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Purpose: To analyze and compare the differences in MRI features between combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA) and intrahepatic cholangiocarcinoma (iCCA) with arterial phase peripheral enhancement, so as to provide valuable references for preoperative differential diagnosis., Methods: Seventy cHCC-CCA patients and 74 iCCA patients confirmed by pathology were included in this study. Their contrast-enhanced MRI showed rim arterial phase hyperenhancement (Rim APHE). The differences of clinicopathological data and MRI features between cHCC-CCA and iCCA were compared. Then, the sensitivity, specificity, and area under curve (AUC) were also analyzed and compared., Results: Seventy cHCC-CCA patients (mean age, 55.7 ± 10.6 years) and 74 iCCA patients (mean age, 61.1 ± 10.5 years) were evaluated. In this study, univariable and multivariable regression analysis showed that AFP > 20 ng/ml (OR = 5.824, p = 0.006), enhancing capsule (OR = 7.252, p = 0.001), and mosaic architecture (OR = 32.732, p < 0.001) were independent risk factors of cHCC-CCA with Rim APHE. However, only hepatic capsule retraction (OR = 0.091, p < 0.001) was an independent predictor of iCCA. In addition, combining AFP > 20 ng/ml with enhancing capsule (96.7% vs. 79.2%, p < 0.001) and/or mosaic architecture (96.4% vs. 94.7%, p < 0.001) can improve the sensitivity of differentiating cHCC-CCA (vs. iCCA) with Rim APHE., Conclusion: The combination of elevated AFP and MRI features, such as enhancing capsule and mosaic architecture, will help in preoperative differential diagnosis of cHCC-CCA and iCCA with Rim APHE., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Lymph node metastasis (LNM) in patients with intrahepatic cholangiocarcinoma (iCCA) affects treatment strategies and prognosis. However, preoperative imaging is not reliable enough for identifying LNM., Purpose: To develop and validate a radiomics nomogram based on dynamic contrast enhanced (DCE)-MR images for identifying LNM and prognosis in iCCA., Study Type: Retrospective., Subjects: Two hundred four patients with pathologically proven iCCA who underwent curative-intent resection and lymphadenectomy (training cohort: N = 107, internal test cohort: N = 46, and external test cohort: N = 51)., Field Strength/sequence: T1- and T2-weighted imaging, diffusion-weighted imaging and DCE imaging at 1.5 T or 3.0 T., Assessment: Radiomics features were extracted from intra- and peri-tumoral regions on preoperative DCE-MR images. Imaging features were evaluated by three radiologists, and significant variables in univariable and multivariable regression analysis were included in clinical model. The best-performing radiomics signature and clinical characteristics (intrahepatic duct dilatation, MRI-reported LNM) were combined to build a nomogram. Patients were divided into high-risk and low-risk groups based on their nomogram scores (cutoff = 0.341). Patients were followed up for 1-102 months (median 12) after surgery, the overall survival (OS) and recurrence-free survival (RFS) were calculated., Statistical Tests: Receiver operating characteristic (ROC) curve, calibration, decision curve, Delong test, Kaplan-Meier curves, log rank test. Two tailed P < 0.05 was considered statistically significant., Results: The nomogram incorporating intra- and peri-tumoral radiomics features, intrahepatic duct dilatation and MRI-reported LNM obtained the best discrimination for LNM, with areas under the ROC curves of 0.946, 0.913, and 0.859 in the training, internal, and external test cohorts. In the entire cohort, high-risk patients had significantly lower RFS and OS than low-risk patients. High-risk of LNM was an independent factor of unfavorable OS and RFS., Data Conclusion: The nomogram integrating intra- and peri-tumoral radiomics signatures has potential to identify LNM and prognosis in iCCA., Evidence Level: 3 TECHNICAL EFFICACY: Stage 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

Aims: To explore the MRI characteristics and clinical outcome of the "very early" intrahepatic cholangiocarcinoma (iCCA) ≤2.0cm., Materials and Methods: Totally 213 pathologically confirmed iCCAs (44 ≤ 2.0cm and 169 of 2.0-5.0cm) from two institutes were included. Forty-four matching non-iCCA malignancies ≤2.0cm were also enrolled. Recurrence-free survival (RFS) was estimated and compared between iCCAs ≤2.0cm and 2.0-5.0cm. MRI features were analyzed and compared between iCCAs ≤2.0cm and 2.0-5.0cm, as well as between iCCAs ≤2.0cm and non-iCCAs ≤2.0cm. Univariate and multivariate regression analyses were performed to identify independent imaging features for discrimination. An MRI-based diagnostic model for iCCA ≤2.0cm was constructed by incorporating the independent imaging features., Results: ICCAs ≤2.0cm had a significantly longer RFS than those of 2.0-5.0cm (log rank P=0.014). Imaging features of homogeneous signal (odds ratio (OR) = 6.677, P<0.001) and lack of vessel invasion (OR=7.56, P<0.001) were more frequently displayed in iCCAs ≤2.0cm compared to iCCAs of 2.0-5.0cm independently. In the small lesions ≤2.0cm, imaging features of progressive or persistent enhancement pattern (OR=27.78, P=0.002) and rim diffusion restriction (OR=5.70, P=0.027) were independent imaging features suggestive of iCCA over non-iCCA malignancy; their combination yielded an area under the curve value of 0.824, with a sensitivity of 97.73%., Conclusion: The "very early" iCCA ≤2.0cm was associated with a favorable outcome after surgery, it displayed different and relatively atypical imaging manifestations compared with those of 2.0-5.0cm. Furthermore, in the small lesions ≤ 2.0cm, MRI can be served as a useful non-invasive diagnostic tool for iCCA in clinical screening with high sensitivity., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background: Tertiary lymphoid structures (TLSs) have prognostic value in intrahepatic cholangiocarcinoma (ICC) patients. Noninvasive tool to preoperatively evaluate TLSs is still lacking., Purpose: To explore the association between TLSs status of ICC and preoperative MRI radiomics analysis., Study Type: Retrospective., Subjects: One hundred and ninety-two patients with ICC, divided into training (T = 105), internal validation groups (V1 = 46), and external validation group (V2 = 41)., Sequence: Coronal and axial single-shot fast spin-echo T2-weighted, diffusion-weighted imaging, T1-weighted, and T1WI fat-suppressed spoiled gradient-recall echo LAVA sequence at 3.0 T., Assessment: The VOIs were drawn manually within the visible borders of the tumors using ITK-SNAP version 3.8.0 software in the axial T2WI, DWI, and portal vein phase sequences. Radiomics features were subjected to least absolute shrinkage and selection operator regression to select the associated features of TLSs and construct the radiomics model. Univariate and multivariate analyses were used to identify the clinical radiological variables associated with TLSs. The performances were evaluated by the area under the receiver operator characteristic curve (AUC)., Statistical Tests: Logistic regression analysis, ROC and AUC, Hosmer-Lemeshow test, Kaplan-Meier method with the log-rank test, calibration curves, and decision curve analysis. P < 0.05 was considered statistically significant., Results: The AUCs of arterial phase diffuse hyperenhancement were 0.59 (95% confidence interval [CI], 0.50-0.67), 0.52 (95% CI, 0.43-0.61), and 0.66 (95% CI, 0.52-0.80) in the T, V1, and V2 cohorts. The AUCs of Rad-score were 0.85 (95% CI, 0.77-0.92), 0.81 (95% CI, 0.67-0.94), and 0.84 (95% CI, 0.71-0.96) in the T, V1, and V2 cohorts, respectively. In cohort T, low-risk group showed significantly better median recurrence-free survival (RFS) than that of the high-risk group, which was also confirmed in cohort V1 and V2., Data Conclusion: A preoperative MRI radiomics signature is associated with the intratumoral TLSs status of ICC patients and correlate significantly with RFS., Level of Evidence: 3 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

This study aims to determine the predictive role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) derived radiomic model in tumor immune profiling and immunotherapy for cholangiocarcinoma. To perform radiomic analysis, immune related subgroup clustering was first performed by single sample gene set enrichment analysis (ssGSEA). Second, a total of 806 radiomic features for each phase of DCE-MRI were extracted by utilizing the Python package Pyradiomics. Then, a predictive radiomic signature model was constructed after a three-step features reduction and selection, and receiver operating characteristic (ROC) curve was employed to evaluate the performance of this model. In the end, an independent testing cohort involving cholangiocarcinoma patients with anti-PD-1 Sintilimab treatment after surgery was used to verify the potential application of the established radiomic model in immunotherapy for cholangiocarcinoma. Two distinct immune related subgroups were classified using ssGSEA based on transcriptome sequencing. For radiomic analysis, a total of 10 predictive radiomic features were finally identified to establish a radiomic signature model for immune landscape classification. Regarding to the predictive performance, the mean AUC of ROC curves was 0.80 in the training/validation cohort. For the independent testing cohort, the individual predictive probability by radiomic model and the corresponding immune score derived from ssGSEA was significantly correlated. In conclusion, radiomic signature model based on DCE-MRI was capable of predicting the immune landscape of chalangiocarcinoma. Consequently, a potentially clinical application of this developed radiomic model to guide immunotherapy for cholangiocarcinoma was suggested.

