Anatomical classification and clinical outcomes of biliary strictures in living donor liver transplantation using right liver grafts.

This study aimed to classify the anatomical types of biliary strictures, including intrahepatic biliary stricture (IHBS), after living donor liver transplantations (LDLTs) using right liver grafts and evaluate their prognosis. Among 692 adult patients who underwent right liver LDLT, 198 recipients with biliary strictures (28.6%) were retrospectively reviewed. Based on data obtained during the first cholangiography, the patients' biliary strictures were classified into the following three types according to the levels and number of branches involved: Types 1 (anastomosis), 2 (second-order branch [a, one; b, two or more; c, extended to the third-order branch]), and 3 (whole graft [a, multifocal strictures; b, diffuse necrosis]). IHBS was defined as a nonanastomotic stricture. Among the 198 recipients with biliary strictures, the IHBS incidence rates were 38.4% ( n = 76). The most common type of IHBS was 2c ( n = 43, 56.6%), whereas Type 3 ( n = 10, 13.2%) was uncommon. The intervention frequency per year significantly differed among the types (Type 1, 2.3; Type 2a, 2.3; Type 2b, 2.8; Type 2c, 4.3; and Type 3, 7.2; p < 0.001). The intervention-free period for more than 1 year, which was as follows, also differed among the types: Type 1, 84.4%; Type 2a, 87.5%; Type 2b, 86.7%; Type 2c, 72.1%; and Type 3, 50.0% ( p = 0.048). The graft survival rates of Type 3 (80.0%) were significantly lower than those of the other types ( p = 0.001). IHBSs are relatively common in right liver LDLTs. Although Type 3 IHBSs are rare, they require more intensive care and are associated with poorer graft survival rates than anastomosis strictures and Type 2 IHBS.

Abbreviated MRI for Secondary Surveillance of Recurrent Hepatocellular Carcinoma After Presumed Curative Treatment.

BACKGROUND: Little is known about the performance of abbreviated MRI (AMRI) for secondary surveillance of recurrent hepatocellular carcinoma (HCC) after curative treatment. PURPOSE: To evaluate the detection performance of AMRI for secondary surveillance of HCC after curative treatment. STUDY TYPE: Retrospective. POPULATION: A total of 243 patients (183 men and 60 women; median age, 65 years) who underwent secondary surveillance for HCC using gadoxetic acid-enhanced MRI after more than 2 year of disease-free period following curative treatment, including surgical resection or radiofrequency ablation (RFA). FIELD STRENGTH/SEQUENCE: A 3.0 T/noncontrast AMRI (NC-AMRI) (T2-weighted fast spin-echo, T1-weighted gradient echo, and diffusion-weighted images), hepatobiliary phase AMRI (HBP-AMRI) (T2-weighted fast spin-echo, diffusion-weighted, and HBP images), and full-sequence MRI ASSESSMENT: Four board-certified radiologists independently reviewed NC-AMRI, HBP-AMRI, and full-sequence MRI sets of each patient for detecting recurrent HCC. STATISTICAL TESTS: Per-lesion sensitivity, per-patient sensitivity and specificity for HCC detection at each set were compared using generalized estimating equation. RESULTS: A total of 42 recurred HCCs were confirmed in the 39 patients. The per-lesion and per-patient sensitivities did not show significant differences among the three image sets for either reviewer (P ≥ 0.358): per-lesion sensitivity: 59.5%-83.3%, 59.5%-85.7%, and 59.5%-83.3%, and per-patient sensitivity: 53.9%-83.3%, 56.4%-85.7%, and 53.9%-83.3% for NC-AMRI, HBP-AMRI, and full-sequence MRI, respectively. Per-lesion pooled sensitivities of NC-AMRI, HBP-AMRI, and full-sequence MRI were 72.6%, 73.2%, and 73.2%, with difference of -0.6% (95% confidence interval: -6.7, 5.5) between NC-AMRI and full-sequence MRI and 0.0% (-6.1, 6.1) between HBP-AMRI and full-sequence MRI. Per-patient specificity was not significantly different among the three image sets for both reviewers (95.6%-97.1%, 95.6%-97.1%, and 97.6%-98.5% for NC-AMRI and HBP-AMRI, respectively; P ≥ 0.117). DATA CONCLUSION: NC-AMRI and HBP-AMRI showed no significant difference in detection performance to that of full-sequence gadoxetic acid-enhanced MRI during secondary surveillance for HCC after more than 2-year disease free interval following curative treatment. Based on its good detection performance, short scan time, and lack of contrast agent-associated risks, NC-AMRI is a promising option for the secondary surveillance of HCC. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

Low dose of contrast agent and low radiation liver computed tomography with deep-learning-based contrast boosting model in participants at high-risk for hepatocellular carcinoma: prospective, randomized, double-blind study.

