To evaluate the diagnostic performance and inter-reader reliability of an abbreviated non-angulated three-plane T2-weighted pelvic MRI protocol for assessing local staging key parameters in cervical cancer. In this retrospective single-center study, 47 patients with cervical cancer who underwent pelvic MRI between January 2023 and December 2024 were included. MRI was performed on a 1.5-T system using a simplified protocol; image interpretation was restricted to axial, sagittal, and coronal T2-weighted turbo spin-echo sequences. Two board-certified radiologists (one subspecialized in gynecological imaging, one general radiologist) independently assessed tumor size, parametrial invasion, vaginal involvement, and local T stage. A composite reference standard consisting of examination under anaesthesia, laparoscopic staging, and histopathology was used. Diagnostic performance metrics and inter-reader agreement (Cohen’s κ, ICC) were calculated. Parametrial invasion was detected with high diagnostic accuracy, with a mean sensitivity of 94.0

This study evaluates the impact of deep learning-enhanced T1-weighted VIBE sequences (DL-VIBE) on image quality and procedural parameters during MR-guided thermoablation of liver malignancies, compared to standard VIBE (SD-VIBE). Between September 2021 and February 2023, 34 patients (mean age: 65.4 years; 13 women) underwent MR-guided microwave ablation on a 1.5 T scanner. Intraprocedural SD-VIBE sequences were retrospectively processed with a deep learning algorithm (DL-VIBE) to reduce noise and enhance sharpness. Two interventional radiologists independently assessed image quality, noise, artifacts, sharpness, diagnostic confidence, and procedural parameters using a 5-point Likert scale. Interrater agreement was analyzed, and noise maps were created to assess signal-to-noise ratio improvements. DL-VIBE significantly improved image quality, reduced artifacts and noise, and enhanced sharpness of liver contours and portal vein branches compared to SD-VIBE (p < 0.01). Procedural metrics, including needle tip detectability, confidence in needle positioning, and ablation zone assessment, were significantly better with DL-VIBE (p < 0.01). Interrater agreement was high (Cohen κ = 0.86). Reconstruction times for DL-VIBE were 3 s for k-space reconstruction and 1 s for superresolution processing. Simulated acquisition modifications reduced breath-hold duration by approximately 2 s. DL-VIBE enhances image quality during MR-guided thermal ablation while improving efficiency through reduced processing and acquisition times.

Interventional therapies for hepatocellular carcinoma (HCC) include various methods such as transarterial chemoembolization (TACE), radiofrequency and microwave ablation (RFA, MWA), selective internal radiotherapy (SIRT), and stereotactic body radiation therapy (SBRT). Imaging follow-up using magnetic resonance imaging (MRI) is essential for the early detection of recurrence, but requires profound knowledge of therapy-related imaging changes. A structured PubMed literature search covering the period from 2000 to 2025 was conducted using the keywords “hepatocellular carcinoma,” “magnetic resonance imaging,” “thermal ablation,” “transarterial chemoembolization,” “transarterial radioembolization,” “stereotactic body radiotherapy,” and “treatment response.” In addition, the study incorporated current national and international guidelines, as well as institutional clinical experience. Post-interventional imaging changes on MRI vary depending on the therapeutic approach applied. Typical morphological changes are observed immediately after thermoablation and TACE, whereas therapeutic effects of SIRT and SBRT become clearly evident only after weeks to months. Profound knowledge of standardized evaluation systems such as mRECIST, EASL, and LI-RADS-TR is crucial to ensure a precise and structured assessment of therapeutic response. Knowledge of specific MRI findings and standardized assessment systems is essential for structured follow-up of hepatocellular carcinoma after interventional therapy. Limitations arise from the heterogeneity of imaging findings, variable temporal patterns, and potential influences of combination therapies. Systemic therapies were not considered, restricting generalizability.