Aim: To establish a machine-learning model based on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) to differentiate combined hepatocellular-cholangiocarcinoma (cHCC-CC) from hepatocellular carcinoma (HCC) before surgery., Materials and Methods: Clinical and MRI data of 194 patients with histopathologically diagnosed cHCC-CC (n=52) or HCC (n=142) were analysed retrospectively. ITK-SNAP software was used to delineate three-dimensional (3D) lesions and extract high-throughput features. Feature selection was carried out based on Pearson's correlation coefficient and least absolute shrinkage and selection operator (LASSO) regression analysis. A radiomics model (radiomics features), a clinical model (i.e., clinical-image features), and a fusion model (i.e., radiomics features + clinical-image features) were established using six machine-learning classifiers. The performance of each model in distinguishing between cHCC-CC and HCC was evaluated with the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), sensitivity, and specificity., Results: Significant differences in liver cirrhosis, tumour number, shape, edge, peritumoural enhancement in the arterial phase, and lipid were identified between cHCC-CC and HCC patients (p<0.05). The AUC of the fusion model based on logistic regression was 0.878 (95% CI: 0.766-0.949) in the arterial phase in the test set, and the sensitivity/specificity was 0.844/0.714; however, the AUC of the clinical and radiomics models was 0.759 (95% CI: 0.663-0.861) and 0.838 (95% CI: 0.719-0.921) in the test set, respectively., Conclusion: The fusion model based on DCE-MRI in the arterial phase can significantly improve the diagnostic rate of cHCC-CC and HCC as compared with conventional approaches., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Purpose: The study aims to investigate the predictability of the radiological response in intrahepatic cholangiocarcinoma (iCC) patients undergoing Yttrium-90 transarterial radioembolization (TARE) with a combined model built on dynamic magnetic resonance imaging (MRI)-based radiomics and clinical features., Methods: Thirty-six naive iCC patients who underwent TARE were included in this study. The tumor segmentation was performed on the axial T2-weighted (T2W) without fat suppression, axial T2W with fat suppression, and axial T1-weighted (T1W) contrast-enhanced (CE) sequence in equilibrium phase (Eq). At the sixth month MRI follow-up, all patients were divided into responders and non-responders according to the modified Response Evaluation Criteria in Solid Tumors. Subsequently, a radiomics score (rad-score) and a combined model of the rad-score and clinical features for each sequence were generated and compared between the groups., Results: Thirteen (36.1%) patients were considered responders, and the remaining 23 (63.9%) were non-responders. Responders exhibited significantly lower rad-scores than non-responders ( P < 0.050 for all sequences). The radiomics models showed good discriminatory ability with an area under the curve (AUC) of 0.696 [95% confidence interval (CI), 0.522–0.870] for the axial T1W-CE-Eq, AUC of 0.839 (95% CI, 0.709–0.970) for the axial T2W with fat suppression, and AUC of 0.836 (95% CI, 0.678–0.995) for the axial T2W without fat suppression., Conclusion: Radiomics models created by pre-treatment MRIs can predict the radiological response to Yttrium- 90 TARE in iCC patients with high accuracy. Combining radiomics with clinical features could increase the power of the test. Large-scale studies of multi-parametric MRIs with internal and external validations are needed to determine the clinical value of radiomics in iCC patients., Competing Interests: The authors declared no conflicts of interest.

As a rare biliary tract tumor, intraductal papillary neoplasm of the bile duct (IPNB) is most common in elderly men and can progress to cholangiocarcinoma- (CCa) if left untreated. It is reported that IPNB usually communicates with the bile duct. As a result, the downstream bile ducts are imaged asymmetrically dilated. However, a case of IPNB that we report here is different. Enhanced MRI revealed a lack of connectivity with the bile duct in this case. Based on this, the purpose of this case study is to suggest that the majority of imaging doctors should widely understand the various imaging manifestations of the disease to avoid misdiagnosis. In addition, although this feature was not indicated by ultrasound in this case, given previous studies and considering the convenience and non-ionizing radiation damage of CEUS, we recommend its use as a screening method for IPNB to improve diagnostic accuracy.

Objective: To investigate whether pre-treatment contrast-enhanced MRI could predict the therapeutic response of systemic treatment in advanced intrahepatic cholangiocarcinoma (ICC)., Methods: This retrospective study enrolled 61 ICC participants with contrast-enhanced MRI before combined systemic therapy. Clinical characteristics and MRI features were compared between patients with and without therapeutic response by univariate and multivariate logistic regression analyses. Then, a combined MRI-based model and the nomogram were established based on the results of the multivariate analysis. The diagnostic performances of significant findings and the combined model were evaluated and compared. The progression-free survival (PFS) rates between patients with high and low combined index values were compared., Results: Thirty (49.18%) patients showed overall response after therapy. In multivariate analysis, tumor margin (odds ratio (OR) = 5.004, p = 0.014), T2 homogeneity (OR = 14.93, p = 0.019), and arterial peritumoral enhancement (OR = 5.076, p = 0.042) were independent predictive factors associated with therapeutic response. The C-index with the formulated nomogram incorporating the three independent imaging features was 0.828 (95% CI 0.710-0.913). Diagnostic characteristics of the combined index were superior to any single feature alone (p = 0.0007-0.0141). ICCs with high combined index values showed higher PFS rates than those with low values (χ 2 = 13.306, p < 0.0001)., Conclusions: Pre-treatment contrast-enhanced MRI can be used to predict therapeutic response in advanced ICC with systemic therapy. The combination model incorporating significant MRI features achieved an improved predictive value, which may play an important role in identifying appropriate therapeutic candidates., Key Points: • Contrast-enhanced MRI can predict response of systemic therapy in advanced ICC. • MRI features of tumor margin, T2 homogeneity, and arterial peritumoral enhancement are related to therapeutic response. • The combined MRI-based model may help to identify appropriate therapeutic candidates., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Background: Intrahepatic cholangiocarcinoma (ICC) is the second most common type of primary hepatic malignancy. Aim of this work is to analyse the features of ICC and its differential diagnosis at MRI, assessing two categories intraparenchymal and peribiliary lesions., Methods: The study population included 88 patients with histological diagnosis of ICCs: 61 with mass-forming type, 23 with periductal-infiltrating tumours and 4 with intraductal-growing type. As a control study groups, we identified: 86 consecutive patients with liver colorectal intrahepatic metastases (mCRC) (groups A); 35 consecutive patients with peribiliary metastases (groups B); 62 consecutive patients (groups C) with hepatocellular carcinoma (HCC); 18 consecutive patients (groups D) with combined hepatocellular cholangiocarcinoma (cHCC-CCA); and 26 consecutive patients (groups E) with hepatic hemangioma. For all lesions, magnetic resonance (MR) features were assessed according to Liver Imaging Reporting and Data System (LI-RADS) version 2018. The liver-specific gadolinium ethoxybenzyl dimeglumine-EOB (Primovist, Bayer Schering Pharma, Germany), was employed. Chi-square test was employed to analyse differences in percentage values of categorical variable, while the nonparametric Kruskal-Wallis test was used to test for statistically significant differences between the median values of the continuous variables. However, false discovery rate adjustment according to Benjamin and Hochberg for multiple testing was considered., Results: T1- and T2-weighted signal intensity (SI), restricted diffusion, transitional phase (TP) and hepatobiliary phase (HP) aspects allowed the differentiation between study group (mass-forming ICCs) and each other control group (A, C, D, E) with statistical significance, while arterial phase (AP) appearance allowed the differentiation between study group and the control groups C and D with statistical significance and PP appearance allowed the differentiation between study group and the control groups A, C and D with statistical significance. Instead, no MR feature allowed the differentiation between study group (periductal-infiltrating type) and control group B., Conclusion: T1 and T2 W SI, restricted diffusion, TP and HP appearance allowed the differentiation between mass-forming ICCs and mimickers with statistical significance, while AP appearance allowed the differentiation between study group and the control groups C and D with statistical significance and PP appearance allowed the differentiation between study group and the control groups A, C and D., (© 2021. Italian Society of Medical Radiology.)