OBJECTIVE: To investigate the image quality and lesion conspicuity of a deep-learning-based contrast-boosting (DL-CB) algorithm on double-low-dose (DLD) CT of simultaneous reduction of radiation and contrast doses in participants at high-risk for hepatocellular carcinoma (HCC). METHODS: Participants were recruited and underwent four-phase dynamic CT (NCT04722120). They were randomly assigned to either standard-dose (SD) or DLD protocol. All CT images were initially reconstructed using iterative reconstruction, and the images of the DLD protocol were further processed using the DL-CB algorithm (DLD-DL). The primary endpoint was the contrast-to-noise ratio (CNR), the secondary endpoint was qualitative image quality (noise, hepatic lesion, and vessel conspicuity), and the tertiary endpoint was lesion detection rate. The t-test or repeated measures analysis of variance was used for analysis. RESULTS: Sixty-eight participants with 57 focal liver lesions were enrolled (20 with HCC and 37 with benign findings). The DLD protocol had a 19.8% lower radiation dose (DLP, 855.1 ± 254.8 mGy·cm vs. 713.3 ± 94.6 mGy·cm, p = .003) and 27% lower contrast dose (106.9 ± 15.0 mL vs. 77.9 ± 9.4 mL, p < .001) than the SD protocol. The comparative analysis demonstrated that CNR (p < .001) and portal vein conspicuity (p = .002) were significantly higher in the DLD-DL than in the SD protocol. There was no significant difference in lesion detection rate for all lesions (82.7% vs. 73.3%, p = .140) and HCCs (75.7% vs. 70.4%, p = .644) between the SD protocol and DLD-DL. CONCLUSIONS: DL-CB on double-low-dose CT provided improved CNR of the aorta and portal vein without significant impairment of the detection rate of HCC compared to the standard-dose acquisition, even in participants at high risk for HCC. KEY POINTS: • Deep-learning-based contrast-boosting algorithm on double-low-dose CT provided an improved contrast-to-noise ratio compared to standard-dose CT. • The detection rate of focal liver lesions was not significantly differed between standard-dose CT and a deep-learning-based contrast-boosting algorithm on double-low-dose CT. • Double-low-dose CT without a deep-learning algorithm presented lower CNR and worse image quality.

Performance of LI-RADS Version 2018 on CT for Determining Eligibility for Liver Transplant According to Milan Criteria in Patients at High Risk for Hepatocellular Carcinoma.

BACKGROUND. LI-RADS has been investigated primarily in terms of detection of hepatocellular carcinoma (HCC), with less attention given to its performance, particularly on CT, in determining eligibility for liver transplant (LT). OBJECTIVE. The purpose of our study was to assess the performance of LI-RADS version 2018 (v2018) on CT for the diagnosis of HCC and determination of LT eligibility according to the Milan criteria (MC). METHODS. This retrospective study included 136 patients (110 men, 26 women; mean age, 53.9 ± 8.1 [SD] years) at high-risk for HCC who underwent liver protocol CT within 3 months before LT between January 2010 and December 2018. Two radiologists independently reviewed CT examinations using LI-RADS v2018; Organ Procurement and Transplantation Network (OPTN) classes were constructed from the LI-RADS interpretations. Histopathologic analysis of liver explants served as the reference standard for determining the presence of HCC and LT eligibility based on MC. Diagnostic performance was evaluated. Overall survival (OS) was assessed based on medical record review. RESULTS. Based on histopathologic evaluation of liver explants in the 136 patients, 27 patients had no malignancy, 77 were eligible for LT due to HCC within MC, and 32 were unsuitable for LT (i.e., HCC beyond MC in 16 patients, HCC with macrovascular invasion in 12, non-HCC malignancy in four). LR-5 exhibited per-lesion sensitivity and PPV for HCC of 55.9% and 92.8%, respectively, for reader 1 and 39.8% and 86.5% for reader 2. When considering LR-5 observations to represent HCC in assessing MC, LI-RADS had accuracy for determining LT eligibility of 92.7% for reader 1 and 85.3% for reader 2; OPTN criteria had accuracy for determining LT eligibility of 89.0% for reader 1 and 84.4% for reader 2. Five-year OS for patients within MC versus 5-year OS for patients unsuitable for LT was 92.2 months versus 56.0 months for LI-RADS, 92.6 months versus 47.6 months for OPTN criteria, and 93.3 months versus 55.1 months for histopathologic assessment of liver explants. CONCLUSION. LI-RADS v2018, as evaluated on CT in high-risk patients, shows high PPV for HCC detection and high accuracy for determining LT eligibility based on MC. LT eligibility based on preoperative LI-RADS evaluation is associated with post-LT survival. CLINICAL IMPACT. These findings support the use of LI-RADS on CT in assessing eligibility in patients who are candidates for LT.

Development of a predictive model for extragastric recurrence after curative resection for early gastric cancer.

BACKGROUND: Stratification of patients who undergo curative resection for early gastric cancer (EGC) is warranted due to the heterogeneity in the risk of developing extragastric recurrence (EGR). Therefore, we aimed to stratify the need for postoperative surveillance for EGR detection in patients with EGC by developing a model for predicting EGR-free survival. METHODS: This retrospective cohort study included patients who underwent postoperative surveillance after curative resection of EGC (n = 4149). Cox proportional hazard models were used to identify predictors to build a model for predicting EGR-free survival. Bootstrap-corrected c-index and calibration plots were used for internal and external (n = 2148) validations. RESULTS: A risk-scoring system was constructed using variables significantly associated with EGR-free survival: pathologic T stage (pT1b[sm1], hazard ratio [HR] 4.928; pT1b[sm2], HR 5.235; pT1b[sm3], HR 7.748) and N stage (pN1, HR 4.056; pN2, HR 9.075; pN3, HR 30.659). Patients were dichotomized into a very-low-risk group or a low-or-greater-risk group. The 5-year EGR-free survival rates differed between the two groups (99.9 vs. 97.3%). The discriminative performance of the model was 0.851 (Uno's c-index) and 0.751 in the internal and external cohorts, respectively. The calibration slope was 0.916 and 1.131 in the internal and external cohorts, respectively. CONCLUSIONS: Our model for predicting EGR-free survival based on the pathologic T and N stages may be useful for stratifying patients who have undergone curative surgery for EGC. The results suggest that patients in the very-low-risk group may be spared from postoperative surveillance considering their extremely high EGR-free survival rate.

