the NNLS method yielded diffusion spectra with 3 distinguishable components that may be linked to the slow tissue water diffusion, intermediate tubular and vascular flow, and fast blood flow in larger vessels with the relative signal fractions, f , f and f , respectively. In the pathological kidneys, the diffusion spectra varied substantially from those acquired in the healthy kidneys. Overall, the renal cyst showed substantially higher f and lower f , whereas the fibrotic kidney, failed renal graft, and renal cell carcinoma demonstrated the opposite trend.

Conclusion: NNLS-based intravoxel incoherent motion could potentially become a valuable tool in assessing changes in tubular and vascular volume fractions under pathophysiological conditions.
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http://dx.doi.org/10.1002/mrm.28631DOI Listing
June 2021

Prospective Correlation of Prognostic Immunohistochemical Markers With SUV and ADC Derived From Dedicated Hybrid Breast 18F-FDG PET/MRI in Women With Newly Diagnosed Breast Cancer.

Clin Nucl Med 2021 03;46(3):201-205

From the Department of Diagnostic and Interventional Radiology, Medical Faculty, University Düsseldorf, Düsseldorf.

Purpose: The aim of this study was to correlate prognostically relevant immunohistochemical parameters of breast cancer with simultaneously acquired SUVs and apparent diffusion coefficient (ADC) values derived from hybrid breast PET/MRI.

Patients And Methods: Fifty-six women with newly diagnosed, therapy-naive, histologically proven breast cancer (mean age, 54.1 ± 12.0 years) underwent dedicated prone 18F-FDG breast PET/MRI. Diffusion-weighted imaging (b-values: 0, 500, 1000 s/mm2) was performed simultaneously with the PET acquisition. A region of interest encompassing the entire primary tumor on each patient's PET/MRI scan was used to determine the glucose metabolism represented by maximum and mean SUV as well as into corresponding ADC maps to assess tumor cellularity represented by mean and minimum ADC values. Histopathological tumor grading and prognostically relevant immunohistochemical markers, that is, Ki67, progesterone receptor, estrogen receptor, and human epidermal growth factor receptor 2 (HER2), were assessed. Pearson correlation coefficients were calculated to compare SUV and ADC values as well as the immunohistochemically markers and molecular subtype. For the comparison with the tumor grading, a Wilcoxon test was used.

Results: A significant inverse correlation between SUV and ADC values derived from breast PET/MRI (r = -0.49 for SUVmean vs ADCmean; r = -0.43 for SUVmax vs ADCmin; both P's < 0.001) was found. Tumor grading and Ki67 both showed a positive correlation with SUVmean from breast PET/MRI (r = 0.37 and r = 0.32, P < 0.01). For immunohistochemical markers, HER2 showed an inverse correlation with ADC values from breast PET/MRI (r = -0.35, P < 0.01). Molecular subtypes significantly correlate with SUVmax and SUVmean (r = 0.52 and r = 0.42, both P's < 0.05). In addition, estrogen receptor expression showed an inverse correlation with SUVmax and SUVmean from breast PET/MRI (r = -0.45 and r = -0.42, P < 0.001).

Conclusions: The present data show a correlation between increased glucose metabolism, cellularity, tumor grading, estrogen and HER2 expression, as well as molecular subtype of breast cancer primaries. Hence, simultaneous 18F-FDG PET and diffusion-weighted imaging from hybrid breast PET/MRI may serve as a predictive tool for identifying high-risk breast cancer patients in initial staging and guide-targeted therapy.
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http://dx.doi.org/10.1097/RLU.0000000000003488DOI Listing
March 2021

Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance.

Rofo 2020 Dec 16. Epub 2020 Dec 16.

University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf, Germany.

Background:  Primary aldosteronism (PA) is the most common detectable cause of secondary hypertension. The majority of patients have either an adrenal aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH) demanding different therapeutic approaches. Screening tests and imaging cannot reliably distinguish between a unilateral or bilateral PA.

Methods:  This review article gives an overview concerning etiology, diagnostics, and therapeutic options of PA, and reviews the indication, the technique, and relevance of selective adrenal venous sampling (AVS) in the context of the current literature and the authors' experience.

Results:  AVS can verify or exclude a unilaterally dominated secretion with a high success rate. Patients with PA and a unilateral APA can be treated curatively by adrenalectomy.

Conclusions:  AVS is an established diagnostic examination for differentiation of unilateral from bilateral adrenal disease in patients with PA.

Key Points: · Selective adrenal venous sampling (AVS) is a safe, reliable, and minimally invasive method to detect a unilateral or bilateral adrenal adrenal gland disease.. · Verification of lateralization by AVS has direct therapeutic relevance for patients with primary aldosteronism (PA).. · AVS can be performed with low radiation exposure, without contrast medium, and with a high success rate when performed by an experienced interventional radiologist..