Background/Objectives: Hepatocyte-specific contrast agent (Gd-EOB-DTPA) can improve the detection of liver lesions during MRI-guided thermal ablation. This study aimed to assess the impact of contrast agent administration on the delineation of the ablation zone during therapy monitoring. Methods: From 2010 to 2020, 358 patients with primary and secondary hepatic malignancies underwent MRI-guided thermoablation. A total of 27 patients with 30 liver lesions received Gd-EOB-DTPA during the procedure to improve target lesion visibility (Group 1), while 30 patients with 30 lesions underwent MRI-guided thermoablation without contrast administration (Group 2). T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences were used for intraprocedural imaging, and post-procedural control imaging involved intravenous Gadobutrol administration in both groups. The contrast-to-noise ratio (CNR) was assessed for three key structures: the target lesion before applicator placement, the ablation zone during unenhanced therapy monitoring, and the ablation zone in contrast-enhanced control imaging. A statistical comparison of CNR values between the two groups was performed using the non-parametric Wilcoxon test (p < 0.05). Results: The CNR of lesions in group 1 significantly increased following the administration of Gd-EOB-DTPA. During therapy monitoring, the ablation zone in group 2 exhibited a significantly higher CNR compared to group 1 (median: 7.9 vs. 2.1; p < 0.001). Similarly, at the contrast-enhanced final control, the CNR of the ablation zone remained significantly greater in group 2 than in group 1 (median: 7.7 vs. 2.0; p < 0.001). Conclusions: The administration of a hepatocyte-specific contrast agent (Gd-EOB-DTPA) prior to intervention improves the visualization of liver lesions that are poorly demarcated but significantly reduces the contrast of the ablation zone during intra- and post-procedural imaging. Therefore, its use should be reserved for cases in which the target lesion cannot be sufficiently delineated without contrast.

PURPOSE:The management of soft tissue sarcoma (STS) at reference centers with specialized multidisciplinary tumor boards (MTB) improves patient survival. The German Cancer Society (DKG) certifies sarcoma centers in German-speaking countries, promoting high standards of care. This study investigated the variability in treatment recommendations for localized STS across different German-speaking tertiary sarcoma centers. METHODS:In this cross-sectional case-based survey study, 5 anonymized patient cases with imaging data of localized STS were presented to MTBs of 21 German-speaking tertiary referral hospitals. Centers provided recommendations on treatment sequence and modalities, along with the consensus level within their MTB. Agreement percentages were calculated, and consensus levels were rated on a scale of 1 to 10. RESULTS:Five patient cases were discussed resulting in 105 recommendations. Agreement percentages for case 1 to 5 were 14.3%, 61.9%, 33.3%, 52.4% and 9.3%, with a median agreement percentage of 33.3%. Grouping pre- and postoperative therapies as "perioperative" and including recommendations with and without regional hyperthermia raised the median agreement to 47.6%. The mean consensus level within each center across all 5 cases was 9.5. CONCLUSION:This first case-based analysis of inter-center agreement for STS management in German-speaking countries reveals low inter-center agreement but high intra-center consensus. Our study includes nearly all tertiary sarcoma centers in German-speaking countries, affirming its strong external validity. These findings suggest potential and clinically very relevant differences in treatment standards among sarcoma centers. Enhanced case-based exchanges and collaborative efforts are needed to reduce discrepancies and standardize the management of STS patients.

AIMS:Understanding determinants of thoracic aortic morphology is crucial for precise diagnostics and therapeutic approaches. This study aimed to automatically characterize ascending aortic morphology based on 3D non-contrast-enhanced magnetic resonance angiography (NC-MRA) data from the epidemiological cross-sectional German National Cohort (NAKO) and to investigate possible determinants of mid-ascending aortic diameter (mid-AAoD). METHODS AND RESULTS:Deep learning (DL) automatically segmented the thoracic aorta and ascending aortic length, volume, and diameter was extracted from 25 073 NC-MRAs. Statistical analyses investigated relationships between mid-AAoD and demographic factors, hypertension, diabetes, alcohol, and tobacco consumption. Males exhibited significantly larger mid-AAoD than females (M: 35.5 ± 4.8 mm, F: 33.3 ± 4.5 mm). Age and body surface area (BSA) were positively correlated with mid-AAoD (age: male: r²=0.20, P < 0.001, female: r²=0.16, P < 0.001; BSA: male: r²=0.08, P < 0.001, female: r²=0.05, P < 0.001). Hypertensive and diabetic subjects showed higher mid-AAoD (ΔHypertension=2.9±0.5 mm; ΔDiabetes=1.5±0.6 mm). Hypertension was linked to higher mid-AAoD regardless of age and BSA, while diabetes and mid-AAoD were uncorrelated across age-stratified subgroups. Daily alcohol consumption (male: 37.4 ± 5.1 mm, female: 35.0 ± 4.8 mm) and smoking history exceeding 16.5 pack-years (male: 36.6 ± 5.0 mm, female: 33.9 ± 4.3 mm) exhibited the highest mid-AAoD. Causal analysis (Peter-Clark algorithm) suggested that age, BSA, hypertension, and alcohol consumption are possibly causally related to mid-AAoD, while diabetes and smoking are likely spuriously correlated. CONCLUSION:This study demonstrates the potential of DL and causal analysis for understanding ascending aortic morphology. By disentangling observed correlations using causal analysis, this approach identifies possible causal determinants, such as age, BSA, hypertension, and alcohol consumption. These findings can inform targeted diagnostics and preventive strategies, supporting clinical decision-making for cardiovascular health.

