Pre-emptive Aortic Side Branch Embolization during Endovascular Aneurysm Repair Using the Excluder Stent-Graft System: A Prospective Multicenter study.

PURPOSE: To evaluate the effectiveness and safety of pre-emptive transcatheter arterial embolization (P-TAE) for aortic side branches (ASBs) to prevent Type 2 endoleaks (EL2) before endovascular aneurysm repair (EVAR) using the Excluder stent-graft system (Excluder). MATERIALS AND METHODS: In this prospective, multicenter study, 80 patients (mean age, 79.1 years [SD ± 6.7]; 85.0% were men; mean aneurysmal sac diameter, 48.4 mm [SD ± 7.4]) meeting the eligibility criteria were prospectively enrolled from 9 hospitals. Before EVAR, P-TAE was performed to embolize the patent ASBs originating from the abdominal aortic aneurysm. Contrast-enhanced computed tomography (CT) was performed at 1 month and 6 months after EVAR. The primary endpoint was EL2 incidence at 6 months, and the secondary endpoints were aneurysmal sac diameter changes at 6 and 12 months, P-TAE outcomes, adverse events related to P-TAE, reintervention, and aneurysm-related mortality. RESULTS: All patients successfully underwent P-TAE without serious. Coil embolization was successful in 81.6% of ASBs. EL2 incidence at 6 months was identified in 18 of 70 (25.7%) patients. Aneurysmal sac diameter shrinkage (≥5 mm) was observed in 30.0% of patients at 6 months and in 40.9% at 12 months. Only 1 patient required reintervention for EL2 within 1 year of EVAR; aneurysm-related deaths were not observed. CONCLUSIONS: P-TAE for ASBs before EVAR using Excluder is a safe and effective strategy. It aids in achieving early aneurysmal sac shrinkage and reduces EL2 reintervention at 1 year after EVAR.

Magnetic resonance imaging-based risk factors of hepatocellular carcinoma after direct-acting antiviral therapy: A multicenter observational study.

AIM: To determine risk factors associated with hepatocellular carcinoma (HCC) development following direct-acting antiviral (DAA) therapy. METHODS: We enrolled patients with chronic hepatitis C who underwent direct-acting antiviral therapy and achieved sustained virologic response at 12 weeks between 2012 and 2018. Subsequently, patients were followed up. The primary endpoint was the development of HCC or the date of the last follow up when the absence of HCC was confirmed. Uni- and multivariate Cox proportional hazards models were used to identify factors contributing to HCC development, including gadoxetic acid-enhanced magnetic resonance imaging findings. The cumulative incidence rates of HCC development were calculated using the Kaplan-Meier method, and differences between groups were assessed using the log-rank test. RESULTS: The final study cohort comprised 482 patients (median age 70.5 years; 242 men). The median follow-up period was 36.8 months. Among 482 patients, 96 developed HCC (19.9%). The 1-, 3-, and 5-year cumulative rates of HCC development were 4.9%, 18.6%, and 30.5%, respectively. Multivariate analysis revealed that age, male sex, history of HCC, and hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were independent risk factors significantly associated with HCC development (p < 0.001-0.04). The highest risk group included patients with both a history of HCC and the presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement (the 1- and 3-year cumulative HCC development rates were 14.2% and 62.2%, respectively). CONCLUSION: History of HCC and presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were strong risk factors for HCC development following direct-acting antiviral therapy.

Association between tumor morphology and efficacy of atezolizumab plus bevacizumab for advanced hepatocellular carcinoma.