Prediction of residual tumor and overall survival after first-line surgery in patients with pancreatic ductal adenocarcinoma using preoperative magnetic resonance imaging findings.

BACKGROUND: Complete resection is the only potentially curative treatment in patients with pancreatic ductal adenocarcinoma (PDA) and is associated with a longer overall survival (OS) than incomplete resection of tumor. Hence, prediction of the resection status after surgery would help predict the prognosis of patients with PDA. PURPOSE: To predict residual tumor (R) classification and OS in patients who underwent first-line surgery for PDA using preoperative magnetic resonance imaging (MRI). MATERIAL AND METHODS: In this study, 210 patients with PDA who underwent MRI and first-line surgery were randomly categorized into a test group (n=150) and a validation group (n=60). The R classification was divided into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). Preoperative MRI findings associated with R classification and OS were assessed by using logistic regression and Cox proportional hazard models. In addition, the prediction models for the R classification and OS were validated using calibration plots and C statistics. RESULTS: On preoperative MRI, portal vein encasement (odds ratio 4.755) was an independent predictor for R1/R2 resection (P=0.040). Tumor size measured on MRI (hazard ratio [HR] per centimeter 1.539) was a predictor of OS, along with pathologic N1 and N2 stage (HR 1.944 and 3.243, respectively), R1/R2 resection (HR 3.273), and adjuvant chemoradiation therapy (HR 0.250) (P<0.050). Calibration plots demonstrated satisfactory predictive performance. CONCLUSION: Preoperative MRI was valuable for predicting R1/R2 resection using portal vein encasement. Tumor size measured on MRI was useful for the prediction of OS after first-line surgery for PDA.

Accuracy of Two-Dimensional Shear Wave Elastography and Attenuation Imaging for Evaluation of Patients With Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: We evaluated the accuracy of a multiparametric approach using attenuation imaging and 2-dimensional shear wave elastography (2D-SWE) for the detection of steatosis and fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: We studied 102 patients with increased levels of liver enzymes or suspicion of NAFLD, examined by attenuation imaging and 2D-SWE, immediately before biopsy collection and analysis (reference standard), from January 2018 to July 2019. We collected data on the attenuation coefficient (dB/cm/MHz) from attenuation imaging, liver stiffness measurements, and shear wave dispersion slope (SWDS, [m/s]/kHz) from 2D-SWE. Multivariate linear regression analysis was performed to identify factors associated with each parameter. Diagnostic performance was determined from area under the receiver operating curve (AUROC) values. RESULTS: The attenuation coefficient was associated with steatosis grade (P < .01) and identified patients with steatosis grades S1 or higher, S2 or higher, and S3 or higher, with AUROC values of 0.93, 0.88, and 0.83, respectively. Liver stiffness associated with fibrosis stage (P < .01) and lobular inflammatory activity was the only factor associated with SWDS (P < .01). SWDS detected inflammation grades I1 or higher, I2 or higher, and I3 or higher with AUROC values of 0.89, 0.85, and 0.78, respectively. We developed a risk scoring system to detect steatohepatitis based on the attenuation coefficient (score of 1 for 0.64 < attenuation coefficient ≤ 0.70; score of 2 for 0.70 < attenuation coefficient ≤ 0.73; and score of 3 for attenuation coefficient >0.73) and SWDS (score of 2 for 10.5 [m/s]/kHz < SWDS ≤ 11.7 [m/s]/kHz; and score of 3 for SWDS >11.7 [m/s]/kHz), using an unweighted sum of each score. Based on histopathology analysis, 55 patients had steatohepatitis. Risk scores correlated with NAFLD activity score (rho = 0.73; P < .01). Our scoring system identified patients with steatohepatitis with an AUROC of 0.93-this value was significantly higher than that of other parameters (P < .05), except SWDS (AUROC, 0.89; P = .18). CONCLUSIONS: In the evaluation of patients with suspected NAFLD, the attenuation coefficient can identify patients with steatosis and liver stiffness can detect fibrosis accurately. SWDS was associated significantly with lobular inflammation. We developed a risk scoring system based on the attenuation coefficient and SWDS that might be used to detect steatohepatitis.

Gadoxetate-enhanced MRI Features of Proliferative Hepatocellular Carcinoma Are Prognostic after Surgery.