CT-based fractional flow reserve (CT-FFR) is a promising noninvasive method for the functional assessment of coronary stenosis. It expands the diagnostic capabilities of coronary CT angiography (cCTA) by providing hemodynamic information and potentially reducing unnecessary invasive coronary angiography examinationsThis review summarizes current technological developments, study results, and clinical applications of CT-FFR. It also discusses the advantages and disadvantages of various software solutions, including artificial intelligence (AI)-based on-site analyses, and their potential integration into the clinical routine.Studies show that CT-FFR improves diagnostic accuracy compared to cCTA and can optimize patient management. Advances in artificial intelligence and new imaging techniques such as photon-counting CT could further refine CT-FFR and expand its applicability. Despite promising results, further research is needed regarding long-term validation, standardized workflows, and economic feasibility.CT-FFR is a promising complementary tool for assessing the hemodynamic relevance of coronary stenoses. CT-FFR is particularly helpful in complex, long-segment, or consecutive stenosis, because a purely anatomical visual examination is not always sufficient. The combination of technical innovations and AI-assisted image analysis could have the potential to transform noninvasive coronary diagnostics. · CT-FFR increases specificity and diagnostic accuracy compared to cCTA alone.. · Technological advances could further refine CT-FFR and expand its applicability.. · The increasing adoption and improved applicability of CT-FFR in routine clinical practice is promising.. · Kloth C, Brendel JM, Kübler J et al. CT-FFR: How a new technology could transform cardiovascular diagnostic imaging. Rofo 2025; DOI 10.1055/a-2697-5413.

Background: Pathologies of the thoracic aorta are associated with chronic cardiovascular disease and can be of life-threatening nature. Understanding determinants of thoracic aortic morphology is crucial for precise diagnostics and preventive and therapeutic approaches. This study aimed to automatically characterize ascending aortic morphology based on 3D non-contrast-enhanced magnetic resonance angiography (NE-MRA) data from the large epidemiological cross-sectional German National Cohort (NAKO) and to investigate possible determinants of mid-ascending aortic diameter (mid-AAoD). Methods: Deep learning was used to automatically segment the thoracic aorta and extract ascending aortic length, volume, and diameter from 25,073 NE-MRAs. Descriptive statistics, correlation analyses, and multivariable regression were used to investigate statistical relationships between mid-AAoD and demographic factors, hypertension, diabetes, alcohol, and tobacco consumption. Additionally, automated causal discovery analysis using the Peter-Clark algorithm was performed to identify possible causal interactions. Results: Males exhibited significantly larger mid-AAoD than females (M: 35.5±4.8 mm, F: 33.3±4.5 mm). Age and body surface area (BSA) were positively correlated with mid-AAoD. Hypertensive and diabetic subjects showed higher mid-AAoD. Hypertension was linked to higher mid-AAoD regardless of age and BSA, while diabetes and mid-AAoD were uncorrelated across age-stratified subgroups. Daily alcohol consumption and smoking history exceeding 16.5 pack-years exhibited highest mid-AAoD. Causal analysis revealed that age, BSA, hypertension, and alcohol consumption are possibly causally related to mid-AAoD, while diabetes and smoking are likely spuriously correlated. Conclusions: Mid-AAoD varies significantly within the unique large-scale NAKO population depending on demographic factors, individual health, and lifestyle. This work provides a proof-of-concept for automated causal analysis which can help disentangle observed correlations and identify potential causal determinants of ascending aortic morphology. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This project was conducted with data from the German National Cohort (NAKO) (www.nako.de). The NAKO is funded by the Federal Ministry of Education and Research (BMBF) [project funding reference numbers: 01ER1301A/B/C, 01ER1511D and 01ER1801A/B/C/D], federal states of Germany and the Helmholtz Association, the participating universities, and the institutes of the Leibniz Association. We thank all participants who took part in the German National Cohort and the staff in this research program. This project was partially funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) project number 428219130 and supported under Germany?s Excellence Strategy ? EXC 2064/1 ? project number 390727645. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The responsible ethics committees of individual studies approved all study-related analyses: GUIDE: 202/22 approved by the Ethics Committee of the Medical Faculty of the Rheinische Friedrich-Wilhelm-University Bonn ELISA: University of Luebeck (Az. 20-150) NAKO: The study is continuously approved by the responsible local ethics committees of the German Federal States where all study centers are located in (original ethics approvals of the leading ethics committee of the Bayerische Landesaerztekammer (protocol code 13023, Approval Date: 27 March 2013 and 14 February 2014 (rectification of documents, study protocol, consent form)). An external ethics advisory board has been established that accompanies NAKO over the full study period. A 'Code of Ethics' of NAKO (Ethikkodex) has been developed and the study is under steady surveillance by the ethics committees of the regional study centers (8). STAAB: Ethics committee of the Medical Faculty of the University Wuerzburg (STAAB: #98/13) MuSPAD: Ethics committee of Hannover Medical School (9086\_BO\_S\_2020 for MuSPAD), Dresden paedSAXCOVID: Ethics Committee of the Technische University (TU) Dresden (BO-EK-156042020). Bochum CorKID: Ethics Committee of the Ruhr University Bochum (Nr. 20-6927\_7) Wuerzburg Wue-KITa-CoV: Wuerzburg, Kennzeichen 105/21 IMMUNEBRIDGE_ED: Ethics Committee of University Medical Center Goettingen (21/6/22) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study are available from the German National Cohort but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available.

