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Objectives: To compare 0.15 mmol/kg gadobutrol for late gadolinium enhancement (LGE) imaging of chronic myocardial infarction with a relaxivity-adjusted dose of gadoterate meglumine (Gd-DOTA).Methods: Seventeen patients with suspected chronic myocardial infarction underwent LGE imaging at 1.5 T, acquiring an inversion-recovery-prepared gradient echo sequence 15 min after contrast agent administration. Each patient underwent LGE imaging twice, once after administration of 0.15 mmol/kg gadobutrol (r1 = 5.2 l mmol(-1) s(-1)) and after 0.22 mmol/kg Gd-DOTA (r1 = 3.6 l mmol(-1) s(-1)). Two readers independently determined infarct size and contrast-to-noise ratios of infarcted myocardium to remote myocardium (CNR(remote)) and to the left ventricular lumen (CNR(lumen)).Results: LGE was present in 14 patients. Infarct sizes determined after administration of gadobutrol [23.4 ml; 95 % CI (14.4; 32.5)] and Gd-DOTA [22.1 ml; 95 % CI (13.0; 31.1)] were not statistically different (P = 0.22). The CNR(remote) of LGE in infarcted myocardium on gadobutrol- and Gd-DOTA-enhanced images was 44.1 [95 % CI (31.0; 57.1)] and 45.2 [95 % CI (32.2; 58.3)], respectively (P = 0.73). CNR(lumen) was significantly higher on gadobutrol-enhanced LGE images [12.7; 95 % CI (2.5; 23.0) versus 6.8; 95 % CI (-3.5; 17.0); P = 0.02].Conclusion: At relaxivity-adjusted doses, gadobutrol and Gd-DOTA yielded similar infarct sizes with superior contrast between infarcted myocardium and left ventricular lumen on gadobutrol-enhanced images. [ABSTRACT FROM AUTHOR]

Objectives: To assess the value of the viscoelastic parameters in the characterisation of liver tumours at MR elastography.Patients and Methods: Ninety-four patients with liver tumours >1 cm prospectively underwent MR elastography using 50-Hz mechanical waves and a full three-directional motion-sensitive sequence. The model-free viscoelastic parameters (the complex shear modulus and its real and imaginary parts, i.e. the storage and loss moduli) were calculated in 72 lesions after exclusion of cystic, treated or histopathologically undetermined tumours.Results: We observed higher absolute shear modulus and loss modulus in malignant versus benign tumours (3.38 ± 0.26 versus 2.41 ± 0.15 kPa, P < 0.01 and 2.25 ± 0.26 versus 1.05 ± 0.13 kPa, P < 0.001, respectively). Moreover, the loss modulus of hepatocellular carcinomas was significantly higher than in benign hepatocellular tumours. The storage modulus did not differ significantly between malignant and benign tumours. The area under the receiver-operating characteristic curve of loss modulus was significantly larger than that of the absolute shear modulus and storage modulus when comparing malignant and benign lesions.Conclusions: The increased loss modulus is a better discriminator between benign and malignant tumours than the increased storage modulus or absolute value of the shear modulus.Key Points: • Magnetic Resonance elastography is a new method of assessing the liver. • Increased loss modulus is an indicator of malignancy in hepatic tumours. • Loss modulus is a better discriminator than absolute shear modulus values. • The viscoelastic properties of lesions offer promise for characterising liver tumours. [ABSTRACT FROM AUTHOR]

Objective: To assess active myocardial inflammation by cardiovascular magnetic resonance (CMR) and endomyocardial biopsy (EMB) amongst adult patients with dilated cardiomyopathy (DCM).Methods: We evaluated 23 adults with chronic DCM, who had successfully undergone both CMR and EMB within 3.5 ± 2.6 days. EMB was considered the gold standard. CMR assessment of myocardial inflammation used the following parameters as recommended by the recently published "Lake Louise Criteria": global myocardial oedema, global relative enhancement (RE), and late gadolinium enhancement (LGE). According to "Lake Louise Criteria", myocardial inflammation was diagnosed if two or more of the three above-mentioned parameters were positive.Results: Myocardial inflammation was confirmed by immunohistology in 12 patients (52.2%). Sensitivity, specificity, and diagnostic accuracy of CMR to detect immunohistologically confirmed myocardial inflammation were 75.0%, 72.7%, and 73.9%, respectively. Sensitivity, specificity, and diagnostic accuracy of the individual CMR parameters to detect myocardial inflammation were as follows: global myocardial oedema, 91.7%, 81.8%, and 87.0%, respectively; global RE, 58.3%, 63.6%, and 60.9%, respectively; LGE, 58.3%, 45.4%, and 52.2%, respectively.Conclusion: Global myocardial oedema was identified as a promising CMR parameter for assessment of myocardial inflammation in patients with DCM. In these patients, global myocardial oedema yielded superior diagnostic performance compared to "Lake Louise Criteria". [ABSTRACT FROM AUTHOR]

