Validation of US Liver Imaging Reporting and Data System Version 2017 in Patients at High Risk for Hepatocellular Carcinoma

Background: The 2017 version of the Liver Imaging Reporting and Data System (LI- RADS) recently included standardized interpretation, reporting, and management guidelines for US (US LI-RADS); however, this system has not yet been validated. Purpose: To evaluate the diagnostic performance of US LI-RADS version 2017 for detecting hepatocellular carcinoma (HCC) in participants at high risk and to determine the clinical factors associated with a poor visualization score. Materials and Methods: This study included 407 prospectively recruited participants (mean age, 56 years; age range, 28-76 years) with cirrhosis at high risk for HCC who underwent US surveillance from November 2011 to August 2012. Two radiologists retro-spectively analyzed US images, assigning a LI-RADS category (US-1 = negative, US-2 = subthreshold, US-3 = positive) and a visualization score (A = no or minimal limitations, B = moderate limitations, C = severe limitations). The sensitivity and specificity for diagnosing HCC were calculated on a per-patient and per- lesion basis, using pathologic results and typical CT or MRI as reference standards. The risk factors for a poor visualization score were determined by using univariable and multivariable analyses. Results: Of 429 lesions in 407 participants, there were 32 HCCs in 28 participants. In the per- lesion analysis, the specificity for US-3 was 366 of 397 (92%; 95% confidence interval [CI]: 89%, 95%) and the sensitivity was 11 of 32 ( 34%; 95% CI: 20%, 52%). In the perpatient analysis, the specificity for US-3 was 352 of 379 (93%; 95% CI: 90%, 95%) and the sensitivity was 11 of 28 (39%; 95% CI: 24%, 58%). Visualization score C (114 of 407 [28%] participants) had the highest false-negative rate (six of seven [86%] participants). High body weight (adjusted odds ratio [OR], 2.1 [95% CI: 1.2, 3.6]; P = .01), Child-Pugh class Bdisease ( OR, 2.9 [95% CI: 1.7, 4.9]; P < .001), and moderate to severe fatty liver (OR, 1.7 [95% CI: 1.0, 2.8]; P = .047) were associatedwith a poor visualization score of C. Conclusion: The US-3 category demonstrated high specificity but low sensitivity for diagnosing hepatocellular carcinoma. The visualization score C had a higher false-negative rate than scores A or B, and patients with high body weight, Child-Pugh class B disease, and moderate to severe fatty liver may present limitations for US surveillance. (C) RSNA, 2019