This study evaluates the diagnostic performance of artificial intelligence (AI)-based coronary computed tomography angiography (CCTA) for detecting coronary artery disease (CAD) and assessing fractional flow reserve (FFR) in asymptomatic male marathon runners. We prospectively recruited 100 asymptomatic male marathon runners over the age of 45 for CAD screening. CCTA was analyzed using AI models (CorEx and Spimed-AI) on a local server. The models focused on detecting significant CAD (≥ 50

PURPOSE:The purpose of this study was to evaluate the diagnostic performance of automated deep learning in the detection of coronary artery disease (CAD) on photon-counting coronary CT angiography (PC-CCTA). MATERIALS AND METHODS:Consecutive patients with suspected CAD who underwent PC-CCTA between January 2022 and December 2023 were included in this retrospective, single-center study. Non-ultra-high resolution (UHR) PC-CCTA images were analyzed by artificial intelligence using two deep learning models (CorEx, Spimed-AI), and compared to human expert reader assessment using UHR PC-CCTA images. Diagnostic performance for global CAD assessment (at least one significant stenosis ≥ 50 %) was estimated at patient and vessel levels. RESULTS:A total of 140 patients (96 men, 44 women) with a median age of 60 years (first quartile, 51; third quartile, 68) were evaluated. Significant CAD on UHR PC-CCTA was present in 36/140 patients (25.7 %). The sensitivity, specificity, accuracy, positive predictive value), and negative predictive value of deep learning-based CAD were 97.2 %, 81.7 %, 85.7 %, 64.8 %, and 98.9 %, respectively, at the patient level and 96.6 %, 86.7 %, 88.1 %, 53.8 %, and 99.4 %, respectively, at the vessel level. The area under the receiver operating characteristic curve was 0.90 (95 % CI: 0.83-0.94) at the patient level and 0.92 (95 % CI: 0.89-0.94) at the vessel level. CONCLUSION:Automated deep learning shows remarkable performance for the diagnosis of significant CAD on non-UHR PC-CCTA images. AI pre-reading may be of supportive value to the human reader in daily clinical practice to target and validate coronary artery stenosis using UHR PC-CCTA.