Rationale and Objectives: Automated evaluation of abdominal computed tomography (CT) scans should help radiologists manage their massive workloads, thereby leading to earlier diagnoses and better patient outcomes. Our objective was to develop a machine-learning model capable of reliably identifying suspected bowel obstruction (BO) on abdominal CT., Materials and Methods: The internal dataset comprised 1345 abdominal CTs obtained in 2015-2022 from 1273 patients with suspected BO; among them, 670 were annotated as BO yes/no by an experienced abdominal radiologist. The external dataset consisted of 88 radiologist-annotated CTs. We developed a full preprocessing pipeline for abdominal CT comprising a model to locate the abdominal-pelvic region and another model to crop the 3D scan around the body. We built, trained, and tested several neural-network architectures for the binary classification (BO, yes/no) of each CT. F1 and balanced accuracy scores were computed to assess model performance., Results: The mixed convolutional network pretrained on a Kinetics 400 dataset achieved the best results: with the internal dataset, the F1 score was 0.92, balanced accuracy 0.86, and sensitivity 0.93; with the external dataset, the corresponding values were 0.89, 0.89, and 0.89. When calibrated on sensitivity, this model produced 1.00 sensitivity, 0.84 specificity, and an F1 score of 0.88 with the internal dataset; corresponding values were 0.98, 0.76, and 0.87 with the external dataset., Conclusion: The 3D mixed convolutional neural network developed here shows great potential for the automated binary classification (BO yes/no) of abdominal CT scans from patients with suspected BO., Clinical Relevance Statement: The 3D mixed CNN automates bowel obstruction classification, potentially automating patient selection and CT prioritization, leading to an enhanced radiologist workflow., Key Points: • Bowel obstruction's rising incidence strains radiologists. AI can aid urgent CT readings. • Employed 1345 CT scans, neural networks for bowel obstruction detection, achieving high accuracy and sensitivity on external testing. • 3D mixed CNN automates CT reading prioritization effectively and speeds up bowel obstruction diagnosis., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To identify preoperative degenerative features on traction MR arthrography associated with failure after arthroscopic femoroacetabular impingement (FAI) surgery., Methods: Retrospective study including 102 patients (107 hips) undergoing traction magnetic resonance arthrography (MRA) of the hip at 1.5 T and subsequent hip arthroscopic FAI surgery performed (01/2016 to 02/2020) with complete follow-up. Clinical outcomes were assessed using the International Hip Outcome Tool (iHOT-12) score. Clinical endpoint for failure was defined as an iHOT-12 of < 60 points or conversion to total hip arthroplasty. MR images were assessed by two radiologists for presence of 9 degenerative lesions including osseous, chondrolabral/ligamentum teres lesions. Uni- and multivariate Cox regression analysis was performed to assess the association between MRI findings and failure of FAI surgery., Results: Of the 107 hips, 27 hips (25%) met at least one endpoint at a mean 3.7 ± 0.9 years follow-up. Osteophytic changes of femur or acetabulum (hazard ratio [HR] 2.5-5.0), acetabular cysts (HR 3.4) and extensive cartilage (HR 5.1) and labral damage (HR 5.5) > 2 h on the clockface were univariate risk factors (all p < 0.05) for failure. Three risk factors for failure were identified in multivariate analysis: Acetabular cartilage damage > 2 h on the clockface (HR 3.2, p = 0.01), central femoral osteophyte (HR 3.1, p = 0.02), and femoral cartilage damage with ligamentum teres damage (HR 3.0, p = 0.04)., Conclusion: Joint damage detected by preoperative traction MRA is associated with failure 4 years following arthroscopic FAI surgery and yields promise in preoperative risk stratification., Clinical Relevance Statement: Evaluation of negative predictors on preoperative traction MR arthrography holds the potential to improve risk stratification based on the already present joint degeneration ahead of FAI surgery., Key Points: • Osteophytes, acetabular cysts, and extensive chondrolabral damage are risk factors for failure of FAI surgery. • Extensive acetabular cartilage damage, central femoral osteophytes, and combined femoral cartilage and ligamentum teres damage represent independent negative predictors. • Survival rates following hip arthroscopy progressively decrease with increasing prevalence of these three degenerative findings., (© 2023. The Author(s).)

Objective: To compare image quality and diagnostic performance of preoperative direct hip magnetic resonance arthrography (MRA) performed with gadolinium contrast agent and saline solution., Methods: IRB-approved retrospective study of 140 age and sex-matched symptomatic patients with femoroacetabular impingement, who either underwent intra-articular injection of 15-20 mL gadopentetate dimeglumine (GBCA), 2.0 mmol/L ("GBCA-MRA" group, n = 70), or 0.9% saline solution ("Saline-MRA" group, n = 70) for preoperative hip MRA and subsequent hip arthroscopy. 1.5 T hip MRA was performed including leg traction. Two readers assessed image quality using a 5-point Likert scale (1-5, excellent-poor), labrum and femoroacetabular cartilage lesions. Arthroscopic diagnosis was used to calculate diagnostic accuracy which was compared between groups with Fisher's exact tests. Image quality was compared with the Mann-Whitney U tests., Results: Mean age was 33 years ± 9, 21% female patients. Image quality was excellent (GBCA-MRA mean range, 1.1-1.3 vs 1.1-1.2 points for Saline-MRA) and not different between groups (all p > 0.05) except for image contrast which was lower for Saline-MRA group (GBCA-MRA 1.1 ± 0.4 vs Saline-MRA 1.8 ± 0.5; p < 0.001). Accuracy was high for both groups for reader 1/reader 2 for labrum (GBCA-MRA 94%/ 96% versus Saline-MRA 96%/93%; p > 0.999/p = 0.904) and acetabular (GBCA-MRA 86%/ 83% versus Saline-MRA 89%/87%; p = 0.902/p = 0.901) and femoral cartilage lesions (GBCA-MRA 97%/ 99% versus Saline-MRA 97%/97%; both p > 0.999)., Conclusion: Diagnostic accuracy and image quality of Saline-MRA and GBCA-MRA is high in assessing chondrolabral lesions underlining the potential role of non-gadolinium-based hip MRA., Key Points: • Image quality of Saline-MRA and GBCA-MRA was excellent for labrum, acetabular and femoral cartilage, ligamentum teres, and the capsule (all p > 0.18). • The overall image contrast was lower for Saline-MRA (Saline-MRA 1.8 ± 0.5 vs. GBCA-MRA 1.1 ± 0.4; p < 0.001). • Diagnostic accuracy was high for Saline-MRA and GBCA-MRA for labrum (96% vs. 94%; p > 0.999), acetabular cartilage damage (89% vs. 86%; p = 0.902), femoral cartilage damage (97% vs. 97%; p > 0.999), and extensive cartilage damage (97% vs. 93%; p = 0.904)., (© 2023. The Author(s).)