Citation Format: · Loberg C, Antoch G, Stegbauer J et al. Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. Fortschr Röntgenstr 2020; DOI: 10.1055/a-1299-1878.
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http://dx.doi.org/10.1055/a-1299-1878DOI Listing
December 2020

Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society.

Rofo 2021 May 16;193(5):513-520. Epub 2020 Dec 16.

III Medical Clinic, Day Therapy Centre, Medical Faculty of the University of Heidelberg, Mannheim, Germany.

Due to its excellent intrinsic soft tissue contrast, magnetic resonance imaging allows excellent visualization and anatomical separation of therapy-relevant risk structures such as the mesorectal fascia, local lymph nodes, and vascular structures in patients with rectal carcinoma. This makes magnetic resonance imaging (MRI) a valuable evaluation method for further therapeutic stratification. In particular, MRI is indispensable for the decision to refrain from neoadjuvant therapy and to choose a primary surgical approach. In addition to the oncologically generally relevant T-, N-, and M-criteria, two further parameters are included: the extramural vascular infiltration and the circumferential resection margin. Due to the significant impact of MRI on further therapeutic decision-making, standardized MR image quality is considered essential. KEY POINTS::   · Magnetic resonance imaging is a valuable evaluation method for further therapeutic stratification.. · Critical anatomic landmarks for evaluation are circumferential resection margins.. CITATION FORMAT: · Attenberger UI, Clasen S, Ghadimi M et al. Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. Fortschr Röntgenstr 2021; 193: 513 - 520.
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http://dx.doi.org/10.1055/a-1299-1807DOI Listing
May 2021

Joint Imaging Platform for Federated Clinical Data Analytics.

JCO Clin Cancer Inform 2020 11;4:1027-1038

German Cancer Consortium, Heidelberg, Germany.

Purpose: Image analysis is one of the most promising applications of artificial intelligence (AI) in health care, potentially improving prediction, diagnosis, and treatment of diseases. Although scientific advances in this area critically depend on the accessibility of large-volume and high-quality data, sharing data between institutions faces various ethical and legal constraints as well as organizational and technical obstacles.

Methods: The Joint Imaging Platform (JIP) of the German Cancer Consortium (DKTK) addresses these issues by providing federated data analysis technology in a secure and compliant way. Using the JIP, medical image data remain in the originator institutions, but analysis and AI algorithms are shared and jointly used. Common standards and interfaces to local systems ensure permanent data sovereignty of participating institutions.

Results: The JIP is established in the radiology and nuclear medicine departments of 10 university hospitals in Germany (DKTK partner sites). In multiple complementary use cases, we show that the platform fulfills all relevant requirements to serve as a foundation for multicenter medical imaging trials and research on large cohorts, including the harmonization and integration of data, interactive analysis, automatic analysis, federated machine learning, and extensibility and maintenance processes, which are elementary for the sustainability of such a platform.

Conclusion: The results demonstrate the feasibility of using the JIP as a federated data analytics platform in heterogeneous clinical information technology and software landscapes, solving an important bottleneck for the application of AI to large-scale clinical imaging data.
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http://dx.doi.org/10.1200/CCI.20.00045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7713526PMC
November 2020

Influence of a novel deep-learning based reconstruction software on the objective and subjective image quality in low-dose abdominal computed tomography.

Br J Radiol 2021 Jan 23;94(1117):20200677. Epub 2020 Oct 23.

Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany.

Objectives: Modern reconstruction and post-processing software aims at reducing image noise in CT images, potentially allowing for a reduction of the employed radiation exposure. This study aimed at assessing the influence of a novel deep-learning based software on the subjective and objective image quality compared to two traditional methods [filtered back-projection (FBP), iterative reconstruction (IR)].

Methods: In this institutional review board-approved retrospective study, abdominal low-dose CT images of 27 patients (mean age 38 ± 12 years, volumetric CT dose index 2.9 ± 1.8 mGy) were reconstructed with IR, FBP and, furthermore, post-processed using a novel software. For the three reconstructions, qualitative and quantitative image quality was evaluated by means of CT numbers, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in six different ROIs. Additionally, the reconstructions were compared using SNR, peak SNR, root mean square error and mean absolute error to assess structural differences.

Results: On average, CT numbers varied within 1 Hounsfield unit (HU) for the three assessed methods in the assessed ROIs. In soft tissue, image noise was up to 42% lower compared to FBP and up to 27% lower to IR when applying the novel software. Consequently, SNR and CNR were highest with the novel software. For both IR and the novel software, subjective image quality was equal but higher than the image quality of FBP-images.