AIM: The IMbrave150 trial revealed that atezolizumab plus bevacizumab (AtezoBv) showed a higher objective response rate (ORR) in patients with advanced hepatocellular carcinoma (HCC). Although conversion therapy after AtezoBv has been recently reported, markers predictive of its efficacy, particularly radiological imaging markers, have not yet been identified. The present study focused on tumor morphological appearance on radiological imaging and evaluated whether it could be associated with AtezoBv efficacy. METHODS: Ninety-five intrahepatic lesions in 74 patients who were given AtezoBv for advanced HCC were recruited for evaluation. The lesions were divided into two groups, simple nodular (SN group) and non-simple nodular (non-SN group), based on the gross morphology on pretreatment imaging, and retrospectively evaluated for treatment response and other relevant clinical outcomes. RESULTS: Assessing the size of individual tumors after treatment, waterfall plots showed that tumor shrinkage in the non-SN group including 56 lesions was higher than that in the SN group comprising 39 lesions. The ORR was significantly higher in the non-SN group (39.3% vs. 15.4%, p = 0.012). Additionally, the median time to nodular progression was longer in the non-SN group (21.0 months vs. 8.1 months, p = 0.119) compared to the SN group. Six patients with non-SN lesions underwent sequential local therapy. CONCLUSIONS: Atezolizumab plus bevacizumab may show increased therapeutic efficacy in patients with tumors with a higher potential for aggressive oncological behavior, such as non-SN lesions. Treatment strategies focusing on conversion therapy may be crucial in patients with non-SN lesions.

Deep learning image reconstruction to improve accuracy of iodine quantification and image quality in dual-energy CT of the abdomen: a phantom and clinical study.

OBJECTIVES: To investigate the effect of deep learning image reconstruction (DLIR) on the accuracy of iodine quantification and image quality of dual-energy CT (DECT) compared to that of other reconstruction algorithms in a phantom experiment and an abdominal clinical study. METHODS: An elliptical phantom with five different iodine concentrations (1-12 mgI/mL) was imaged five times with fast-kilovoltage-switching DECT for three target volume CT dose indexes. All images were reconstructed using filtered back-projection, iterative reconstruction (two levels), and DLIR algorithms. Measured and nominal iodine concentrations were compared among the algorithms. Contrast-enhanced CT of the abdomen with the same scanner was acquired in clinical patients. In arterial and portal venous phase images, iodine concentration, image noise, and coefficients of variation for four locations were retrospectively compared among the algorithms. One-way repeated-measures analyses of variance were used to evaluate differences in the iodine concentrations, standard deviations, coefficients of variation, and percentages of error among the algorithms. RESULTS: In the phantom study, the measured iodine concentrations were equivalent among the algorithms: within ± 8% of the nominal values, with root-mean-square deviations of 0.08-0.36 mgI/mL, regardless of radiation dose. In the clinical study (50 patients; 35 men; mean age, 68 ± 11 years), iodine concentrations were equivalent among the algorithms for each location (all p > .99). Image noise and coefficients of variation were lower with DLIR than with the other algorithms (all p < .01). CONCLUSIONS: The DLIR algorithm reduced image noise and variability of iodine concentration values compared with other reconstruction algorithms in the fast-kilovoltage-switching dual-energy CT. KEY POINTS: • In the phantom study, standard deviations and coefficients of variation in iodine quantification were lower on images with the deep learning image reconstruction algorithm than on those with other algorithms. • In the clinical study, iodine concentrations of measurement location in the upper abdomen were consistent across four reconstruction algorithms, while image noise and variability of iodine concentrations were lower on images with the deep learning image reconstruction algorithm.

Consensus report from the 10th Global Forum for Liver Magnetic Resonance Imaging: developments in HCC management.

The 10th Global Forum for Liver Magnetic Resonance Imaging (MRI) was held as a virtual 2-day meeting in October 2021, attended by delegates from North and South America, Asia, Australia, and Europe. Most delegates were radiologists with experience in liver MRI, with representation also from specialists in liver surgery, oncology, and hepatology. Presentations, discussions, and working groups at the Forum focused on the following themes: • Gadoxetic acid in clinical practice: Eastern and Western perspectives on current uses and challenges in hepatocellular carcinoma (HCC) screening/surveillance, diagnosis, and management • Economics and outcomes of HCC imaging • Radiomics, artificial intelligence (AI) and deep learning (DL) applications of MRI in HCC. These themes are the subject of the current manuscript. A second manuscript discusses multidisciplinary tumor board perspectives: how to approach early-, mid-, and late-stage HCC management from the perspectives of a liver surgeon, interventional radiologist, and oncologist (Taouli et al, 2023). Delegates voted on consensus statements that were developed by working groups on these meeting themes. A consensus was considered to be reached if at least 80% of the voting delegates agreed on the statements. CLINICAL RELEVANCE STATEMENT: This review highlights the clinical applications of gadoxetic acid-enhanced MRI for liver cancer screening and diagnosis, as well as its cost-effectiveness and the applications of radiomics and AI in patients with liver cancer. KEY POINTS: • Interpretation of gadoxetic acid-enhanced MRI differs slightly between Eastern and Western guidelines, reflecting different regional requirements for sensitivity vs specificity. • Emerging data are encouraging for the cost-effectiveness of gadoxetic acid-enhanced MRI in HCC screening and diagnosis, but more studies are required. • Radiomics and artificial intelligence are likely, in the future, to contribute to the detection, staging, assessment of treatment response and prediction of prognosis of HCC-reducing the burden on radiologists and other specialists and supporting timely and targeted treatment for patients.