Background Hepatocellular carcinomas (HCCs) are heterogeneous neoplasms, and the prognosis varies based on the subtype. Two broad molecular classes of HCC have been proposed: a proliferative and a nonproliferative class. Purpose To evaluate the gadoxetate-enhanced MRI findings of the proliferative class HCC and its prognostic significance after surgery. Materials and Methods This retrospective cohort study evaluated patients with surgically resected treatment-naive single HCC (≤5 cm) who underwent hepatic resection from January 2010 through February 2013 and preoperative gadoxetate-enhanced MRI. A Cox proportional hazards model was used to determine the predictive factors for overall survival (OS), intrahepatic distant recurrence, and extrahepatic metastasis (EM). The mean follow-up period was 75.5 months ± 30.2 (standard deviation). Multivariable logistic regression was performed to determine factors associated with proliferative class HCC. Results A total of 158 patients (mean age, 57 years ± 11; 128 men and 30 women) were evaluated. Forty-two of the 158 HCCs (26.6%) were proliferative class HCCs (17 macrotrabecular-massive HCCs, 14 keratin 19-positive HCCs, 10 scirrhous HCCs, and one sarcomatoid HCC). The proliferative class was associated with worse OS (hazard ratio [HR], 3.1; 95% CI: 1.5, 6.0; P = .01) and higher rates of intrahepatic distant recurrence (HR, 1.83; 95% CI: 1.1, 2.9; P = .01) and EM (HR, 9.97; 95% CI: 3.2, 31.4; P < .001). Rim arterial phase hyperenhancement (APHE) at gadoxetate-enhanced MRI (odds ratio [OR], 6.35; 95% CI: 1.9, 21.7; P = .01) and high serum α-fetoprotein (>100 ng/mL) (OR, 4.18; 95% CI: 1.64, 10.7; P = .01) were independent predictors for proliferative HCC. The presence of rim APHE was associated with poor OS (HR, 2.4; 95% CI: 1.2, 4.9; P = .02) and higher rates of EM (HR, 7.4; 95% CI: 2.5, 21.7; P < .01). Conclusion The proliferative class of hepatocellular carcinoma (HCC) is an independent factor for poor overall survival with increased rates of intrahepatic and extrahepatic metastasis. Rim arterial phase hyperenhancement at gadoxetate-enhanced MRI may help to identify proliferative class HCC and predict poor overall survival and an increased incidence of extrahepatic metastasis. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Krinsky and Shanbhogue in this issue.

Added value of [68Ga]Ga-DOTA-TOC PET/CT for characterizing pancreatic neuroendocrine neoplasms: a comparison with contrast-enhanced CT and/or MRI in a large study cohort.

OBJECTIVES: To investigate an additional value of [68Ga]Ga-DOTA-TOC PET/CT for characterizing suspected pancreatic neuroendocrine neoplasms (NENs) in a large study cohort. METHODS: This retrospective study included 167 patients who underwent [68Ga]Ga-DOTA-TOC PET/CT for suspected pancreatic NENs detected by contrast-enhanced CT (n = 153) and/or MRI (n = 85). Two board-certified radiologists independently reviewed CT and/or MRI as well as [68Ga]Ga-DOTA-TOC PET/CT and scored the probability of NEN on a 5-point scale. Radiologists' diagnostic performances with and without [68Ga]Ga-DOTA-TOC PET/CT were compared using pathologic findings as the standard of reference. RESULTS: All 167 patients were pathologically diagnosed with NENs (n = 131) or non-NENs (n = 36) by surgery (n = 93) or biopsy (n = 74). The non-NEN group included focal pancreatitis (n = 7), gastrointestinal stromal tumor (n = 6), serous cystadenoma (n = 5), metastatic renal cell carcinoma (n = 4), intrapancreatic accessory spleen (n = 4), ductal adenocarcinoma (n = 3), solid pseudopapillary neoplasm (n = 2), intraductal papillary mucinous carcinoma (n = 1), adenosquamous carcinoma (n = 1), schwannoma (n = 1), paraganglioma (n = 1), and solitary fibrous tumor (n = 1). Radiologists' diagnostic performance significantly improved after the addition of [68Ga]Ga-DOTA-TOC PET/CT (AUC of CT: 0.737 vs. 0.886 for reviewer 1 [p = 0.0004]; 0.709 vs. 0.859 for reviewer 2 [p = 0.0002], AUC of MRI: 0.748 vs. 0.872 for reviewer 1 [p = 0.023]; 0.670 vs. 0.854 for reviewer 2 [p = 0.001]). [68Ga]Ga-DOTA-TOC PET/CT significantly improved sensitivity (CT: 87.4% vs. 96.6% for reviewer 1 [p = 0.001]; 74.8% vs. 92.5% for reviewer 2 [p = 0.0001], MRI: 86.9% vs. 98.4% for reviewer 1 [p = 0.016]; 70.5% vs. 91.8% for reviewer 2 [p = 0.002]). CONCLUSIONS: [68Ga]Ga-DOTA-TOC PET/CT provided an additional value over conventional CT or MRI for the characterization of suspected pancreatic NENs. KEY POINTS: • [68Ga]Ga-DOTA-TOC PET/CT could provide additional value over conventional CT and/or MRI for the exact characterization of suspected pancreatic NENs by increasing AUC values and sensitivity. • Diagnostic improvement was significant, especially in NENs showing an atypical enhancement pattern. • The inter-observer agreement was improved when [68Ga]Ga-DOTA-TOC PET/CT was added to CT and/or MRI.

Hepatobiliary phase of gadoxetic acid-enhanced MRI in patients with HCC: prognostic features before resection, ablation, or TACE.