Conclusion: The assessed software reduces image noise while maintaining image information, even in comparison to IR, allowing for a potential dose reduction of approximately 20% in abdominal CT imaging.

Advances In Knowledge: The assessed software reduces image noise by up to 27% compared to IR and 48% compared to FBP while maintaining the image information.The reduced image noise allows for a potential dose reduction of approximately 20% in abdominal imaging.
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http://dx.doi.org/10.1259/bjr.20200677DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7774679PMC
January 2021

F-flutemetamol positron emission tomography in cardiac amyloidosis.

J Nucl Cardiol 2020 Oct 6. Epub 2020 Oct 6.

Department of Nuclear Medicine, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany.

Purpose: Bone-tracer scintigraphy has an established role in diagnosis of cardiac amyloidosis (CA) as it detects transthyretin amyloidosis (ATTR). Positron emission tomography (PET) with amyloid tracers has shown high sensitivity for detection of both ATTR and light-chain (AL) CA. We aimed to investigate the accuracy of F-flutemetamol in CA.

Methods: We enrolled patients with CA or non-amyloid heart failure (NA-HF), who underwent cardiac F-flutemetamol PET/MRI or PET/CT. Myocardial and blood pool standardized tracer uptake values (SUV) were estimated. Late gadolinium enhancement (LGE) and T1 mapping/ extracellular volume (ECV) estimation were performed.

Results: We included 17 patients (12 with CA, 5 with NA-HF). PET/MRI was conducted in 13 patients, while PET/CT was conducted in 4. LGE was detected in 8 of 9 CA patients. Global relaxation time and ECV were higher in CA (1448 vs. 1326, P = 0.02 and 58.9 vs. 33.7%, P = 0.006, respectively). Positive PET studies were demonstrated in 2 of 12 patients with CA (AL and ATTR). Maximal and mean SUV did not differ between groups (2.21 vs. 1.69, P = 0.18 and 1.73 vs. 1.30, P = 0.13).

Conclusion: Although protein-independent binding is supported by our results, the diagnostic yield of PET was low. We demonstrate here for the first time the low sensitivity of PET for CA.
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http://dx.doi.org/10.1007/s12350-020-02363-2DOI Listing
October 2020

Serum neurofilament light chain: No clear relation to cognition and neuropsychiatric symptoms in stable MS.

Neurol Neuroimmunol Neuroinflamm 2020 11 24;7(6). Epub 2020 Sep 24.

From the Department of Neurology (O.A., M.G., K.L., N.G., J.G., H.-P.H., P.A., I.-K.P.), Medical Faculty, University Düsseldorf, Germany; Cogito Center for Applied Neurocognition and Neuropsychological Research (A.R., M.F., S.B., N.S., I.-K.P.), Düsseldorf, Germany; Department of Neurology (A.H., M.S., M.O., H.T.), University Hospital Ulm, Germany; Department of Neurology (C.E., D.P.), Research Unit for Neuronal Plasticity and Repair, Medical University of Graz, Austria; Division of Neuroradiology, Vascular and Interventional Radiology (C.E.), Department of Radiology, Medical University of Graz, Austria; Department of Diagnostic and Interventional Radiology (G.A., B.T.), Medical Faculty, University Düsseldorf, Germany; and Department of Neurology (H.T.), Dietenbronn, Germany.

Objective: To explore the hypothesis that serum neurofilament light chain (sNfL) indicative of neuroaxonal damage may improve precise disease profiling with regard to cognition and neuropsychiatric symptoms, we analyzed potential associations of sNfL levels with cognitive test scores, fatigue, depression, and anxiety.

Methods: Patients with relapsing-remitting and secondary progressive MS (SPMS) underwent an elaborated assessment including MRI, various cognitive tests, and patient-reported outcomes. We determined sNfL levels by single molecule array (Simoa) assay. Relationships between sNfL, cognition, neuropsychiatric symptoms, and demographical data were analyzed using correlations, group comparisons, and regressions.

Results: In 45 clinically stable patients with MS (Expanded Disability Status Scale = 2.73 ± 1.12, disease duration = 10.03 ± 7.49 years), 40.0% were cognitively impaired. Mean sNfL levels were 16.02 ± 10.39 pg/mL, with higher levels in the SPMS subgroup ( = 0.038). sNfL levels did reliably link neither with the investigated cognitive and affective parameters nor with fatigue levels. The only relationship found in a small subgroup of patients with SPMS (n = 7) with visuospatial learning ( = -0.950, = 0.001) and memory ( = -0.813; = 0.026) disappeared when further controlling for age, educational level, and sex.