We compared the performance of computed tomography (CT) and magnetic resonance imaging (MRI) for preoperative clinical staging of mass-forming intrahepatic cholangiocarcinoma (iCCA), using the eighth American Joint Committee on Cancer (AJCC) system. This retrospective, multicenter, cohort study consecutively identified patients who underwent partial hepatectomy for mass-forming iCCA and had preoperative CT and MRI performed from January 2009 to December 2015. CT and MRI characteristics were used to determine clinical stage based on the eighth AJCC system. Performances of CT and MRI for clinical T and N staging were compared using generalized estimating equations. In 334 patients (median age, 63 years; 221 men), MRI sensitivities were significantly higher than CT sensitivities for detecting T1b or higher stages (91.0% vs. 80.5%, respectively, P < 0.001), T2 or higher stages (89.1% vs. 73.8%, respectively, P < 0.001), and T3 or T4 stage (77.8% vs. 58.0%, respectively, P < 0.001). MRI was also more sensitive at identifying multiple tumors than CT (66.7% vs. 50.0%, respectively, P = 0.026), without a significant difference in specificity (78.1% vs. 80.1%, respectively, P = 0.342). Sensitivities were comparable between CT and MRI for determination of size >5 cm (i.e., T1b for single tumor) and extrahepatic organ invasion (i.e., T4). Sensitivities of CT and MRI were not different for N stage (65.0% vs. 64.0%, respectively, P = 0.808), but the specificity of CT was significantly higher than that of MRI (80.7% vs. 72.9%, respectively, P = 0.001) when using a composite reference standard. Conclusion: MRI showed superior sensitivity to CT for diagnosing T2 and T3 stages, particularly multiple tumors. CT and MRI had comparable sensitivity for N staging, but CT provided higher specificity than MRI., (© 2021 The Authors. Hepatology Communications published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Background: Radiomics may provide more objective and accurate predictions for extrahepatic cholangiocarcinoma (ECC). In this study, we developed radiomics models based on magnetic resonance imaging (MRI) and machine learning to preoperatively predict differentiation degree (DD) and lymph node metastasis (LNM) of ECC., Methods: A group of 100 patients diagnosed with ECC was included. The ECC status of all patients was confirmed by pathology. A total of 1200 radiomics features were extracted from axial T1 weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion weighted imaging (DWI), and apparent diffusion coefficient (ADC) images. A systematical framework considering combinations of five feature selection methods and ten machine learning classification algorithms (classifiers) was developed and investigated. The predictive capabilities for DD and LNM were evaluated in terms of area under precision recall curve (AUPRC), area under the receiver operating characteristic (ROC) curve (AUC), negative predictive value (NPV), accuracy (ACC), sensitivity, and specificity. The prediction performance among models was statistically compared using DeLong test., Results: For DD prediction, the feature selection method joint mutual information (JMI) and Bagging Classifier achieved the best performance (AUPRC = 0.65, AUC = 0.90 (95% CI 0.75-1.00), ACC = 0.85 (95% CI 0.69-1.00), sensitivity = 0.75 (95% CI 0.30-0.95), and specificity = 0.88 (95% CI 0.64-0.97)), and the radiomics signature was composed of 5 selected features. For LNM prediction, the feature selection method minimum redundancy maximum relevance and classifier eXtreme Gradient Boosting achieved the best performance (AUPRC = 0.95, AUC = 0.98 (95% CI 0.94-1.00), ACC = 0.90 (95% CI 0.77-1.00), sensitivity = 0.75 (95% CI 0.30-0.95), and specificity = 0.94 (95% CI 0.72-0.99)), and the radiomics signature was composed of 30 selected features. However, these two chosen models were not significantly different to other models of higher AUC values in DeLong test, though they were significantly different to most of all models., Conclusion: MRI radiomics analysis based on machine learning demonstrated good predictive accuracies for DD and LNM of ECC. This shed new light on the noninvasive diagnosis of ECC., (© 2021. The Author(s).)

Aim: The aim of this study is to develop and test radiomics models based on magnetic resonance imaging (MRI) to preoperatively and respectively predict the T stage, perineural invasion, and microvascular invasion of extrahepatic cholangiocarcinoma (eCCA) through a non-invasive approach., Methods: This research included 101 eCCA patients (29-83 years; 45 females and 56 males) between August 2011 and December 2019. Radiomics features were retrospectively extracted from T1-weighted imaging, T2-weighted imaging, diffusion-weighted imaging, and apparent diffusion coefficient map using MaZda software. The region of interest was manually delineated in the largest section on four MRI images as ground truth while keeping 1-2 mm margin to tumor border, respectively. Pretreatment, dimension reduction method, and classifiers were used to establish radiomics signatures for assessing three pathological characteristics of eCCA. Finally, independent training and testing datasets were used to assess radiomics signature performance based on receiver operating characteristic curve analysis, accuracy, precision, sensitivity, and specificity., Results: This study extracted 1208 radiomics features from four MRI images of each patient. The best performing radiomics signatures for assessing the T stage, perineural invasion, and microvascular invasion were respectively produced by L1&#95;normalization + linear discriminant analysis (LDA) + logistic regression, Box&#95;Cox transformer + LDA + K-nearest neighbor, and L2&#95;normalization + LDA + AdaBoost. The area under the curve values of the radiomics signatures for predicting the training and testing cohorts in each subgroup were respectively 1 and 0.962 (T stage), 1 and 1 (both perineural invasion and microvascular invasion)., Conclusion: These proposed radiomic models based on MR images had powerful performance and high potential in predicting T stage, perineural, and microvascular invasion of eCCA., Reporting Guidelines/research Design: Prognostic study., Competing Interests: Conflict of interest statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This study was designed to assess 3D vs. 1D and 2D quantitative tumor analysis for prediction of overall survival (OS) in patients with Intrahepatic Cholangiocarcinoma (ICC) who underwent conventional transarterial chemoembolization (cTACE). 73 ICC patients who underwent cTACE were included in this retrospective analysis between Oct 2001 and Feb 2015. The overall and enhancing tumor diameters and the maximum cross-sectional and enhancing tumor areas were measured on baseline images. 3D quantitative tumor analysis was used to assess total tumor volume (TTV), enhancing tumor volume (ETV), and enhancing tumor burden (ETB) (ratio between ETV and liver volume). Patients were divided into low (LTB) and high tumor burden (HTB) groups. There was a significant separation between survival curves of the LTB and HTB groups using enhancing tumor diameter (p = 0.003), enhancing tumor area (p = 0.03), TTV (p = 0.03), and ETV (p = 0.01). Multivariate analysis showed a hazard ratio of 0.46 (95%CI: 0.27-0.78, p = 0.004) for enhancing tumor diameter, 0.56 (95% CI 0.33-0.96, p = 0.04) for enhancing tumor area, 0.58 (95%CI: 0.34-0.98, p = 0.04) for TTV, and 0.52 (95%CI: 0.30-0.91, p = 0.02) for ETV. TTV and ETV, as well as the largest enhancing tumor diameter and maximum enhancing tumor area, reliably predict the OS of patients with ICC after cTACE and could identify ICC patients who are most likely to benefit from cTACE.

OBJECTIVE. The purpose of our study was to retrospectively characterize the CT and MRI features of primary intrahepatic lymphoepithelioma-like cholangiocarcinoma (LELCC). MATERIALS AND METHODS. Eleven patients (10 women and one man; age range, 30-63 years) with 11 pathologically proven LELCCs were enrolled retrospectively from April 2016 to December 2018. Triphasic enhanced images were obtained of all patients: MR images of five patients, CT images of five patients, and both CT and MR images of one patient. The clinical data and CT and MRI findings were reviewed. RESULTS. All LELCC cases were associated with Epstein-Barr virus (EBV) infection. Eight of the 11 patients had hepatitis B virus (HBV) infection. The tumor diameter ranged from 1.1 to 8.7 cm. All tumors were well defined with a smooth or lobulated margin. A cystic area was noted in two of the 11 tumors. After the administration of contrast material, the tumors showed homogeneous ( n = 7) or heterogeneous ( n = 4) hypervascular arterial enhancement and gradual washout, delayed central scar or irregular enhancement ( n = 9), delayed circular thin or incomplete pseudocapsule enhancement ( n = 7), and homogeneous hypointensity in the hepatobiliary phase ( n = 2). No cirrhosis, focal dilatation of intrahepatic ducts, or satellite nodules were detected. Lymphadenopathy were detected in four patients, appearing as hypervascular enhancement and no necrosis (even in multiple nodes > 3 cm) or as moderate peripheral enhancement and necrosis. CONCLUSION. A liver mass in a middle-aged woman with EBV and HBV infection that appears on CT and MRI to have a well-defined boundary and a combination of hypervascularity, washout, delayed intratumoral enhancement, or pseudocapsule enhancement may suggest an imaging diagnosis of primary LELCC. More cases are needed to better understand this disease.

Background: Accurate clinical staging of patients with cholangiocarcinoma (CCA) has a significant impact on treatment decisions. In this study, we aimed to compare the diagnostic value of magnetic resonance imaging (MRI) and 18-fludeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) for staging of CCA., Methods: We performed comprehensive systematic search in Web of Science (including MEDLINE) and Excerpta Medica Database for relevant diagnostic studies in accordance with the preferred reporting items for systematic reviews and meta-analysis statement. Based on data extracted from patient-based analysis, we calculated the pooled sensitivity and specificity with the 95% confidence intervals (CIs). In addition, the publication bias was assessed by Deek funnel plot of the asymmetry test. The potential heterogeneity was explored by threshold effect analysis and subgroup analyses., Results: Thirty-two studies with 1626 patients were included in present analysis. In T stage, the pooled sensitivity and specificity of MRI were 0.90 (95% CI 0.86-0.93), 0.84 (95% CI 0.73-0.91) respectively. The pooled sensitivity and specificity of F-FDG PET/CT were 0.91 (95% CI 0.83-0.95) and 0.85 (0.64-0.95) respectively. In N stage, the pooled sensitivity and specificity of MRI were 0.64 (95% CI 0.52-0.74) and 0.69 (95% CI 0.51-0.87) respectively. The pooled sensitivity and specificity of PET/CT were 0.52 (95% CI 0.37-0.66) and 0.92 (95% CI 0.79-0.97) respectively. In M stage, the pooled sensitivity and specificity of F-FDG PET/CT were 0.56 (95% CI, 0.42-0.69) and 0.95 (95% CI, 0.91-0.97) respectively. The Deek test revealed no significant publication bias. No threshold effect was identified. The subgroup analyses showed that pathological type (extrahepatic cholangiocarcinoma vs hilar cholangiocarcinoma/intrahepatic cholangiocarcinoma), country (Asia vs non-Asia) and type of MRI (1.5T vs. 3.0T) were potential causes for the heterogeneity of MRI studies and country (Asia vs non-Asia) was a potential source for F-FDG PET/CT studies., Conclusion: The analysis suggested that both modalities provide reasonable diagnostic accuracy in T stage without significant differences between them. We recommend that both modalities be considered based on local availability and practice for the diagnosis of primary CCA tumors. In N stage, the diagnosis of lymph node metastasis (N) of CCA is still limited by MRI and F-FDG PET/CT, due to unsatisfactory diagnostic accuracy of both. Nevertheless, F-FDG PET/CT can be used to confirm lymph node metastasis while a negative result may not rule out metastasis. Furthermore, F-FDG PET/CT have a low sensitivity and a high specificity for detection of distant metastasis.

