Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy?

BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma(HCC). Diffusionweighted imaging(DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging(MRI) for HCC.AIM To determine whether the use of DWI can improve the diagnostic efficiency of LIRADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC.METHODS In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity(SE), specificity(SP), accuracy(AC), positive predictive value(PPV), and negative predictive value(NPV) of LI-RADS were calculated.Youden index values were used to compare the diagnostic performance of LIRADS with or without DWI.RESULTS Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS(kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR-4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%,75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647.CONCLUSION LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.

A Macaca mulatta model of fulminant hepatic failure

AIM:To establish an appropriate primate model of fulminant hepatic failure (FHF).METHODS:We have,for the first time,established a large animal model of FHF in Macaca mulatta by intraperitoneal infusion of amatoxin and endotoxin.Clinical features,biochemical indexes,histopathology and iconography were examined to dynamically investigate the progress and outcome of the animal model.RESULTS:Our results showed that the enzymes and serum bilirubin were markedly increased and the enzyme-bilirubin segregation emerged 36 h after toxin administration.Coagulation activity was significantly decreased.Gradually deteriorated parenchymal abnormality was detected by magnetic resonance imaging (MRI) and ultrasonography at 48 h.The liver biopsy showed marked hepatocyte steatosis and massive parenchymal necrosis at 36 h and 49 h,respectively.The autopsy showed typical yellow atrophy of the liver.Hepatic encephalopathy of the models was also confirmed by hepatic coma,MRI and pathological changes of cerebral edema.The lethal effects of the extrahepatic organ dysfunction were ruled out by their biochemical indices,imaging and histopathology.CONCLUSION:We have established an appropriate large primate model of FHF,which is closely similar to clinic cases,and can be used for investigation of the mechanism of FHF and for evaluation of potential medical therapies.

Contrast-enhanced ultrasonographic findings of hepatic paragonimiasis

AIM: To investigate the features of hepatic paragonimiasis on contrast-enhanced ultrasound (CEUS) imag- ing. METHODS: Fifteen patients with hepatic paragonimiasis who were admitted to our hospital between March 2008 and August 2012 were enrolled to this study. The conventional ultrasound and CEUS examinations were performed with a Philips IU22 scanner with a 1-5-MHz convex transducer. After conventional ultrasound scanning was completed, the CEUS study was performed. Pulse inversion harmonic imaging was used for CEUS. A bolus injection of 2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue) was administered. CEUS features were retrospectively reviewed and correlated with pathological findings. RESULTS: In total, 16 lesions were detected on CEUS. The mean size of the lesions was 4.4 ± 1.6 cm (range, 1.7-6.6 cm). Subcapsular location was found in 12 lesions (75%). All the lesions were hypoechoic. Six lesions (37.5%) were of mixed content, seven (43.8%) were solid with small cystic areas, and the other three (18.8%) were completely solid. Ten lesions (62.5%) were rim enhanced with irregular tract-like nonenhanced internal areas. Transient wedge-shaped hyperenhancement of the surrounding liver parenchyma was seen in seven lesions (43.8%). Areas with hyperor iso-enhancement in the arterial phase showed contrast wash-out and appeared hypoenhanced in the late phase. The main pathological findings included: (1) coagulative or liquefactive necrosis within the lesion, infiltration of a large number of eosinophils with the formation of chronic eosinophilic abscesses and sporadic distribution of Charcot-Leyden crystals; and (2) hyperplasia of granulomatous and fibrous tissue around the lesion. CONCLUSION: Subcapsular location, hypoechogenicity, rim enhancement and tract-like nonenhanced areas could be seen as the main CEUS features of hepatic paragonimiasis.

Radiomics signature:A potential biomarker forβ-arrestin1 phosphorylation prediction in hepatocellular carcinoma