Conclusions: In patients with stable MS at less advanced disease stages, sNfL did not convincingly relate to cognitive performance, fatigue, depression, or anxiety and thus may not serve as a surrogate biomarker for neuropsychological status in such populations.
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http://dx.doi.org/10.1212/NXI.0000000000000885DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673283PMC
November 2020

Functional MR imaging beyond structure and inflammation-radiographic axial spondyloarthritis is associated with proteoglycan depletion of the lumbar spine.

Arthritis Res Ther 2020 09 17;22(1):219. Epub 2020 Sep 17.

Rheumazentrum Ruhrgebiet Herne, Ruhr University Bochum, Claudiusstr. 45, 44649, Herne, Germany.

Background: To compare the glycosaminoglycan (GAG) content of lumbar intervertebral disks (IVDs) of patients with ankylosing spondylitis (AS) and healthy volunteers and to investigate the association of GAG depletion and disease-related clinical and imaging features.

Methods: Lumbar spines of 50 AS patients (mean age 50 ± 10.5 years) and 30 age-matched volunteers were studied with 3-T magnetic resonance imaging (MRI) and conventional radiographs (CR). The MRI protocol included high-resolution morphological sequences and the compositional GAG chemical exchange saturation transfer imaging technique (gagCEST). Morphological images were analyzed by three raters for inflammatory activity, fat deposition, disk degeneration, and structural changes on CR. Clinical and serological measures included the Bath AS Disease Activity (BASDAI) and Bath AS Function (BASFI) Indices and C-reactive protein (CRP) levels. GagCEST values of both groups were compared using a linear mixed model. Kendall-Tau correlation analyses were performed.

Results: GagCEST values were significantly lower in AS patients (2.0 ± 1.7%) vs. healthy volunteers (2.4 ± 1.8%), p = 0.001. Small, yet significant correlations were found between gagCEST values and CRP levels (τ = - 0.14, p = 0.007), BASFI (τ = - 0.18, p < 0.001) and presence of syndesmophytes (τ = - 0.17, p = 0.001). No significant correlations were found with BASDAI, inflammation, and fat deposition MRI scores.

Conclusions: Lumbar spines of r-AS patients undergo significant GAG depletion, independently associated with syndesmophyte formation, functional disability, and increased serological inflammation markers. Beyond establishing a pathophysiological role of the cartilage in AS, these findings suggest that gagCEST imaging may have an adjunct confirmatory role in the assessment of disease-related pathological MRI findings in axial spondyloarthritis.

Trial Registration: 3980 ( https://studienregister.med.uni-duesseldorf.de ).
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http://dx.doi.org/10.1186/s13075-020-02312-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7499866PMC
September 2020

Analysis of different image-registration algorithms for Fourier decomposition MRI in functional lung imaging.

Acta Radiol 2020 Jul 29:284185120944902. Epub 2020 Jul 29.

Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.

Background: Motion correction is mandatory for the functional Fourier decomposition magnetic resonance imaging (FD-MRI) of the lungs. Therefore, it is important to evaluate the quality of various image-registration algorithms for pulmonary FD-MRI and to determine their impact on FD-MRI outcome.

Purpose: To evaluate different image-registration algorithms for FD-MRI in functional lung imaging.

Material And Methods: Fifteen healthy volunteers were examined in a 1.5-T whole-body MR scanner (Magnetom Avanto, Siemens AG) with a non-contrast enhanced 2D TrueFISP pulse sequence in coronal view and free-breathing (acquisition time 45 s, 250 images). Three image-registration algorithms were used to compensate the spatial variation of the lungs (fMRLung 3.0, ANTs, and Elastix). Quality control for image registration was performed by edge detection (ED), quotient image criterion (QI), and dice similarity coefficient (DSC). Ventilation, perfusion, and a ventilation/perfusion quotient (V/Q) were calculated using the three registered datasets.

Results: Average computing times for the three image-registration algorithms were 1.0 ± 1.6 min, 38.0 ± 13.5 min, and 354 ± 78 min for fMRLung, ANTs, and Elastix, respectively. No significant difference in the quality of motion correction provided by different image-registration algorithms occurred. Significant differences were observed between fMRLung- and Elastix-based perfusion values ​​of the left lung as well as fMRLung- and ANTs-based V/Q quotient of the right and the entire lung ( < 0.05). Other ventilation and perfusion values were not significantly different.

Conclusion: The mandatory motion correction for functional FD-MRI of the lung can be achieved through different image-registration algorithms with consistent quality. However, a significantly difference in computing time between the image-registration algorithms still requires an optimization.
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http://dx.doi.org/10.1177/0284185120944902DOI Listing
July 2020

Detection of early cartilage degeneration in the tibiotalar joint using 3 T gagCEST imaging: a feasibility study.

