Impact of radiological response and pattern of progression in patients with HCC treated by atezolizumab-bevacizumab.

BACKGROUND AND AIMS: We aim to assess the role of radiological response to atezolizumab-bevacizumab in patients with HCC to predict overall survival. APPROACH AND RESULTS: We retrospectively included patients with HCC treated by atezolizumab-bevacizumab in 2 tertiary centers. A retrospective blinded analysis was performed by 2 radiologists to assess Response Evaluation Criteria in Solid Tumor (RECIST 1.1) and modified RECIST (mRECIST) criteria at 12 weeks. Imaging response and treatment decisions in the multidisciplinary tumor board at 12 weeks were registered. Among 125 patients, 9.6% and 20.8% had a response, 39.2% and 35.2% had stable disease, and 51.2% and 44% had progression, according to RECIST 1.1 and mRECIST, respectively, with a substantial interobserver agreement (k coefficient=0.79). Metastasis was independently associated with a higher risk of progression. Patients classified as responders did not reach median survival, which was 16.2 and 15.9 months for patients classified as stable and 9.1 and 9.0 months for patients classified as progressors, in RECIST 1.1 and mRECIST criteria, respectively. We observed a wide variability in the identification of progression in the multidisciplinary tumor board in clinical practice compared with the blind evaluation by radiologists mainly due to discrepancy in the evaluation of the increase in size of intrahepatic lesions. The appearance of new extrahepatic lesions or vascular invasion lesions was associated with a worse overall survival ( p =0.032). CONCLUSIONS: RECIST 1.1 and mRECIST criteria predict overall survival with more responders identified by mRECIST and the appearance of new extrahepatic lesion or vascular invasion was associated with a poor prognosis. A noticeable discrepancy was observed between patients classified as progressors at reviewing and the decision reached during the multidisciplinary tumor board.

Association of LI-RADS and Histopathologic Features with Survival in Patients with Solitary Resected Hepatocellular Carcinoma.

Background Both Liver Imaging Reporting and Data System (LI-RADS) and histopathologic features provide prognostic information in patients with hepatocellular carcinoma (HCC), but whether LI-RADS is independently associated with survival is uncertain. Purpose To assess the association of LI-RADS categories and features with survival outcomes in patients with solitary resected HCC. Materials and Methods This retrospective study included patients with solitary resected HCC from three institutions examined with preoperative contrast-enhanced CT and/or MRI between January 2008 and December 2019. Three independent readers evaluated the LI-RADS version 2018 categories and features. Histopathologic features including World Health Organization tumor grade, microvascular and macrovascular invasion, satellite nodules, and tumor capsule were recorded. Overall survival and disease-free survival were assessed with Cox regression models. Marginal effects of nontargetoid features on survival were estimated using propensity score matching. Results A total of 360 patients (median age, 64 years [IQR, 56-70 years]; 280 male patients) were included. At CT and MRI, the LI-RADS LR-M category was associated with increased risk of recurrence (CT: hazard ratio [HR] = 1.83 [95% CI: 1.26, 2.66], P = .001; MRI: HR = 2.22 [95% CI: 1.56, 3.16], P < .001) and death (CT: HR = 2.47 [95% CI: 1.72, 3.55], P < .001; MRI: HR = 1.80 [95% CI: 1.32, 2.46], P < .001) independently of histopathologic features. The presence of at least one nontargetoid feature was associated with an increased risk of recurrence (CT: HR = 1.80 [95% CI: 1.36, 2.38], P < .001; MRI: HR = 1.93 [95% CI: 1.81, 2.06], P < .001) and death (CT: HR = 1.51 [95% CI: 1.10, 2.07], P < .010) independently of histopathologic features. In matched samples, recurrence was associated with the presence of at least one nontargetoid feature at CT (HR = 2.06 [95% CI: 1.15, 3.66]; P = .02) or MRI (HR = 1.79 [95% CI: 1.01, 3.20]; P = .048). Conclusion In patients with solitary resected HCC, LR-M category and nontargetoid features were negatively associated with survival independently of histopathologic characteristics. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Kartalis and Grigoriadis in this issue.

