Validation of Liver Imaging Reporting and Data System 2017 (LI‐RADS) Criteria for Imaging Diagnosis of Hepatocellular Carcinoma

Abstract

Background The Liver Imaging Reporting and Data System (LI‐RADS) is being adapted by many clinical practices. To support continuation of its use, LI‐RADS (LR) is in need of multicenter validation studies of recent LI‐RADS iterations. Furthermore, while both gadoxetate and extracellular agents have been incorporated into LI‐RADS, comparison of the diagnostic performance between the two has yet to be determined. Purpose/Hypothesis To evaluate the rate, diagnostic performance, and interreader reliability (IRR) of LI‐RADS 2017 for hepatocellular carcinoma, including LR major and ancillary features, with both gadoxetate and extracellular agent‐enhanced MRI against a reference standard of histopathology or imaging follow‐up. Study Type Retrospective. Population In all, 114 patients with 144 observations were included who met LR 2017 criteria for at risk and had at least one hepatic observation on liver MRI performed with either gadoxetate (n = 52) or an extracellular agent (n = 92) between 2010–2016, with histopathology (n = 103) or follow‐up imaging (n = 41). Field Strength/Sequence 1.5 and 3.0T/T1‐T2WI, diffusion‐weighted imaging. Assessment Three radiologists independently assessed major/ancillary features and assigned overall LI‐RADS category for every observation. Statistical Tests Diagnostic performance of LR5/TIV+LR5 for identifying hepatocellular carcinoma (HCC) was compared between contrast agents with a generalized estimating equation. Weighted kappa was performed for interrater reliability. Results The frequency of HCCs among LR1, LR2, LR3, L4, LR5, LRTIV+LR5, and LRM observations were: 0% (all readers), 0–12.5%, 11.4–26.9%, 50–76%, 83.0–95.1%, 83.3–100.0%, and 45.0–65.0%, respectively. Sensitivity of LR5/LRTIV+LR5 for HCC was 59.7–71.4% and specificity 85.0–96.8%. LI‐RADS specificity and positive predictive value for observations imaged with gadoxetate was higher than extracellular agent for the most inexperienced reader (R3) (P = 0.009–0.034). IRR for LI‐RADS categorization was substantial (k = 0.661). Data Conclusion Increasing numerical LI‐RADS 2017 categories demonstrate a greater percentage of HCCs. LR5/TIV+LR5 demonstrates excellent specificity and fair sensitivity for HCC. MRI with gadoxetate in liver transplant candidates may be beneficial for less experienced readers, although further large‐scale prospective studies are needed. Level of Evidence: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:e205–e215.

Diagnostic Performance of CT/MRI Liver Imaging Reporting and Data System v2017 for Hepatocellular Carcinoma: A Systematic Review and Meta‐Analysis

“…In that study, five of 10 studies had only used pathology as the reference standard, which might have led to verification bias and overestimation of the probability of HCC for LR‐2 5 . In our meta‐analysis using CT/MRI LI‐RADS v2017, only one of six studies that reported the proportion of HCC for LR‐2 used pathology 13 and the other five studies used pathology and CCRS as the reference standard 12,16,18,21,24 . In addition, the definition of the LR‐2 distinctive nodule without malignant features (solid nodule <20 mm distinctive in imaging appearance compared to background nodules and with no major feature of HCC, no feature of LR‐M, and no ancillary feature of malignancy) was clearer in CT/MRI LI‐RADS v2017 4 compared to the LR‐2 cirrhosis‐associated nodule in LI‐RADS v2014, 29 which may refine the LR‐2 category so that it achieves ≤5% probability of HCC.…”

“…In our meta‐analysis, the pooled specificity of 92% in the LR‐5 of CT/MRI LI‐RADS v2017 was somewhat lower than desired. As the LI‐RADS algorithm is designed to emphasize specificity over sensitivity for HCC diagnosis, 21 LR‐5 is considered to indicate with almost 100% certainty that the observation is an HCC, eliminating the need of pathological confirmation 25 . In other words, LR‐5 is intended to achieve nearly 100% specificity for the imaging diagnosis of HCC 26 …”

Liver imaging reporting and data system category M: A systematic review and meta‐analysis

“…Of these, 126 articles were excluded on the basis of their titles and abstracts, and 39 further articles were excluded after a full‐text review. The remaining 10 eligible articles 12‐21 reported the probabilities of HCC and non‐HCC malignancy in LR‐M (Table 1) and among these, six articles 12,14,15,17,18,21 also reported the frequency of each imaging feature associated with LR‐M. A search of the bibliographies of the 10 articles did not yield any further additional eligible articles.…”

“…Of the 10 included articles, all had a retrospective design and five were case control‐type studies 12,15,17,18,21 . Regarding subject enrolment, three articles consecutively enrolled study subjects during clinical practice, 16,19,20 while the other seven articles included only pathologically proven subjects. Furthermore, of the seven articles, six included only malignant lesions 12,13,15,17,18,21 .…”

“…Two articles used only 3.0‐T MRI, 16,21 and seven used only a hepatocyte‐specific contrast agent (gadoxetate disodium or gadobenate dimeglumine) 12,13,16‐19,21 . In all but one study, 16 multiple reviewers performed the image analysis, with the reviewers working independently in five studies 12‐15,20 and in consensus in four 17‐19,21 . Seven studies used pathological diagnosis as the reference standard, 12‐15,17,18,21 while three used a combination of pathological diagnosis and imaging follow‐up as the reference standard 16,19,20 …”