OBJECTIVES: Patients with hepatocellular carcinoma (HCC) receiving different treatments might have specific prognostic factors that can be captured in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced magnetic resonance imaging (GA-MRI). We aimed to identify the clinical findings and HBP features with prognostic value in patients with HCC. METHODS: In this retrospective, single-institution study, we included patients with Barcelona Clinic Liver Cancer very early/early stage HCC who underwent GA-MRI before treatment. After performing propensity score matching, 183 patients received the following treatments: resection, radiofrequency ablation (RFA), and transarterial chemoembolization (TACE) (n = 61 for each). Cox regression models were used to identify clinical factors and HBP features associated with disease-free survival (DFS) and overall survival (OS). RESULTS: In the resection group, large tumor size was associated with poor DFS (hazard ratio [HR] 4.159 per centimeter; 95% confidence interval [CI], 1.669-10.365) and poor OS (HR 8.498 per centimeter; 95% CI, 1.072-67.338). In the RFA group, satellite nodules on HBP images were associated with poor DFS (HR 5.037; 95% CI, 1.061-23.903) and poor OS (HR 9.398; 95% CI, 1.480-59.668). Peritumoral hypointensity on HBP images was also associated with poor OS (HR 13.062; 95% CI, 1.627-104.840). In addition, serum albumin levels and the prothrombin time-international normalized ratio were associated with DFS and/or OS. Finally, in the TACE group, no variables were associated with DFS/OS. CONCLUSIONS: Different HBP features and clinical factors were associated with DFS/OS among patients with HCC receiving different treatments. KEY POINTS: • In patients who underwent resection for HCC, a large tumor size on HBP images was associated with poor disease-free survival and overall survival. • In the RFA group, satellite nodules and peritumoral hypointensity on HBP images, along with decreased serum albumin levels and PT-INR, were associated with poor disease-free survival and/or overall survival. • In the TACE group, no clinical or HBP imaging features were associated with disease-free survival or overall survival.

Important CT and histopathological findings for recurrence and overall survival in patients with pancreatic ductal adenocarcinoma who underwent surgery after neoadjuvant FOLFIRINOX.

OBJECTIVES: To investigate important factors for recurrence-free survival (RFS) and overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDA) who underwent surgery after neoadjuvant FOLFIRINOX using CT and histopathological findings. MATERIALS AND METHODS: Sixty-nine patients with PDA who underwent surgery after neoadjuvant FOLFIRINOX were retrospectively included. All patients underwent baseline and first follow-up CT. Two reviewers assessed the CT findings and resectability based on the NCCN guideline. They graded extrapancreatic perineural invasion (EPNI) using a 3-point scale focused on 5 routes. Clinical and histopathological results, such as T- and N-stage, tumor regression grade (TRG) using the College of American Pathology (CAP) grading system, and resection status, were also investigated. Kaplan-Meier methods were used for RFS and OS. The Cox proportional hazard model and logistic regression model were used to identify significant predictive factors. RESULTS: There were 57 patients (82.6%) without residual tumors (R0) and 12 patients (17.4%) with residual tumors (R1 or R2). The median RFS was 13 months (range 0~22 months). For RFS, EPNI on baseline CT (hazard ratio (HR) 2.53, 95% confidence interval (CI) 1.116-5.733, p = 0.026) and TRG (HR 1.76, 95% CI 1.000-3.076, p = 0.046) were important predictors of early recurrence. The mean OS was 48 months (range 11~35 months). For OS, TRG (HR 1.05, 95% CI 1.251-6.559, p = 0.013) was a significant factor. However, there were no independent predictors for residual tumors according to the CT findings. CONCLUSION: EPNI on baseline CT and TRG were important prognostic factors for tumor recurrence. In addition, TRG was also an important prognostic factor for OS. KEY POINTS: • CT and histopathological findings are helpful for predicting early recurrence and poor survival. • EPNI on baseline CT (HR 2.53, p = 0.026) is an important predictor of early recurrence. • The TRG is an important prognostic factor for early recurrence (HR 1.76, p = 0.046) and poor survival (HR 1.05, p = 0.013).

Assessment of malignant potential in intraductal papillary mucinous neoplasms of the pancreas using MR findings and texture analysis.

OBJECTIVES: To investigate the utility of MR findings and texture analysis for predicting the malignant potential of pancreatic intraductal papillary mucinous neoplasms (IPMNs). METHODS: Two hundred forty-eight patients with surgically confirmed IPMNs (106 malignant [invasive carcinoma/high-grade dysplasia] and 142 benign [low/intermediate-grade dysplasia]) and who underwent magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) were included. Two reviewers independently analyzed MR findings as proposed by the 2017 international consensus guidelines. Texture analysis of MRCP was also performed. A multivariate logistic regression analysis was used to identify predictors for malignant IPMNs. Diagnostic performance was also analyzed using receiver operating curve analysis. RESULTS: Among MR findings, enhancing mural nodule size ≥ 5 mm, main pancreatic duct (MPD) ≥ 10 mm or MPD of 5 to 9 mm, and abrupt change of MPD were significant predictors for malignant IPMNs (p < 0.05). Among texture variables, significant predictors were effective diameter, surface area, sphericity, compactness, entropy, and gray-level co-occurrence matrix entropy (p < 0.05). At multivariate analysis, enhancing mural nodule ≥ 5 mm (odds ratios (ORs), 6.697 and 6.968, for reviewers 1 and 2, respectively), MPD ≥ 10 mm or MPD of 5 to 9 mm (ORs, 4.098 and 4.215, and 2.517 and 3.055, respectively), larger entropy (ORs, 1.485 and 1.515), and smaller compactness (ORs, 0.981 and 0.977) were significant predictors for malignant IPMNs (p < 0.05). When adding texture variable to MR findings, diagnostic performance for predicting malignant IPMNs improved from 0.80 and 0.78 to 0.85 and 0.85 in both reviewers (p < 0.05), respectively. CONCLUSIONS: MRCP-derived texture features are useful for predicting malignant IPMNs, and the addition of texture analysis to MR features may improve diagnostic performance for predicting malignant IPMNs. KEY POINTS: • Among the MR imaging findings, an enhancing mural nodule size ≥ 5 mm and dilated main pancreatic ducts are independent predictors for malignant IPMNs. • Greater entropy and smaller compactness on MR texture analysis are independent predictors for malignant IPMNs. • The addition of MR texture analysis improved the diagnostic performance for predicting malignant IPMNs from 0.80 and 0.78 to 0.85 and 0.85, respectively.