Purpose: To determine the impact of the COVID-19 on the CT activities in French radiological centers during the epidemic peak., Materials and Methods: A cross-sectional prospective CT scan survey was conducted between March 16 and April 12, 2020, in accordance with the local IRB. Seven hundred nine radiology centers were invited to participate in a weekly online survey. Numbers of CT examinations related to COVID-19 including at least chest (CT covid ) and whole chest CT scan activities (CT chest ) were recorded each week. A sub-analysis on French departments was performed during the 4 weeks of the study. The impact of the number of RT-PCRs (reverse transcriptase polymerase chain reactions) on the CT workflow was tested using two-sample t test and Pearson's test., Results: Five hundred seventy-seven structures finally registered (78%) with mean response numbers of 336 ± 18.9 (323; 351). Mean CT chest activity per radiologic structure ranged from 75.8 ± 133 (0-1444) on week 12 to 99.3 ± 138.6 (0-1147) on week 13. Mean ratio of CT covid on CT chest varied from 0.36 to 0.59 on week 12 and week 14 respectively. There was a significant relationship between the number of RT-PCR performed and the number of CT covid (r = 0.73, p = 3.10 -16 ) but no link with the number of positive RT-PCR results., Conclusion: In case of local high density COVID-19, CT workflow is strongly modified and redirected to the management of these specific patients., Key Points: • Over the 4-week survey period, 117,686 chest CT (CT total ) were performed among the responding centers, including 61,784 (52%) CT performed for COVID-19 (CT covid ). • Across the country, the ratio CT covid /CT total varied from 0.36 to 0.59 and depended significantly on the local epidemic density (p = 0.003). • In clinical practice, in a context of growing epidemic, in France, chest CT was used as a surrogate to RT-PCR for patient triage.

Objectives: We aimed to assess cortical damage in patients with relapsing-remitting multiple sclerosis (RRMS)/clinically isolated syndrome (CIS) with a multiparametric, surface-based quantitative MRI (qMRI) approach and to evaluate the correlation of imaging-derived parameters with cognitive scores, hypothesizing that qMRI parameters are correlated with cognitive abilities., Methods: Multiparametric qMRI-data (T1, T2 and T2* relaxation times and proton density (PD)) were obtained from 34 patients/24 matched healthy control subjects. Cortical qMRI values were analyzed on the reconstructed cortical surface with Freesurfer. We tested for group differences of cortical microstructural parameters between the healthy and patient collectives and for partial Pearson correlations of qMRI parameters with cognitive scores, correcting for age., Results: Cortical T2-/T2*-/PD values and four cognitive parameters differed between groups (p ≤ 0.046). These cognitive scores, reflecting information processing speed, verbal memory, visuospatial abilities, and attention, were correlated with cortical T2 (p ≤ 0.02) and T2* (p ≤ 0.03). Cortical changes appeared heterogeneous across the cortex and their distribution differed between the parameters. Vertex-wise correlation of T2 with neuropsychological parameters revealed specific patterns of cortical damage being related to distinct cognitive deficits., Conclusions: Microstructural changes are distributed heterogeneously across the cortex in RRMS/CIS. QMRI has the potential to provide surrogate parameters for the assessment of cognitive impairment in these patients for clinical studies. The characteristics of cognitive impairment in RRMS might depend on the distribution of cortical changes., Key Points: • The goal of the presented study was to investigate cortical changes in RRMS/CIS and their relation to the cognitive status, using multiparametric quantitative MRI. • Cortical T2, T2*, and PD increases observed in patients appeared heterogeneous across the cortex and their distribution differed between the parameters. • Vertex-wise correlation of T2 with neuropsychological scores revealed specific patterns of cortical changes being related to distinct cognitive deficits.

Objectives: To assess the potential of T1 mapping-based extracellular volume fraction (ECV) for the identification of higher grade clear cell renal cell carcinoma (cRCC), based on histopathology as the reference standard., Methods: For this single-center, institutional review board-approved prospective study, 27 patients (17 men, median age 62 ± 12.4 years) with pathologic diagnosis of cRCC (nucleolar International Society of Urological Pathology (ISUP) grading) received abdominal MRI scans at 1.5 T using a modified Look-Locker inversion recovery (MOLLI) sequence between January 2017 and June 2018. Quantitative T1 values were measured at different time points (pre- and postcontrast agent administration) and quantification of the ECV was performed on MRI and histological sections (H&E staining)., Results: Reduction in T1 value after contrast agent administration and MR-derived ECV were reliable predictors for differentiating higher from lower grade cRCC. Postcontrast T1 diff values (T1 diff  = T1 difference between the native and nephrogenic phase) and MR-derived ECV were significantly higher for higher grade cRCC (ISUP grades 3-4) compared with lower grade cRCC (ISUP grades 1-2) (p < 0.001). A cutoff value of 700 ms could distinguish higher grade from lower grade tumors with 100% (95% CI 0.69-1.00) sensitivity and 82% (95% CI 0.57-0.96) specificity. There was a positive and strong correlation between MR-derived ECV and histological ECV (p < 0.01, r = 0.88). Interobserver agreement for quantitative longitudinal relaxation times in the T1 maps was excellent., Conclusions: T1 mapping with ECV measurement could represent a novel in vivo biomarker for the classification of cRCC regarding their nucleolar grade, providing incremental diagnostic value as a quantitative MR marker., Key Points: • Reduction in MRI T1 relaxation times after contrast agent administration and MR-derived extracellular volume fraction are useful parameters for grading of clear cell renal cell carcinoma (cRCC). • T1 differences between the native and the nephrogenic phase are higher for higher grade cRCC compared with lower grade cRCC and MRI-derived extracellular volume fraction (ECV) and histological ECV show a strong correlation. • T1 mapping with ECV measurement may be helpful for the noninvasive assessment of cRCC pathology, being a safe and feasible method, and it has potential to optimize individualized treatment options, e.g., in the decision of active surveillance.