BACKGROUND The phosphorylation status ofβ-arrestin1 influences its function as a signal strongly related to sorafenib resistance.This retrospective study aimed to develop and validate radiomics-based models for predictingβ-arrestin1 phosphorylation in hepatocellular carcinoma(HCC)using whole-lesion radiomics and visual imaging features on preoperative contrast-enhanced computed tomography(CT)images.AIM To develop and validate radiomics-based models for predictingβ-arrestin1 phosphorylation in HCC using radiomics with contrast-enhanced CT.METHODS Ninety-nine HCC patients(training cohort:n=69;validation cohort:n=30)receiving systemic sorafenib treatment after surgery were enrolled in this retrospective study.Three-dimensional whole-lesion regions of interest were manually delineated along the tumor margins on portal venous CT images.Radiomics features were generated and selected to build a radiomics score using logistic regression analysis.Imaging features were evaluated by two radiologists independently.All these features were combined to establish clinico-radiological(CR)and clinico-radiological-radiomics(CRR)models by using multivariable logistic regression analysis.The diagnostic performance and clinical usefulness of the models were measured by receiver operating characteristic and decision curves,and the area under the curve(AUC)was determined.Their association with prognosis was evaluated using the Kaplan-Meier method.RESULTS Four radiomics features were selected to construct the radiomics score.In the multivariate analysis,alanine aminotransferase level,tumor size and tumor margin on portal venous phase images were found to be significant independent factors for predictingβ-arrestin1 phosphorylation-positive HCC and were included in the CR model.The CRR model integrating the radiomics score with clinico-radiological risk factors showed better discriminative performance(AUC=0.898,95%CI,0.820 to 0.977)than the CR model(AUC=0.794,95%CI,0.686 to 0.901;P=0.011),with increased clinical usefulness confirmed in both the training and validation cohorts using decision curve analysis.The risk ofβ-arrestin1 phosphorylation predicted by the CRR model was significantly associated with overall survival in the training and validation cohorts(log-rank test,P<0.05).CONCLUSION The radiomics signature is a reliable tool for evaluatingβ-arrestin1 phosphorylation which has prognostic significance for HCC patients,providing the potential to better identify patients who would benefit from sorafenib treatment.

Role of imaging in evaluating the response after neoadjuvant treatment for pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma(PDAC)is a highly aggressive malignancy.Despite the development of multimodality treatments,including surgical resection,radiotherapy,and chemotherapy,the long-term prognosis of patients with PDAC remains poor.Recently,the introduction of neoadjuvant treatment(NAT)has made more patients amenable to surgery,increasing the possibility of R0 resection,treatment of occult micro-metastasis,and prolongation of overall survival.Imaging plays a vital role in tumor response evaluation after NAT.However,conventional imaging modalities such as multidetector computed tomography have limited roles in the assessment of tumor resectability after NAT for PDAC because of the similar appearance of tissue fibrosis and tumor infiltration.Perfusion computed tomography,using blood perfusion as a biomarker,provides added value in predicting the histopathologic response of PDAC to NAT by reflecting the changes in tumor matrix and fibrosis content.Other imaging technologies,including diffusion-weighted imaging of magnetic resonance imaging and positron emission tomography,can reveal the tumor response by monitoring the structural changes in tumor cells and functional metabolic changes in tumors after NAT.In addition,with the renewed interest in data acquisition and analysis,texture analysis and radiomics have shown potential for the early evaluation of the response to NAT,thus improving patient stratification to achieve accurate and intensive treatment.In this review,we briefly introduce the application and value of NAT in resectable and unresectable PDAC.We also summarize the role of imaging in evaluating the response to NAT for PDAC,as well as the advantages,limitations,and future development directions of current imaging techniques.

Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid Renal Tumors （≤4 cm） at 3.0T Magnetic Resonance Imaging

Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.

Imaging biomarkers for predicting poor prognosis of hepatocellular carcinoma: a review

Hepatocellular carcinoma(HCC)is a primary malignancy of the liver with a high mortality rate.Heterogeneity is the main biological characteristic of HCC,which manifests through the different biological behaviors of each phenotype and ultimately,affects patient prognosis and treatment efficacy.Various aggressive biological behaviors are considered to be associated with the poor prognosis of HCC patients including poor differentiation,microvascular invasion,intracellular fat accumulation,invasive growth,bile duct invasion or tumor thrombosis,and tumor spread and metastasis,and have been reported as prognostic biomarkers.In addition,HCC results from multifactor synergistic damage,and various factors related to genetics,molecular pathology and immunohistochemistry such asβ-catenin,Ki67,cytokeratin-19,and epithelial cell adhesion molecule have an impact on HCC differentiation and prognosis.This article is an overview of the biological behaviors that lead to poor prognosis of HCC,and the roles of morphological and quantitative noninvasive imaging biomarkers in the evaluation and prediction of these behaviors.Some common biomarkers related to genetics,molecular pathology and immunohistochemistry are also briefly summarized.It is hoped that this review will provide clinicians and radiologists with an update on the development of liver imaging,and provide directions for the combination of radiology,genetics,molecular pathology and histopathology to better predict the prognosis of HCC patients.