Intra-individual comparison of dual portal venous phases for non-invasive diagnosis of hepatocellular carcinoma at gadoxetic acid-enhanced liver MRI.

OBJECTIVES: To compare the diagnostic performances of first and second portal venous phases (PVP1 and PVP2) in revealing washout and capsule appearance for non-invasive HCC diagnoses in gadoxetic acid-enhanced MRI (Gd-EOB-MRI). METHODS: This retrospective study included 123 at-risk patients with 160 hepatic observations (HCCs, n = 116; non-HCC malignancies, n = 18; benign, n = 26) showing arterial phase hyper-enhancement (APHE) ≥ 1 cm at Gd-EOB-MRI. The mean time intervals from gadoxetic acid injection to PVP1 and PVP2 acquisitions were 53 ± 2 s and 73 ± 3 s, respectively. After evaluating image findings independently, imaging findings and diagnoses were finalized by a consensus of two radiologists using either PVP1 or PVP2 image sets according to the LI-RADS v2018 or EASL criteria. Sensitivity, specificity, and accuracy were compared. RESULTS: Among HCCs, more washout and enhancing capsule were observed in PVP2 (83.6% and 27.6%) than in PVP1 (50.9% and 19.8%) (p < 0.001, both). The PVP2 set presented significantly higher sensitivity (83.6% vs. 53.5%, LI-RADS; 82.8% vs. 50.0%, EASL; p < 0.001, both) and accuracy (0.88 vs. 0.73, LI-RADS; 0.88 vs. 0.72, EASL; p < 0.001, both) than the PVP1 set without significant specificity loss (93.2% vs. 93.2%, by LI-RADS or EASL; p = 0.32, both). None of the non-HCC malignancy was non-invasively diagnosed as HCC in both PVP image sets. CONCLUSION: Late acquisition of PVP detected washout and enhancing capsule of HCC more sensitively than early acquisition, enabling accurate diagnoses of HCC, according to LI-RADS or EASL criteria. KEY POINTS: • Among HCCs, more washout and enhancing capsules were observed in PVP2 than PVP1, quantitatively and qualitatively. • The portal venous phase acquired at around 70 s after contrast media administration (PVP2) provided significantly higher sensitivity and AUC value than PVP1 by using LI-RADS v2018 or EASL criteria. • More HCCs were categorized as LR-5 in PVP2 than in PVP1 images, and the specificity of PVP2 (93.5%) was comparable with PVP1 (93.5%).

2D shear wave elastography is better than transient elastography in predicting post-hepatectomy complication after resection.

OBJECTIVES: Both transient elastography (TE) and 2D shear wave elastography (SWE) are accurate methods to evaluate liver fibrosis. We aimed to evaluate the diagnostic performance of 2D-SWE in predicting post-hepatectomy complication and to compare it with TE. METHODS: We prospectively enrolled 125 patients with liver tumors. Liver stiffness (LS) (kilopascal [kPa]) was measured using both TE and 2D-SWE before surgery. All post-operative complication was evaluated using the comprehensive complication index (CCI), and CCI ≥ 26.2 was defined as severe complication. Logistic regression analysis was performed to identify predictive factors for severe complication. Receiver operating characteristic analysis was used to evaluate the diagnostic performance of TE/2D-SWE in detecting liver fibrosis and severe complication. RESULTS: Severe complication developed in 18 patients. The median LS in patients with severe complication was significantly higher for both 2D-SWE (11.4 kPa vs. 7.0 kPa, p < 0.001) and TE (8.9 kPa vs. 6.2 kPa, p = 0.009). LS obtained from 2D-SWE was a significant factor correlated with severe complication (odds ratio: 1.27 per kPa [1.10-1.46], p = 0.001). The diagnostic performance of 2D-SWE was significantly higher than that of TE in detecting both ≥F3 (p = 0.024) and F4 (p = 0.048). The area under the curve of 2D-SWE to predict severe complication was 0.854, significantly higher than 0.692 of TE (p = 0.004). The optimal cut-off LS from 2D-SWE to predict severe complication was 8.6 kPa, with sensitivity of 88.9% (16/18) and specificity of 73.8% (79/107). CONCLUSION: LS obtained from 2D-SWE was a significant predictive factor for severe complication, and 2D-SWE showed significantly a better diagnostic performance than TE in detecting liver fibrosis and severe complication. KEY POINTS: • The diagnostic performance of 2D-SWE was significantly higher than that of TE in detecting both ≥ F3 (AUC: 0.853 vs. 0.779, p = 0.024) and F4 (AUC: 0.929 vs. 0.872, p = 0.048). • Liver stiffness value obtained from 2D-SWE was a significant factor correlated with the development of severe complication defined as CCI ≥ 26.2 after hepatic resection for liver tumors (odds ratio: 1.27 per kPa [1.10-1.46], p = 0.001). • 2D-SWE provided significantly a better diagnostic performance in predicting severe complication after hepatic resection than TE (AUC for 2D-SWE: 0.853 vs. AUC for TE: 0.692, p = 0.004).

Preoperative assessment of the resectability of pancreatic ductal adenocarcinoma on CT according to the NCCN Guidelines focusing on SMA/SMV branch invasion.