Consensus report from the 10th global forum for liver magnetic resonance imaging: multidisciplinary team discussion.

The 10th Global Forum for Liver Magnetic Resonance Imaging was held in October 2021. The themes of the presentations and discussions at this Forum are described in detail in the review by Taouli et al (2023). The focus of this second manuscript developed from the Forum is on multidisciplinary tumor board perspectives in hepatocellular carcinoma (HCC) management: how to approach early-, mid-, and late-stage management from the perspectives of a liver surgeon, an interventional radiologist, and an oncologist. The manuscript also includes a panel discussion by multidisciplinary experts on three selected cases that explore challenging aspects of HCC management. CLINICAL RELEVANCE STATEMENT: This review highlights the importance of a multidisciplinary team approach in liver cancer patients and includes the perspectives of a liver surgeon, an interventional radiologist, and an oncologist, including illustrative case studies. KEY POINTS: • A liver surgeon, interventional radiologist, and oncologist presented their perspectives on the treatment of early-, mid-, and late-stage HCC. • Different perspectives on HCC management between specialties emphasize the importance of multidisciplinary tumor boards. • A multidisciplinary faculty discussed challenging aspects of HCC management, as highlighted by three case studies.

Lenvatinib Mitigates Transarterial Embolization-Induced Polarization of Tumor-Associated Macrophages in a Rat Hepatocellular Carcinoma Model.

PURPOSE: To investigate the effect of transarterial embolization (TAE) on macrophage polarization and the modulatory effect of lenvatinib when used in combination with TAE in a rat hepatocellular carcinoma model. MATERIALS AND METHODS: A N1S1-bearing orthotopic rat model was subjected to TAE and administered 5 mg/kg of lenvatinib. CD8+, CD68+, and CD206+ cells were examined in 4 groups: sham (n = 5), lenvatinib (n = 5), TAE (n = 5), and combination of TAE and lenvatinib (n = 5). Transcriptome analysis was performed to assess gene expression related to macrophage polarization in the sham, TAE, and combination groups. An in vitro coculture experiment with bone marrow-derived macrophages was performed to identify lenvatinib target in macrophage polarization. RESULTS: There were no significant differences in the number of CD8+ and CD68+ cells among the 4 groups. Tumor-associated macrophage positivity for CD206 was significantly higher in the TAE group (58.1 ± 20.9) than in the sham (11.2 ± 14.3; P < .001) and combination (27.1 ± 19.7; P = .003) groups. In the transcriptome analysis, compared with the genes in the sham group, 5 macrophage polarization-related genes, including St6gal1, were upregulated by more than 1.5 fold in the TAE group and downregulated by more than 1.5 fold in the combination group. The coculture experiment showed that lenvatinib did not affect macrophages but affected N1S1 cells, leading to macrophage polarization. CONCLUSIONS: TAE-induced M2 macrophage polarization. Lenvatinib administration with TAE could reprogram macrophage polarization, improving tumor immune microenvironment.

Reevaluation of Makuuchi's criteria for resecting hepatocellular carcinoma: A Japanese nationwide survey.

