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Objectives: To develop and validate imaging-based models for predicting the malignancy risk of intraductal papillary mucinous neoplasm (IPMN)., Materials and Methods: We retrospectively analyzed data from 241 IPMN patients who underwent preoperative CT and MRI for model development. Cyst size, presence and size of the enhancing mural nodule (EMN), main pancreatic duct (MPD) diameter, thickened/enhancing cyst wall, abrupt MPD caliber change with distal atrophy, and lymphadenopathy were assessed. Multiple logistic regression models predicting malignancy risk were created using either continuous (Model C) or dichotomized variables (Model D) using these imaging features. Validation included internal (n = 55) and external (n = 43) datasets. Model performance was assessed using the area under the receiver operating characteristic curve (AUC) and compared with that of the international guideline-based model (Model F)., Results: Model C identified age, EMN size, MPD diameter, and lymphadenopathy as independent predictors on CT, and age and presence and size of EMN on MRI. Model D identified age ≥ 68, cyst size ≥ 31 mm, EMN ≥ 6 mm, MPD ≥ 7 mm, and lymphadenopathy as independent predictors on CT, and age ≥ 68, EMN ≥ 4.5 mm, and lymphadenopathy on MRI. Model C (AUC, 0.763-0.899) performed slightly better than Model D (AUC, 0.753-0.912) without statistical significance. No significant difference was observed between Models C and F (AUC, 0.729-0.952). Combining Model C with obstructive jaundice improved performance (AUC, 0.802-0.941) without statistical significance., Conclusion: Our imaging-based models effectively predicted the malignancy risk of IPMNs, comparable to international consensus guidelines., Clinical Relevance Statement: Imaging features are important for predicting the malignant potential of IPMNs. Our imaging-based model may help determine surgical candidacy for patients with IPMNs., Key Points: Non-invasively determining the malignant potential of intraductal papillary mucinous neoplasms (IPMNs) allows for appropriate treatment decision-making We identified multiple imaging features that are associated with malignant transformation and developed models for this prediction. Our model performs comparably with international consensus guidelines in predicting the malignant potential of IPMNs., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To investigate the imaging features of pancreatic ductal adenocarcinoma (PDAC) with histological large duct pattern., Methods: Our study included 37 patients (mean age, 66.5 years; 22 women) with surgically proven PDAC with histological large duct pattern, whose imaging features were classified into four types: Type I, solid mass; Type II, predominantly cystic mass with intracystic solid components; Type III, predominantly solid mass with intratumoral cysts; and Type IV, solid mass with peritumoral retention cysts or pseudocysts. Two radiologists independently analyzed both CT and MRI images for the morphological type, presence of abrupt main pancreatic duct (MPD) cutoff, adjacent vascular invasion, diffusion restriction, and reached consensus., Results: On CT, 26 patients (70.3%) had Type I tumors, five (13.5%) had Type II, three (8.1%) had Type III, and three (8.1%) had Type IV. Among the 26 patients with Type I tumors on CT, 16 had tumors with multiple intratumoral cysts within the solid mass on MRI and were subsequently classified as Type III. Accordingly, 10 patients (27.0%) were classified as Type I, five (13.5%) as Type II, 19 (51.7%) as Type III, and three (8.1%) as Type IV on MRI. Of the 37 patients, 27 (73.0%) had an abrupt MPD cutoff, 15 (40.5%) had adjacent vascular invasion, and 25 (67.6%) had diffusion restriction on MRI., Conclusions: Predominantly solid pancreatic masses with small intratumoral cysts visualized on MRI may be a characteristic imaging finding of PDAC with histological large duct pattern, and differentiate it from conventional PDAC or other cystic pancreatic tumors., Clinical Relevance Statement: Radiologists should be familiar with the various imaging features of PDAC with histological large duct pattern and should be aware that it may mimic other solid or cystic tumors of the pancreas., Key Points: Imaging features of pancreatic ductal adenocarcinoma with histological large duct pattern can be classified into four types. This pathology more frequently appears as a predominantly solid mass with intratumoral cysts on MRI than on CT. Adding MRI to CT may help identify pancreatic ductal adenocarcinoma with histological large duct pattern., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To predict tumor recurrence in patients who underwent surgical resection of ampullary adenocarcinoma using preoperative magnetic resonance (MR) imaging findings combined with clinical findings., Methods: In this multicenter study, a total of 113 patients (mean age, 62.9 ± 9.8 years; 58 men and 55 women) with ampullary adenocarcinoma who underwent preoperative MR imaging and surgery with margin-negative resection between 2006 and 2017 were retrospectively included. The MR imaging findings were evaluated by two radiologists. Preoperative clinical findings were obtained. Cox