No correlation between MASLD and poor outcome of Atezolizumab-Bevacizumab therapy in patients with advanced HCC.

INTRODUCTION: It has been suggested that in patients with hepatocellular carcinoma (HCC) of metabolic aetiology, the efficacy of immunotherapy may be reduced. The aim was to investigate the impact of metabolic-associated steatotic liver disease (MASLD) and metabolic risk factors (MRF) on the outcomes of Atezolizumab-Bevacizumab (AtezoBev). METHODS: We collected data from 295 AtezoBev-treated patients, starting in 2020. MASLD was defined by the current/past presence of MRF, namely BMI ≥ 30 kg/m2, type 2 diabetes, arterial hypertension or dyslipidaemia and no other cause of liver disease (daily alcohol ≤30 g in males and ≤20 g in females). The influence of baseline characteristics on progression (PFS) and overall survival (OS) was assessed by uni/multivariate analysis using the Cox model. RESULTS: Risk factors for cirrhosis were viral infection in 47%, excessive alcohol consumption in 45% and MASLD in 13%. In the whole cohort, 27% had 1 MRF, 23% had 2 MRF, 15% had 3 MRF and 6% had 4 MRF. Median PFS and OS were 6.5 and 15.6 months, respectively, and similar in patients with or without MASLD in Log rank analysis. The number of MRF or MALSD was not associated with PFS or OS in the univariate analysis. Factors associated with PFS in multivariate analysis included ALBI grade 3 (HR = 1.60, p = .03), AFP (HR = 1.01, p = .01) and metastasis (HR = 1.77, p < .001). During follow-up, 10% of patients experienced immune-related adverse events, with age and female gender, but not MRF or MASLD, as independent predictors. CONCLUSION: Our study suggests that the presence of MASLD or the number of MRF did not lead to worse outcomes in advanced HCC patients treated with AtezoBev.

Deep learning for automatic bowel-obstruction identification on abdominal CT.

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.

Reliability of extracellular contrast versus gadoxetic acid in assessing small liver lesions using liver imaging reporting and data system v.2018 and European association for the study of the liver criteria.

BACKGROUND & AIMS: The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v.2018 and European Association for the Study of the Liver (EASL) criteria for the diagnosis of HCC have been widely evaluated, but their reliability should be investigated. We aimed to assess and compare the reliability of LI-RADS v.2018 and EASL criteria for the diagnosis of HCC using MRI with extracellular contrast agents (ECAs) and gadoxetic acid (GA) and determine the effect of ancillary features on LI-RADS reliability. APPROACH & RESULTS: Ten readers reviewed MRI studies of 92 focal liver lesions measuring <3 cm acquired with ECAs and GA <1 month apart from two prospective trials, assessing EASL criteria, LI-RADS major and ancillary features, and LI-RADS categorization with and without including ancillary features. Inter-reader agreement for definite HCC diagnosis was substantial and similar for the two contrasts for both EASL and LI-RADS criteria. For ECA-MRI and GA-MRI, respectively, inter-reader agreement was k = 0.72 (95% CI, 0.63-0.81) and k = 0.72 (95% CI, 0.63-0.80); for nonrim hyperenhancement, k = 0.63 (95% CI, 0.54-0.72) and k = 0.57 (95% CI, 0.48-0.66); and for nonperipheral washout, k = 0.49 (95% CI, 0.40-0.59) and k = 0.48 (95% CI, 0.37-0.58) for enhancing capsule. The inter-reader agreement for LI-RADS after applying ancillary features remained in the same range of agreement. CONCLUSIONS: Agreement for definite HCC was substantial and similar for both scoring systems and the two contrast agents in small focal liver lesions. Agreement for LI-RADS categorization was lower for both contrast agents, and including LI-RADS ancillary features did not improve agreement.

Baseline ALBI score and early variation of serum AFP predicts outcomes in patients with HCC treated by atezolizumab-bevacizumab.