This study investigated the efficacy of single-phase dual-energy CT (DECT) in differentiating pulmonary hamartomas from malignant lung lesions using virtual non-contrast (VNC), iodine, and fat quantification. Forty-six patients with 47 pulmonary lesions (mean age: 65.2 ± 12.1 years; hamartomas-to-malignant lesions = 22:25; male: 67%) underwent portal venous DECT using histology, PET-CT and follow-up CTs as a reference. Quantitative parameters such as VNC, fat fraction, iodine density and CT mixed values were statistically analyzed. Significant differences were found in fat fractions (hamartomas: 48.9%; malignancies: 22.9%; p ≤ 0.0001) and VNC HU values (hamartomas: −20.5 HU; malignancies: 17.8 HU; p ≤ 0.0001), with hamartomas having higher fat content and lower VNC HU values than malignancies. CT mixed values also differed significantly (p ≤ 0.0001), but iodine density showed no significant differences. ROC analysis favored the fat fraction (AUC = 96.4%; sensitivity: 100%) over the VNC, CT mixed value and iodine density for differentiation. The study concludes that the DECT-based fat fraction is superior to the single-energy CT in differentiating between incidental pulmonary hamartomas and malignant lesions, while post-contrast iodine density is ineffective for differentiation.

Magnetic resonance (MR) image guidance has demonstrated significant potential in the field of interventional radiology in several applications. This article covers the main points of MR -guided hepatic tumor ablation as a representative of MR-guided procedures. Patient selection and appropriate equipment utilization are essential for successful MR-guided tumor ablation. Intra-procedural planning imaging enables the visualization of the tumor and surrounding ana-tomical structures in most cases without the application of a contrast agent, ensuring optimal planning of the applicator tract. MRI enables real-time, multiplanar imaging, thus simultaneous observation of the applicator and target tumor is possible during targeting with adaptable slice angulations in case of challenging tumor positions. Typical ablation zone appearance during therapy monitoring with MRI enables safe assessment of the therapy result, resulting in a high primary efficacy rate. Recent advancements in ablation probes have shortened treatment times, while technical strategies address applicator visibility issues. MR-imaging immediately after the procedure is used to rule out complications and to assess technical success. Especially in smaller neoplasms, MRI-guided liver ablation demonstrates positive outcomes in terms of tech-nical success rates, as well as promising survival and recurrence rates. Additionally, percuta-neous biopsy under MR guidance offers an alternative to classic guidance modalities, providing high soft tissue contrast and thereby increasing the reliability of lesion detection, par-ticularly in cases involving smaller lesions. Despite these advantages, the use of MR guidance in clinical routine is still limited to few indications and centers, due to by high costs, extended duration, and the need for specialized expertise. In conclusion, MRI-guided interventions could benefit from ongoing advancements in hardware, software, and devices. Such progress has the potential to expand diagnostic and treatment options in the field of interventional radiology. Tech Vasc Interventional Rad 26:100914 (c) 2023 Elsevier Inc. All rights reserved.

ABSTRACT The aim was to investigate side-to-side and sex differences of anterior and inferior capsule thickness (ACT, ICT) between the throwing and non-throwing shoulder (TS, NTS) in youth elite handball players. 125 youth female and male elite handball players (14.1±0.7yo) were assessed for ACT and ICT by ultrasound . ACT measurement was performed from anterior (3 o’clock) in upright position and for ICT from inferior (6 o’clock) in supine position. Measurements of ICT in the TS of all athletes (1.4±0.2 mm) differed significantly but marginally to those in the NTS (1.3±0.2 mm) (p = 0.001). Female (1.2±0.2 mm vs. 1.3±0.2 mm; p = 0.007) but not male youth players (1.4±0.2 mm vs. 1.4±0.2 mm, p = n.s.) demonstrated slight differences in ICT in the TS compared with the NTS. Although significant, the thickness in the TS compared to the NTS was within the measurement accuracy of the ultrasonic assessment. No difference in ACT was observed in the TS (1.4±0.3 mm) compared to the NTS (1.4±0.3 mm) for both sexes (n.s.). In conclusion, the anterior and inferior capsule thickness in youth elite handball athletes is not or only marginally different between throwing and non-throwing shoulders.