proportional regression analyses were used to identify the independent prognostic factors for recurrence-free survival (RFS). A nomogram was created based on the multivariable analysis and was internally validated., Results: Multivariable analysis revealed that presence of infiltrative tumor margin (hazard ratio [HR]: 2.18, p = 0.019), adjacent organ invasion (HR: 3.31, p = 0.006), adjacent vessel invasion (HR: 5.42, p = 0.041), peripancreatic lymph node enlargement (HR: 2.1, p = 0.019), and jaundice (HR: 1.93, p = 0.043) were significantly associated with worse RFS of ampullary adenocarcinoma after surgical resection. These MR imaging and clinical findings were used to construct a nomogram. On internal validation, the calibration plots showed excellent agreement between the predicted probabilities and the actual rates of tumor recurrence, with Harrell's c-index of 0.746., Conclusions: Combination of preoperative MR imaging and clinical findings can be useful for predicting tumor recurrence after surgical resection of ampullary adenocarcinoma. Identifying these features before surgery may aid in better treatment planning and management of these patients., Clinical Relevance Statement: A predictive nomogram using preoperative MR imaging and clinical findings can be useful in estimating the recurrence-free survival after surgical resection of ampullary adenocarcinoma., Key Points: • Presently, tumor size on imaging is the only non-invasive factor that correlates with recurrence-free survival from ampullary adenocarcinoma; other factors are obtained postoperatively. • Infiltrative tumor margin, adjacent organ invasion, adjacent vessel invasion, peripancreatic lymph node enlargement on MRI, and jaundice are significant predictors for recurrence. • A nomogram incorporating significant MR imaging and clinical findings showed good performance in predicting recurrence-free survival, which can help in treatment planning., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: Three-dimensional (3D) printing has been increasingly used to create accurate patient-specific 3D-printed models from medical imaging data. We aimed to evaluate the utility of 3D-printed models in the localization and understanding of pancreatic cancer for surgeons before pancreatic surgery., Methods: Between March and September 2021, we prospectively enrolled 10 patients with suspected pancreatic cancer who were scheduled for surgery. We created an individualized 3D-printed model from preoperative CT images. Six surgeons (three staff and three residents) evaluated the CT images before and after the presentation of the 3D-printed model using a 7-item questionnaire (understanding of anatomy and pancreatic cancer [Q1-4], preoperative planning [Q5], and education for trainees or patients [Q6-7]) on a 5-point scale. Survey scores on Q1-5 before and after the presentation of the 3D-printed model were compared. Q6-7 assessed the 3D-printed model's effects on education compared to CT. Subgroup analysis was performed between staff and residents., Results: After the 3D-printed model presentation, survey scores improved in all five questions (before 3.90 vs. after 4.56, p < 0.001), with a mean improvement of 0.57‒0.93. Staff and resident scores improved after a 3D-printed model presentation (p < 0.05), except for Q4 in the resident group. The mean difference was higher among the staff than among the residents (staff: 0.50‒0.97 vs. residents: 0.27‒0.90). The scores of the 3D-printed model for education were high (trainees: 4.47 vs. patients: 4.60) compared to CT., Conclusion: The 3D-printed model of pancreatic cancer improved surgeons' understanding of individual patients' pancreatic cancer and surgical planning., Clinical Relevance Statement: The 3D-printed model of pancreatic cancer can be created using a preoperative CT image, which not only assists surgeons in surgical planning but also serves as a valuable educational resource for patients and students., Key Points: • A personalized 3D-printed pancreatic cancer model provides more intuitive information than CT, allowing surgeons to better visualize the tumor's location and relationship to neighboring organs. • In particular, the survey score was higher among staff who performed the surgery than among residents. • Individual patient pancreatic cancer models have the potential to be used for personalized patient education as well as resident education., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To identify useful features to predict hidden pancreatic malignancies in patients with main pancreatic duct (MPD) abrupt cutoff and dilatation, but without visible focal pancreatic lesions on CT., Methods: This retrospective study included 92 patients (mean age, 63.4 ± 10.6 years, 63 men and 29 women) with MPD abrupt cutoff and dilatation, but without visible focal pancreatic lesion on contrast-enhanced CT between 2009 and 2021. Two radiologists independently evaluated the CT imaging features. Multivariable logistic regression analysis was performed to identify clinical and CT imaging features for hidden pancreatic malignancies. A nomogram was developed based on these results and assessed its performance., Results: Thirty-eight (41.3%) and 54 (58.7%) were classified into the malignant