BACKGROUND: The combination of atezolizumab and bevacizumab (AtezoBev) is the current first-line treatment for patients with hepatocellular carcinoma (HCC). Our aim was to evaluate the prognostic role of alpha-foetoprotein (AFP) early response and its combination with albumin-bilirubin (ALBI) in these patients. METHODS: Patients with HCC under AtezoBev with AFP > 20 ng/ml were included in three centres. The optimal threshold of AFP variation after 3 weeks of treatment was identified for overall survival (OS) and radiological response (RR) using RECIST 1.1 and mRECIST and its ability to predict progression-free survival (PFS) and OS was tested using univariate and multivariate analysis in derivation and validation cohorts. RESULTS: Seventy-five patients with AFP values >20 ng/ml were included. Fifty-eight patients were male with a median age of 63.5 years; 73% had cirrhosis and HCC stage was classified as BCLC B (18.7%) or C (81.3%). In the derivation cohort (n = 38), a decline in AFP ≥ 20% at 3 weeks (AFP early response) was associated with RR using mRECIST criteria (OR: 13.09 95% CI: 1.44-19.34 p = .02), PFS (HR: 0.42; 95% CI: 0.19-0.93, p = .03) and OS (HR: 0.35; 95% CI: 0.15-0.83, p = .01). AFP early response was confirmed as predictor of RR (p = .02 for mRECIST) and OS (p = .03) in the validation cohort (n= 37). In the whole cohort, the combination of ALBI and AFP early response was significantly associated with OS (p = .046) and PFS (p = .012) with a poor prognosis in patients belonging to the ALBI2-AFP non-responders class. CONCLUSION: AFP early response at 3 weeks predicts oncological outcomes in HCC patients treated with AtezoBev and combination with ALBI grade refines prognostic discrimination.

Validation of a screening algorithm for hepatic fibrosis by Doppler ultrasound and elastography in a general population.

BACKGROUND: Early detection can prevent the initial stages of fibrosis from progressing to cirrhosis. PURPOSE: To evaluate an algorithm combining three echographic indicators and elastographic measurements to screen for hepatic fibrosis in an unselected population. MATERIAL AND METHODS: From May 2017 to June 2018, all patients with no history and no known chronic liver disease who were referred for an ultrasound (US) were prospectively included in eight hospitals. The indicators being sought were liver surface irregularity, demodulation of hepatic veins, and spleen length >110 mm. Patients presenting at least one of these underwent elastography measurements with virtual touch quantification (VTQ) or supersonic shear imaging (SSI). If elastography was positive, patients were referred to hepatologist for fibrosis evaluation. Reference standard was obtained by FibroMeterVCTE or biopsy. A FibroMeterVCTE result >0.384 indicated a "necessary referral" to a hepatologist. RESULTS: Of the 1501 patients included, 504 (33.6%) were positive for at least one US indicator. All of them underwent US elastography, with 85 being positive. Of the patients, 58 (3.6%) had a consultation with a liver specialist: 21 had positive FibroMeterVCTE and nine had an indication of biopsy for suspicion of fibrosis. This screening algorithm made it possible to diagnose 1.6% of patients in our population with unknown fibrosis. Of the patients, 50% referred to the liver specialist were "necessary referrals." CONCLUSION: Our study suggests that three simple US indicators with no systematic elastographic measurement could be applied in day-to-day practice to look for hepatic fibrosis in an unsuspected population allowing relevant referrals to a hepatologist.

A history of variceal bleeding is associated with further bleeding under atezolizumab-bevacizumab in patients with HCC.