The diagnostic performance of the Liver Imaging Reporting and Data System (LI-RADS) in differentiating hepatocellular carcinoma (HCC) from other hepatic malignancies has not been investigated in Chinese patients with chronic liver disease from hepatitis B virus (HBV) infection. The aim of this study was to evaluate the accuracy of the LI-RADS version 2018 in differentiating HCC, intrahepatic cholangiocarcinoma (ICCA), and combined HCC-cholangiocarcinoma (cHCC-CCA) in Chinese patients with HBV infection. Seventy consecutive HBV-infected patients with ICCA (n = 48) or cHCC-CCA (n = 22) who underwent contrast-enhanced magnetic resonance imaging (CE-MRI) between 2006 and 2017 were enrolled along with a comparison cohort of 70 patients with HCC and CE-MRI-matched for tumor size (10-19 mm, 20-30 mm, 31-50 mm, and >50 mm). Imaging feature frequencies for each tumor type were compared using Fisher's exact test. The classification accuracy of LR-5 and LR-M was estimated for HCC versus non-HCC (ICCA and cHCC-CCA). The interobserver agreement was good for LI-RADS categories of HCC and moderate for non-HCC. After consensus read, 66 of 70 (94%) HCCs were categorized LR-5 (including tumor in vein [TIV] with LR-5), while 42 of 48 (88%) ICCAs and 13 of 22 (59%) cHCC-CCAs were categorized LR-M (including TIV with LR-M) (p < 0.001). Thus, assignment of LR-5 provided 94% sensitivity and 81% specificity for HCC. LR-M provided 79% sensitivity and 97% specificity for non-HCC (ICCA and cHCC-CCA); and the sensitivity and accuracy were lower in differentiating HCC from non-HCC (tumor size <20 mm). LI-RADS v2018 category 5 and M reliably differentiated HBV-related HCC from ICCA. However, a substantial proportion of cHCC-CCAs were categorized LR-5 rather than LR-M. While management is controversial for these combined tumors, accurate prospective differentiation is desired for optimal treatment.

Background: The presence of microvascular invasion (MVI) in intrahepatic cholangiocarcinoma (ICC) is a significant adverse prognostic factor. This study sought to investigate the correlation between preoperative imaging parameters and MVI in ICC., Methods: A total of 108 patients with surgically resected single ICC tumors (34 MVI-positive and 74 MVI-negative lesions) who underwent MRI examination, including T1WI, T2WI, DWI, and dynamic enhancement imaging, were enrolled in this retrospective study. The following qualitative and quantitative characteristics were evaluated: tumor morphology, signal features on T1WI and T2WI, intrahepatic duct dilatation, hepatic capsule retraction, target sign on DWI, dynamic enhancement pattern, arterial phase enhancement pattern, dot-/band-like enhancement inside the tumor, visible vessel penetration inside the tumor (hepatic artery, portal vein, or hepatic vein), integrity of the enhancement edge of the arterial phase, peripheral hepatic enhancement, tumor size, maximum enhancement edge thickness, arterial edge enhancement ratio, and delayed phase enhancement ratio. Other clinicopathological features were also used to predict and evaluate MVI in ICC. Chi-square test, Fisher's exact test, and independent t-test were used for univariate analysis to determine the relationships among the presence of MVI and these MR parameters. Logistic regression analysis was used to identify predictors of MVI among these MR parameters., Results: Among MRI characteristics, tumor morphology, intrahepatic duct dilatation, arterial phase enhancement pattern, visible hepatic artery penetration sign, maximum diameter of the tumor and the arterial phase edge enhancement ratio were correlated with MVI (P = 0.007, 0.003, 0.008, 0.000, 0.003, and 0.002, respectively). Furthermore, higher CA19-9 levels (≥37 U/ml) and pathological tumor grade III were also related to MVI (P = 0.014 and 0.004, respectively). However, multivariate logistic regression analysis demonstrated that none of the parameters were independent risk factors for the diagnosis of MVI in ICCs., Conclusion: For the preoperative prediction of MVI in ICC, six qualitative and quantitative data obtained on preoperative MRI, as well as one tumorigenic marker and the pathological tumor grade, were statistically significant. More research is needed to identify MR characteristics that can be used as independent risk factors.

Non-invasive diagnosis of hepatocellular carcinoma (HCC) in cirrhotic patients requires demonstration of wash-in and wash-out on contrast-enhanced imaging. Recent studies have reported misclassification of mass-forming intrahepatic cholangiocarcinoma (MFCCC) as HCC. We aimed to analyze the contrast enhancement patterns of MFCCC, focusing especially on lesions mimicking HCC. We retrospectively evaluated all consecutive patients with MFCCC who underwent surgery between 2007 and 2017. Patients with mixed HCC-MFCCC were excluded. Two expert radiologists reviewed preoperative CT and MRI. Full-nodule hyperenhancement in the arterial phase in conjunction with hypoenhancement in the portal/late phase was classified as an "HCC-like pattern". Imaging of MFCCCs with an HCC-like pattern was reviewed by an additional radiologist blinded to clinical data. Ninety-two patients were analyzed. All patients were investigated with multiphase CT and 85 with MRI. Twelve tumors (13%) showed full-nodule arterial hyperenhancement. Of these, four were hypoenhancing in the portal/late phase. Overall, 4/92 (4%) MFCCCs (4/45 in patients with cirrhosis/hepatitis, 9%) showed an HCC-like pattern accounting for misclassification as HCC on imaging review. HCC-like MFCCCs accounted for 9% of single tumors ≤ 50 mm. All HCC-like MFCCCs occurred in patients with cirrhosis or hepatitis, whereas only 47% of non-HCC-like MFCCCs did so (p = 0.053). After a median follow-up of 29 months, all patients with HCC-like MFCCCs are alive and disease free (median 64 months). In conclusion, MFCCC was misdiagnosed as typical HCC in 4% of all cases and in 9% of patients with single tumors ≤ 50 mm or with cirrhosis/hepatitis. The risk of misdiagnosis should be considered prior to treatment planning.

OBJECTIVE. CT or MRI is most commonly used for characterizing focal hepatic lesions. However, findings on CT and MRI are occasionally indeterminate. Contrast-enhanced ultrasound (CEUS), with its unique characteristics as a purely intravascular contrast agent and real-time evaluation of enhancement, is a useful next step. The purpose of this article is to review the evidence for performing CEUS in the assessment of indeterminate hepatic lesions seen on CT and MRI. CONCLUSION. CEUS is a useful problem-solving tool in the evaluation of liver lesions that are indeterminate on CT and MRI. Uses include detection of arterial phase hyperenhancement; differentiation between hepatocellular carcinoma and intrahepatic cholangiocarcinoma; determination of benign versus malignant tumor thrombus, benign versus neoplastic cystic hepatic lesions, and hepatocellular adenoma versus focal nodular hyperplasia; and monitoring for recurrence in postablative therapies. CEUS can help establish a confident diagnosis and determine the need for further invasive diagnosis or treatment.

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver malignancies. HCC and ICC have characteristic imaging findings, but a number of benign entities can appear similar and can cause diagnostic dilemma. Ideally, accurate and timely diagnosis of these conditions can help the patient to avoid a needle biopsy or even unnecessary treatment. In this article, we present various benign liver lesions that display imaging characteristics that are similar to HCC and ICC on magnetic resonance imaging (MRI) and discuss salient features that may assist in accurate diagnosis.

Cholangiocarcinoma (CC) is a malignant tumor which arises from the biliary epithelium and most cases represent adenocarcinoma. CC can be classified into intrahepatic CC (ICC), perihilar CC, and distal CC, based on the site of anatomic origin. The incidence of ICC is increasing in both Western and Eastern countries, while that of extrahepatic cholangiocarcinoma remains fairly stable. ICC infiltrates into adjacent nerves and lymphatic vessels, resulting in progressive disease with a poor prognosis; thus, early detection of ICC is critical for achieving better outcomes and providing better patient care. However, it is difficult for clinicians to detect an ICC, especially in its early stage. Different from hepatocellular carcinoma, the lack of surveillance system for the high-risk group of CC does not allow for a reliable screening examination. In this context, for early detection and diagnosis of ICC, radiologists need to know predisposing conditions that can lead to the development of ICC, such as chronic biliary or hepatic inflammation, primary sclerosing cholangitis, congenital biliary diseases, and other conditions. In this article, we discuss and illustrate the radiologic features of ICC with special attention to early disease stages and of predisposing conditions of ICC.

Background: Partial hepatectomy is the first option for intrahepatic mass-forming cholangiocarcinoma (IMCC) treatment, which would prolong survival. The main reason for the poor outcome after curative resection is the high incidence of early recurrence (ER). The aim of this study was to investigate the combined predictive performance of qualitative and quantitative magnetic resonance imaging (MRI) features and prognostic immunohistochemical markers for the ER of IMCC., Methods: Forty-seven patients with pathologically proven IMCC were enrolled in this retrospective study. Preoperative contrast-enhanced MRI and post-operative immunohistochemical staining of epidermal growth factor receptors (EGFR), vascular endothelial growth factor receptor (VEGFR), P53 and Ki67 were performed. Univariate analysis identified clinic-radiologic and pathological risk factors of ER. Radiomics analysis was performed based on four MRI sequences including fat suppression T2-weighted imaging (T2WI/FS), arterial phase (AP), portal venous phase (PVP), and delayed phase (DP) contrast enhanced imaging. A clinicoradiologic-pathological (CRP) model, radiomics model, and combined model were developed. And ROC curves were used to explore their predictive performance for ER stratification., Results: Enhancement patterns and VEGFR showed significant differences between the ER group and non-ER group (P = 0.001 and 0.034, respectively). The radiomics model based on AP, PVP and DP images presented superior AUC (0.889, 95% confidence interval (CI): 0.783-0.996) among seven radiomics models with a sensitivity of 0.938 and specificity of 0.839. The combined model, containing enhancement patterns, VEGFR and radiomics features, showed a preferable ER predictive performance compared to the radiomics model or CRP model alone, with AUC, sensitivity and specificity of 0.949, 0.875 and 0.774, respectively., Conclusions: The combined model was the superior predictive model of ER. Combining qualitative and quantitative MRI features and VEGFR enables ER prediction, thus facilitating personalized treatment for patients with IMCC.