MAGMA 2021 Apr 28;34(2):249-260. Epub 2020 Jul 28.

Department of Diagnostic and Interventional Radiology, Medical Faculty, University Hospital Düsseldorf, University Dusseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany.

Objective: To establish and optimize a stable 3 Tesla (T) glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging protocol for assessing the articular cartilage of the tibiotalar joint in healthy volunteers and patients after a sustained injury to the ankle.

Methods: Using Bloch-McConnell simulations, we optimized the sequence protocol for a 3 T MRI scanner for maximum gagCEST effect size within a clinically feasible time frame of less than 07:30 min. This protocol was then used to analyze the gagCEST effect of the articular cartilage of the tibiotalar joint of 17 healthy volunteers and five patients with osteochondral lesions of the talus following ankle trauma. Reproducibility was tested with the intraclass correlation coefficient.

Results: The mean magnetization transfer ratio asymmetry (MTR), i.e., the gagCEST effect size, was significantly lower in patients than in healthy volunteers (0.34 ± 1.9% vs. 1.49 ± 0.11%; p < 0.001 [linear mixed model]). Intra- and inter-rater reproducibility was excellent with an average measure intraclass correlation coefficient (ICC) of 0.97 and a single measure ICC of 0.91 (p < 0.01).

Discussion: In this feasibility study, pre-morphological tibiotalar joint cartilage damage was quantitatively assessable on the basis of the optimized 3 T gagCEST imaging protocol that allowed stable quantification gagCEST effect sizes across a wide range of health and disease in clinically feasible acquisition times.
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http://dx.doi.org/10.1007/s10334-020-00868-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8018923PMC
April 2021

Is there a connection between immunohistochemical markers and grading of lung cancer with apparent diffusion coefficient (ADC) and standardised uptake values (SUV) of hybrid 18F-FDG-PET/MRI?

J Med Imaging Radiat Oncol 2020 Dec 24;64(6):779-786. Epub 2020 Jul 24.

Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, Dusseldorf, Germany.

Introduction: To correlate tumour grading and prognostic immunohistochemical markers of lung cancer with simultaneously acquired standardised uptake values (SUV) and apparent diffusion coefficient (ADC) derived from hybrid PET/MRI.

Methods: In this retrospective study, 55 consecutive patients (mean age 62.5 ± 9.2 years) with therapy-naïve, histologically proven lung cancer were included. All patients underwent whole-body PET/MRI using 18F-flourdeoxyglucose (18F-FDG) as a radiotracer. Diffusion-weighted imaging of the chest (DWI, b-values: 0, 500, 1000 s/mm ) was performed simultaneously with PET acquisition. Histopathological tumour grading was available in 43/55 patients. In 15/55 patients, immunohistochemical markers, that is, phospho-AKT Ser473 (pAKTS473), phosphorylated extracellular signal-regulated kinase (pERK), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (erbB2) were available.

Results: The average SUVmax, SUVmean, ADCmin and ADCmean in lung cancer primaries were 12.6 ± 5.9, 7.7 ± 4.6, 569.9 ± 96.1 s/mm and 825.8 ± 93.2 s/mm , respectively. We found a significant inverse correlation between the ADCmin and SUVmax (r = -0.58, P < 0.001) as well as between the ADCmin and SUVmean (r = -0.44, P < 0.001). Tumour grading showed a significant positive correlation with SUVmax and SUVmean (R = 0.34 and R = 0.31, both P < 0.05) and a significant inverse correlation with ADCmin and ADCmean (r = -0.30 and r = -0.40, both P < 0.05). In addition, erbB2 showed a significant inverse correlation with SUVmax and SUVmean (r = -0.50 and r = -0.49, both P < 0.05). The other immunohistochemical markers did not show any significant correlation.

Conclusion: 18F-FDG-PET/MRI showed weak to moderate correlations between SUV, ADC, tumour grading and erbB2-expression of lung cancer. Hence, 18F-FDG-PET/MRI may, to some extent, offer complementary information to the histopathology of lung cancer, for the evaluation of tumour aggressiveness and treatment response.
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http://dx.doi.org/10.1111/1754-9485.13087DOI Listing
December 2020

Performance of the CoreValve Evolut R and PRO in Severely Calcified Anatomy: A Propensity Score Matched Analysis.

Heart Lung Circ 2020 Dec 16;29(12):1847-1855. Epub 2020 Jun 16.