BACKGROUND: Atezolizumab-bevacizumab is the new standard for advanced hepatocellular carcinoma (HCC) but its impact on portal hypertension (PHT) is unknown. We aimed to identify predictive factors of acute variceal bleeding (AVB) and to monitor PHT parameters under treatment. METHODS: We conducted a prospective study including all cirrhotic patients treated with atezolizumab-bevacizumab since 2020. We performed monitoring of PHT using upper endoscopy at inclusion and at 6 months and hepatic venous pressure gradient (HVPG) at inclusion, 3 and 6 months after the beginning of treatment. We also included a retrospective series of patients treated with sorafenib. Time-to-events data were estimated by Kaplan-Meier with the log-rank test, along with Cox models. RESULTS: Forty-three patients treated with atezolizumab-bevacizumab were included (male 79.1%, Child-Pugh A 86%). At baseline, 48.8% were treated with curative anticoagulation, 16.3% already experienced AVB and 25.6% had large oesophageal varices (EV). Sorafenib group characteristics were similar. Vascular invasion was present in 60.5% and median was HVPG 8.5 mm Hg. No significant modification in HVPG and EV size was observed at 6 months in the whole cohort but also when considering vascular invasion and radiological response. 14% presented AVB within a median time of occurrence of 3 months, without bleeding-related death. In multivariate analysis, history of AVB (HR = 10.58, p = .03) was associated with AVB. AVB incidence was higher in atezolizumab-bevacizumab compared to sorafenib group (21% vs. 5% at 1 year, p = .02). CONCLUSIONS: Atezolizumab-bevacizumab treatment was associated with a higher risk of AVB compared to sorafenib. A history of AVB was associated with AVB during follow-up, which questions the use of bevacizumab in this setting.

Multiparametric magnetic resonance imaging shows promising results to assess renal transplant dysfunction with fibrosis.

Here we assessed the diagnostic value of a quantitative multiparametric magnetic resonance imaging (mpMRI) protocol for evaluation of renal allograft dysfunction with fibrosis. Twenty-seven renal transplant patients, including 15 with stable functional allografts (eGFR mean 71.5 ml/min/1.73m2), and 12 with chronic dysfunction/established fibrosis (eGFR mean 30.1 ml/min/1.73m2), were enrolled in this prospective single-center study. Sixteen of the patients had renal biopsy (mean 150 days) before the MRI. All patients underwent mpMRI at 1.5T including intravoxel-incoherent motion diffusion-weighted imaging, diffusion tensor imaging, blood oxygen level dependent (BOLD R2*) and T1 quantification. True diffusion D, pseudodiffusion D*, perfusion fraction PF, apparent diffusion coefficient (ADC), fractional anisotropy (FA), R2* and T1 were calculated for cortex and medulla. ΔT1 was calculated as (100x(T1 Cortex-T1 Medulla)/T1 Cortex). Test-retest repeatability and inter-observer reproducibility were assessed in four and ten patients, respectively. mpMRI parameters had substantial test-retest and interobserver repeatability (coefficient of variation under 15%), except for medullary PF and D* (coefficient of variation over 25%). Cortical ADC, D, medullary ADC and ΔT1 were all significantly decreased, while cortical T1 was significantly elevated in fibrotic allografts. Cortical T1 showed positive correlation to the Banff fibrosis and tubular atrophy scores. The combination of ΔT1 and cortical ADC had excellent cross-validated diagnostic performance for detection of chronic dysfunction with fibrosis. Cortical ADC and T1 had good performance for predicting eGFR decline at 18 months (4 or more ml/min/1.73m2/year). Thus, the combination of cortical ADC and T1 measurements shows promising results for the non-invasive assessment of renal allograft histology and outcomes.

Treatment intensification with hepatic arterial infusion chemotherapy in patients with liver-only colorectal metastases still unresectable after systemic induction chemotherapy - a randomized phase II study -- SULTAN UCGI 30/PRODIGE 53 (NCT03164655)- study protocol.