Objective: To compare computed high b-value diffusion-weighted images (c-DWI) derived from low b-value DWI images and acquired high b-value DWI (a-DWI), in overall image quality and prostate cancer detection rate., Materials and Methods: A total of 124 consecutive men with suspected prostate cancer (PCa) underwent diagnosis prostate MRI on a 3.0 T MR system using a 32-channel phased-array torso coil. Among them, 63 underwent prostate biopsy. MRI protocol included 3DT2w images, high resolution Fov Optimized and Constrained Undistorted Single-Shot (FOCUS™) DWI images with b-values of 100, 400, 800, and 2000 s/mm 2 and dynamic contrast enhanced images. C-DWI images (2000 and 2500 s/mm 2 ) were derived from the three lower acquired b-value DWI images using a mono-exponential diffusion decay. C-DWI and acquired high b-value DWI (a-DWI) (2000 s/mm 2 ) were compared for image quality (background signal suppression, anatomic clarity, ghosting, distortion) and tumor conspicuity by four radiologists., Results: C-DWIs demonstrated higher rating than a-DWIs for overall image quality despite worsened ghosting. In patients with a biopsy, similar detection rate was observed while conspicuity was better with c-DWI (p < 0.001). Non-acquisition of high b-value a-DWI reduced total acquisition time by 220 s per patient., Conclusion: C-DWI provides a substantial reduction in acquisition time while maintaining comparable prostate cancer detection rate and improving global image quality., Key Points: • Computed DWI improves global quality of prostate MRI. • Computed DWI improves analysis of DWI images with decrease acquisition time. • Computed DWI provides greater background suppression of parenchyma and improves conspicuity of suspicious lesion.

Objectives: Early tumor shrinkage (ETS) has been reported to be associated with survival of metastatic colorectal cancer (mCRC) patients. Our aim was to analyze long-term tumor-size evolution, according to early mCRC best responses during the first-line therapy, to evaluate first best response-survival links., Methods: Sixty-five patients with unresectable mCRCs, treated between 2010 and 2015, were included retrospectively in this descriptive monocenter study and grouped according to their RECIST 1.1 first-line best responses: progressive disease (PD fl ), stable disease with tumor-size evolution between 0 and + 19% (SD fl +) or 0 and - 29% (SD fl -), and partial responders (PRs), who were classed PR with ETS (ETS fl ) or without (PR fl ). Tumor-size evolution and best tumor responses to each chemotherapy line were analyzed., Results: Tumor loads of ETS fl or PR fl mCRCs tended to remain inferior to their initial values: 60% of patients died with target lesion sums below baseline. For first-line SD fl + or PD fl mCRCs, rapid tumor load increases continued during successive lines: > 80% died with target lesion sums above baseline. ETS fl mCRCs responded better to subsequent lines (37.5% second-line PR), whereas PD fl mCRCs remained refractory to other therapies (0% second- and third-line PR). Overall survival rates were significantly (p = 0.03) longer for the ETS fl group (29.9 [95% CI: 12.6-47.1] months) and shorter for the PD fl group (17.1 [95% CI: 1.5-37.5] months)., Conclusion: Tumors responding to first-line chemotherapy also responded better to subsequent lines, whereas PD fl mCRCs remained refractory, which may explain the better survival associated with ETS fl ., Key Points: • Early shrinking tumors under first-line chemotherapy responded better to subsequent lines, maintaining low tumor loads, potentially explaining the link between early tumor shrinkage and overall survival of metastatic colorectal cancer (mCRC) patients. • mCRCs progressing under first-line chemotherapy remained refractory to other therapies and their tumor loads increased rapidly. • Even outside a clinical trial, an early first CT scan reevaluation with RECIST criteria 8 weeks after starting first-line therapy is crucial to determine long-term mCRC evolution.

Objective: The aim of this study was to evaluate the diagnostic performance of susceptibility-weighted magnetic resonance imaging (SW-MRI) for the evaluation of osseous foraminal stenosis (FS) of the cervical spine compared to conventional MRI-sequences, using computed tomography (CT) as a reference standard., Materials and Methods: Twenty-one patients with suspected radiculopathy of the cervical spine were prospectively included. CT and MRI data sets were available for all patients. As standard of reference, 280 neuroforamina of the cervical spine, including 58 foraminal stenosis, were identified on sagittal CT images. T1-, T2-, and SW-MRI of the cervical spine were performed. The presence of foraminal stenosis was assessed on sagittal views in all sequences. Sensitivity and specificity were calculated and differences in detection rate and severity scoring of foraminal stenosis between the different sequences were tested. CT was used as reference standard for all analysis., Results: Fifty-six of 58 osseous foraminal stenosis could be correctly identified on SW-MR magnitude images. SW-MRI achieved a sensitivity of 96.6% and specificity of 99.5% for the identification of foraminal stenosis. In comparison, conventional T1-weighted MRI sequences achieved a sensitivity and specificity of 43.1% and 100% respectively. T2-weighted MRI sequences achieved a sensitivity and specificity of 65.5% and 99.1%, respectively. The overall detection rate was significantly (p < 0.05) higher on SW-MRI and there was no significant difference (p > 0.05) in severity scoring compared to CT. T1- and T2-weighted MRI underestimated the degree of foraminal stenosis. Intermodality and interobserver agreements were highest for SW-MRI., Conclusions: SW-MRI enables the reliable detection of osseous foraminal stenosis of the cervical spine in patients with spinal radiculopathy with a higher sensitivity compared to conventional T1- and T2-MRI sequences, with CT as a reference standard., Key Points: • Susceptibility-weighted magnetic resonance imaging enables the reliable detection of osseous foraminal stenosis of the cervical spine with CT as a reference standard. • This could be relevant for younger patients in order to prevent unnecessary radiation exposure. • This may also facilitate a one-stop-shop approach and speed up diagnostic work-up.