Purpose To investigate reduction of radiation exposure in unenhanced CT in suspicion of renal calculi using a tin-filtered high tube voltage protocol compared to a standard low-dose protocol without spectral shaping. Materials and Methods A phantom study using 7 human renal calculi was performed to test both protocols. 120 consecutive unenhanced CT examinations performed due to suspicion of renal calculi were included in this retrospective, monocentric study. 60 examinations were included with the standard-dose protocol (SP) (100kV/130mAs), whereas another 60 studies were included using a low-dose protocol (LD) applying spectral shaping with tin filtration of high tube voltages (Sn150kV/80mAs). Image quality was assessed by two radiologists in consensus blinded to technical parameters using an equidistant Likert scale ranging from 1 – 5 with 5 being the highest score. Quantitative image quality was assessed using regions of interest in abdominal organs, muscles, and adipose tissue to analyze image noise and signal-to-noise ratios (SNR). Commercially available dosimetry software was used to determine and compare effective dose (ED) and size-specific dose estimates (SSDEmean). Results All seven renal calculi of the phantom could be detected with both protocols. There was no difference regarding calcluli size between the two protocols except for the smallest one. The smallest concretion measured 1.5 mm in LD and 1.0 mm in SP (ground CTDIvol was Unterschied zwischen der Erkennbarkeit und den Größenmessungen zwischen beiden Protokollen, außer beim kleinsten Konkrement. Die Erkennbarkeit des kleinsten Konkrements wurde bei der Niedrigdosis-Bildgebung als gut und bei der Standarddosis-Bildgebung als ausreichend bewertet.

The purpose of this study was to evaluate the potential of dual-energy CT (DECT) with virtual unenhanced imaging (VNC) and iodine maps (IM) to differentiate between intraperitoneal hematomas (IH) and bowel structures (BS) compared to linearly blended DECT (DE-LB) images (equivalent to single-energy CT). This retrospective study included the DECT of 30 patients (mean age: 64.5 ± 15.1 years, 19 men) with intraperitoneal hematomas and 30 negative controls. VNC, IM, and DE-LB were calculated. Imaging follow-up and surgical reports were used as references. Three readers assessed diagnostic performance and confidence in distinguishing IH and BS for DE-LB, VNC, and IM. Diagnostic confidence was assessed on a five-point Likert scale. The mean values of VNC, IM, and DE-LB were compared with nonparametric tests. Diagnostic accuracy was assessed by calculating receiver operating characteristics (ROC). The results are reported as medians with interquartile ranges. Subjective image analysis showed higher diagnostic performance (sensitivity: 96.7–100% vs. 88.2–96.7%; specificity: 100% vs. 96.7–100%; p < 0.0001; ICC: 0.96–0.99) and confidence (Likert: 5; IRQ [5–5] vs. 4, IRQ [3–4; 4–5]; p < 0.0001; ICC: 0.80–0.96) for DECT compared to DE-LB. On objective image analysis, IM values for DECT showed significant differences between IH (3.9 HU; IQR [1.6, 8.0]) and BS (39.5 HU; IQR [29.2, 43.3]; p ≤ 0.0001). VNC analysis revealed a significantly higher attenuation of hematomas (50.5 HU; IQR [44.4, 59.4]) than BS (26.6 HU; IQR [22.8, 32.4]; p ≤ 0.0001). DE-LB revealed no significant differences between hematomas (60.5 HU, IQR [52.7, 63.9]) and BS (63.9 HU, IQR [58.0, 68.8]; p > 0.05). ROC analysis revealed the highest AUC values and sensitivity for IM (AUC = 100%; threshold by Youden-Index ≤ 19 HU) and VNC (0.93; ≥34.1 HU) compared to DE-LB (0.64; ≤63.8; p < 0.001). DECT is suitable for accurate discrimination between IH and BS by calculating iodine maps and VNC images.

Background Radiofrequency ablation (RFA) is a minimal-invasive, local therapy in patients with circumscribed metastatic disease. Although widely used, long time survival analysis of treated liver metastases is still pending while also analysing the patients’ experience of MR-based radiofrequency. Methods Monocentric, retrospective analysis of long-time overall and progression free survival (OS; PFS) of 109 patients, treated with MRI-guided hepatic RFA between 1997 and 2010, focusing on colorectal cancer patients (CRC). Complimentary therapies were evaluated and Kaplan Meier-curves were calculated. Patients’ experience of RFA was retrospectively assessed in 28 patients. Results 1-, 3-, 5-, 10-year OS rates of 109 patients with different tumour entities were 83.4%, 53.4%, 31.0% and 22.9%, median 39.2 months, with decreasing survival rates for larger metastases size. For 72 CRC patients 1-, 3-, 5-, 10-year OS rates of 90.2%, 57.1%, 36.1% and 26.5% were documented (median 39.5 months). Thereof, beneficial outcome was detected for patients with prior surgery of the CRC including chemotherapy (median 53.0 months), and for liver metastases up to 19 mm (28.5% after 145 months). Hepatic PFS was significantly higher in patients with liver lesions up to 29 mm compared to larger ones ( p = 0.035). 15/28 patients remembered RFA less incriminatory than other applied therapies. Conclusions This is the first single-centre, long-time OS and PFS analysis of MRI-guided hepatic RFA of liver metastases from different tumour entities, serving as basis for further comparison studies. Patients’ experience of MR based RFA should be analysed simultaneously to the performed RFA in the future.