Medical Faculty, Division of Cardiology, Pulmonology and Vascular Medicine, Heinrich Heine University Düsseldorf, Düsseldorf, Germany. Electronic address:

Background: The CoreValve Evolut R and PRO (Medtronic, Minneapolis, MN, USA) are among the newest-generation of self-expandable transcatheter aortic valve replacement (TAVR) devices and show excellent results. Treating patients with severely calcified (SC) native aortic valve anatomy may be challenging because of the increased risk of periprocedural complications. This study investigated the performance of Evolut R and PRO in this special patient subset.

Methods: Patients who underwent TAVR with the CoreValve Evolut R or PRO (n=381) from September 2015 to March 2018 were divided by aortic valve calcification extent. Patients with SC aortic valve anatomy (n=98; men, >2,062 and women, >1,377 Agatston units) were compared with those with non-severely calcified (NCS) aortic valve anatomy after 1:2 propensity score matching. Outcomes were evaluated according to the updated valve academic research consortium criteria.

Results: Patients with SC anatomy were older (83 years vs 80 years, p<0.001) and had a smaller aortic valve area (0.63 cm vs 0.70 cm, p=0.028). Pre-dilatation was more often performed (30.6% vs 15.8%, p=0.003) and a permanent pacemaker implantation was more often necessary (32.9% vs 8.8%, p<0.001) in the SC group. None/mild aortic regurgitation (AR) was evenly distributed (SC, 96.9% vs NCS, 99.5%, p=0.109); moderate AR was present in 3.1% of SC patients and in 0.5% of NSC patients. Severe AR was not observed.

Conclusion: The CoreValve Evolut R and PRO showed good clinical safety profiles and excellent haemodynamic results in patients with SC anatomy and who more often required permanent pacemaker implantation.
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http://dx.doi.org/10.1016/j.hlc.2020.05.096DOI Listing
December 2020

GABAergic and glutamatergic effects on nigrostriatal and mesolimbic dopamine release in the rat.

Rev Neurosci 2020 Aug;31(6):569-588

Clinic of Nuclear Medicine, University Hospital Düsseldorf, Moorenstr. 5, D-40225, Düsseldorf, Germany.

In this review, a series of experiments is presented, in which γ-amino butyric acid (GABA)ergic and glutamatergic effects on dopamine function in the rat nigrostriatal and mesolimbic system was systematically assessed after pharmacological challenge with GABAA receptor (R) and and N-methyl d-aspartate (NMDA)R agonists and antagonists. In these studies, [123I]iodobenzamide binding to the D2/3R was mesured in nucleus accumbens (NAC), caudateputamen (CP), substantia nigra/ventral tegmental area (SN/VTA), frontal (FC), motor (MC) and parietal cortex (PC) as well as anterior (aHIPP) and posterior hippocampus (pHIPP) with small animal SPECT in baseline and after injection of either the GABAAR agonist muscimol (1 mg/kg), the GABAAR antagonist bicuculline (1 mg/kg), the NMDAR agonist d-cycloserine (20 mg/kg) or the NMDAR antagonist amantadine (40 mg/kg). Muscimol reduced D2/3R binding in NAC, CP, SN/VTA, THAL and pHIPP, while, after amantadine, decreases were confined to NAC, CP and THAL. In contrast, d-cycloserine elevated D2/3R binding in NAC, SN/VTA, THAL, frontal cortex, motor cortex, PC, aHIPP and pHIPP, while, after bicuculline, increases were confined to CP and THAL. Taken together, similar actions on regional dopamine levels were exterted by the GABAAR agonist and the NMDAR antagonist on the one side and by the GABAAR antagonist and the NMDAR agonist on the other, with agonistic action, however, affecting more brain regions. Thereby, network analysis suggests different roles of GABAARs and NMDARs in the mediation of nigrostriatal, nigrothalamocortical and mesolimbocortical dopamine function.
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http://dx.doi.org/10.1515/revneuro-2019-0112DOI Listing
August 2020

Dose-optimised chest computed tomography for diagnosis of Coronavirus Disease 2019 (COVID-19) - Evaluation of image quality and diagnostic impact.

J Radiol Prot 2020 09;40(3):877-891

Medical Faculty, Department of Diagnostic and Interventional Radiology, University Hospital Düsseldorf, Düsseldorf D-40225, Germany.

Objectives: The detection of Coronavirus Disease 2019 (COVID-19) by reverse transcription polymerase chain reaction (RT-PCR) has varying sensitivity. Computed tomography (CT) of the chest can verify infection in patients with clinical symptoms and a negative test result, accelerating treatment and actions to prevent further contagion. However, CT employs ionising radiation. The purpose of this study was to evaluate protocol settings, associated radiation exposure, image quality and diagnostic performance of a low-dose CT protocol in a university hospital setting.