AIM: Although Makuuchi's criteria are widely used to determine the cut-off for safe liver resection, there have been few reports of concrete data supporting their validity. Here, we verified the utility of Makuuchi's criteria by comparing the operative mortality rates associated with liver resection between hepatocellular carcinoma (HCC) patients meeting or exceeding the criteria. METHODS: A database was built using data from 15 597 patients treated between 2000 and 2007 for whom values for all three variables included in Makuuchi's criteria for liver resection (clinical ascites, serum bilirubin, and indocyanine green clearance) were available. The patients were divided into those fulfilling (n = 12 175) or exceeding (n = 3422) the criteria. The postoperative mortality (death for any reason within 30 days) and long-term survival were compared between the two groups. RESULTS: The operative mortality rate was significantly lower in patients meeting the criteria than in those exceeding the criteria (1.07% vs. 2.01%, respectively; p < 0.001). On multivariate analysis, exceeded the criteria was significantly associated with the risk for operative mortality (relative risk 2.08; 95% confidence interval (CI), 1.23-3.52; p = 0.007). Surgical indication meeting or exceeding the criteria was an independent factor for overall survival (hazard ratio 1.27; 95% CI, 1.18-1.36; p < 0.001). CONCLUSION: Makuuchi's criteria are suitable for determining the indication for resection of HCC due to the reduction in risk of operative mortality.

Report of the 23rd nationwide follow-up survey of primary liver cancer in Japan (2014-2015).

For the 23rd Nationwide Follow-up Survey of Primary Liver Cancer in Japan, data from 20 889 newly registered patients and 42 274 previously registered follow-up patients were compiled from 516 institutions over a 2-year period from January 1, 2014 to December 31, 2015. Basic statistics compiled for patients newly registered in the 23rd survey were cause of death, past medical history, clinical diagnosis, imaging diagnosis, treatment-related factors, pathological diagnosis, recurrence status, and autopsy findings. Compared with the previous 22nd survey, the population of patients with hepatocellular carcinoma (HCC) was older at the time of clinical diagnosis, had more female patients, had more patients with non-B non-C HCC, had smaller tumor diameter, and was more frequently treated with hepatectomy. Cumulative survival rates were calculated for HCC, intrahepatic cholangiocarcinoma, and combined hepatocellular cholangiocarcinoma (combined HCC and intrahepatic cholangiocarcinoma) by treatment type and background characteristics for patients newly registered between 2004 and 2015 whose final outcome was survival or death. The median overall survival and cumulative survival rates for HCC were calculated by dividing patients by combinations of background factors (number of tumors, tumor diameter, Child-Pugh grade, or albumin-bilirubin grade) and by treatment type (hepatectomy, radiofrequency ablation therapy, transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy, and systemic therapy). The same values were also calculated according to registration date by dividing patients newly registered between 1978 and 2015 into five time period groups. The data obtained from this nationwide follow-up survey are expected to contribute to advancing clinical research and treatment of primary liver cancer in the world.

Clinical Practice Guidelines for Hepatocellular Carcinoma: The Japan Society of Hepatology 2021 version (5th JSH-HCC Guidelines).

The fifth version of the Clinical Practice Guidelines for Hepatocellular Carcinoma was revised by the Japan Society of Hepatology, according to the methodology of evidence-based medicine and partly to the Grading of Recommendations Assessment, Development and Evaluation system, which was published in October 2021 in Japanese. In addition to surveillance-diagnostic and treatment algorithms, a new algorithm for systemic therapy has been created, as multiple drugs for hepatocellular carcinoma can be currently selected. Here, new or revised algorithms and evidence on which the recommendations are based are described.

