Addition of Reliability Measurement Index to Point Shear Wave Elastography: Prospective Validation via Diagnostic Performance and Reproducibility.

The clinical value of the reliability measurement index (RMI), newly added to point shear wave elastography (pSWE), was investigated. Forty-nine patients underwent both pSWE providing RMI (range: 0.0-1.0) and transient elastography (TE) before hepatic surgery. Interclass correlation coefficients (ICCs) between the median of the first two to nine measurements (as categorized by RMI values ≥0.0 (liver stiffness-reliability measurement index [LS-RMI] 0.0), ≥0.4 (LS-RMI 0.4) and ≥0.7 (LS-RMI 0.7) and the median of 10 consecutive measurements (LS-REF) were obtained. Compared with LS-REF, minimums of 7 LS-RMI 0.0, 5 LS-RMI 0.4 and 3 LS-RMI 0.7 measurements were required to obtain an ICC ≥0.95 with high inter-observer agreement (ICC ≥0.90). Diagnostic performance did not differ (p values >0.05) using these reduced numbers of LS measurements. Significant correlations were found between the reduced number of LS measurements and TE or METAVIR (p values <0.001). Therefore, RMI helped to improve reliability and reduce the number of LS measurements while maintaining the diagnostic performance of pSWE.

Diagnostic Performance of Gadoxetic Acid-enhanced Liver MR Imaging versus Multidetector CT in the Detection of Dysplastic Nodules and Early Hepatocellular Carcinoma.

Purpose To compare the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging with that of contrast material-enhanced multidetector computed tomography (CT) in the detection of borderline hepatocellular nodules in patients with liver cirrhosis and to determine the Liver Imaging Reporting and Data System (LI-RADS) categories of these detected nodules. Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Sixty-eight patients with pathologically proven dysplastic nodules (DNs) (low-grade DNs, n = 20; high-grade DNs, n = 17), early hepatocellular carcinomas (HCCs) (n = 42), or progressed HCCs (n = 33) underwent gadoxetic acid-enhanced MR imaging and multidetector CT. An additional 57 patients without any DNs or HCCs in the explanted livers were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale and assigned LI-RADS categories by using imaging findings. Jackknife alternative free-response receiver operating characteristics (JAFROC) software was used to compare the diagnostic accuracy of each modality in lesion detection. Results Reader-averaged figures of merit estimated with JAFROC software to detect hepatocellular nodules were 0.774 for multidetector CT and 0.842 for MR imaging (P = .002). Readers had significantly higher detection sensitivity for early HCCs with MR imaging than with multidetector CT (78.6% vs 52.4% [P = .001], 71.4% vs 50.0% [P = .011], and 73.8% vs 50.0% [P = .001], respectively). A high proportion of overall detected early HCCs at multidetector CT (59.4%) and MR imaging (72.3%) were categorized as LI-RADS category 4. Most early HCCs (76.2%) and high-grade DNs (82.4%) demonstrated hypointensity on hepatobiliary phase images. In total, 30 more LI-RADS category 4 early HCCs were identified with MR imaging than with multidetector CT across all readers. Conclusion Gadoxetic acid-enhanced MR imaging performed significantly better in the detection of high-risk borderline nodules, especially early HCCs, than did multidetector CT. © RSNA, 2017 Online supplemental material is available for this article.

Staging of hepatic fibrosis: comparison of magnetic resonance elastography and shear wave elastography in the same individuals.

OBJECTIVE: To cross-validate liver stiffness (LS) measured on shear wave elastography (SWE) and on magnetic resonance elastography (MRE) in the same individuals. MATERIALS AND METHODS: We included 94 liver transplantation (LT) recipients and 114 liver donors who underwent either MRE or SWE before surgery or biopsy. We determined the technical success rates and the incidence of unreliable LS measurements (LSM) of SWE and MRE. Among the 69 patients who underwent both MRE and SWE, the median and coefficient of variation (CV) of the LSM from each examination were compared and correlated. Areas under the receiver operating characteristic curve in both examinations were calculated in order to exclude the presence of hepatic fibrosis (HF). RESULTS: The technical success rates of MRE and SWE were 96.4% and 92.2%, respectively (p = 0.17), and all of the technical failures occurred in LT recipients. SWE showed 13.1% unreliable LSM, whereas MRE showed no such case (p < 0.05). There was moderate correlation in the LSM in both examinations (r = 0.67). SWE showed a significantly larger median LSM and CV than MRE. Both examinations showed similar diagnostic performance for excluding HF (Az; 0.989, 1.000, respectively). CONCLUSION: MRE and SWE show moderate correlation in their LSMs, although SWE shows higher incidence of unreliable LSMs in cirrhotic liver.