OBJECTIVES: For patients with pancreatic adenocarcinoma (PAC), adequate determination of disease extent is critical for optimal management. We aimed to evaluate diagnostic accuracy of CT in determining the resectability of PAC based on 2020 NCCN Guidelines. METHODS: We retrospectively enrolled 368 consecutive patients who underwent upfront surgery for PAC and preoperative pancreas protocol CT from January 2012 to December 2017. The resectability of PAC was assessed based on 2020 NCCN Guidelines and compared to 2017 NCCN Guidelines using chi-square tests. Overall survival (OS) was estimated using the Kaplan-Meier method and compared using log-rank test. R0 resection-associated factors were identified using logistic regression analysis. RESULTS: R0 rates were 80.8% (189/234), 67% (71/106), and 10.7% (3/28) for resectable, borderline resectable, and unresectable PAC according to 2020 NCCN Guidelines, respectively (p < 0.001). The estimated 3-year OS was 28.9% for borderline resectable PAC, which was significantly lower than for resectable PAC (43.6%) (p = 0.004) but significantly higher than for unresectable PAC (0.0%) (p < 0.001). R0 rate was significantly lower in patients with unresectable PAC according to 2020 NCCN Guidelines (10.7%, 3/28) than in those with unresectable PAC according to the previous version (31.7%, 20/63) (p = 0.038). In resectable PAC, tumor size ≥ 3 cm (p = 0.03) and abutment to portal vein (PV) (p = 0.04) were independently associated with margin-positive resection. CONCLUSIONS: The current NCCN Guidelines are useful for stratifying patients according to prognosis and perform better in R0 prediction in unresectable PAC than the previous version. Larger tumor size and abutment to PV were associated with margin-positive resection in patients with resectable PAC. KEY POINTS: • The updated 2020 NCCN Guidelines were useful for stratifying patients according to prognosis. • The updated 2020 NCCN Guidelines performed better in the prediction of margin-positive resection in unresectable cases than the previous version. • Tumor size ≥ 3 cm and abutment to the portal vein were associated with margin-positive resection in patients with resectable pancreatic adenocarcinoma.

Prediction of tumor recurrence and poor survival of ampullary adenocarcinoma using preoperative clinical and CT findings.

OBJECTIVES: To predict poor survival and tumor recurrence in patients with ampullary adenocarcinoma using preoperative clinical and CT findings. MATERIALS AND METHODS: A total of 216 patients with ampullary adenocarcinoma who underwent preoperative CT and surgery were retrospectively included. CT was assessed by two radiologists. Clinical and histopathological characteristics including histologic subtypes were investigated. A Cox proportional hazard model and the Kaplan-Meier method were used to identify disease-free survival (DFS) and overall survival (OS). A nomogram was created based on the multivariate analysis. The optimal cutoff size of the tumor was evaluated and validated by internal cross validation. RESULTS: The median OS was 62.8 ± 37.9, and the median DFS was 54.3 ± 41.2 months. For OS, tumor size (hazard ratio [HR] 2.79, p < 0.001), papillary bulging (HR 0.63, p = 0.049), organ invasion on CT (HR 1.92, p = 0.04), male sex (HR 1.59, p = 0.046), elevated CA 19-9 (HR 1.92, p = 0.01), pT stage (HR 2.45, p = 0.001), and pN stage (HR 3.04, p < 0.001) were important predictors of survival. In terms of recurrence, tumor size (HR 2.37, p = 0.04), pT stage (HR 1.76, p = 0.03), pN stage (HR 2.23, p = 0.001), and histologic differentiation (HR 4.31, p = 0.008) were important predictors of recurrence. In terms of tumor size on CT, 2.65 cm and 3.15 cm were significant cutoff values for poor OS and RFS (p < 0.001). CONCLUSION: Preoperative clinical and CT findings were useful to predict the outcomes of ampullary adenocarcinoma. In particular, tumor size, papillary bulging, organ invasion on CT, male sex, and elevated CA 19-9 were important predictors of poor survival after surgery. KEY POINTS: • Clinical staging based on preoperative clinical information and CT findings can be useful to predict the prognosis of ampullary adenocarcinoma patients. • In terms of survival, tumor size (HR 2.79), papillary bulging (HR 0.63), organ invasion on CT (HR 1.92), male sex (HR 1.59), and elevated CA 19-9 (HR 1.92) were important clinical predictors of poor survival. • Tumor size on CT was of special importance for both poor overall survival and disease-free survival, with optimal cutoff values of 2.65 cm and 3.15 cm, respectively (p < 0.001).

Quantitative Assessment of Fatty Liver using Ultrasound with Normalized Local Variance Technique.

PURPOSE: To assess the diagnostic performance of the normalized local variance (NLV) ultrasound technique in the detection of the fatty liver using histopathology as a reference standard. MATERIALS AND METHODS: We prospectively enrolled 194 consecutive patients with clinical suspicion of diffuse liver disease or history of liver transplantation. Conventional grayscale ultrasound and NLV examinations were performed and immediately followed by liver biopsies. The degrees of fatty liver, necroinflammatory activity, and fibrosis stage were evaluated by histopathological assessment. The diagnostic performance of the NLV values in detecting each grade of fatty liver was determined using receiver operating characteristics analyses, and multivariate linear regression analyses were performed to identify variables significantly associated with the NLV values. RESULTS: The number of patients in each degree of fatty liver and hepatic fibrosis was 118/37/26/13 and 81/68/24/6/14 for none/mild/moderate/severe steatosis and F0 / F1/F2 / F3/F4 fibrosis on histopathological examinations, respectively. The area under the receiver operating characteristics curve and optimal cut-off NLV value for detecting fatty liver of varying degrees were 0.911 and 1.095 for ≥ S1, 0.974 and 1.055 for ≥ S2, and 0.954 and 1.025 for ≥ S3, respectively. Multivariate analyses revealed that not fibrosis or inflammation but rather the degree of steatosis was associated with the NLV value. CONCLUSION: The NLV value demonstrated excellent diagnostic performance for detecting varying degrees of fatty liver, and the degree of steatosis on histopathological examinations was the only significant factor affecting the NLV value.