BACKGROUND: Approximately 40% of colorectal cancer patients will develop colorectal liver metastases (CRLM). The most effective approach to increase long-term survival is CRLM complete resection. Unfortunately, only 10-15% of CRLM are initially considered resectable. The objective response rates (ORR) after current first-line systemic chemotherapy (sys-CT) regimens range from 40 to 80% and complete resection rates (CRR) range from 25 to 50% in patients with initially unresectable CRLM. When CRLM patients are not amenable to complete resection after induction of sys-CT, ORRs obtained with second-line sys-CT are much lower (between 10 and 30%) and consequently CRRs are also low (< 10%). Hepatic arterial infusion (HAI) oxaliplatin may represent a salvage therapy in patients with CRLM unresectable after one or more sys-CT regimens with ORRs and CRRs up to 60 and 30%, respectively. This study is designed to evaluate the efficacy of an intensification strategy based on HAI oxaliplatin combined with sys-CT as a salvage treatment in patients with CRLM unresectable after at least 2 months of first-line induction sys-CT. OBJECTIVES AND ENDPOINTS OF THE PHASE II STUDY: Our main objective is to investigate the efficacy, in term of CRR (R0-R1), of treatment intensification in patients with liver-only CRLM not amenable to curative-intent resection (and/or ablation) after at least 2 months of induction sys-CT. Patients will receive either HAI oxaliplatin plus systemic FOLFIRI plus targeted therapy (i.e. anti-EGFR antibody or bevacizumab) or conventional sys-CT plus targeted therapy (i.e. anti-EGFR or antiangiogenic antibody). Secondary objectives are to compare: progression-free survival, overall survival, objective response rate, depth of response, feasibility of delivering HAI oxaliplatin including HAI catheter-related complications, and toxicity (NCI-CTCAE v4.0). METHODS: This study is a multicenter, randomized, comparative phase II trial (power, 80%; two-sided alpha-risk, 5%). Patients will be randomly assigned in a 1:1 ratio to receive HAI oxaliplatin combined with systemic FOLFIRI plus targeted therapy (experimental arm) or the best sys-CT plus targeted therapy on the basis of their first-line prior sys-CT history and current guidelines (control arm). One hundred forty patients are required to account for non-evaluable patients. TRIAL REGISTRATION: ClinicalTrials.gov, (NCT03164655). Trial registration date: 11th May 2017.

Comparison of pulsed and oscillating gradient diffusion-weighted MRI for characterizing hepatocellular nodules in liver cirrhosis: ex vivo study in a rat model.

BACKGROUND: In contrast to classical pulsed gradient diffusion-weighted MRI, oscillating gradient diffusion-weighted MR imaging (DWI) is sensitive to short distance diffusion changes at the intracellular level. PURPOSE: To compare the diagnostic performance of pulsed and oscillating DWI for characterizing hepatocellular nodules in a rat model of hepatic cirrhosis. STUDY TYPE: Prospective, experimental study. ANIMAL MODEL: Cirrhosis was induced by weekly intraperitoneal injection of diethylnitrosamine in Wistar rats. FIELD STRENGTH/SEQUENCE: Ex vivo liver MRI was performed at 7T with T1 -weighted, T2 -weighted, pulsed, and oscillating gradient diffusion-weighted sequences. ASSESSMENT: Apparent diffusion coefficient from pulsed (ADCpulsed ) and oscillating gradient (ADCoscillating ) sequences was calculated in 82 nodules identified on the T1 /T2 -weighted images and on pathological examination. Two pathologists classified the nodules in three categories: benign (regenerative and low-grade dysplastic nodules), with intermediate malignancy (high-grade dysplastic nodules and early hepatocellular carcinomas) and overtly malignant (progressed hepatocellular carcinomas). STATISTICAL TESTS: Differences between groups were assessed with Kruskal-Wallis and Mann-Whitney tests. RESULTS: ADC, mainly ADCoscillating , increased in the group of nodules with intermediate malignancy (ADCpulsed : 0.75 ± 0.25 × 10-3 mm2 /s vs. 0.64 ± 0.07 × 10-3 mm2 /s in benign nodules, P = 0.025; ADCoscillating : 0.81 ± 0.20 × 10-3 mm2 /s vs. 0.65 ± 0.13 × 10-3 mm2 /s, P = 0.0008) and ADCpulsed decreased in the group of progressed hepatocellular carcinomas (ADCpulsed : 0.60 ± 0.08 × 10-3 mm2 /s, P = 0.042; ADCoscillating : 0.68 ± 0.08 × 10-3 mm2 /s, P = 0.1). DATA CONCLUSION: ADC during hepatocarcinogenesis in rats increased in nodules with intermediate malignancy and decreased in progressed hepatocellular carcinomas. Our results suggest that oscillating gradient DWI is more sensitive to the early steps of hepatocarcinogenesis and might be useful for differentiating between high-grade dysplastic nodules / early hepatocellular carcinomas and regenerating nodules / low-grade dysplastic nodules. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1065-1074.