and benign groups, respectively. In the multivariable analysis, CA19-9 elevation (odds ratio [OR] 7.5, p = 0.003), duct cutoff site at the head/neck (OR 7.6, p = 0.006), parenchymal contour abnormality at the duct cutoff site (OR 13.7, p < 0.001), and presence of acute pancreatitis (OR 11.5, p = 0.005) were independent predictors of pancreatic malignancy. A combination of any two significant features showed an accuracy of 77.2%, and a combination of any three features exhibited a specificity of 100%. The CT-based nomogram showed an area under the curve (AUC) of 0.84 (95% confidence interval, 0.77-0.90)., Conclusions: The three CT imaging features and CA19-9 elevation translated into a nomogram permit a reliable estimation of hidden pancreatic malignancies in patients with MPD abrupt cutoff without visible focal pancreatic lesion. It may facilitate determining whether to proceed to further diagnostic tests., Key Points: • Isoattenuating pancreatic ductal adenocarcinoma can manifest only as an isolated main pancreatic duct (MPD) dilatation with abrupt cutoff, making it difficult to distinguish from benign strictures. • Along with the serum CA 19-9 elevation, MPD cutoff site at the pancreas head or neck, parenchymal contour abnormality at the duct cutoff site, and associated acute pancreatitis indicated a higher probability of the malignant MPD strictures. • The CT-based nomogram provided excellent diagnostic performance (AUC of 0.84) for hidden pancreatic malignancies in patients with MPD abrupt cutoff and dilatation., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To construct a predictive nomogram for differentiating malignant from benign ampullary strictures using contrast-enhanced computed tomography (CT) findings combined with clinical findings., Methods: In this retrospective study, 152 patients with ampullary stricture (98 benign and 54 malignant) who underwent contrast-enhanced CT were included. Various imaging findings of the ampulla, bile duct, main pancreatic duct, and periampullary area were evaluated and clinical findings including the presence of jaundice, carbohydrate antigen 19-9 level, and history of cholecystectomy were collected. Among them, statistically significant findings were identified using univariable and multivariable logistic regression analyses. A nomogram was constructed to differentiate benign and malignant ampullary strictures and was internally validated., Results: Multivariable analysis revealed that jaundice (odds ratio [OR]: 17.33, p < 0.001), presence of an ampullary mass (OR: 24.40, p < 0.001), non-similar enhancement of the ampulla to the duodenum (OR: 31.96, p = 0.003), and proportional dilatation of the bile duct (OR: 7.98, p = 0.001) were independent significant factors for predicting the malignant ampullary stricture, and were used to construct a nomogram. Among them, non-similar enhancement of the ampulla to the duodenum showed the highest OR and predictor point on the nomogram. The calibration plots showed excellent agreement between the predicted probabilities and the actual rates of malignant ampullary strictures, on internal validation., Conclusions: Combination of clinical and imaging findings could aid in predicting malignant ampullary strictures using significant findings of jaundice, presence of ampullary mass, non-similar enhancement of the ampulla to the duodenum, and proportional dilatation of the bile duct., Key Points: • The presence of jaundice, ampullary mass, non-similar enhancement of the ampulla, and proportional bile duct dilatation were significant findings for predicting malignant ampullary strictures. • Non-similar enhancement of the ampulla to the duodenum was a significant feature with the highest odds ratio for differentiating benign and malignant ampullary strictures. • The nomogram constructed using contrast-enhanced computed tomography imaging and clinical findings could aid in predicting malignant ampullary strictures., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To compare the image quality and radiation dose of a deep learning image reconstruction (DLIR) algorithm compared with iterative reconstruction (IR) and filtered back projection (FBP) at different tube voltages and tube currents., Materials and Methods: A customized body phantom was scanned at different tube voltages (120, 100, and 80 kVp) with different tube currents (200, 100, and 60 mA). The CT datasets were reconstructed with FBP, hybrid IR (30% and 50%), and DLIR (low, medium, and high levels). The reference image was set as an image taken with FBP at 120 kVp/200 mA. The image noise, contrast-to-noise ratio (CNR), sharpness, artifacts, and overall image quality were assessed in each scan both qualitatively and quantitatively. The radiation dose was also evaluated with the volume CT dose index (CTDI vol ) for each dose scan., Results: In qualitative and quantitative analyses, compared with reference images, low-dose CT with DLIR significantly reduced the noise and artifacts and improved the overall image quality, even with decreased sharpness (p < 0.05). Despite the reduction of image sharpness, low-dose CT with DLIR could maintain the image quality comparable to routine-dose CT with FBP, especially when using the medium strength