Purpose : Accurate lymph node (LN) status evaluation for intrahepatic cholangiocarcinoma (ICC) patients is essential for surgical planning. This study aimed to develop and validate a prediction model for preoperative LN status evaluation in ICC patients. Methods and Materials : A group of 106 ICC patients, who were diagnosed between April 2011 and February 2016, was used for prediction model training. Image features were extracted from T1-weighted contrast-enhanced MR images. A support vector machine (SVM) model was built by using the most LN status-related features, which were selected using the maximum relevance minimum redundancy (mRMR) algorithm. The mRMR method ranked each feature according to its relevance to the LN status and redundancy with other features. An SVM score was calculated for each patient to reflect the LN metastasis (LNM) probability from the SVM model. Finally, a combination nomogram was constructed by incorporating the SVM score and clinical features. An independent group of 42 patients who were diagnosed from March 2016 to November 2017 was used to validate the prediction models. The model performances were evaluated on discrimination, calibration, and clinical utility. Results : The SVM model was constructed based on five selected image features. Significant differences were found between patients with LNM and non-LNM in SVM scores in both groups (the training group: 0.5466 (interquartile range (IQR), 0.4059-0.6985) vs. 0.3226 (IQR, 0.0527-0.4659), P <0.0001; the validation group: 0.5831 (IQR, 0.3641-0.8162) vs. 0.3101 (IQR, 0.1029-0.4661), P =0.0015). The combination nomogram based on the SVM score, the CA 19-9 level, and the MR-reported LNM factor showed better discrimination in separating patients with LNM and non-LNM, comparing to the SVM model alone (AUC: the training group: 0.842 vs. 0.788; the validation group: 0.870 vs. 0.787). Favorable clinical utility was observed using the decision curve analysis for the nomogram. Conclusion : The nomogram, incorporating the SVM score, CA 19-9 level and the MR-reported LNM factor, provided an individualized LN status evaluation and helped clinicians guide the surgical decisions., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Background and Objective: Cholangiocarcinoma (CCA) is an aggressive malignancy with high prevalence rate in Asia. The CCA premalignant lesions, including Biliary intraepithelial neoplasia (Bil-IN) and Intraductal papillary neoplasm of biliary tract (IPNB), share a common carcinogenesis; however, on imaging, patterns of presentation are different. Patterns and imaging characteristics on ultrasonography (US) and Magnetic resonance imaging (MRI) of both Bil-IN and IPNB are reported herein., Methods: In this retrospective study of imaging findings in premalignant CCA, pathology-proven cases of Bil-IN and IPNB at Chulabhorn Hospital were analyzed. Demographics, locations of lesions, imaging characteristics of both Bil-IN and IPNB were assessed, compared, and described., Results: Twenty-one premalignant lesions, 13 Bil-INs and 8 IPNBs, from 18 patients were included. Both Bil-IN and IPNB lesions were found more commonly at the right than left intrahepatic ducts (66.7% vs. 33.3%), and had more peripheral than central locations (85.7% vs. 14.3%). On US, Bil-IN commonly presented as focal bile duct dilatation (76.9%), whereas IPNB was more variable with hyperechoic nodules (37.5%), focal bile duct dilatation (37.5%), and diffuse bile duct dilatation with intraductal nodules (25%). On MRI, focal bile duct dilatation and nonfunctioning bile excretion are the most sensitive findings with sensitivities in the range of 84.6% to 100%. The presence of intraductal nodules and connection to the biliary system are findings that were significantly different between IPNB and Bil-IN, 62.5% versus 7.7% (p = 0.014) and 75% versus 15.4% (p = 0.018), respectively., Conclusions: Premalignant lesions of CCA, including Bil-IN and IPNB, have different imaging presentations. Knowledge of imaging presentations may improve early detection and increase confidence in diagnosis.

Purpose: To compare the cross-sectional imaging findings of immunoglobulin G4-related sclerosing cholangiopathy (IgG4-SC) and cholangiocarcinoma (CCA)., Methods: Retrospective search of radiology and pathology databases identified 24 patients with IgG4-SC and over 500 patients with CCA from January 2009 to December 2016. Patients with no pre-treatment imaging studies available on PACS, non-contrasted imaging only, presence of mass lesions, metastatic disease or biliary stents were excluded. 17 patients with IgG4-SC and a selected group of 20 (age and gender matched) patients with CCA were obtained. Images were blinded and independently reviewed by two radiologists. Differences in proportions and means between groups were analyzed using Fishers and Mann-Whitney tests, respectively., Results: Both readers identified a statistically significant difference in the presence of abrupt common bile duct narrowing between IgG4-SC and CCA (6.7% vs. 68.4%, p < 0.001; 33.3% vs. 75%, p = 0.019). No difference was seen in biliary wall thickening, wall enhancement, extrahepatic exclusive location of disease, or pancreatic duct dilation. Inter-observer variability was κ = 0.52. Total bilirubin and CA 19-9 were unable to differentiate between IgG4-SC and CCA. Serum IgG4 was positive in two of six IgG4-SC patients who were tested., Conclusion: IgG4-SC and CCA share many clinical and imaging findings on CT and MRI. Abrupt bile duct cut sign strongly favors CCA. In the absence of this finding, IgG4-SC should be considered in the differential diagnosis in all cases of suspected extrahepatic CCA.

Purpose: To determine the differential features of inflammatory myofibroblastic tumor (IMT) and intrahepatic cholangiocarcinoma (ICC) manifesting as target appearance on gadoxetic acid-enhanced MRI., Methods: Twenty-seven patients with 36 IMTs (1.2-6.0 cm) and 34 patients with 34 ICCs (1.5-6.0 cm) who underwent gadoxetic acid-enhanced MRI were enrolled in this study. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and gadoxetic acid-enhanced imaging., Results: As for 32 IMTs with target appearance, IMTs most commonly demonstrated early target appearance characterized by a peripheral hypointense rim on unenhanced T1WI (n = 27, 84.4%), central enhanced area with a hypointense rim on arterial phase (AP) and portal venous phase (PVP) (n = 29, 90.6%), and transitional phase (TP) (n = 28, 87.5%). Meanwhile, most of the ICCs showed homogeneous hypointensity on T1WI (100%), a hyperenhancing rim on AP, late target appearance on TP (n = 32, 94.1%) and HBP (n = 32, 94.1%). Target appearance on DWI appearing as hyperintensity with central hypointense area was seen in 2 IMTs and 32 ICCs. On T2WI, 24 IMTs (n = 24, 75.0%) displayed central iso- and peripheral hyperintensity and 27 ICCs (84.4%) showed layered hyperintensity with either brighter or darker area in center. The remaining six IMTs with no target were observed as cystic appearing nodules (n = 3) or ill-defined hypovascular nodules (n = 2) and fibrotic mass (n = 1)., Conclusion: IMTs often show early target appearance on unenhanced T1WI, and early dynamic phases of gadoxetic acid-enhanced MRI. Target appearance on later phases, such as TP and HBP, and DWI target appearance were commonly in ICCs, but rare in IMTs.

Purpose: To identify imaging markers that independently predict the post-operative outcome of intrahepatic mass-forming cholangiocarcinoma (IMCC) using gadoxetate disodium-enhanced magnetic resonance imaging (MRI)., Methods: Data from 54 patients who underwent pre-operative gadoxetate disodium-enhanced MRI and curative surgery for IMCC were retrospectively evaluated. The prognostic power of various imaging and pathological features reportedly associated with recurrence-free survival (RFS) and overall survival (OS) was analyzed using Cox regression models. A model combining imaging and pathological features was developed and its performance was evaluated using the Harrell C-index and Akaike information criterion., Results: Capsule penetration (P = 0.016) and tumor size (P = 0.015) were independent markers for worse RFS, while capsule penetration (P = 0.012) and hepatic vein obstruction (HVO, P = 0.016) were independent markers for worse OS, respectively, in the imaging-based model. Capsule penetration was the only imaging marker identified in the combined prediction model of RFS, and the combined model showed a higher C-index and lower AIC value compared with the model based on pathological features alone., Conclusions: Capsule penetration and HVO on MRI are significantly worse imaging prognostic factors for post-operative outcomes in patients with IMCC. Incorporation of capsule penetration and HVO into a surgical staging system may improve prediction of the post-operative prognosis of IMCC.