Correction to: Prediction of pancreatic neuroendocrine tumour grade with MR imaging features: added value of diffusion-weighted imaging.

The original version of this article, published on 19 August 2016, unfortunately contained a mistake.

COVID-19 impact assessment on the French radiological centers: a nationwide survey.

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 (CTcovid) and whole chest CT scan activities (CTchest) 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 CTchest 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 CTcovid on CTchest 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 CTcovid (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 (CTtotal) were performed among the responding centers, including 61,784 (52%) CT performed for COVID-19 (CTcovid). • Across the country, the ratio CTcovid/CTtotal 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.

Hemodynamic measurements with an abdominal 4D flow MRI sequence with spiral sampling and compressed sensing in patients with chronic liver disease.

BACKGROUND: The test-retest/interobserver repeatability and diagnostic value of 4D flow MRI in liver disease is underreported. PURPOSE: To determine the reproducibility/repeatability of flow quantification in abdominal vessels using a spiral 4D flow MRI sequence; to assess the value of 4D flow parameters in diagnosing cirrhosis and degree of portal hypertension. STUDY TYPE: Prospective. SUBJECTS: Fifty-two patients with chronic liver disease. FIELD STRENGTH/SEQUENCE: 1.5T/spiral 4D flow acquired in one breath-hold. ASSESSMENT: Thirteen abdominal vessels were identified and segmented by two independent observers to measure maximum and time-averaged through-plane velocity, net flow, and vessel cross-section area. Interobserver agreement and test-retest repeatability were evaluated in 15 and 4 cases, respectively. Prediction of the presence and severity of cirrhosis and portal hypertension was assessed using 4D flow parameters. STATISTICAL TESTS: Cohen's kappa coefficient, coefficient of variation (CV), Bland-Altman, Mann-Whitney tests, logistic regression. RESULTS: For all vessels combined, measurements showed acceptable agreement between observers, with Cohen's kappa = 0.70 (P < 0.001), CV < 21%, Bland-Altman bias <5%, but high limits of agreement ([-75%,75%]). Test-retest repeatability was excellent in large vessels (CV = 1-15%, bias = 1-25%, Bland-Altman limits of agreement [BALA] = [4%,150%]), and poor in small vessels (CV = 7-130%, bias = 10-200%, BALA = [8%,190%]). Average velocity in the right hepatic vein and average area of the splenic vein were higher in cirrhosis (P = 0.027/0.0039). Flow in the middle hepatic vein strongly correlated with Child-Pugh score (ρ = 0.84, P = 0.0238), while flow in the splenic vein (ρ = 0.43, P = 0.032), time-average (ρ = 0.46, P = 0.02) and peak velocity in the superior mesenteric vein (ρ = 0.45, P = 0.032), and peak velocity in the infrarenal IVC (ρ = 0.39, P = 0.032) positively correlated with an imaging-based portal hypertension score. Average area of the splenic vein predicted cirrhosis (P = 0.019; area under the curve AUC [95% confidence interval, CI] = 0.87 [0.71,1.00]) and clinically significant portal hypertension (P = 0.042; AUC [95% CI] = 0.78 [0.57-0.99]). DATA CONCLUSION: Spiral 4D flow allows comprehensive assessment of abdominal vessels in one breath-hold, with substantial interobserver reproducibility, but variable test-retest repeatability. 4D flow may potentially reflect vascular changes due to cirrhosis and portal hypertension. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:994-1005.

MRI for prostate cancer: can computed high b-value DWI replace native acquisitions?

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/mm2 and dynamic contrast enhanced images. C-DWI images (2000 and 2500 s/mm2) 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/mm2) 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.

Tumor-size responses to first-line is a predictor of overall survival in metastatic colorectal cancer.