Abbreviated Gadoxetic Acid-Enhanced MRI for the Detection of Liver Metastases in Patients With Potentially Resectable Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Gadoxetic acid-enhanced magnetic resonance imaging (MRI) is useful in detecting liver metastases from pancreatic ductal adenocarcinoma (PDAC). However, the long examination time limits its utility in the initial workup of patients with PDAC. PURPOSE: To evaluate the incremental value of an abbreviated gadoxetic acid-enhanced MRI for the detection of liver metastases in patients with PDAC. STUDY TYPE: Retrospective. POPULATION: Patients (N = 130) with potentially resectable PDAC (women, 58 [44.6%]). FIELD STRENGTH/SEQUENCE: 1.5 T and 3 T; gradient dual-echo T1-weighted (in-phase and opposed-phase), fat-suppressed fast spin-echo T2-weighted, single-shot echo-planar diffusion-weighted, and three-dimensional fat-suppressed T1-weighted gradient-echo dynamic contrast-enhanced and hepatobiliary phase sequences, as well as contrast-enhanced computed tomography (CECT). ASSESSMENT: Three radiologists independently reviewed three different image sets to detect liver metastases: set 1, CECT alone; set 2, CECT and abbreviated MRI comprising fat-suppressed T2-weighted, diffusion-weighted, and hepatobiliary phase images; and set 3, CECT and standard gadoxetic acid-enhanced MRI. STATISTICAL TESTS: Figure of merit (FOM) was compared using the jackknife alternative free-response receiver operating characteristics, and other per-lesion and per-patient diagnostic parameters for each image set were compared using McNemar's and Fisher's test. P < 0.05 was considered statistically significant. RESULTS: A total of 43 liver metastases were identified in 13 patients. Reader-averaged FOM to detect liver metastases were significantly higher for sets 2 (0.884) and 3 (0.886) than for set 1 (0.609), while they were comparable between sets 2 and 3 (P = 0.96). The mean per-patient sensitivities, negative predictive values, and accuracies were significantly higher for sets 2 and 3 than for set 1, while those between sets 2 and 3 were not significantly different (not applicable, P > 0.99, and P > 0.99, respectively). DATA CONCLUSION: Gadoxetic acid-enhanced MRI combined with CECT had higher diagnostic performance than CECT alone for the detection of liver metastases in patients with PDAC. The incremental values were comparable for the abbreviated MRI and standard MRI. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Estimation of pancreatic fibrosis and prediction of postoperative pancreatic fistula using extracellular volume fraction in multiphasic contrast-enhanced CT.

OBJECTIVE: To investigate the diagnostic performance of the extracellular volume (ECV) fraction in multiphasic contrast-enhanced computed tomography (CE-CT) for estimating histologic pancreatic fibrosis and predicting postoperative pancreatic fistula (POPF). METHODS: Eighty-five patients (49 men; mean age, 69 years) who underwent multiphasic CE-CT followed by pancreaticoduodenectomy with pancreaticojejunal anastomosis between January 2012 and December 2018 were retrospectively included. The ECV fraction was calculated from absolute enhancements of the pancreas and aorta between the precontrast and equilibrium-phase images, followed by comparisons among histologic pancreatic fibrosis grades (F0‒F3). The diagnostic performance of the ECV fraction in advanced fibrosis (F2‒F3) was evaluated using receiver operating characteristic curve analysis. Multivariate logistic regression analysis was used to evaluate the associations of the risk of POPF development with patient characteristics, histologic findings, and CT imaging parameters. RESULTS: The mean ECV fraction of the pancreas was 34.4% ± 9.5, with an excellent intrareader agreement of 0.811 and a moderate positive correlation with pancreatic fibrosis (r = 0.476; p < 0.001). The mean ECV fraction in advanced fibrosis was significantly higher than that in no/mild fibrosis (44.4% ± 10.8 vs. 31.7% ± 6.7; p < 0.001), and the area under the receiver operating characteristic curve for the diagnosis of advanced fibrosis was 0.837. Twenty-two patients (25.9%) developed clinically relevant POPF. Multivariate logistic regression analysis demonstrated that the ECV fraction was a significant predictor of POPF. CONCLUSIONS: The ECV fraction can offer quantitative information for assessing pancreatic fibrosis and POPF after pancreaticojejunal anastomosis. KEY POINTS: • There was a moderate positive correlation of the extracellular volume (ECV) fraction of the pancreas in contrast-enhanced CT with the histologic grade of pancreatic fibrosis (r = 0.476; p < 0.001). • The ECV fraction was higher in advanced fibrosis (F2‒F3) than in no/mild fibrosis (F0‒F1) (p < 0.001), with an AUC of 0.837 for detecting advanced fibrosis. • The ECV fraction was an independent risk factor for predicting subclinical (odds ratio, 0.81) and clinical (odds ratio, 0.80) postoperative pancreatic fistula.

Report of the 22nd nationwide follow-up Survey of Primary Liver Cancer in Japan (2012-2013).