level., Conclusion: The new DLIR algorithm reduced noise and artifacts and improved overall image quality, compared to FBP and hybrid IR. Despite reduced image sharpness in CT images of DLIR algorithms, low-dose CT with DLIR seems to have an overall greater potential for dose optimization., Key Points: • Using deep learning image reconstruction (DLIR) algorithms, image quality was maintained even with a radiation dose reduced by approximately 70%. • DLIR algorithms yielded lower image noise, higher contrast-to-noise ratios, and higher overall image quality than FBP and hybrid IR, both subjectively and objectively. • DLIR algorithms can provide a better image quality, much better than FBP and even better than hybrid IR, while facilitating a reduction in radiation dose., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: To identify independent imaging and histopathologic factors that affect washout appearance of hepatocellular carcinoma (HCC) in CT images., Methods: This retrospective study included 264 patients who had undergone surgical resection for treatment-naïve single HCC between January 2014 and December 2015 and had available preoperative multiphasic CT images. Two reviewers evaluated the CT imaging features of HCC using LI-RADS v2018. The "washout" was visually assessed in portal venous or equilibrium phases. Depending on the presence of washout appearance of HCC, all patients were divided into "washout" (n = 228) and "no washout" (n = 36) groups. Multivariable logistic regression analysis was used to identify factors associated with the absence of washout appearance of HCC., Results: A total of 264 HCCs (median size, 2.6 cm) were analyzed. Histologically proven hepatic steatosis (macrovesicular steatosis ≥ 5%) (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.05-6.74; p = 0.040), tumor capsule on histopathology (OR, 0.17; 95% CI, 0.06-0.50; p = 0.001), and mosaic appearance on CT image (OR, 0.34; 95% CI, 0.14-0.85; p = 0.021) were independent factors associated with the absence of washout appearance of HCC. In 189 patients with available unenhanced CT images, CT-diagnosed hepatic steatosis was also an independent factor for the absence of washout appearance of HCC (OR, 9.26; 95% CI, 3.06-28.02; p < 0.001)., Conclusions: Washout appearance of HCC in CT images could be obscured in both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis, and could be enhanced with tumor capsule on histopathology and mosaic appearance on CT image., Key Points: • Hepatic steatosis is an independent factor related to the absence of washout appearance of hepatocellular carcinoma in CT images, in both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis. • Both histologically proven hepatic steatosis and CT-diagnosed hepatic steatosis have higher odds of absence of washout appearance of hepatocellular carcinoma compared to non-steatotic liver. • Tumor capsule on histopathology and mosaic appearance on CT image are independent factors that enhance the probability that washout appearance of hepatocellular carcinoma is visible., (© 2021. European Society of Radiology.)

Objectives: To evaluate the postoperative prognostic value of the Liver Imaging Reporting and Data System (LI-RADS) category on gadoxetic acid-enhanced MRI and 18F-fluorodeoxyglucose PET-CT in patients with primary liver carcinomas (PLCs)., Methods: A total of 189 patients with chronic liver disease and surgically proven single PLC (42 intrahepatic cholangiocarcinomas and 21 combined hepatocellular-cholangiocarcinomas and 126 hepatocellular carcinomas [2:1 matching to non-HCC malignancies]) were retrospectively evaluated with gadoxetic acid-enhanced MRI and PET-CT. Two independent reviewers assigned an LI-RADS category for each observation. The tumor-to-liver standardized uptake value ratio (TLR) was calculated. The overall survival (OS), recurrence-free survival (RFS), and the associated factors were evaluated., Results: In multivariable analysis, LI-RADS category (LR-4 or LR-5 [LR-4/5] vs. LR-M; OS, hazard ratio [HR] 2.24, p = 0.006; RFS, HR 1.61, p = 0.028) and TLR (low, < 2.3 vs. high, ≥ 2.3; OS, HR 2.09, p = 0.014; RFS, HR 2.17, p < 0.001) were the independent factors for OS and RFS. For the LR-M group, the high TLR group showed lower OS and RFS rates than the low TLR group (OS, p = 0.008; RFS, p < 0.001). For the LR-4/5 group, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p > 0.05)., Conclusions: Both LI-RADS category on MRI and TLR on PET-CT are associated with the postoperative prognosis of PLCs. The prognosis of PLCs classified as LR-M can be further stratified according to the TLR group, but not for the PLCs classified as LR-4/5., Key Points: • The LI-RADS category (LR-4/5 vs. LR-M) and tumor-to-liver standardized uptake value ratio (TLR, low vs. high) were independent factors for postoperative prognosis of primary liver carcinomas (PLCs). • For PLCs classified as LR-M, the TLR group helps stratify the postoperative prognosis of PLCs, with the high TLR group having a poor prognosis and the low TLR group having a better prognosis (p = 0.008 for OS and p < 0.001 for RFS). • For PLCs classified as LR-4/5, the OS and RFS rates were not significantly different between the high TLR and low TLR groups (both p > 0.05).