Materials And Methods: Chest CT examinations were performed on a single scanner (Somatom Definition Edge, Siemens Healthineers, Germany) in 105 symptomatic patients (60 male, 45 female). Images were evaluated with regard to protocol parameters, image quality, radiation exposure and diagnostic accuracy. Serial RT-PCR served as the standard of reference. Based on this reference standard sensitivity, specificity, positive and negative predictive values of CT with 95% confidence interval were calculated.

Results: The mean effective dose was 1.3 ± 0.4 mSv (0.7-2.9 mSv) for the patient cohort (mean age 66.6 ± 16.7 years (19-94 years), mean body mass index (BMI) 26.6 ± 5.3 kg m (16-46 kg/m)). A sensitivity of 100 [95% CI: 82-100]%, a specificity of 78 [95% CI: 68-86]%, a positive predictive value of 50 [95% CI: 33-67]% and a negative predictive value of 100 [95% CI: 95-100]% were obtained. No COVID-19 diagnoses were missed by CT. Image noise did not strongly correlate with BMI or patient diameter and was rated as average.

Conclusions: We presented a robust imaging procedure with a chest CT protocol for confident diagnosis of COVID-19. Even for an overweight patient cohort, an associated radiation exposure of only 1.3 ± 0.4 mSv was achieved with sufficient diagnostic quality to exclude COVID-19.
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http://dx.doi.org/10.1088/1361-6498/aba16aDOI Listing
September 2020

[Structured reporting in oncologic hybrid imaging: a consensus recommendation].

Nuklearmedizin 2020 Aug 16;59(4):288-293. Epub 2020 Jun 16.

Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.

Since the clinical introduction of PET/CT in the year of 2001 and PET/MRI in the year of 2010, hybrid imaging-guided precision medicine has become an important component of diagnostic algorithms in oncology. The written report represents the primary mode of communication between the referring physician and both the nuclear medicine physician and the radiologist. Reports have considerable impact on patient management and patient outcome, and serve as a legal documentation of the services provided and the expert impression of the interpreting physician. A high-quality hybrid imaging study should result in a likewise high-quality, structured written report which satisfactorily answers the clinical question of the referring physician. In this manuscript, consensus recommendations for structure and content of oncologic hybrid imaging reports and conclusive impressions are provided. Moreover, exemplary structured reports are provided. The recommendations for structured reporting provided in this document should foster further standardization and harmonization of oncologic reports in the context of hybrid imaging. They should also simplify communication with referring physicians and support both acceptance and appreciation of the clinical value of oncologic hybrid imaging. CITATION FORMAT: · Derlin T, Gatidis S, Krause BJ et al. Konsensusempfehlung zur strukturierten Befunderstellung onkologischer PET-Hybridbildgebung. Nuklearmedizin 2020; 59: DOI:10.1055/a-1176-0275.
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http://dx.doi.org/10.1055/a-1176-0275DOI Listing
August 2020

Diagnostic value and forensic relevance of a novel photorealistic 3D reconstruction technique in post-mortem CT.

Br J Radiol 2020 Aug 18;93(1112):20200204. Epub 2020 Jun 18.

Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, D-40225, Dusseldorf, Germany.

Objectives: Evaluation of performance and forensic relevance of a novel, photorealistic, 3D reconstruction method (cinematic rendering, (CR)) in comparison with conventional post-mortem CT (PMCT) and volume rendering (VR) technique for visualization of traumatic injuries.

Methods: 112 pathologies (fractures, soft tissue injuries and foreign bodies) from 33 human cadavers undergoing whole body PMCT after traumatic death were retrospectively analyzed. Pathologies were reconstructed with CR and VR techniques. Fractures were classified according to their dislocation. Images were evaluated according to their expressiveness and judicial relevance by two forensic pathologists using a five-level Likert-scale (1: high expressiveness, 5: low expressiveness). They decided whether CR reconstructions were suitable for judicial reviews. The detection rate of pathologies was determined by two radiologists.

Results: CR was more expressive than VR for all three trauma categories ( < 0.01) and than conventional CT when used for fractures with dislocation ( < 0.001), injuries of the ventral body surface ( < 0.001), and demonstration of foreign bodies ( = 0.033). CR and VR became more expressive with a higher grade of fracture dislocation ( < 0.001). 20% of all pathologies in the CR and VR reconstructions were not detectable by radiologists.

Conclusion: CR reconstructions are superior to VR regarding the expressiveness. For fractures with substantial dislocation, soft tissue injuries, and foreign bodies , CR showed a significantly better expressiveness than conventional PMCT. CR and VR have significant limitations in cases of fractures with minor dislocations and covered soft tissue injuries.