In the 22nd Nationwide Follow-up Survey of Primary Liver Cancer in Japan, data from 21 155 newly registered patients and 43 041 previously registered follow-up patients were compiled from 538 institutions over a 2-year period from January 1, 2012 to December 31, 2013. Basic statistics compiled for patients newly registered in the 22nd survey were cause of death, past medical history, clinical diagnosis, imaging diagnosis, treatment-related factors, pathologic diagnosis, recurrence status and autopsy findings. Compared with the previous 21st survey, the population of patients with hepatocellular carcinoma (HCC) was older at the time of clinical diagnosis, had more female patients, more patients with non-B non-C HCC, smaller tumor diameter and was more frequently treated with hepatectomy. Cumulative survival rates were calculated for HCC, intrahepatic cholangiocarcinoma, and combined hepatocellular cholangiocarcinoma (combined HCC and intrahepatic cholangiocarcinoma) by treatment type and background characteristics for patients newly registered between 2002 and 2013 whose final outcome was survival or death. Median overall survival and cumulative survival rates for HCC were calculated by dividing patients by combinations of background factors (number of tumors, tumor diameter or Child-Pugh grade) and by treatment type (hepatectomy, radiofrequency ablation therapy, transcatheter arterial chemoembolization, hepatic arterial infusion chemotherapy and systemic therapy). The same values were also calculated according to registration date by dividing patients newly registered between 1978 and 2013 into five time period groups. The data obtained from this nationwide follow-up survey are expected to contribute to advancing clinical research and treatment of primary liver cancer worldwide.

Response Evaluation Criteria in Cancer of the liver version 6 (Response Evaluation Criteria in Cancer of the Liver 2021 revised version).

Response Evaluation Criteria in Solid Tumors (RECIST) is inappropriate to assess the direct effects of treatment on hepatocellular carcinoma (HCC) by locoregional therapies, such as radiofrequency ablation or transarterial chemoembolization. Therefore, establishment of response evaluation criteria solely devoted to HCC is needed in clinical practice, as well as in clinical trials of HCC treatment, such as systemic therapies, which cause necrosis of the tumor. Response Evaluation Criteria in Cancer of the Liver (RECICL) was revised in 2021 by the Liver Cancer Study Group of Japan based on the 2019 version of RECICL, which was commonly used in Japan. The major revised points of the RECICL 2021 is inclusion of RECIST version 1.1 and modified RECIST as response evaluation criteria in systemic therapy for HCC. We hope this new treatment response criteria, RECICL, proposed by the Liver Cancer Study Group of Japan will benefit the HCC treatment response evaluation in the setting of daily clinical practice and clinical trials as well, not only in Japan, but also internationally.

Effect of Diameter and Number of Hepatocellular Carcinomas on Survival After Resection, Transarterial Chemoembolization, and Ablation.

INTRODUCTION: Most studies predicting survival after resection, transarterial chemoembolization (TACE), and ablation analyzed diameter and number of hepatocellular carcinomas (HCCs) as dichotomous variables, resulting in an underestimation of risk variation. We aimed to develop and validate a new prognostic model for patients with HCC using largest diameter and number of HCCs as continuous variables. METHODS: The prognostic model was developed using data from patients undergoing resection, TACE, and ablation in 645 Japanese institutions. The model results were shown after balanced using the inverse probability of treatment-weighted analysis and were externally validated in an international multi-institution cohort. RESULTS: Of 77,268 patients, 43,904 patients, including 15,313 (34.9%) undergoing liver resection, 13,375 (30.5%) undergoing TACE, and 15,216 (34.7%) undergoing ablation, met the inclusion criteria. Our model (http://www.u-tokyo-hbp-transplant-surgery.jp/about/calculation.html) showed that the 5-year overall survival (OS) in patients with HCC undergoing these procedures decreased with progressive incremental increases in diameter and number of HCCs. For patients undergoing resection, the inverse probability of treatment-weighted-adjusted 5-year OS probabilities were 10%-20% higher compared with patients undergoing TACE for 1-6 HCC lesions <10 cm and were also 10%-20% higher compared with patients undergoing ablation when the HCC diameter was 2-3 cm. For patients undergoing resection and TACE, the model performed well in the external cohort. DISCUSSION: Our novel prognostic model performed well in predicting OS after resection and TACE for HCC and demonstrated that resection may have a survival benefit over TACE and ablation based on the diameter and number of HCCs.