Objectives: To establish a prognostic nomogram for patients undergoing R0 resection for gallbladder cancer based on preoperative CT., Methods: A total of 151 patients (64 males, 87 females; mean age, 73.26 years) with gallbladder cancer who underwent CT and surgery with margin-negative resection were retrospectively collected at two tertiary institutions. The demographic and radiologic parameters were analyzed using univariate and multivariate Cox regression analyses to identify independent prognostic factors. The final CT-based nomogram was constructed to predict prognosis after curative resection of gallbladder cancer. Calibration curves for the survival probabilities were obtained for internal validation., Results: Mass-forming type (hazard ratio [HR], 28.80), bile duct invasion (HR, 4.76), duodenal invasion (HR, 6.32), colon invasion (HR, 4.37), gallstones (HR, 0.09), and cholecystitis (HR, 2.56) were significant independent predictors for recurrence-free survival (p < .05). Mass-forming type (HR, 8.16, p < .001), bile duct invasion (HR, 2.92, p = .013), duodenal invasion (HR, 3.72, p = .012), and regional lymph node metastasis (HR, 2.07, p = .043) were independent predictors of poor cancer-specific survival (CSS) and were used to construct the nomogram. The nomogram showed a good predictive ability for the probabilities of survival on the calibration curves, and the concordance index of the model in predicting CSS was .768., Conclusion: Preoperative CT findings could predict the prognosis of gallbladder cancer, and the CT-based nomogram accurately predicted CSS in patients with gallbladder cancer after attempted curative resection., Key Points: • Among the preoperative imaging features, mass-forming type, bile duct invasion, duodenal invasion, and regional lymph node metastasis were independent predictors of poor cancer-specific survival. • The nomogram constructed using preoperative CT findings showed a good predictive ability for the survival on calibration curves, and the concordance index of the model in predicting cancer-specific survival was 0.768.

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).

Objective: To clarify the pre-operative imaging and clinical features differentiating malignant from benign intraductal papillary mucinous neoplasm (IPMN) of the pancreas and develop a nomogram for estimating the individualized risk of malignant IPMN., Methods: One hundred twenty-six patients with IPMN (72 benign and 54 malignant) who underwent pre-operative contrast-enhanced CT or MRI from 2010 to 2018 were retrospectively evaluated in two tertiary institutions. All lesions were pathologically proven by surgery or biopsy. Significant imaging and clinical findings for malignancy were assessed by univariate and multivariable logistic regression analyses. Based on the significant variables in the multivariable analysis, we developed a nomogram to predict malignant potential in patients with IPMNs, and the area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic value., Results: Multivariable analysis revealed that enhancing mural nodule ≥ 5 mm (odds ratio (OR), 48.30; 95% confidence interval (CI), 11.69-199.49), increased serum carbohydrate antigen 19-9 (CA19-9) (OR, 8.69; 95% CI, 2.04-36.92), main pancreatic duct (MPD) diameter ≥ 10 mm (OR, 6.34; 95% CI, 1.21-33.30), and acute pancreatitis (OR, 4.77; 95% CI, 1.12-20.36) were independent significant parameters to predict malignant IPMN. Among them, enhancing mural nodule ≥ 5 mm showed the highest OR and predictor point on the nomogram. The AUC for the nomogram was 0.955 (95% CI, 0.903-0.984)., Conclusions: Pre-operative imaging findings could aid in predicting malignant potential of IPMN using the significant findings of enhancing mural nodule ≥ 5 mm, increased serum CA19-9, MPD diameter ≥ 10 mm, and acute pancreatitis., Key Points: • Among pre-operative imaging and clinical features, enhancing mural nodule ≥ 5 mm, increased serum CA19-9, main pancreatic duct diameter ≥ 10 mm, and acute pancreatitis were independent significant parameters to predict malignant IPMN. • Enhancing mural nodule ≥ 5 mm was a single predictor for malignant IPMN, with the highest diagnostic values compared to other significant parameters. • A constructed nomogram using these parameters could aid in predicting malignant potential in patients with IPMN of the pancreas.