Objectives: To determine the prevalence and significance of extracardiac findings (ECF) in a large set of cardiac magnetic resonance (MR) imaging examinations., Methods: The institutional review board (IRB) of the Charité approved this retrospective, single-centre study. A total of 4376 cardiac MR imaging reports of 3553 patients (age 37.4 ± 20 years, 60.8 % male) examined from 2000 to 2014 were included. Findings with a recommendation for follow-up were considered "major ECF". To analyse the association of indication, age and gender with ECF, Poisson regression and computed incidence rate ratios (IRR) were evaluated., Results: The overall prevalence of ECF was 34% (95% confidence interval [CI] 32.5-35.6%). Major ECF were present in 3.4% (95% CI 2.9-4.1%) while findings that changed patient management were found in 0.9% (95% CI 0.7-1.3%). In the cases of congenital heart disease, ECF prevalence was higher compared to myocarditis (IRR, 6.0; 95% CI 5.1-7.1%; p < 0.001), while the prevalence of major ECF was lower (IRR, 0.2; 95% CI 0.02-0.51%; p < 0.05). Older patient age was associated with more nonvascular ECF (p < 0.001). Female patients had the same probability of having an ECF as male patients (IRR, 1.04; 95% CI 0.95-1.1%; p = 0.43)., Conclusion: ECF in cardiac MR imaging are present in about every third patient while relevant ECF that change patient management can be found in about one out of 100 patients. Our data suggest that it is important to involve well-trained radiologists in reading cardiac MR images, which often reveal ECF if congenital heart disease is the clinical indication., Key Points: • Extracardiac findings are present in about every third patient. • Relevant ECF changing patient management are found in one out of 100 findings. • Chance of ECF is high in patients with CHD and vascular indications.

Objective: To compare image quality, observer confidence, radiation exposure in the standard-dose (SD-CCTA) and low-dose (LD-CCTA) protocols of coronary CT angiography (CCTA) in patients with atrial fibrillation (AF)., Material and Methods: CCTA was performed in 303 patients using a CT scanner with 16-cm coverage (111 scans during sinus rhythm (SR); 192 during AF). LD-CCTA was used in 218 patients; SD-CCTA in 85 patients suspected of having coronary artery disease (CAD). Image quality and observer confidence were evaluated on 5-point scales. Radiation doses were recorded., Results: Image quality was superior in the SD-CCTA compared to the LD-CCTA (SR 1.45±0.40; AF 1.72±0.46; vs. SR 1.83±0.48; AF 1.92±0.50; p < 0.001). Observers were more confident with SD-CCTA than with LD-CCTA (SR 1.38±0.33; AF 1.61±0.43; vs. SR 1.70±0.45; AF 1.82±0.50; p < 0.001). Radiation doses in AF were significantly higher than in the SR (LD-CCTA, 1.68±0.71 mSv; SD-CCTA, 3.72±1.95 mSv; vs. LD-CCTA, 1.3 ±0.52 mSv; SD-CCTA, 2.67±1.47 mSv; p < 0.001)., Conclusion: Using a low-dose protocol in AF, radiation exposure can be decreased by 50 % at the expense of 20 % impaired image quality. A low-dose CCTA protocol can be considered in young patients, whereas the standard-dose protocol is recommended for older patients and those suspected of having CAD., Key Points: • Whole-heart CT allows visualization of the coronary arteries in atrial fibrillation. • Low-dose CT decreases radiation exposure by 50%, image quality by 20%. • Standard-dose CT seems advantageous when concomitant coronary artery disease is suspected.

Objective: To correlate qualitative and quantitative diffusion weighted imaging (DWI) characteristics of intrahepatic cholangiocarcinoma (ICC) with histopathologic tumour grade and fibrosis content., Methods: Fifty-one patients (21M/30F; mean age 61y) with ICC and MRI including DWI were included in this IRB-approved multicentre retrospective study. Qualitative tumour features were assessed. Tumour apparent diffusion coefficient (ADC) mean, minimum, and normalized (nADC liver ) values were computed. Tumour grade [well(G1), moderately(G2), or poorly differentiated(G3)] and tumour fibrosis content [minimal(1), moderate(2), or abundant(3)] were categorized pathologically. Imaging findings and ADC values were compared with pathologic measures. Utility of ADC values for predicting tumour grade was assessed using ROC analysis., Results: 51 ICCs (mean size 6.5±1.1 cm) were assessed. 33/51(64%) of ICCs demonstrated diffuse hyperintensity and 15/51(29%) demonstrated target appearance on DWI. Infiltrative morphology (p=0.02) and tumour size (p=0.04) were associated with G3. ADCmean and nADCmean of G3 (1.32±0.47x10 -3 mm 2 /sec and 0.97±0.95) were lower than G1+G2 (1.57±0.39x10 -3 mm 2 /sec and 1.24±0.49; p=0.03 and p=0.04). ADCmean and nADCmean were inversely correlated with tumour grade (p<0.025). No correlation was found between ADC and tumour fibrosis content. AUROC, sensitivity and specificity of nADCmean for G3 versus G1+G2 were 0.71, 89.5% and 55.5%., Conclusion: ADC quantification has reasonable accuracy for predicting ICC grade., Key Points: • ADC quantification was useful for predicting ICC tumour grade. • Infiltrative tumour morphology and size were associated with poorly differentiated ICCs. • ADC values depended more on ICC tumour grade than fibrosis content. • Ability to predict ICC tumour grade non-invasively could impact patient management.

Purpose: To test the diagnostic performance of susceptibility-weighted MRI (sMRI) for the evaluation of vertebral body fractures versus standard MRI-sequences, using CT as reference standard., Methods: In this prospective study 88 vertebral fractures (45 healed, 43 non-healed) were detected in 39 patients who underwent T1/T2/TIRM MRI-sequences and sMRI. All fractures were evaluated with CT as reference standard. In all modalities/sequences, displacement and height of the posterior vertebral body cortex and visibility of fracture lines and cortical breaks were assessed. Sensitivity, specificity and inter-reader agreement between MRI and CT were calculated., Results: sMRI demonstrated highest diagnostic accuracy for detection of posterior vertebral body cortex involvement (sensitivity: 98 %/specificity: 100 %), fracture lines (86 %/99 %) and cortical breaks (93 %/100 %) versus T1/T2/TIRM sequences. Regarding evaluation of posterior vertebral body cortex displacement and height, sMRI demonstrated the closest intermodality agreement (R 2 =0.96; 95 % CI -0.92-0.89/R 2 =0.97; 95 % CI -1.67-1.23) with CT and the closest interobserver agreement (R 2 =0.97; 95 % CI -0.71-1.01)., Conclusion: sMRI allows reliable evaluation of vertebral body fractures with regard to posterior vertebral body cortex displacement and height, cortical breaks and fracture lines with higher accuracy versus standard MRI, especially in patients with non-healed vertebral body fractures., Key Points: • sMRI allows a reliable evaluation of vertebral body fractures. • sMRI has higher accuracy than standard-MRI for evaluation of vertebral body fractures. • sMRI is especially useful in patients with non-healed vertebral body fractures.