Deep learning model for predicting gestational age after the first trimester using fetal MRI.

OBJECTIVES: To evaluate a deep learning model for predicting gestational age from fetal brain MRI acquired after the first trimester in comparison to biparietal diameter (BPD). MATERIALS AND METHODS: Our Institutional Review Board approved this retrospective study, and a total of 184 T2-weighted MRI acquisitions from 184 fetuses (mean gestational age: 29.4 weeks) who underwent MRI between January 2014 and June 2019 were included. The reference standard gestational age was based on the last menstruation and ultrasonography measurements in the first trimester. The deep learning model was trained with T2-weighted images from 126 training cases and 29 validation cases. The remaining 29 cases were used as test data, with fetal age estimated by both the model and BPD measurement. The relationship between the estimated gestational age and the reference standard was evaluated with Lin's concordance correlation coefficient (ρc) and a Bland-Altman plot. The ρc was assessed with McBride's definition. RESULTS: The ρc of the model prediction was substantial (ρc = 0.964), but the ρc of the BPD prediction was moderate (ρc = 0.920). Both the model and BPD predictions had greater differences from the reference standard at increasing gestational age. However, the upper limit of the model's prediction (2.45 weeks) was significantly shorter than that of BPD (5.62 weeks). CONCLUSIONS: Deep learning can accurately predict gestational age from fetal brain MR acquired after the first trimester. KEY POINTS: • The prediction of gestational age using ultrasound is accurate in the first trimester but becomes inaccurate as gestational age increases. • Deep learning can accurately predict gestational age from fetal brain MRI acquired in the second and third trimester. • Prediction of gestational age by deep learning may have benefits for prenatal care in pregnancies that are underserved during the first trimester.

Dose-dependent accumulation of glucose in the intestinal wall and lumen induced by metformin as revealed by 18 F-labelled fluorodeoxyglucose positron emission tomography-MRI.

AIM: To investigate the relationships between various clinical variables and the metformin-induced accumulation of fluorodeoxyglucose (FDG) in the intestine, with distinction between the intestinal wall and lumen, in individuals with type 2 diabetes who were receiving metformin treatment and underwent 18 F-labelled FDG ([18 F]FDG) positron emission tomography (PET)-MRI. MATERIALS AND METHODS: We evaluated intestinal accumulation of [18 F]FDG with both subjective (a five-point visual scale determined by two experienced radiologists) and objective analyses (measurement of the maximum standardized uptake value [SUVmax ]) in 26 individuals with type 2 diabetes who were receiving metformin and underwent [18 F]FDG PET-MRI. [18 F]FDG accumulation within the intestinal wall was discriminated from that in the lumen on the basis of SUVmax . RESULTS: SUVmax for the large intestine was correlated with blood glucose level (BG) and metformin dose, but not with age, body mass index, HbA1c level or estimated glomerular filtration rate (eGFR). SUVmax for the small intestine was not correlated with any of these variables. Visual scale analysis yielded essentially similar results. Metformin dose and eGFR were correlated with SUVmax for the wall and lumen of the large intestine, whereas BG was correlated with that for the wall. Multivariable analysis identified metformin dose as an explanatory factor for SUVmax in the wall and lumen of the large intestine after adjustment for potential confounders including BG and eGFR. CONCLUSIONS: Metformin dose is an independent determinant of [18 F]FDG accumulation in the wall and lumen of the large intestine in individuals treated with this drug.

Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging.

OBJECTIVES: The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid-enhanced imaging. METHODS: As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid-enhanced MRI in primary liver cancer and metastatic liver disease. RESULTS AND CONCLUSIONS: Gadoxetic acid-enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid-enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid-enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers. KEY POINTS: • Gadoxetic acid-enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy. • Gadoxetic acid-enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies. • Abbreviated protocols for gadoxetic acid-enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid-enhanced MRI for the assessment of liver and biliary function is under active investigation.

VI-RADS: Multiinstitutional Multireader Diagnostic Accuracy and Interobserver Agreement Study.