Objectives: To identify CT features that reliably predict the presence of radiolucent common bile duct (CBD) stones., Materials and Methods: This retrospective study included 112 patients (mean age, 60.6 years) with clinically suspected CBD stones that were not visible on CT. All patients had undergone CT followed by endoscopic retrograde cholangiopancreatography (ERCP) to confirm the presence (n = 66) or absence (n = 46) of CBD stones. Two radiologists independently evaluated the CT images. Univariable and multivariable logistic regression analyses were performed to identify demographic, laboratory, and CT predictors for CBD stones. We developed a nomogram based on these results and assessed its performance., Results: In the multivariate analysis, CBD diameter ≥ 8 mm (odds ratio [OR], 10.12; p < 0.001), pericholecystic fat infiltration (OR, 3.76, p = 0.014), and papillitis (OR, 2.85; p < 0.049) were independent CT predictors of CBD stones. Combination of all three features had a specificity of 100%. Of these features, CBD diameter ≥ 8 mm was the best single predictor. The CT-based nomogram had an area under the curve (AUC) of 0.847 (95% confidence interval [CI], 0.777-0.916) and an accuracy of 77.7% (95% CI, 69.1-84.4%)., Conclusions: The combination of significant CT features (CBD diameter ≥ 8 mm, pericholecystic fat infiltration, and papillitis) translated into a nomogram allows a reliable estimation of CBD stone presence. It may serve as a decision support tool to determine whether to proceed to further diagnostic tests or treatment option., Key Points: • CBD diameter ≥ 8 mm (odds ratio [OR] = 10.12, p < 0.001), pericholecystic fat infiltration (OR = 3.76, p = 0.014), and papillitis (OR = 2.85, p = 0.049) were independent predictors of radiolucent CBD stones. • A CBD diameter ≥ 8 mm was the best predictor of CBD stones. • A nomogram based on a combination of these three CT signs predicted the presence of CBD stones and helped classify patients that should go immediately to ERCP, those who require a further investigation, and those who can safely be managed conservatively.

Objectives: To predict residual tumor (R) classification in patients with a surgery for gallbladder (GB) cancer, using preoperative CT., Methods: One hundred seventy-three patients with GB cancer who underwent CT and subsequent surgery were included. Two radiologists assessed CT findings, including tumor morphology, location, T stage, adjacent organ invasion, hepatic artery (HA) invasion, portal vein invasion, lymph node metastasis, metastasis, resectability, gallstone, and combined cholecystitis. The R classification was categorized as no residual tumor (R0) and residual tumor (R1 or R2). We analyzed the correlation between CT findings and R classification. We also followed up the patients as long as five years and analyzed the relationship between the R classification and the overall survival (OS)., Results: There were 134 patients with R0 and 39 patients with R1/R2. On multivariable analysis, liver invasion (Exp(B) = 3.19, p = 0.010), bile duct invasion (Exp(B) = 3.69, p = 0.031), and HA invasion (Exp(B) = 3.74, p = 0.039) were independent, significant predictors for residual tumor. When two of these three criteria were combined, the accuracy for predicting a positive resection margin was 83.38% with a specificity of 93.28%. The OS and the median patient survival time differed significantly according to the resection margin, i.e., 56.0% and 134.4 months in the R0 resection and 5.1% and 10.8 months in the R1/R2 resection group (p < 0.001)., Conclusions: Preoperative CT findings could aid in planning surgery and determining the resectability using the high-risk findings of residual tumor, including liver invasion, bile duct invasion, and HA invasion., Key Points: • Liver invasion, bile duct invasion, and HA invasion were significant preoperative CT predictors for residual tumor in GB cancer. • HA invasion showed the highest OR on multivariate analysis and the highest predictor point on a nomogram for predicting a positive resection margin. • Association of two factors can predict positive resection margin with an accuracy of 83.38% and a specificity of 93.28%.

Objectives: To assess utility of CT findings and texture analysis for predicting the resectability and prognosis in patients after neoadjuvant therapy for pancreatic ductal adenocarcinoma (PDAC)., Materials and Methods: Among 308 patients, 45 with PDAC underwent neoadjuvant therapy (concurrent-chemoradiation-therapy, CCRT, n = 27 and chemotherapy, ChoT, n = 18) before surgery were included. All underwent baseline and preoperative CT. Two reviewers assessed CT findings and resectability. We analyzed relationship between CT resectability and residual tumor. CT texture values obtained by subtracting preoperative from baseline CT were analyzed using multivariate Cox/logistic regression analysis to identify significant parameters predicting resectability and prognosis., Results: There were 30 patients without residual tumor (CCRT, n = 20; ChoT, n = 10) and 15 with residual tumor (CCRT, n = 7; ChoT, n = 8). Considering borderline as resectable was more accurate for R0 resectability than considering borderline as unresectable (68.9% vs 55.6% and 51.1%, p < 0.001). Particularly, neoadjuvant CCRT provided better accuracy than that in (p < 0.001). In CT texture analysis, higher subtracted entropy (cut-off: 0.03, HR 0.159, p = 0.005) and lower subtracted GLCM entropy (cut-off: -0.35, HR 10.235, p = 0.036) are important parameters for prediction of longer overall survival., Conclusion: CT findings with texture analysis can be useful for predicting a patient's outcome, including resectability and prognosis, after neoadjuvant therapy for PDAC., Key Points: • Considering borderline resectable tumor as resectable have better accuracy for resectability. • Considering borderline as resectable, CCRT-patients have better resectability accuracy than chemotherapy-patients. • Higher subtracted entropy and lower subtracted GLCM entropy are predictors of favorable outcome.