Advances In Knowledge: CR is a helpful tool to present pathologies found in PMCT for judicial reviews.
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http://dx.doi.org/10.1259/bjr.20200204DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7446014PMC
August 2020

Impact of different iterative metal artifact reduction (iMAR) algorithms on PET/CT attenuation correction after port implementation.

Eur J Radiol 2020 Aug 15;129:109065. Epub 2020 May 15.

University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, D-40225 Dusseldorf, Germany.

Purpose: To evaluate the effect of various interactive metal artifact reduction (iMAR) algorithms on attenuation correction in the vicinity of port chambers in PET/CT.

Material And Methods: In this prospective study, 30 oncological patients (12 female, 18 male, mean age 59.6 ± 10.5y) with implanted port chambers undergoing 18F-FDG PET/CT were included. CT images were reconstructed with standard weighted filtered back projection (WFBP) and three different iMAR algorithms (hip, dental filling (DF) and pacemaker (PM)). PET attenuation correction was performed with all four CT datasets. SUVmean, SUVmax and HU measurements were performed in fat and muscle tissue in the vicinity of the port chamber at the location of the strongest bright and dark band artifacts. Differences between HU and SUV values across all CT- and PET-images were investigated using a paired t-test. Bonferroni correction was used to prevent alpha-error accumulation (p < 0.008).

Results: In comparison to WFBP (fat: 94.2 ± 53.9 HU, muscle: 197.6 ± 49.2 HU) all three iMAR algorithms led to a decrease of HU in bright band artifacts. iMAR-DF led to a decrease of 159.2 % (fat: -51.9 ± 58.5 HU, muscle: 94.5 ± 55.3 HU), iMAR-hip of 138.3 % (fat: -30.3 ± 58.5, muscle: 70.4 ± 28.8) and iMAR-PM of 122.3 % (fat: -21.2 ± 47.2 HU, muscle: 72.5 ± 25.1 HU; for all p < 0.008). There was no significant effect of iMAR on SUV measurements in comparison to WFBP.

Conclusion: iMAR leads to a significant change of HU values in artifacts caused by port catheter chambers in comparison to WFBP. However, no significant differences in attenuation correction and consecutive changes in SUV measurements can be observed.
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http://dx.doi.org/10.1016/j.ejrad.2020.109065DOI Listing
August 2020

Proteoglycan loss in the articular cartilage is associated with severity of joint inflammation in psoriatic arthritis-a compositional magnetic resonance imaging study.

Arthritis Res Ther 2020 05 29;22(1):124. Epub 2020 May 29.

Department and Hiller Research Unit for Rheumatology, UKD, Heinrich Heine University Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany.

Background: Even though cartilage loss is a known feature of psoriatic arthritis (PsA), little is known about its role in the pathogenesis of PsA. Using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) as a non-invasive marker of the tissue's proteoglycan content, such early (i.e., pre-morphological) changes have been associated with inflammation in rheumatoid arthritis (RA). Yet, this association has not been studied before in PsA.

Methods: The metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints of 17 patients with active PsA were evaluated by high-resolution clinical standard morphological and dGEMRIC sequences using a 3T MRI scanner (Magnetom Skyra, Siemens) and a dedicated 16-channel hand coil. Images were analyzed by two independent raters for dGEMRIC indices, PsA MRI scores (PsAMRIS), and total cartilage thickness (TCT). Kendall tau correlation coefficients (τ) were calculated.

Results: We found significant negative correlations between dGEMRIC indices and total PsAMRIS (τ = - 0.5, p = 0.012), synovitis (τ = - 0.56, p = 0.006), flexor tenosynovitis (τ = - 0.4, p = 0.049), and periarticular inflammation (τ = - 0.72, p < 0.001). Significant positive correlations were found between TCT and dGEMRIC indices at all joint levels (τ = 0.43, p < 0.001). No significant correlations were determined between dGEMRIC indices and bone erosion, bone edema, or bone proliferation.

Conclusion: In PsA, proteoglycan loss as assessed by dGEMRIC is associated with periarticular inflammation, synovitis, and flexor tenosynovitis, but not with bone erosion or proliferation. Thereby, these findings contribute to in vivo concepts of the disease's pathophysiology. Beyond morphology, advanced MRI techniques may be used to assess cartilage composition in PsA and to identify early changes in the cartilage as an imaging biomarker with potential application in detection, monitoring, and prediction of outcomes of PsA.

Trial Registration: 2014123117, December 2014.
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http://dx.doi.org/10.1186/s13075-020-02219-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7257142PMC
May 2020