Background: Fibrolamellar Carcinoma (FLC) and Combined Hepatocellular- Cholangiocarcinoma (CHC) are rare primary liver tumours, which are related to different clinical settings. In both tumours, correlation with clinical data and laboratory tests are extremely important., Discussion: Typically, FLC is diagnosed in young patients without any chronic disease and with normal biochemical tests, whereas CHC arises in cirrhotic patients with elevated tumour markers: AFP and/or CA 19-9. The review describes epidemiology, aetiology, pathogenesis, radiological features and treatment of these tumours. Imaging features typical for FLC are: The presence of central scar, calcifications, the large size, heterogeneous and early contrast-enhancement., Conclusion: The diagnosis of CHC may be suggested in case of elevation of both AFP and CA 19- 9 or inconsistency between elevated tumour markers and imaging findings (i.e., elevated CA 19-9 and radiological features of HCC, or elevated AFP with imaging findings characteristic of ICC)., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: To explore the value of parameters of multiphase dynamic contrast-enhanced magnetic resonance imaging (MDCE-MRI) in the qualitative diagnosis of hepatic masses., Methods: Eighty patients with hepatic masses were retrospectively analyzed. All the patients underwent MDCE-MRI at 3.0 T MR before treatment. Mean enhancement time (MET), positive enhancement integral (PEI), a maximum slope of increase (MSI), and a maximum slope of decrease (MSD) were measured., Results: There were significant differences between benign and malignant hepatic masses with respect to MET, PEI, and MSI values. The PEI and MSI values between hemangiomas, hepatocellular carcinomas (HCCs), cholangiocarcinomas, and metastatic tumors had significant differences. The MSD value between metastatic tumors, HCCs, and hemangiomas were significantly different. The area under the curve (AUC) values of the receiver operator characteristic curves for MET, PEI, and MSI were 0.70, 0.72, and 0.80, respectively. The specificity of MET, PEI, and MSI were all 77%, and the sensitivities of MSI was the highest, of which was 82.40%. Logistic regression analysis showed the regression equation to be P = 1/[1 + e 0.008 × 1 + 0.007 × 2-6.707 ], and taking the Youden index maximum points as a diagnostic point was 0.2946., Conclusion: Some parameters of MDCE-MRI have significant roles in differentiating hepatic masses.

Purpose To evaluate whether baseline MRI can help predict survival in patients with unresectable intrahepatic cholangiocarcinoma (ICCA) undergoing transcatheter arterial chemoembolization (TACE). Materials and Methods This retrospective study was compliant with HIPAA and approved by the institutional review board. The requirement to obtain informed consent was waived. The study included 111 patients (mean age, 62 years ± 12; range, 29-86 years), with 44 men (mean age, 61 years ± 12; range, 29-81 years) and 67 women (mean age, 63 years ± 12; range, 34-86 years). Patients underwent TACE after baseline MRI, which included contrast-enhanced and diffusion-weighted imaging with apparent diffusion coefficient (ADC) mapping between 2003 and 2016. The single largest tumor was assessed independently by a radiologist for anatomic and functional (viable tumor volume, percentage viable tumor volume [100 × viable tumor volume/whole tumor volume], viable tumor burden [100 × viable tumor volume/whole liver volume], and ADC) parameters. Survival analysis was performed with Kaplan-Meier and Cox regression analysis. Results Overall survival (OS) was higher with a baseline ADC of 1415 × 10 -6 mm 2 /sec or less compared with greater than 1415 × 10 -6 mm 2 /sec (P = .005; 25th percentile of OS, 17 months vs 7 months, respectively), percentage viable tumor volume greater than 90% compared with 90% or less (P = .001; 25th percentile of OS, 20 months vs 7 months, respectively), and viable tumor burden greater than 6.6% compared with 6.6% or less (P = .09; 25th percentile of OS, 17 months vs 7 months, respectively). Baseline ADC greater than 1415 × 10 -6 mm 2 /sec (hazard ratio [HR]: 2.176 [95% confidence interval: 1.217, 3.891]; P = .009) and percentage viable tumor volume greater than 90% (HR: 0.319 [95% confidence interval: 0.148, 0.685]; P = .003) were associated with OS independent of clinical confounders (age and sex). At multiparametric MRI risk stratification (with low ADC and high percentage viable tumor volume considered favorable for survival), differences in OS were noted (P = .002; 25th percentile of OS for low vs intermediate vs high risk, 22 months vs 10 months vs 7 months, respectively). Conclusion Baseline multiparametric MRI assessment including volumetric ADC, percentage viable tumor volume, and viable tumor burden can help predict mortality risk among patients with intrahepatic cholangiocarcinoma undergoing transcatheter arterial chemoembolization. © RSNA, 2018 Online supplemental material is available for this article.

Background: Primary hepatic sarcomatous carcinoma (PHSC) is a rare malignancy composed of both carcinomatous (either hepatocellular or cholangiocellular) and sarcomatous components. The purpose of our study was to evaluate the imaging and clinical findings of PHSCs, improving the understanding and diagnosis of tumors., Methods: We retrospectively reviewed the imaging and clinical findings of ten patients with pathologically proven PHSCs, including two cases of sarcomatous intrahepatic cholangiocarcinoma (S-ICC), seven cases of sarcomatous hepatocellular carcinoma (S-HCC) and one case of sarcomatous combined hepatocellular and cholangiocarcinoma (S-HCC-CC). Six patients underwent computed tomography (CT) scans and five underwent magnetic resonance imaging (MRI) scans with one of them having both CT and MRI scans., Results: Eight of ten patients had a background of chronic hepatitis or cirrhosis. The elevation of alpha-fetoprotein (AFP) was positive in half of the patients. All the tumors were located near the liver subcapsular area and six of ten cases were massive with round or oval shapes and ill-defined. The lesion textures were mainly heterogeneous in eight tumors for the necrosis or hemorrhage. Eight tumors showed hypo-enhancement and nine tumors exhibited initial peripheral rim (five cases) or heterogeneous (four cases) enhancement, followed by progressive (six cases) and peripheral or partial washout (three cases) on the later phases. Of the seven surgically resected tumors, five showed liver capsular invasion with one of them rupturing into the perihepatic space. Vascular thrombosis (five cases), intrahepatic metastasis (four cases), adjacent organ invasion or seeding (three cases), and lymph node metastasis (four cases) were found on imaging or in pathology. The follow-up period ranged from one to 36 months. Four patients with T3-T4 staging died from recurrence and metastasis between 2 and 5 months, and three patients with T1 staging did not have any recurrence between 16 and 24 months., Conclusion: PHSC generally presents as a subcapsular mass with hypovascularity and may be characterized by rim-like or heterogeneous enhancement on the arterial phase and a progressive dynamic pattern. These tumors usually coincide with chronic hepatitis or cirrhosis and poor prognosis appears to be associated with TNM staging.

Objectives: We compared the interobserver agreement for the recently introduced contrast-enhanced ultrasound (CEUS)-based algorithm CEUS-LI-RADS (Liver Imaging Reporting and Data System) versus the well-established magnetic resonance imaging (MRI)-LI-RADS for non-invasive diagnosis of hepatocellular carcinoma (HCC) in high-risk patients., Methods: Focal liver lesions in 50 high-risk patients (mean age 66.2 ± 11.8 years; 39 male) were assessed retrospectively with CEUS and MRI. Two independent observers reviewed CEUS and MRI examinations, separately, classifying observations according to CEUS-LI-RADSv.2016 and MRI-LI-RADSv.2014. Interobserver agreement was assessed with Cohen's kappa., Results: Forty-three lesions were HCCs; two were intrahepatic cholangiocarcinomas; five were benign lesions. Arterial phase hyperenhancement was perceived less frequently with CEUS than with MRI (37/50 / 38/50 lesions = 74%/78% [CEUS; observer 1/observer 2] versus 46/50 / 44/50 lesions = 92%/88% [MRI; observer 1/observer 2]). Washout appearance was observed in 34/50 / 20/50 lesions = 68%/40% with CEUS and 31/50 / 31/50 lesions = 62%/62%) with MRI. Interobserver agreement was moderate for arterial hyperenhancement (ĸ = 0.511/0.565 [CEUS/MRI]) and "washout" (ĸ = 0.490/0.582 [CEUS/MRI]), fair for CEUS-LI-RADS category (ĸ = 0.309) and substantial for MRI-LI-RADS category (ĸ = 0.609). Intermodality agreement was fair for arterial hyperenhancement (ĸ = 0.329), slight to fair for "washout" (ĸ = 0.202) and LI-RADS category (ĸ = 0.218) CONCLUSION: Interobserver agreement is substantial for MRI-LI-RADS and only fair for CEUS-LI-RADS. This is mostly because interobserver agreement in the perception of washout appearance is better in MRI than in CEUS. Further refinement of the LI-RADS algorithms and increasing education and practice may be necessary to improve the concordance between CEUS and MRI for the final LI-RADS categorization., Key Points: • CEUS-LI-RADS and MRI-LIRADS enable standardized non-invasive diagnosis of HCC in high-risk patients. • With CEUS, interobserver agreement is better for arterial hyperenhancement than for "washout". • Interobserver agreement for major features is moderate for both CEUS and MRI. • Interobserver agreement for LI-RADS category is substantial for MRI, and fair for CEUS. • Interobserver-agreement for CEUS-LI-RADS will presumably improve with ongoing use of the algorithm.