Objectives: To compare the sensitivity of Liver Imaging Reporting and Data System (LI-RADS) v2017 for diagnosis of hepatocellular carcinoma (HCC) using multiphasic computed tomography (CT) between patients with and without moderate to severe fatty liver (MSFL)., Methods: This retrospective study included a total of 106 high-risk patients with 112 pathologically proven HCCs who underwent multiphasic CT. Patients were classified as MSFL (24 men, 2 women; mean age, 59.5 years [range, 38-79 years]) and non-MSFL (64 men, 16 women; mean age, 62.9 years [range, 40-89 years]) groups according to unenhanced CT liver and spleen parenchymal attenuation. Two independent radiologists assigned LI-RADS categories and accessed HCC features on CT. Sensitivities for LR-5 assignment and frequencies of HCC features were compared between the two groups., Results: Sensitivities of LR-5 assignment for diagnosing HCCs were not significantly different between MSFL and non-MSFL groups (65.4% [17/26] vs. 76.7% [66/86] for reviewer 1, p = 0.247; 73.1% [19/26] vs. 76.74% [66/86] for reviewer 2, p = 0.702). No significant differences in the frequencies of arterial hyperenhancement, washout, and capsule were observed between the two groups (96.2% [25/26] vs. 98.8% [85/86], p = 0.412; 80.8% [21/26] vs. 89.5% [77/86], p = 0.308; and 53.8% [14/26] vs. 57% [49/86], p = 0.778, respectively)., Conclusions: LI-RADS v2017 using CT showed comparable sensitivity for diagnosing HCC regardless of MSFL., Key Points: • Using LI-RADS v2017 with CT, diagnosis of HCC in patients with MSFL showed similar sensitivity to that in patients without MSFL. • Frequencies of major HCC features (arterial hyperenhancement, washout, and capsule) on CT between the MSFL and non-MSFL groups were not significantly different. • LI-RADS using CT may be feasible for diagnosing HCC in patients with fatty liver.

Objectives: To determine ancillary features that help distinguish between scirrhous hepatocellular carcinoma (S-HCC) and intrahepatic cholangiocarcinoma (ICC) and investigate added value of ancillary features to enhancement pattern-based diagnosis on gadoxetic acid-enhanced MRI., Methods: This retrospective study included 96 patients with S-HCCs and 120 patients with ICCs who underwent gadoxetic acid MRI before surgical resection. Two observers reviewed MRIs of the tumours. After determining ancillary features for differentiating tumour types, we measured the diagnostic performance of adding ancillary features to enhancement pattern-based diagnosis., Results: T2 central darkness, capsule and septum were significant and independent features differentiating S-HCC from ICC (p ≤ .06). Adding ancillary features to enhancement pattern led to increased accuracy (observer 1, 78.9 vs. 93.8 %; observer 2, 80.3 vs. 92.8 %; p < .001), sensitivity (observer 1, 74.5 vs. 96.4 %; observer 2, 77.1 vs. 93.2 %; p < .001 and .001), and specificity (observer 1, 82.5 vs. 91.7 %; observer 2, 82.9 vs. 92.5 %; p = .006 and .005) for diagnosis of S-HCC by differentiation from ICC., Conclusions: Adding ancillary features capsule, septum and T2 central darkness to conventional enhancement patterns on gadoxetic acid-enhanced MRI improved accuracy, sensitivity and specificity for S-HCC diagnosis with differentiation from ICC., Key Points: • Capsule, septum, and T2 central darkness were ancillary features for S-HCC. • A typical HCC enhancement was seen in 31.3% of S-HCCs. • Ancillary MRI features were useful in differentiation between S-HCC and ICC.

