2D shear wave elastography offers noninvasive evaluation of fibrosis
Researchers found 2D shear wave elastography had good to excellent efficiency for evaluating liver fibrosis in patients, particularly those with hepatitis B, according to a recently published study.
“For decades, liver biopsy has been used as reference standard for staging liver fibrosis. Liver biopsy, however, is an invasive method associated with patient’s discomfort, cost and rarely serious complications. In addition, its accuracy is limited due to intra- and inter-observer variability and sampling error,” the researchers wrote. “[2D shear wave elastography (2D-SWE)] has proven to be efficient for the evaluation of liver fibrosis in several small to moderate size trials, which reported equivalent to superior diagnostic accuracies as compared to [transient elastography (TE)] and [point shear wave elastography] for the assessment of liver fibrosis.”
The researchers enrolled 1,134 patients from 13 clinical sites between February 2010 and July 2014 to evaluate the efficacy of 2D-SWE using the Aixplorer (Supersonic Image) ultrasound system. Liver disease etiologies included chronic hepatitis C (n = 379), HBV (n = 400), non-alcoholic fatty liver disease (n = 156) and other liver diseases consisting mostly of alcoholic liver disease (n = 199).
The area under receiver operating characteristics of 2D-SWE for diagnosing significant fibrosis in patients were 86.3% for HCV, 90.6% for HBV and 90.6% for NAFLD. The AUROCs for diagnosing cirrhosis were 92.9% for HCV, 95.5% for HBV and 91.7% for NAFLD.
For HBV patients, the cut-off point identified for diagnosing severe fibrosis was 8.1 kPa, and for cirrhosis it was 11.5 kPa. This was slightly lower than the cut-off for all other patients, which was 9.2 kPa for diagnosing severe fibrosis and 13.4 for diagnosing cirrhosis.
According to this study’s prevalence rates of 22.1% for significant fibrosis, 15.9% for severe fibrosis and 16.2% for cirrhosis, the overall correct classification rates were 69.7% for significant fibrosis, 89.3% for severe fibrosis and 82.9% for cirrhosis.
The researchers compared the 2D-SWE results with TE and found that the AUROCs of 2D-SWE were 4.2% to 11.2% larger than TE for diagnosing significant fibrosis in patients with HBV (P < .001) and patients with all other etiologies (P = .001). The AUROCs for 2D-SWE were also 1.4% to 12.8% larger than TE for diagnosing severe fibrosis in patients with NAFLD (P = .003) and patients with all other etiologies (P = .035). Finally, the AUROCs for diagnosing cirrhosis were 1.4% to 6.7% larger using 2D-SWE than TE in HBV patients (P = .007) and patients with all other etiologies (P = .022).
“Up to now, there is limited information on recommendations for obtaining high quality 2D-SWE measurements and the necessary number of acquisitions,” the researchers wrote. “First evaluations show a favorable reproducibility. A preliminary analysis of a subset of our dataset with more detailed data on single acquisitions indicates that reliability is high even for single measurements. Overall, it may not be reasonable to apply the recommendations from TE to the assessment with 2D-SWE. Further detailed analysis and future studies are needed to answer this important question.” – by Talitha Bennett
Disclosures: Herrmann reports no relevant financial disclosures. Please see the full study for the other researchers’ relevant financial disclosures.