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 (PDfl), stable disease with tumor-size evolution between 0 and + 19% (SDfl+) or 0 and - 29% (SDfl-), and partial responders (PRs), who were classed PR with ETS (ETSfl) or without (PRfl). Tumor-size evolution and best tumor responses to each chemotherapy line were analyzed. RESULTS: Tumor loads of ETSfl or PRfl mCRCs tended to remain inferior to their initial values: 60% of patients died with target lesion sums below baseline. For first-line SDfl+ or PDfl mCRCs, rapid tumor load increases continued during successive lines: > 80% died with target lesion sums above baseline. ETSfl mCRCs responded better to subsequent lines (37.5% second-line PR), whereas PDfl mCRCs remained refractory to other therapies (0% second- and third-line PR). Overall survival rates were significantly (p = 0.03) longer for the ETSfl group (29.9 [95% CI: 12.6-47.1] months) and shorter for the PDfl group (17.1 [95% CI: 1.5-37.5] months). CONCLUSION: Tumors responding to first-line chemotherapy also responded better to subsequent lines, whereas PDfl mCRCs remained refractory, which may explain the better survival associated with ETSfl. 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.

Earlier Anti-Tumor Necrosis Factor Therapy of Crohn's Disease Correlates with Slower Progression of Bowel Damage.

INTRODUCTION: Crohn's disease (CD) follows a relapsing and remitting course incurring cumulative bowel damage over time. The question of whether or not the timing of the initiating biologic therapy affects long-term disease progression remains unanswered. Herein, we calculated rates of change in the Lémann index-which quantifies accumulated bowel damage-as a function of the time between the disease onset and initiation of biologic therapy. We aimed to explore the impact of the earlier introduction of biologics on the rate of progression of long-term cumulative bowel damage. METHODS: Medical records of CD patients treated during 2009-2014 at The Mount Sinai Hospital were queried. Inclusion criteria were two comprehensive assessments allowing calculation of the index at t1 and t2: two time-points ≥ 1 year apart. Patients with biologics introduced before or within 3 months at inclusion (t1) were defined as Bio-pre-t1 and those who did not as Bio-post-t1. The rate of disease progression was calculated as the change in the index per year during t1-t2. RESULTS: A total of 88 patients were studied: 58 Bio-pre-t1 and 30 Bio-post-t1. Among the 58 Bio-pre-t1 cases, damage progressed in 29 (50%), regressed in 20 (34.5%), and stabilized in 9 (15.5%). Median time to initiation of biologics among patients whose index improved was nominally shorter compared to that in patients whose index progressed (8 vs. 15 years). Earlier introduction of biologics tended to correlate with the slower rate of progression (ρ = 0.241; p = 0.069). CONCLUSIONS: Earlier introduction of biologics tended to correlate with the slower progression of bowel damage in CD, reflected by the reduced rate of Lémann index progression.

Quantitative Elastography Methods in Liver Disease: Current Evidence and Future Directions.

Chronic liver diseases often result in the development of liver fibrosis and ultimately, cirrhosis. Treatment strategies and prognosis differ greatly depending on the severity of liver fibrosis, thus liver fibrosis staging is clinically relevant. Traditionally, liver biopsy has been the method of choice for fibrosis evaluation. Because of liver biopsy limitations, noninvasive methods have become a key research interest in the field. Elastography enables the noninvasive measurement of tissue mechanical properties through observation of shear-wave propagation in the tissue of interest. Increasing fibrosis stage is associated with increased liver stiffness, providing a discriminatory feature that can be exploited by elastographic methods. Ultrasonographic (US) and magnetic resonance (MR) imaging elastographic methods are commercially available, each with their respective strengths and limitations. Here, the authors review the technical basis, acquisition techniques, and results and limitations of US- and MR-based elastography techniques. Diagnostic performance in the most common etiologies of chronic liver disease will be presented. Reliability, reproducibility, failure rate, and emerging advances will be discussed. © RSNA, 2018 Online supplemental material is available for this article.

Accuracy, repeatability, and interplatform reproducibility of T1 quantification methods used for DCE-MRI: Results from a multicenter phantom study.