Objective: To determine the added value of capsule, septum, and T2 hyperintense foci for differentiating large hepatocellular carcinoma (HCC; ≥ 5 cm) from intrahepatic cholangiocarcinoma (ICC) using gadoxetic acid MRI., Methods: The study included 116 patients (94 men, 22 women; mean age, 56.8 years) with surgically confirmed HCCs (n = 87, 5.0-18.0 cm) or ICCs (n = 29, 5.0-14.0 cm) who underwent gadoxetic acid MRI. Three observers independently reviewed MRIs in two sessions, examining enhancement patterns only and then adding capsule, septum, and T2 hyperintense foci. Reviewers used a five-point scale to score accuracy, sensitivity, and specificity., Results: A significant increase was observed in accuracy when ancillary features (96.1-98.3%) were added compared to enhancement pattern only (83.6-88.4%; p ≤ 0.02). Sensitivity was significantly increased with combined reading (97.1-98.3%) compared to enhancement features only (81.6-88.5%; p ≤ 0.006) for two observers, with no difference in specificity (84.5-89.7% vs. 86.2-98.3%; p > 0.05). We found substantial to excellent interobserver agreement for ancillary features (0.598-0.976)., Conclusion: Adding capsule, septum, and T2 hyperintense foci to enhancement patterns for gadoxetic acid MRI increased diagnostic performance for characterizing large HCC by differentiating it from ICC., Key Points: • Capsule, septum, and T2 hyperintense foci were useful for characterizing large HCC. • Adding ancillary features to enhancement pattern increased accuracy for diagnosing large HCC. • Interobserver agreement was substantial to excellent for ancillary features.

Objectives: We aimed to identify features that differentiate hepatic microabscess from hepatic metastasis on gadoxetic acid-enhanced MRI in patients with periampullary cancer., Methods: We included 72 patients (31 patients with 83 hepatic microabscesses and 41 patients with 71 hepatic metastases) who had a history of periampullary cancer and underwent gadoxetic acid-enhanced MRI. Image analysis was performed for margin, signal intensity, rim enhancement, perilesional hyperaemia, pattern on DWI and dynamic phases, and size discrepancy between sequences by consensus of two observers., Results: Multivariate analysis revealed that the following significant parameters favour microabscess: a history of bile duct cancer, perilesional hyperaemia, persistent arterial rim enhancement through the transitional phase (TP), and size discrepancy between T1WI and T2WI and between T1WI and hepatobiliary phase image (HBPI). The diagnostic accuracy for microabscess was highest (90.9%) when showing a size discrepancy ≥30% between T1WI and HBPI or persistent arterial rim enhancement through the TP. When the lesion was positive for both these variables, specificity reached 100%., Conclusion: The combination of a size discrepancy between T1WI and HBPI and persistent arterial rim enhancement through the TP represents a reliable MRI feature for distinguishing between hepatic microabscess and metastasis in patients with periampullary cancer., Key Points: • Gadoxetic acid-enhanced MRI is useful for distinguishing hepatic microabscess from metastasis. • Hepatic microabscess showed significant size discrepancy ≥30% between T1WI and HBPI. • Arterial rim enhancement persistent through the TP indicates hepatic microabscess.

Objectives: To assess the added value of diffusion-weighted imaging (DWI) to conventional magnetic resonance imaging (MRI) for differentiating benign from malignant bile duct strictures., Methods: Twenty-seven patients with a benign stricture and 42 patients with a malignant stricture who had undergone gadoxetic acid-enhanced MRI with DWI were enrolled. Qualitative (signal intensity, dynamic enhancement pattern) and quantitative (wall thickness and length) analyses were performed. Two observers independently reviewed a set of conventional MRI and a combined set of conventional MRI and DWI, and receiver operating characteristic (ROC) curve analysis was assessed., Results: Benign strictures showed isointensity (18.5-70.4 %) and a similar enhancement pattern (22.2 %) to that of normal bile duct more frequently than malignant strictures (0-40.5 % and 0 %) on conventional MRI (P < 0.05). Malignant strictures (90.5-92.9 %) showed hypervascularity on arterial and portal venous phase images more frequently than benign strictures (37.0-70.4 %) (P < 0.01) On DWI, all malignant strictures showed hyperintensity compared with benign cases (70.4 %) (P < 0.001). Malignant strictures were significantly thicker and longer than benign strictures (P < 0.001). The diagnostic performance of both observers improved significantly after additional review of DWI., Conclusions: Adding DWI to conventional MRI is more helpful for differentiating benign from malignant bile duct strictures than conventional MRI alone., Key Points: • Accurate diagnosis and exclusion of benign strictures of bile duct are important. • Diffusion-weighted MRI helps to distinguish benign from malignant bile duct strictures. • DWI plus conventional MRI provides superior diagnostic accuracy to conventional MRI alone.