Purpose Evaluation of machine learning-based fully automated artery-specific coronary artery calcium (CAC) scoring software, using semi-automated software as a reference. Methods A total of 505 patients underwent non-contrast-enhanced calcium scoring computed tomography (CSCT). Automated, machine learning-based software quantified the Agatston score (AS), volume score (VS), and mass score (MS) of each coronary artery [right coronary artery (RCA), left main (LM), circumflex (CX) and left anterior descending (LAD)]. Identified CAC of readers who annotated the data with semi-automated software served as a reference standard. Statistics included comparisons of evaluation time, agreement of identified CAC, and comparisons of the AS, VS, and MS of the reference standard and the fully automated algorithm. Results The machine learning-based software correlated strongly with the reference standard for the AS, VS, and MS (Spearmanʼs rho > 0.969) (p < 0.001), with excellent agreement (ICC > 0.919) (p < 0.001). The mean assessment time of the reference standard was 59 seconds (IQR 39–140) and that of the automated algorithm was 5.9 seconds (IQR 3.9–16) (p < 0.001). The Bland-Altman plots mean difference and 1.96 upper and lower limits of agreement for all arteries combined were: AS 0.996 (1.33 to 0.74), VS 0.995 (1.40 to 0.71), and MS 0.995 (1.35 to 0.74). The mean bias was minimal: 0.964–1.0429. Risk class assignment showed high accuracy for the AS in total (weighed κ = 0.99) and for each individual artery (κ = 0.96–0.99) with corresponding correct risk group assignment in 497 of 505 patients (98.4 %). Conclusion The fully automated artery-specific coronary calcium scoring algorithm is a time-saving procedure and shows excellent correlation and agreement compared with the clinically established semi-automated approach. Key points: Citation Format

PURPOSE Differentiation of incidental adrenal lesions remains a challenge in diagnostic imaging, especially on single-phase portal venous computed tomography (CT) in the oncological setting. The aim of the study was to explore the ability of dual-energy CT (DECT)-based iodine quantification and virtual non-contrast (VNC) imaging and advanced radiomic analysis of DECT for differentiation of adrenal adenomas from metastases. METHODS A total of 46 patients with 49 adrenal lesions underwent clinically indicated staging DECT and magnetic resonance imaging. Median values of quantitative parameters such as VNC, fat frac- tion, and iodine density in DECT images were collected and compared between adenomas and metastases using non-parametric tests. Magnetic resonance imaging, washout CT, and clinical follow-up were used as a reference standard. Diagnostic accuracy was assessed by calculat- ing receiver operating characteristics. A DECT tumor analysis prototype software was used for semiautomatic segmentation of adrenal lesions and extraction of radiomic features. A radiomics prototype was used to analyze the data with multiple logistic regression and random forest clas- sification to determine the area under the curve (AUC). RESULTS The study cohort (60.87% women; mean age: 66.91 ± 12.93 years) consisted of 32 adenomas and 17 metastases. DECT-based VNC imaging (AUC=0.89) and fat quantification (AUC=0.86) differentiate between adrenal adenomas and metastases with high diagnostic accuracy (P < .001). Analysis of radiomic features revealed that DECT features such as VNC imaging and fat fraction (AUC = 0.87-0.89; < .001) and radiomic features such as 90th percentile and total energy (AUC = 0.88-0.93; P < .001) differentiate with high diagnostic accuracy between adrenal adeno- mas and metastases. Random forest classification revealed an AUC of 0.83 for separating adrenal adenomas from metastases. CONCLUSION Virtual non-contrast imaging and fat quantification as well as extraction of radiomic features accurately differentiate between adrenal adenomas and metastases on single-phase oncologic staging DECT.