Objectives: In this preliminary study, we examined whether imaging-based phenotypes are associated with reported predictive gene signatures in hepatocellular carcinoma (HCC)., Methods: Thirty-eight patients (M/F 30/8, mean age 61 years) who underwent pre-operative CT or MR imaging before surgery as well as transcriptome profiling were included in this IRB-approved single-centre retrospective study. Eleven qualitative and four quantitative imaging traits (size, enhancement ratios, wash-out ratio, tumour-to-liver contrast ratios) were assessed by three observers and were correlated with 13 previously reported HCC gene signatures using logistic regression analysis., Results: Thirty-nine HCC tumours (mean size 5.7 ± 3.2 cm) were assessed. Significant positive associations were observed between certain imaging traits and gene signatures of aggressive HCC phenotype (G3-Boyault, Proliferation-Chiang profiles, CK19-Villanueva, S1/S2-Hoshida) with odds ratios ranging from 4.44-12.73 (P <0.045). Infiltrative pattern at imaging was significantly associated with signatures of microvascular invasion and aggressive phenotype. Significant but weak associations were also observed between each enhancement ratio and tumour-to-liver contrast ratios and certain gene expression profiles., Conclusions: This preliminary study demonstrates a correlation between phenotypic imaging traits with gene signatures of aggressive HCC, which warrants further prospective validation to establish imaging-based surrogate markers of molecular phenotypes in HCC., Key Points: • There are associations between imaging and gene signatures of aggressive hepatocellular carcinoma. • Infiltrative type is associated with gene signatures of microvascular invasion and aggressiveness. • Infiltrative type may be a surrogate marker of microvascular invasion gene signature.

Aim: To assess anatomic changes on computed tomography (CT) after neoadjuvant FOLFIRINOX (5-fluorouracil/leucovorin/irinotecan/oxaliplatin) chemotherapy for secondary resected borderline resectable (BR) and locally advanced (LA) pancreatic adenocarcinoma and their accuracy to predict resectability and pathological response., Methods: Thirty-six patients with secondary resected BR/LA pancreatic adenocarcinoma after neoadjuvant FOLFIRINOX chemotherapy (± chemoradiotherapy) were retrospectively included. Two radiologists reviewed baseline and pre-surgical CTs in consensus. NCCN (National Comprehensive Cancer Network) classification, largest axis, product of the three axes (P3A), and arterial/venous involvement were studied and compared to pathological response and resection status and to disease-free survival (DFS)., Results: Thirty-one patients had R0 resection, including only six exhibiting a downstaging according to the NCCN classification. After treatment, the largest axis and P3A decreased (P < 0.0001). The pre-surgical largest axis and P3A were smaller in case of R0 resection (P = 0.019/P = 0.021). The largest axis/P3A variations were higher in case of complete pathological response (P = 0.011/P = 0.016). A decrease of the arterial/venous involvement was not able to predict R0 or ypT0N0 (P > 0.05). Progression of the vascular involvement was seen in two (5 %) patients and led to a shorter DFS., Conclusion: In BR/LA pancreatic adenocarcinoma after the neoadjuvant FOLFIRINOX regimen (± chemoradiotherapy), significant tumour size decreases were observed on CT. However, CT staging was not predictive of resectability and pathological response., Key Points: • Significant tumour size decreases were observed on CT after FOLFIRINOX (± chemoradiotherapy). • CT is not able to predict R0 resection accurately after FOLFIRINOX (± chemoradiotherapy). • CT is not able to predict complete response accurately after FOLFIRINOX (± chemoradiotherapy). • Even with a stable NCCN classification, BR/LA pancreatic adenocarcinoma could have R0 resection.

Objectives: To evaluate the value of MR imaging including diffusion-weighted imaging (DWI) for the grading of pancreatic neuroendocrine tumours (pNET)., Material and Methods: Between 2006 and 2014, all resected pNETs with preoperative MR imaging including DWI were included. Tumour grading was based on the 2010 WHO classification. MR imaging features included size, T1-w, and T2-w signal intensity, enhancement pattern, apparent (ADC) and true diffusion (D) coefficients., Results: One hundred and eight pNETs (mean 40 ± 33 mm) were evaluated in 94 patients (48 women, 51 %, mean age 52 ± 12). Fifty-five (51 %), 42 (39 %), and 11 (10 %) tumours were given the following grades (G): G1, G2, and G3. Mean ADC and D values were significantly lower as grade increased (ADC: 2.13 ± 0.70, 1.78 ± 0.72, and 0.86 ± 0.22 10 -3 mm 2 /s, and D: 1.92 ± 0.70, 1.75 ± 0.74, and 0.82 ± 0.19 10 -3 mm 2 /s G1, G2, and G3, all p < 0.001). A higher grade was associated with larger sized tumours (p < 0.001). The AUROC of ADC and D to differentiate G3 and G1-2 were 0.96 ± 0.02 and 0.95 ± 0.02. Optimal cut-off values for the identification of G3 were 1.19 10 -3 mm 2 /s for ADC (sensitivity 100 %, specificity 92 %) and 1.04 10 -3 mm 2 /s for D (sensitivity 82 %, specificity 92 %)., Conclusion: Morphological/functional MRI features of pNETS depend on tumour grade. DWI is useful for the identification of high-grade tumours., Key Points: • Morphological and functional MRI features of pNETs depend on tumour grade. • Their combination has a high predictive value for grade. • All pNETs should be explored by MR imaging including DWI. • DWI is helpful for identification of high-grade and poorly-differentiated tumours.