BACKGROUND. The Vesical Imaging Reporting and Data System (VI-RADS), based on multiparametric MRI (mpMRI), was developed to provide accurate information for the diagnosis of muscle-invasive bladder cancer (MIBC). OBJECTIVE. The purpose of our study was to evaluate the interobserver agreement and diagnostic performance of VI-RADS among readers with different levels of experience. METHODS. This retrospective study included 91 consecutive patients who underwent mpMRI before transurethral resection of bladder tumor (TURBT) from July 2010 through August 2018. After attending a training session, seven radiologists (five radiologists experienced in bladder MRI and two inexperienced radiologists) reviewed and scored all MRI examinations according to VI-RADS. The interobserver agreement was assessed by kappa statistics. ROC analysis was used to evaluate the diagnostic performance for MIBC. AUCs were estimated. RESULTS. Among 91 patients (72 men and 19 women; mean age ± SD, 73.2 ± 10.2 years), 48 (52.7%) had MIBC and 43 (47.3%) had non-muscle-invasive bladder cancer. Sixty-eight patients were treated with TURBT, and 23 were treated with radical cystectomy. Interobserver agreement was moderate to substantial (κ = 0.60-0.80) among the experienced readers, substantial (κ = 0.67) between the two inexperienced readers, and moderate to substantial (κ = 0.55-0.75) between the experienced and inexperienced readers. The pooled AUC was 0.88 (range, 0.82-0.91) for experienced readers and 0.84 (range, 0.83-0.85) for inexperienced readers, and 0.87 for all readers. Using a VI-RADS score of 4 or greater as the cutoff value for MIBC, the pooled sensitivity and specificity were 74.1% (range, 66.0-80.9%) and 94.1% (range, 88.6-97.7%) for experienced readers and 63.9% (range, 59.6-68.1%) and 86.4% (range, 84.1-88.6%) for inexperienced readers. Using a VI-RADS score of 3 or greater as the cutoff value, the pooled sensitivity and specificity were 83.4% (range, 80.9-85.1%) and 77.3% (range, 61.4-88.6%) for experienced readers and 82.0% (range, 80.9-83.0%) and 73.9% (range, 72.7-75.0%) for inexperienced readers. CONCLUSION. We observed moderate to substantial interobserver agreement and a pooled AUC of 0.87 among radiologists of different levels of expertise using VI-RADS. CLINICAL IMPACT. VI-RADS could help determine the depth and range of excision in TURBT, decreasing the risk of complications and enhancing the accuracy of pathologic diagnosis.

Report of the 21st Nationwide Follow-up Survey of Primary Liver Cancer in Japan (2010-2011).

In the 21st Nationwide Follow-up Survey of Primary Liver Cancer in Japan, data from 22,134 new patients and 41,956 previously followed patients were compiled from 546 institutions over a 2-year period from 1 January 2010 to 31 December 2011. Basic statistics compiled for patients newly registered in the 21st survey were cause of death, medical history, clinical diagnosis, imaging diagnosis, treatment-related factors, pathological diagnosis, recurrence status, and autopsy findings. Compared with the previous 20th survey, the population of patients with hepatocellular carcinoma (HCC) was older at the time of clinical diagnosis, had more female patients, had more patients with non-B non-C HCC, had smaller tumor diameter, and was more frequently treated with hepatectomy and with radiofrequency ablation. Cumulative survival rates were calculated for HCC, intrahepatic cholangiocarcinoma, and combined hepatocellular cholangiocarcinoma (combined HCC and intrahepatic cholangiocarcinoma) by treatment type and background characteristics for patients newly registered between 1998 and 2011 whose final outcome was survival or death (excluding unknown). Cumulative survival rates for HCC were calculated by dividing patients by combinations of background factors (number of tumors, tumor diameter, and Child-Pugh grade) and by treatment type (hepatectomy, local ablation therapy, transcatheter arterial chemoembolization, and hepatic arterial infusion chemotherapy). The same values were also calculated according to registration date by dividing patients newly registered between 1978 and 2011 into four time-period groups. The data obtained from this nationwide follow-up survey are expected to contribute to advancing clinical research and treatment of primary liver cancer.