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) comprise the majority of primary liver cancers. Both HCC and ICC have characteristic imaging appearances on multiphase computed tomography (CT) and magnetic resonance imaging (MRI). Several locoregional therapies, including radiation therapy, are used to treat unresectable disease and residual or recurrent tumor. The tumor response following locoregional therapies has variable imaging manifestations. Focal liver reaction, the imaging changes of the liver following radiation treatment, should be recognized and not mistaken for tumor. We review the diagnostic imaging of HCC and ICC, imaging of tumor response to treatment, and imaging of the liver response to radiation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose To determine the performance of magnetic resonance (MR) imaging-based tumor metrics for evaluation of response to transarterial chemoembolization (TACE) in patients with unresectable intrahepatic cholangiocarcinoma (ICCA). Materials and Methods Ninety-four patients with unresectable ICCA underwent baseline and follow-up MR imaging after TACE and were followed up until death or end of study duration. Lesions were analyzed for anatomic (Response Evaluation Criteria in Solid Tumors [RECIST] and tumor volume) and functional (viable tumor volume, viable tumor burden, and apparent diffusion coefficient [ADC]) volumetric MR parameters by using semiautomatic software. Response was assessed by using changes in viable tumor volume by using modified RECIST (mRECIST)-derived thresholds (three-dimensional mRECIST), viable tumor burden, and ADC. Overall survival was the primary endpoint. Cox-regression and Kaplan-Meier survival analysis were used. Results Tumor volume did not change after TACE (P = .07) whereas RECIST diameter showed a small change (-2.6%; P = .02). There was an increase in ADC (20.7%) and a decrease in viable tumor volume (-29.3%) and viable tumor burden (-29.1%; P < .001 for all). Higher overall survival was noted among responders by using thresholds of 25% increase in ADC, 66% decrease in viable tumor volume, and 50% decrease in viable tumor burden (log-rank test, P < .05). Hazard ratio for nonresponders by using ADC, three-dimensional mRECIST, and viable tumor burden at multivariable analysis was 2.9 (P = .004), 4.1 (P = .009), and 4.0 (P = .002), respectively. Survival differences were noted for patients who showed response by using all three parameters (ADC, three-dimensional mRECIST, and viable tumor burden) versus those who showed response by using either one or two of these parameters versus those who showed no response (P < .001). Conclusion Changes in volumetric ADC, viable tumor volume, and viable tumor burden at MR imaging provide prognostic information among patients with unresectable ICCA who undergo TACE. © RSNA, 2018 Online supplemental material is available for this article.

Objective: To identify reliable magnetic resonance (MR) features for distinguishing mass-forming type of intrahepatic cholangiocarcinoma (IMCC) from hepatocellular carcinoma (HCC) based on tumor size., Methods: This retrospective study included 395 patients with pathologically confirmed IMCCs (n = 180) and HCCs (n = 215) who underwent pre-operative contrast-enhanced MRI including diffusion-weighted imaging (DWI). MR features were evaluated and clinical data were also recorded. All the characteristics were compared in small (≤3 cm) and large tumor (>3 cm) groups by univariate analysis and subsequently calculated by multivariable logistic regression analysis., Results: Multivariable analysis revealed that rim arterial phase hyperenhancement [odds ratios (ORs) = 13.16], biliary dilation (OR = 23.42) and CA19-9 (OR = 21.45) were significant predictors of large IMCCs (n = 138), and washout appearance (OR = 0.036), enhancing capsule appearance (OR = 0.039), fat in mass (OR = 0.057), chronic liver disease (OR = 0.088) and alpha fetoprotein (OR = 0.019) were more frequently found in large HCCs (n = 143). For small IMCCs (n = 42) and HCCs (n = 72), rim arterial phase hyperenhancement (OR = 9.68), target appearance at DWI (OR = 12.51), alpha fetoprotein (OR = 0.12) and sex (OR = 0.20) were independent predictors in multivariate analysis., Conclusion: Valuable MR features and clinical factors varied for differential diagnosis of IMCCs and HCCs according to tumor size. Advances in knowledge: MR features for differential diagnosis of large IMCC and HCC (>3 cm) are in keeping with that recommended by LI-RADS. However, for small IMCCs and HCCs (≤3 cm), only rim enhancement on arterial phase and target appearance at DWI are reliable predictors.

Purpose: To determine if rare primary malignancies of the liver may have consistent features on magnetic resonance imaging (MRI)., Materials and Methods: This IRB-compliant retrospective study reviewed the records from the pathology departments of four university centres over an 11-year period from 2005-2016 to identify rare primary malignant tumours, which were cross-referenced with MRI records. MRI studies of these patients were reviewed to determine if these tumours exhibited consistent and distinctive features., Results: Sixty patients were identified with rare primary liver tumours. The following distinctive features and frequency of occurrence were observed: mixed hepatocellular carcinoma-cholangiocarcinoma showed regions of wash-out in 7/19 of patients; 6/6 of fibrolamellar carcinomas demonstrated large heterogeneous lesions with large heterogeneous central scars; epithelioid haemangioendothelioma larger than 2 cm showed target-like enhancement in late-phase enhancement in 9/13; sarcomas excluding angiosarcoma had central necrosis in 3/9 and haemorrhage in 5/9; angiosarcomas showed centripedal progressive nodular enhancement in 3/6 and showed regions of haemorrhage in 3/6; and 7/7 of primary hepatic lymphomas showed encasement of vessels., Conclusion: Although helpful features for the differentiation of rare primary malignancies of the liver are identified, no MRI features appear to be specific and therefore histopathological confirmation is usually required for definitive diagnosis., Key Points: • No MRI features appear to be specific for rare primary liver malignancies. • Haemorrhage is a helpful sign in diagnosis of primary hepatic sarcomas. • Angiosarcomas may show progressive nodular enhancement towards the centre mimicking haemangioma. • Vessel encasement is a helpful sign in diagnosis of primary hepatic lymphoma.

Background: Combined hepatocellular-cholangiocarcinoma (cHCC-CC) is a rare primary liver tumor, which has overlapping imaging features with mass forming intra-hepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC). Previous studies reported imaging features more closely resemble ICC and the aim of our study was to examine the differential MRI features of cHCC-CC and ICC with emphasis on enhancement pattern observations of gadolinium enhanced MRI., Methods: Institutional review board approval with consent waiver was obtained for this retrospective bi-centric study. Thirty-three patients with pathologically proven cHCC-CC and thirty-eight patients with pathologically proven ICC, who had pre-operative MRI, were identified. MRI images were analyzed for tumor location and size, T1 and T2 signal characteristics, the presence/absence of: cirrhosis, intra-lesional fat, hemorrhage/hemosiderin, scar, capsular retraction, tumor thrombus, biliary dilatation, degree of arterial enhancement, enhancement pattern, pseudocapsule and washout. Associations between MRI features and tumor type were examined using the Fisher's exact and chi-square tests., Results: Strong arterial phase enhancement and the presence of: washout, washout and progression, intra-lesional fat and hemorrhage were all strongly associated with cHCC-CC (P < 0.001). While cHCC-CC had a varied enhancement pattern, the two most common enhancement patterns were peripheral persistent (n = 6) and heterogeneous hyperenhancement with washout (n = 6), compared to ICC where the most common enhancement patterns were peripheral hypoenhancement with progression (n = 18) followed by heterogeneous hypoenhancement with progression (n = 14) (P < 0.001)., Conclusion: The cHCC-CC enhancement pattern seems to more closely resemble HCC with the degree of arterial hyperenhancement and the presence of washout being valuable in differentiating cHCC-CC from ICC. However the presence of washout and progression, in the same lesion or a predominantly peripheral /rim hyperenhancing mass were also seen as important features that should alert the radiologist to the possibility of a cHCC-CC.

Purpose: To evaluate the prevalence of major and ancillary imaging features from liver imaging reporting and data systems (LI-RADS) version 2014 and their interreader agreement when comparing hepatocellular carcinoma (HCC) to intrahepatic cholangiocarcinoma (ICC) and combined tumor (cHCC-CC)., Methods: The Institutional Review Board approved this HIPAA-compliant retrospective study and waived the requirement for patients' informed consent. Patients with resected HCC (n = 51), ICC (n = 40), and cHCC-CC (n = 11) and available pre-operative contrast-enhanced MRI were included from 2000 to 2015. Imaging features and final LI-RADS category were evaluated by four radiologists. Imaging features were compared by Fisher's exact test and interreader agreements were assessed by κ statistics., Results: None of the features were unique to either HCC or non-HCC. Imaging features that were significantly more common among HCC compared to ICC and cHCC-CC included washout (76%-78% vs. 10%-35%, p < 0.001), capsule (55%-71% vs. 16%-49%, p < 0.05), and intralesional fat (27%-52% vs. 2%-12%, p < 0.002). Features that were more common among ICC and cHCC-CC included peripheral arterial phase hyperenhancement (40%-64% vs. 10%-14%, p < 0.001) and progressive central enhancement (65%-82% vs. 14%-25%, p < 0.001). The interreader agreement was moderate for each of these imaging features (κ = 0.41-0.55). Moderate agreement was also achieved in the assignment of LR-M (κ = 0.53), with an overall sensitivity and specificity for non-HCC malignancy of 86.3% and 78.4%, respectively., Conclusion: HCC and non-HCC show significant differences in the prevalence of imaging features defined by LI-RADS, and are identified by radiologists with moderate interreader agreement. Using LI-RADS, radiologists also achieved moderate interreader agreement in the assignment of the LR-M category.

LI-RADS v2017 introduces major changes to the diagnostic criteria for LR-M observations to better guide radiologists in the use of this malignant category designation. LR-M is intended to preserve the specificity of the LI-RADS algorithm for diagnosis of HCC while not losing sensitivity for diagnosis of malignancy. The purpose of this paper is to provide a brief background on LR-M, discuss the diagnostic criteria new to v2017, special considerations for its application, and management implications.