Purpose: To prospectively compare 3D flow-dependent subtractive MRA vs. 2D flow-independent non-subtractive MRA for assessment of the calf arteries at 3 Tesla., Methods: Forty-two patients with peripheral arterial occlusive disease underwent nonenhanced MRA of calf arteries at 3 Tesla with 3D flow-dependent subtractive MRA (fast spin echo sequence; 3D-FSE-MRA) and 2D flow-independent non-subtractive MRA (balanced steady-state-free-precession sequence; 2D-bSSFP-MRA). Moreover, all patients underwent contrast-enhanced MRA (CE-MRA) as standard-of-reference. Two readers performed a per-segment evaluation for image quality (4 = excellent to 0 = non-diagnostic) and severity of stenosis., Results: Image quality scores of 2D-bSSFP-MRA were significantly higher compared to 3D-FSE-MRA (medians across readers: 4 vs. 3; p < 0.0001) with lower rates of non-diagnostic vessel segments on 2D-bSSFP-MRA (reader 1: <1 % vs. 15 %; reader 2: 1 % vs. 29 %; p < 0.05). Diagnostic performance of 2D-bSSFP-MRA and 3D-FSE-MRA across readers showed sensitivities of 89 % (214/240) vs. 70 % (168/240), p = 0.0153; specificities: 91 % (840/926) vs. 63 % (585/926), p < 0.0001; and diagnostic accuracies of 90 % (1054/1166) vs. 65 % (753/1166), p < 0.0001., Conclusion: 2D flow-independent non-subtractive MRA (2D-bSSFP-MRA) is a robust nonenhanced MRA technique for assessment of the calf arteries at 3 Tesla with significantly higher image quality and diagnostic accuracy compared to 3D flow-dependent subtractive MRA (3D-FSE-MRA)., Key Points: • 2D flow-independent non-subtractive MRA (2D-bSSFP-MRA) is a robust NE-MRA technique at 3T • 2D-bSSFP-MRA outperforms 3D flow-dependent subtractive MRA (3D-FSE-MRA) as NE-MRA of calf arteries • 2D-bSSFP-MRA is a promising alternative to CE-MRA for calf PAOD evaluation.

Objectives: To evaluate the value of diffusion-weighted imaging (DWI) in detecting residual tumours (RTs) in colorectal liver metastases (CLMs) following chemotherapy, with a focus on tumour periphery., Methods: From January 2009-January 2012, 57 patients who underwent liver resection for CLMs with preoperative MRI (<3 months) including DWI were retrospectively included. CLMs were classified into three response groups on pathology: (1) major histological (MHR, RTs ≤ 10 %), (2) partial histological (PHR, RT = 10-49 %), and (3) no histological (NHR, RT ≥ 50 %). On DWI, regions of interest (ROIs) were drawn around the entire tumour and tumour periphery. Apparent diffusion (ADC) and pure diffusion (D) coefficients were calculated using a monoexponential fit, and compared using Kruskal-Wallis test on a lesion-per-lesion analysis., Results: 111 CLMs were included. Fourteen (12.5 %), 42 (38 %) and 55 (49.5 %) CLMs presented a MHR, PHR and NHR, respectively. ADC and D of the peripheral ROIs were significantly higher in the MHR group (P = 0.013/P = 0.013). ADC and D from the entire tumour were not significantly different among the groups (P = 0.220/P = 0.103)., Conclusion: In CLM treated with chemotherapy, ADC and D values from the entire tumour are not related to the degree of RT, while peripheral zone diffusion parameters could help identify metastases with MHR., Key Points: Peripheral ADC and D of CLMs were higher with major pathological responses. Global ADC and D of CLMs were not different according to residual tumour. Diffusion-weighted images of CLM periphery could be an interesting biomarker of MHR. Diffusion-weighted images could be used to help tailor treatment.

Objectives: We aimed to assess the sensitivity of diffusion-weighted (DW) magnetic resonance (MR) imaging for the detection of pathologically confirmed uveal melanoma liver metastases (UMLM)., Methods: Twenty patients who underwent complete surgical resection of their UMLM (N = 83) were included. Pre-surgery liver MR imaging included T2-weighted, T1-weighted, DW and dynamic-gadolinium-enhanced MR sequences. Two radiologists independently reviewed three sets of images (DW / morphologic-dynamic / combined) for each patient using intraoperative and pathological findings as a standard of reference., Results: The sensitivities of the morphologic-dynamic and DW images for UMLM detection were 63 % and 59 %, respectively, for reader #1 (R1) and 64 % and 53 %, for reader #2 (R2). Sensitivity of the combined set was higher than sensitivity in the two other sets (R1:69 %, R2:67 %), but was only significantly different than the sensitivity of the DW images (McNemar test). For the three sets and the two readers, the sensitivity for UMLM smaller than 5 mm (37-46 %) was significantly lower than that for UMLM larger than 5 mm (67-90 %). The sensitivity for UMLM located in the subcapsular area (41-54 %) was significantly lower than that for intraparenchymal UMLM (68-86 %) (Chi-square test)., Conclusion: Our study shows that the addition of DW imaging to morphologic-dynamic images does not significantly increase MR sensitivities for UMLM detection., Key Points: • The MR imaging sensitivity for uveal melanoma liver metastases (UMLM) was 69 %. • Addition of DW imaging to morphologic-dynamic images does not increase sensitivity significantly. • Sensitivity for subcapsular UMLM was significantly lower than sensitivity for intraparenchymal UMLM. • The T2 shortening effect does not appear to influence lesion detection in DWI.