PURPOSE: To determine the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols used for dynamic contrast-enhanced MRI at 1.5 and 3 T. METHODS: A T1 phantom with 14 samples was imaged at eight centers with a common inversion-recovery spin-echo (IR-SE) protocol and a variable flip angle (VFA) protocol using seven flip angles, as well as site-specific protocols (VFA with different flip angles, variable repetition time, proton density, and Look-Locker inversion recovery). Factors influencing the accuracy (deviation from reference NMR T1 measurements) and repeatability were assessed using general linear mixed models. Interplatform reproducibility was assessed using coefficients of variation. RESULTS: For the common IR-SE protocol, accuracy (median error across platforms = 1.4-5.5%) was influenced predominantly by T1 sample (P < 10-6 ), whereas test-retest repeatability (median error = 0.2-8.3%) was influenced by the scanner (P < 10-6 ). For the common VFA protocol, accuracy (median error = 5.7-32.2%) was influenced by field strength (P = 0.006), whereas repeatability (median error = 0.7-25.8%) was influenced by the scanner (P < 0.0001). Interplatform reproducibility with the common VFA was lower at 3 T than 1.5 T (P = 0.004), and lower than that of the common IR-SE protocol (coefficient of variation 1.5T: VFA/IR-SE = 11.13%/8.21%, P = 0.028; 3 T: VFA/IR-SE = 22.87%/5.46%, P = 0.001). Among the site-specific protocols, Look-Locker inversion recovery and VFA (2-3 flip angles) protocols showed the best accuracy and repeatability (errors < 15%). CONCLUSIONS: The VFA protocols with 2 to 3 flip angles optimized for different applications achieved acceptable balance of extensive spatial coverage, accuracy, and repeatability in T1 quantification (errors < 15%). Further optimization in terms of flip-angle choice for each tissue application, and the use of B1 correction, are needed to improve the robustness of VFA protocols for T1 mapping. Magn Reson Med 79:2564-2575, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Detection of liver fibrosis using qualitative and quantitative MR elastography compared to liver surface nodularity measurement, gadoxetic acid uptake, and serum markers.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) combining different techniques such as MR elastography (MRE) has emerged as a noninvasive approach to diagnose and stage liver fibrosis with high accuracy allowing for anatomical and functional information. PURPOSE: To assess the diagnostic performance of mpMRI including qualitative and quantitative assessment of MRE, liver surface nodularity (LSN) measurement, hepatic enhancement ratios postgadoxetic acid, and serum markers (APRI, FIB-4) for the detection of liver fibrosis. STUDY TYPE: IRB-approved retrospective. SUBJECTS: Eighty-three adult patients. FIELD STRENGTH/SEQUENCE: 1.5T and 3.0T MR systems. MRE and T1 -weighted postgadoxetic acid sequences. ASSESSMENT: Two independent observers analyzed qualitative color-coded MRE maps on a scale of 0-3. Regions of interest were drawn to measure liver stiffness on MRE stiffness maps and on pre- and postcontrast T1 -weighted images to measure hepatic enhancement ratios. Software was used to generate LSN measurements. Histopathology was used as the reference standard for diagnosis of liver fibrosis in all patients. STATISTICAL TESTS: A multivariable logistic analysis was performed to identify independent predictors of liver fibrosis. Receiver operating characteristic (ROC) analysis evaluated the performance of each imaging technique for detection of fibrosis, in comparison with serum markers. RESULTS: Liver stiffness measured with MRE provided the strongest correlation with histopathologic fibrosis stage (r = 0.74, P < 0.001), and the highest diagnostic performance for detection of stages F2-F4, F3-F4, and F4 (areas under the curve [AUCs] of 0.87, 0.91, and 0.89, respectively, P < 0.001) compared to other methods. Qualitative assessment of MRE maps showed fair to good accuracy for detection of fibrosis (AUC range 0.76-0.84). Multivariable logistic analysis identified liver stiffness and FIB-4 as independent predictors of fibrosis with AUCs of 0.90 (F2-F4), 0.93 (F3-F4) and 0.92 (F4) when combined. DATA CONCLUSION: Liver stiffness measured with MRE showed the best performance for detection of liver fibrosis compared to LSN and gadoxetic acid uptake, with slight improvement when combined with FIB-4. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1552-1561.