Rationale and Objectives: This study aimed to investigate the potential of contrast-enhanced magnetic resonance imaging features to differentiate between mass-forming intrahepatic cholangiocellular carcinoma (ICC) and hepatocellular carcinoma (HCC) in cirrhotic livers., Materials and Methods: This study, performed between 2001 and 2013, included 64 baseline magnetic resonance imaging examinations with pathohistologically proven liver cirrhosis, presenting with either ICC (n = 32) or HCC (n = 32) tumors. To distinguish ICC form HCC tumors, 20 qualitative single-lesion descriptors were evaluated by two readers, in consensus, and statistically classified using the chi-square automatic interaction detection (CHAID) methodology. Diagnostic performance was assessed by a receiver operating characteristic analysis., Results: The CHAID algorithm identified three independent categorical lesion descriptors, including (1) liver capsular retraction; (2) progressive or persistent enhancement pattern or wash-out on the T1-weighted delayed phase; and (3) signal intensity appearance on T2-weighted images that could help to reliably differentiate ICC from HCC, which resulted in an AUC of 0.807, and a sensitivity and specificity of 68.8 and 90.6 (95% confidence interval 75.0-98.0), respectively., Conclusions: The proposed CHAID algorithm provides a simple and robust step-by-step classification tool for a reliable and solid differentiation between ICC and HCC tumors in cirrhotic livers., (Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Objectives: To review the gadoxetic acid disodium (EOB)-enhanced magnetic resonance (MR) imaging features of cholangiolocellular carcinoma (CoCC) of the liver and compare them with those of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC)., Methods: EOB-enhanced MR images of 19 patients with CoCC, 23 with ICC, and 51 with HCC were retrospectively evaluated qualitatively and quantitatively. Univariate and multivariate analyses were performed to determine the characteristic MR features of CoCC with histopathological-imaging correlation., Results: Multivariate logistic regression analysis showed that dot-/band-shaped internal enhancement during the arterial and portal phases (P < 0.001), and larger arterial ring enhancement ratio (CoCC, 0.13 ± 0.04; ICC, 0.074 ± 0.04; P = 0.013) were significantly independently associated with CoCC in contrast to ICC, whereas several MR features including progressive enhancement during the portal and late phases (P < 0.001), target appearance in the hepatocyte phase (P = 0.004), and vessel penetration (P = 0.013) were significantly more frequently associated with CoCC than HCC. The dot-/band-like internal enhancement (78.9% of CoCCs) histopathologically corresponded to the tumour cell nest with vascular proliferations and retained Glisson's sheath structure., Conclusions: EOB-enhanced MR features of CoCC largely differ from those of HCC but are similar to those of ICC. However, the finding of thicker arterial ring enhancement with dot-/band-like internal enhancement could help differentiate CoCC from ICC., Key Points: • Gadoxetic acid-enhanced MR features of cholangiolocellular carcinoma (CoCC) resembled those of intrahepatic cholangiocarcinoma (ICC). • Gadoxetic acid-enhanced MR features of CoCC largely differed from those of hepatocellular carcinoma. • Dot-/band-like internal enhancement of CoCC may be helpful for differentiating from ICC. • Arterial ring enhancement of CoCC was larger than that of ICC.

Contrast-enhanced magnetic resonance imaging (MRI) characteristics of small-diameter mass-forming intrahepatic cholangiocarcinomas (ICCs) (diameter ≤3 cm) are still unclear.This study focused on imaging findings of small mass-forming ICCs. The MRI findings for small-diameter mass-forming ICCs were summarized, and the enhancement features of small ICC nodules with different diameters [2 groups were defined: a smaller nodule group (ICC diameter <2 cm) and a larger nodule group (ICC diameter >2 cm)] were compared on contrast-enhanced MRI.In our study, there were 41 small ICC nodules in 41 patients, including 30 men and 11 women (average age, 56 years). The nodules were characterized by peripheral hyperintense in the arterial phase on contrast-enhanced MRI. In the different diameter groups, peripheral hyperintense was the most common in the larger nodule group (56% vs 12%, P < .05) and hypointense was more common in the smaller nodule group (25% vs 0%, P < .05) in the arterial phase on contrast-enhanced MRI. Smaller nodules mainly showed progressive enhancement, whereas larger nodules mainly showed peripheral continuous enhancement (56% vs 6%, P < .05).The small-diameter mass-forming ICC nodules mainly show peripheral continuous enhancement on contrast-enhanced MRI; however, those with diameters <2 cm commonly show progressive enhancement.

Objective: The purpose of this study is to evaluate the effect of subtraction images of gadoxetic acid-enhanced MRI on the image interpretation of focal hepatic lesions in patients at risk for hepatocellular carcinoma (HCC)., Materials and Methods: We retrospectively analyzed 255 malignant nodules from 233 patients with chronic hepatitis or liver cirrhosis (187 men and 46 women; mean age, 55.2 years) who underwent preoperative gadoxetic acid-enhanced MRI and surgical resection. We compared the detection rate of arterial hypervascularity on visual assessment with that of subtraction images. Subgroup analysis was performed according to the pathologic profile of the lesion (HCC vs non-HCC), the lesion size (≤ 3 vs > 3 cm), and the MRI technique (1.5 vs 3 T). We assessed the effect of subtraction images in diagnosing HCC according to the American Association for the Study of Liver Diseases guidelines compared with that of visual assessment., Results: After excluding six patients whose images were not of nondiagnostic quality, 249 nodules (215 HCCs, 27 cholangiocarcinomas, and seven combined HCC and cholangiocarcinomas) from 227 patients were analyzed. Subtraction images more sensitively detected the arterial hypervascularity of all of the hepatic lesions than did visual assessment (sensitivity, 89.2% vs 72.4%; p < 0.001). In all of the subgroup analyses, the same tendency was observed (p = 0.001-0.145). Compared with visual assessment only, arterial hypervascularity determined by both subtraction images and the visual enhancement patterns increased sensitivity from 76.5% to 87.5% (p < 0.001) in diagnosing HCCs, with a minimal decrease in specificity from 80.9% to 78.1% (p = 0.332)., Conclusion: Adding subtraction images with consideration of visual enhancement patterns can enhance the sensitivity in diagnosing HCC by enhancing the detection of arterial hypervascularity.

Objective: The purpose of this study was to examine the associations between preoperative Liver Imaging Reporting and Data System (LI-RADS) categories and prognosis after curative resection of single hepatic malignancies in patients with chronic liver disease., Materials and Methods: Between January 2008 and December 2010, 225 patients with chronic liver disease underwent resection of single hepatic malignant tumors (218 hepatocellular carcinomas, three cholangiocarcinomas, four biphenotypic carcinomas) after undergoing gadoxetic acid-enhanced MRI. Two radiologists retrospectively categorized the tumors into LI-RADS categories. Differences in disease-free survival duration between categories were analyzed by the Kaplan-Meier method with the log-rank test., Results: Reviewer 1 categorized two (0.9%) patients as having LR-3, 53 (23.6%) LR-4, 159 (70.7%) LR-5, and 11 (4.9%) LR-M lesions. The corresponding numbers for reviewer 2 were six (2.7%) LR-3, 30 (13.3%) LR-4, 178 (79.1%) LR-5, and 11 (4.9%) LR-M. The 2-year cumulative recurrence or death rates were 15.1% for lesions categorized LR-3 or LR-4 by reviewer 1, 31.7% for LR-5, and 60% for LR-M. For lesions categorized by reviewer 2 the corresponding rates were 20.6% for LR-3 or LR-4, 29% for LR-5, and 54.5% for LR-M. Disease-free survival was significantly worse among patients with lesions categorized as LR-M than for lesions categorized as LR-3 or LR-4 or as LR-5 (p < 0.01 for both reviewers). Disease-free survival did not significantly differ between patients with LR-3 or LR-4 and those with LR-5 lesions (reviewer 1, p = 0.301; reviewer 2, p = 0.291)., Conclusion: Patients with tumors preoperatively categorized as LR-M may have a worse prognosis than those with tumors categorized LR-3, LR-4, or LR-5 after curative resection of single hepatic malignancy.

Objectives: To obtain specific imaging findings of solitary necrotic nodule of the liver (SNNL) using longer delayed contrast-enhanced MRI and compare them with those of three mimic hepatic diseases., Methods: Sixteen patients with SNNL underwent plain and contrast-enhanced triphasic CT and multiphasic MRI with delayed time prolonged to 2 h after contrast bolus injection. Twenty-three patients with mimic lesions including seven with eight HCCs, five with five iCCs and 11 with metastatic lesions served as the control group. Those patients also received plain and multiphasic contrast-enhanced MRI. Imaging features of lesions such as peripheral wash-out time were evaluated., Results: Among the 16 SNNLs, with a prolonged delayed MRI time, the enhancement degree of tumour periphery increased gradually. When it was up to 1 h, all lesions represented moderate/marked peripheral enhancement with internal hypointensity. However, the peripheral wash-out in seven HCCs (87.5%) and all metastatic lesions except three appeared at 10 or 15 min, one iCC (20%) at 30 min and the other lesions at 1 h., Conclusions: Longer MRI with a delayed time of 1-2 h may be useful in diagnosis SNNL, revealing the specific imaging characteristic of SNNL as pronounced peripheral enhancement with internal hypointensity., Key Points: • Longer delayed MRI plays an important role in the diagnosis of SNNL. • Characteristic imaging feature of SNNL is pronounced peripheral enhancement with internal hypointensity. • Periphery wash-out time can differentiate SNNL from mimic diseases. • Imaging findings of SNNL on routine CT and MRI are unspecific.