Objectives: To assess the contrast-enhanced ultrasound (CEUS) frequencies of centrifugal enhancement, spoke-wheel sign and central scar in focal nodular hyperplasia (FNH) as a function of lesion size., Methods: Ninety-four FNHs were retrospectively reviewed to assess their largest diameter and enhancement pattern, including centrifugal enhancement from one central artery, spoke-wheel sign, diffuse or centripetal enhancement, central scar and late-phase washout., Results: Mean FNH-lesion size was 3.7 ± 2.1 cm. Only 43.6 % of FNHs had centrifugal enhancement, with a spoke-wheel pattern (23.4 %) or without (20.2 %), while 56.4 % showed diffuse or centripetal enhancement. Centrifugal enhancement was observed in 73.9 % of FNHs ≤3.1 cm and 14.6 % of FNHs >3.1 cm (P < 10(-4)). Size and frequency of centrifugal enhancement were negatively correlated (r = -0.57, P < 10(-4)). The spoke-wheel pattern was also seen more frequently in smaller (37 %) than in larger FNHs (10.4 %) (P < 10(-3)). Late-phase washout was described in 5.3 % of FNHs and was not size-dependent. Lesions with a central scar were larger than those without, respectively, 5.7 ± 1.7 and 3.6 ± 2.0 cm (P = 0.012)., Conclusions: Typical centrifugal enhancement yielding a confident FNH diagnosis is seen significantly more frequently when the lesion is ≤3.1 cm., Key Points: • CEUS yields confident diagnoses of FNHs ≤3.1 cm • The larger the FNH, the lower the diagnostic sensitivity of CEUS • Final diagnosis of FNHs >3.1 cm should be obtained with MRI not CEUS.

Objectives: To compare diffusion-weighted (DW) and T2-weighted MR imaging in detecting colorectal liver metastases in a rat model, using histological examination as a reference method., Methods: Eighteen rats had four liver injections of colon cancer cells. MR examinations at 7 T included FSE-T2-weighted imaging and SE-DW MR imaging (b = 0, 20 and 150 s/mm(2)) and were analysed by two independent readers. Histological examination was performed on 0.4-mm slices. McNemar's test was used to compare the sensitivities and the Wilcoxon matched pairs test to compare the average number of false-positives per rat., Results: One hundred and sixty-six liver metastases were identified on histological examination. The sensitivity in detecting liver metastases was significantly higher on DW MR than on T2-weighted images (99/166 (60 %) (reader 1) and 92/166 (55 %) (reader 2) versus 77/166 (46 %), P ≤ 0.001), without an increase in false-positives per rat (P = 0.773/P = 0.850). After stratification according to metastasis diameter, DW MR imaging had a significantly higher sensitivity than T2-weighted imaging only for metastases with a diameter (0.6-1.2 mm) similar to that of the spatial resolution of MR imaging in the current study., Conclusions: This MR study with histological correlations shows the higher sensitivity of DW relative to T2-weighted imaging at 7 T for detecting liver metastases, especially small ones., Key Points: • Diffusion weighted (DW) sequences are increasingly used in magnetic resonance imaging (MRI). • DW has higher sensitivity for liver metastases than T2-weighted imaging at 7 T. • This increase in sensitivity is especially marked for small liver metastasis detection. • This higher sensitivity is confirmed in an animal model with histological correlation. • DW imaging has the potential for earlier diagnosis of small liver metastases.

Objectives: DSA is currently the criterion standard for the assessment of dural arteriovenous fistulas (dAVF). Recently, evolving MRA techniques have emerged as a non-invasive alternative. The aim of this study is to assess the value of 3 T MRI in detecting and describing dAVF and to determine whether MRI can replace DSA as diagnostic procedure., Methods: A total of 19 patients with dAVF and 19 without dAVF underwent the same MRI protocol, including 3D time-of-flight MRA and time-resolved contrast-enhanced MRA. The images were evaluated retrospectively by three independent readers with different levels of experience blinded to clinical information. The readers assessed the presence, the site, the venous drainage and the feeders of dAVF. Sensitivity, specificity, accuracy, intertechnique and interobserver agreements were calculated., Results: DAVF can be detected with high sensitivity, specificity and accuracy by experienced and also by less experienced readers. However, MRI has limitations when used for grading and evaluation of the angioarchitecture of the dAVF. Different experience, the limited resolution of MRI and its inability to selectively display arteries were the reasons for these limitations., Conclusions: With MRI dAVF can be detected reliably. Nevertheless, at present MRI can not fully replace DSA, especially for treatment planning.

The objective of this study is to evaluate multidetector CT (MDCT) in detecting and characterizing anomalous coronary arteries. Forty-four patients with anomalies of the coronaries were selected from a total of 1758 individuals examined with ECG-gated 4- and 16-row MDCT including thinMIP, MPR and VRT post-processing. Twenty-eight patients showed origin and course anomalies of the central coronary segments, and in this subgroup 13 were judged as "malignant" because of interarterial courses between the aortic root and the pulmonary trunk, either of the right coronary artery (n=11) or the left coronary artery (n=2). Twelve non-hemodynamic anomalies were found, affecting the coronary origins only (n=10) or the peripheral vessels courses (n=2). Four arteriovenous fistulas were present, all of them with complex arterial feeders. Regardless of vessel anatomy, coronary opacification was always possible by means of the systemic contrast agent, and the aberrant coronary arteries were visualized synoptically in direct relation to the great mediastinal vessels. In contrast to MDCT, selective cannulation and final diagnosis was possible in only 11 of the 20 catheter angiograms performed (accuracy of 55.0%). In conclusion, its non-invasiveness and precise visualization makes MDCT the standard of reference for evaluating anomalous coronary arteries.

Magnetic resonance imaging of the lung tissue is thought to be hardly possible due to physical limitations especially the low proton density, susceptibility, and motion artifacts. The objective of our study was to evaluate and refine a very fast MR technique at a low field strength which overcomes the limitations in MR lung imaging. Thirty-five investigations were performed in 30 pediatric patients with suspected pneumonia. The MR investigations were performed in coronal slice orientation without cardiac or respiratory triggering in a low-field MR system. An optimized true fast imaging with steady precession sequence was applied. The MR images and the corresponding conventional chest radiographs were evaluated. The examination time per slice was 1.6 s. No motion artifacts could be observed. The signal-to-noise ratio for pulmonary parenchyma ranged from 4.9 to 7.1. All pathological findings of the chest X-ray images were correctly identified by the MRI (kappa=0.82-0.85). Effusions as well as small pneumonic infiltrates were more precisely detected by the MRI investigation (kappa=0.82) as compared with X-ray. Low-field projection MRI is a promising alternative to pediatric chest X-ray. Due to its short examination time, it overcomes the physical limits of usual MRI methods and provides comparable diagnostic information.