Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement

Abstract

This multidisciplinary update of the Society of Radiologists in Ultrasound consensus statement on liver elastography incorporates the large volume of new information available in the literature since the initial publication. The recommended procedure for acquiring stiffness measurements is reviewed. There has been substantial improvement in the acoustic radiation force impulse (ARFI) technology-most notably the addition of a quality assessment of the shear wave propagation. Due to the efforts of the Quantitative Imaging Biomarkers Alliance, or QIBA, the variability of liver stiffness measurements between systems had decreased. There are now effective treatments for hepatitis B and hepatitis C, and follow-up after effective treatment should be based on the use of the delta change of the value obtained at viral eradication or suppression. Because the detection of compensated advanced chronic liver disease (cACLD) is very important, the new guidelines are made based on the probability of cACLD for given stiffness values. The panel recommends a vendor-neutral rule of four for interpretation for ARFI techniques. This new method simplifies interpretation of liver stiffness results and is more clinically relevant.

Elastography for Pediatric Chronic Liver Disease

“…General anesthesia significantly increases LS measurements in healthy children (5.4 kPa vs. 4.2 kPa; p < 0.01) 16 . For those systems that allow real‐time 2D‐SWE, a cine clip of multiple shear wave images can be obtained and then reviewed to locate areas with little motion and neutral breathing 21 …”

US Elastography in Hepatic Fibrosis—Radiology In Training

“…To ensure accurate measurement of the shear-wave speed with acoustic radiation force impulse, standardized acquisition parameters have been recently developed (29)(30)(31)(32). A patient, after fasting at least 4 hours, is positioned supine or slight (,30°) left lateral oblique, with the right arm in maximal abduction to increase the intercostal space for probe placement (Fig 4).…”

“…Imaging in the setting of hepatic inflammation, elevated transaminase levels, and vascular congestion, among other factors, may overestimate liver stiffness (33). Correlation with serum transaminase levels and noting aspartate transferase level or alanine aminotransferase elevation more than five times the upper limit of normal, which may lead to the overestimation of liver fibrosis, is suggested (29). Some investigators have suggested using separate SWE thresholds based on transaminase levels; however, these thresholds are not broadly validated (29,33).…”

“…Until recently, US SWE measurements were inconsistent across vendors, making longitudinal follow-up difficult (45). However, standardized phantoms developed by the Quantitative Image Biomarker Alliance and new guidelines published by the Society of Radiologists in Ultrasound have helped to standardize measurements across different devices, to reduce measurement variability, and to provide consistent liver stiffness threshold values for acoustic radiation force impulse measurements that can be applied across vendors (29)(30)(31)(32)(33). These values are appropriate for use in patients with viral hepatitis and NAFLD while insufficient data exists for other chronic liver diseases such as primary sclerosing cholangitis or drug-induced liver disease.…”

“…These values are appropriate for use in patients with viral hepatitis and NAFLD while insufficient data exists for other chronic liver diseases such as primary sclerosing cholangitis or drug-induced liver disease. The Society of Radiologists in Ultrasound provides guidance on elastography interpretation by categorizing SWE results into five groups: likely normal (1.3 m/sec; 5 kPa), likely normal in the absence of other clinical signs of liver disease (,1.7 m/sec; 9 kPa), suggestive of compensated advanced chronic liver disease that needs independent confirmation (1.7-2.1 m/sec; 9-13 kPa), diagnostic of compensated advanced chronic liver disease (.2.1 m/sec; 13 kPa), and suggestive of clinically significant portal hypertension (.2.4 m/sec; 17 kPa) (29).…”