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). Diffusion-weighted 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 LI-RADS 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 LI-RADS 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%, and 71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and 75.9% 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.

Noninvasive imaging of hepatocellular carcinoma: From diagnosis to prognosis.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Hepatocarcinogenesis is a complex multistep process at molecular, cellular, and histologic levels with key alterations that can be revealed by noninvasive imaging modalities. Therefore, imaging techniques play pivotal roles in the detection, characterization, staging, surveillance, and prognosis evaluation of HCC. Currently, ultrasound is the first-line imaging modality for screening and surveillance purposes. While based on conclusive enhancement patterns comprising arterial phase hyperenhancement and portal venous and/or delayed phase wash-out, contrast enhanced dynamic computed tomography and magnetic resonance imaging (MRI) are the diagnostic tools for HCC without requirements for histopathologic confirmation. Functional MRI techniques, including diffusion-weighted imaging, MRI with hepatobiliary contrast agents, perfusion imaging, and magnetic resonance elastography, show promise in providing further important information regarding tumor biological behaviors. In addition, evaluation of tumor imaging characteristics, including nodule size, margin, number, vascular invasion, and growth patterns, allows preoperative prediction of tumor microvascular invasion and patient prognosis. Therefore, the aim of this article is to review the current state-of-the-art and recent advances in the comprehensive noninvasive imaging evaluation of HCC. We also provide the basic key concepts of HCC development and an overview of the current practice guidelines.

[The Value of Diffusion Kurtosis Imaging in Predicting Post-surgery Early Recurrence of Hepatocellular Carcinoma].

OBJECTIVE: To determine the value of diffusion kurtosis imaging for predicting one-year early recurrence (ER) of hepatocellular carcinoma (HCC) after curative resection. METHODS: 55 HCC patients were enrolled into this prospective study and received preoperative magnetic resonance (MR) examination including diffusion kurtosis imaging (DKI). The patients were followed up for at least one year after curative resection. The morphological features of HCC were assessed using the conventional contrast-enhanced MR images. Mean diffusivity (MD) and mean kurtosis (MK) were calculated for the intratumoral and peritumoral regions. Univariate and multivariate logistic regression analyses were performed to assess the relative value of these parameters as a potential predictor of ER. Receiver operating characteristic (ROC) curve analyses were used to determine the diagnostic performance of these quantitative parameters. RESULTS: Increased alpha-fetoprotein (AFP), BCLC stage, tumor number (≥2), high grade HCC, peritumoral MK, and decreased peritumoral MD were associated with higher one-year ER of HCC (P<0.05). The multivariate analyses confirmed that high grade HCC 〔odds ratio (OR)=5.37,95% confidence interval (CI):1.01-28.50,P=0.048〕 and increased peritumoral MK (OR=5.38,95%CI:1.53-18.92,P=0.009) were independent risk factors for the ER of HCC. The area under curve was 0.79 (P<0.001) for peritumoral MK, with an optimal sensitivity of 85.2% and specificity of 64.3% at the cut-off of 0.96. CONCLUSIONS: Peritumoral MK has moderate diagnostic performance in predicting ER of HCC. Higher peritumoral MK value in combination with high-grade HCC are potential biomarkers for predicting one-year ER of HCC.