Purpose To investigate reduction of radiation exposure in unenhanced CT in suspicion of renal calculi using a tin-filtered high tube voltage protocol compared to a standard low-dose protocol without spectral shaping. Materials and Methods A phantom study using 7 human renal calculi was performed to test both protocols. 120 consecutive unenhanced CT examinations performed due to suspicion of renal calculi were included in this retrospective, monocentric study. 60 examinations were included with the standard-dose protocol (SP) (100 kV/130 mAs), whereas another 60 studies were included using a low-dose protocol (LD) applying spectral shaping with tin filtration of high tube voltages (Sn150 kV/80 mAs). Image quality was assessed by two radiologists in consensus blinded to technical parameters using an equidistant Likert scale ranging from 1–5 with 5 being the highest score. Quantitative image quality was assessed using regions of interest in abdominal organs, muscles, and adipose tissue to analyze image noise and signal-to-noise ratios (SNR). Commercially available dosimetry software was used to determine and compare effective dose (ED) and size-specific dose estimates (SSDEmean). Results All seven renal calculi of the phantom could be detected with both protocols. There was no difference regarding calcluli size between the two protocols except for the smallest one. The smallest concretion measured 1.5 mm in LD and 1.0 mm in SP (ground truth 1.5 mm). CTDIvol was 3.36 mGy in LD (DLP: 119.3 mGycm) and 8.27 mGy in SP (DLP: 293.6 mGycm). The mean patient age in SP was 47 ± 17 years and in LD 49 ± 13 years. Ureterolithiasis was found in 33 cases in SP and 32 cases in LD. The median concretion size was 3 mm in SP and 4 mm in LD. The median ED in LD was 1.3 mSv (interquartile range (IQR) 0.3 mSv) compared to 2.3 mSv (IQR 0.9 mSv) in SP (p < 0.001). The SSDEmean of LD was also significantly lower compared to SP with 2.4 mGy (IQR 0.4 mGy) vs. 4.8 mGy (IQR 2.3 mGy) (p < 0.001). The SNR was significantly lower in LD compared to SP (p < 0.001). However, there was no significant difference between SP and LD regarding the qualitative assessment of image quality with a median of 4 (IQR 1) for both groups (p = 0.648). Conclusion Tin-filtered unenhanced abdominal CT for the detection of renal calculi using high tube voltages leads to a significant reduction of radiation exposure and yields high diagnostic image quality without a significant difference compared to the institution’s standard of care low-dose protocol without tin filtration. Key Points: Citation Format

Subjective and objective image quality comparison of bone microstructure and disease-related abnormalities in multiple myeloma patients using a 1st-generation dual-source photon-counting detector CT(DS-PCD-CT) and a 2nd-generation dual-source dual-energy (energy-integrating detector) CT (DS-EID-CT). Fifty multiple myeloma patients (mean age 67.7 ± 10.9 years,16 females) were prospectively enrolled. Unenhanced whole-body CTs were clinically indicated and performed on DS-EID-CT and DS-PCD-CT (median time difference: 12 months). DS-PCD-CT was performed in Quantumplus UHR mode and DS-EID-CT was performed using dual-energy mode. DS-PCD-CT kernel was set at Br64 with Quantum iterative reconstruction strength Q1; for DS-EID-CT a comparable I70f kernel with SAFIRE iterative reconstruction strength 1 was used. Two independent radiologists assessed image quality subjectively using a 5-point Likert scale considering delineation and sharpness of trabecular bone and lytic bone lesions in the spine and pelvic bones. Additionally, ImageJ was used for quantification of bony septa inside the cancellous bone and through or the edges of osteolysis. Overall quality as well as detectability and sharpness in the delineation of lytic bone lesions were superior for DS-PCD-CT compared with DS-EID-CT (p < 0.0001). The inter-reader agreement for subjective image quality readings showed excellent consistency(α = 94.2–98.8). CTDI and DLP mean values for DS-PCD-CT and DS-EID-CT were 1107.4 ± 247.6 mGy*cm and 8.2 ± 1.8 mGy vs. 1344.3 ± 204.6 mGy*cm and 10.1 ± 1.9 mGy. The quantitative metric for bone microstructure in the femoral head showed significantly better visualization of trabeculae in DS-PCD-CT compared with DS-EID-CT (p < 0.0001). Quantitative analyses of edge sharpness of osteolysis showed significant steeper edges for DS-PCD-CT (p < 0.0001). DS-PCD-CT significantly improves spatial resolution of bony microstructure and lytic bone lesions compared to DS-EID-CT. • Application of photon-counting detector CT is superior to dual-source dual-energy integrating detector in clinical workup of multiple myeloma patients. • Compared to energy integrating detectors, photon-counting detectors significantly increase the spatial resolution of bone microstructure including disease-related lytic bone lesions in patients with multiple myeloma.