Contrast-enhanced US with Sulfur Hexafluoride and Perfluorobutane for the Diagnosis of Hepatocellular Carcinoma in Individuals with High Risk.

Background Perfluorobutane (PFB) and sulfur hexafluoride (SHF) have different physiologic characteristics, but it is unclear whether hepatocellular carcinomas (HCCs) show similar wash-in and washout patterns to both contrast agents at US. Purpose To investigate Contrast-Enhanced US Liver Imaging Reporting and Data System (LI-RADS) version 2017 HCC categorization by comparing PFB-enhanced US and SHF-enhanced US in participants at high risk for HCC. Materials and Methods In this prospective study conducted from February to August 2019, participants at high risk for HCC with treatment-naive hepatic observations (≥1 cm) categorized as LR-3, LR-4, LR-5, or LR-M (intermediate probability of HCC, probable HCC, definitely HCC, and probably malignant but not HCC specific, respectively) on cross-sectional images were screened. They underwent same-day PFB-enhanced US and SHF-enhanced US. Arterial phase hyperenhancement (APHE), washout time and degree, and echogenicity in the Kupffer phase (PFB-enhanced US) were evaluated and categorized by the operator using CEUS LI-RADS, who referred to the radiologist who performed the contrast-enhanced US, and by a reviewer. Diagnostic performance was analyzed using the McNemar test. Results Fifty-nine participants were evaluated (43 with HCC, 10 with non-HCC malignancies, six with benign findings). Nonrim APHE was identically observed in 95% (41 of 43, operator) or 88% (38 of 43, reviewer) of HCCs with both contrast agents. Among 43 HCCs, late (≥60 seconds) and mild washout were more frequent with PFB-enhanced US (34 with operator, 33 with reviewer) than with SHF-enhanced US (24 with operator, 26 with reviewer) (P = .04 or P = .12). The washout time for HCCs was later at PFB-enhanced US (median, 101 seconds ± 11) than at SHF-enhanced US (median, 84 seconds ± 5; P = .04). Sensitivity (34 of 43; 79%; 95% confidence interval [CI]: 64%, 90%) was higher with PFB-enhanced US than with SHF-enhanced US (23 of 43; 54%; 95% CI: 38%, 67%; P = .01). Specificity was 100% (95% CI: 79%, 100%) with both. Hypoenhancement in the Kupffer phase was more common in malignant (49 of 53 [92%] for both operator and reviewer) than in benign (two of six [33%] for operator, one of six [16%] for reviewer) lesions. Conclusion On the basis of the Contrast-Enhanced US Liver Imaging Reporting and Data System version 2017 algorithm, noninvasive US diagnosis of hepatocellular carcinoma by using perfluorobutane-enhanced US had higher diagnostic performance than sulfur hexafluoride-enhanced US, without loss of specificity. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kim and Jang in this issue.

Evaluation of a serum tumour marker-based recurrence prediction model after radiofrequency ablation for hepatocellular carcinoma.

BACKGROUND & AIMS: A recent study showed that serum tumour marker-based MoRAL score (11×√protein induced by vitamin K absence-II [PIVKA] +2×√alpha-foetoprotein [AFP]) can reflect both tumour burden and aggressiveness of hepatocellular carcinoma (HCC). This study aimed to evaluate whether baseline MoRAL score could predict tumour recurrence after radiofrequency ablation (RFA) for very-early/early-stage HCC. METHODS: A total of 576 HCC patients who underwent RFA as initial treatment were enrolled from two tertiary referral hospitals (256 in development cohort and 320 in validation cohort). The primary endpoint was recurrence-free survival (RFS) and the secondary endpoints included cumulative risks of intrahepatic distant recurrence (IDR) and extrahepatic metastasis (EM). RESULTS: In the development cohort, MoRAL score was an independent prognostic factor of RFS (P = .02). The optimal cutoff MoRAL score for predicting RFS was 68. Patients with high MoRAL score (>68) showed significantly shorter RFS than did those with low MoRAL score (hazard ratio [HR] = 2.04, P < .001). The 5-year RFS rates were 32.3% and 53.2% in high- and low-MoRAL groups respectively. Risks of both IDR (HR = 1.76, P = .003) and EM (HR = 8.25, P = .006) were also significantly higher in high MoRAL group. These results were reproduced in the validation cohort: RFS (HR = 1.81, P < .001; 5-year RFS rates = 27.7% vs 53.6%) was significantly shorter and risks of IDR (HR = 1.59, P = .003) and EM (HR = 6.19, P = .004) were significantly higher in high MoRAL group. CONCLUSION: A high MoRAL score of >68 was significant a predictive factor of tumour recurrence after RFA for very-early/early-stage HCC. Moreover, it might be warranted to evaluate EM in patients with high baseline MoRAL scores.