Diagnosing Fibrosis Stage in NAFLD: Transient Elastography Better Than Point Shear Wave Elastography

Transient elastography (TE) has demonstrated superiority over point shear wave elastography (pSWE) in diagnosing the perisinusoidal with portal and periportal stage of fibrosis as well as the bridging stage of fibrosis, according to a study recently published in the Journal of Gastroenterology and Hepatology. 

This study looked at 100 individuals, at or around age 57, with nonalcoholic fatty liver disease, all of whom had liver biopsies. On the day of liver biopsy, they were given 2 examinations each of pSWE and TE by a doctor and a nurse. Both pSWE and TE were performed following at least 2 hours of fasting, and the doctor and nurse performing the operations had not done so before but had received training.

The Non-Alcoholic Steatohepatitis Clinical Research Network Scoring System was used to classify histopathological findings. For fibrosis stages, F0 was graded as no fibrosis, F1 as perisinusoidal fibrosis, F2 as perisinusoidal and portal/periportal fibrosis, F3 as bridging fibrosis, and F4 as cirrhosis. Using the Area Under the Receiver Operating Characteristic Curve (AUROC), diagnostic accuracy was assessed using the median values of the 2 pSWE and 2 TE examinations. Intraclass correlation coefficients were used to examine variability between observers and between individuals’ observations. 

For TE, the AUROC of fibrosis stage F1 or higher was 0.89, both F2 and F3 or higher were 0.83, and F4 was 0.89. For pSWE, the AUROC of F1 or higher was 0.80, F2 or higher was 0.72, F3 or higher was 0.69, and F4 was 0.79. For both F2 and F3 or higher, TE was superior to pSWE in diagnosis. Different operators and the same operator both showed excellent associations for repeated measurements for both TE and pSWE, with an intraclass correlation coefficient of over 0.96. There was a slight difference between operators in the time needed to perform TE (P =.004) but not pSWE (P =.199).

Limitations to this study included same-day repeat examinations that may have affected operator bias, a small number of participants with F0 and F4 fibrosis, and the potential for observer and sampling variability.

Researchers concluded that “TE was good for the diagnosis of all fibrosis stages and was superior compared with pSWE for the diagnosis of fibrosis stages [in F2 and F3 or higher]. …Both TE and pSWE were found to have excellent intra- and interobserver reliability when performed by trained healthcare personnel of different background. pSWE required a longer time to be performed compared to TE, but the magnitude of difference is probably not clinically important.”

Reference

Leong WL, Lai LL, Nik Mustapha NR, et al. Comparing point shear wave elastography (ElastPQ) and transient elastography for diagnosis of fibrosis stage in nonalcoholic fatty liver disease [published online July 16, 2019]. J Gastroenterol Hepatol. doi:10.1111/jgh.14782