Transient elastography with controlled attenuation parameter versus two-dimensional shear wave elastography with attenuation imaging for the evaluation of hepatic steatosis and fibrosis in NAFLD

Abstract

Purpose: This study compared the controlled attenuation parameter (CAP) to attenuation imaging (ATI) in the diagnosis of steatosis and transient elastography (TE) to two-dimensional shear wave elastography (2D-SWE) for the diagnosis of fibrosis in a prospectively constructed nonalcoholic fatty liver disease (NAFLD) patient cohort.

Methods: Participants who underwent TE with CAP were included from a previously constructed NAFLD cohort with multiparametric ultrasound data. The degree of hepatic steatosis and stage of liver fibrosis were assessed. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC) for the grades of steatosis (S1-3) and fibrosis (F0-F4).

Results: There were 105 participants. The distribution of hepatic steatosis grades (S0-S3) and liver fibrosis stages (F0-F4) was as follows: S0, n=34; S1, n=41; S2, n=22; S3, n=8; F0, n=63; F1, n=25; F2, n=5; F3, n=7; and F4, n=5. No significant difference was found between CAP and ATI in detecting ≥S1 (AUROC: 0.93 vs. 0.93, P=0.956) or ≥S2 (0.94 vs. 0.94, P=0.769). However, the AUROC of ATI in detecting ≥S3 was significantly higher than that of CAP (0.94 vs. 0.87, P=0.047). Regarding the detection of liver fibrosis, no significant difference was found between TE and 2D-SWE. The AUROCs of TE and 2D-SWE were as follows: ≥F1, 0.94 vs. 0.89 (P=0.107); ≥F2, 0.89 vs. 0.90 (P=0.644); ≥F3, 0.91 vs. 0.90 (P=0.703); and ≥F4, 0.88 vs. 0.92 (P=0.209).

Conclusion: 2D-SWE and TE showed comparable diagnostic performance in assessing liver fibrosis, and ATI provided significantly better performance in detecting ≥S3 steatosis than CAP.

Keywords: Elasticity imaging techniques; Fatty liver; Liver cirrhosis.

Fig. 1.. Flow diagram showing patient selection details.

TE, transient elastography.

Fig. 2.. Box-and-whisker plots showing (A) the controlled attenuation parameter (CAP) from transient elastography (TE), and (B) the attenuation coefficient (AC) from attenuation imaging (ATI) according to the grade of hepatic steatosis.

The box represents the interquartile range (25th-75th percentile), and the middle line represents the median value of CAP (A) and AC (B). Graphs show the area under the receiver operating characteristic curve (AUROC) of both CAP from TE and AC from ATI for diagnosing steatosis grade ≥S1 (C), ≥S2 (D), and ≥S3 (E). There was no significant difference between CAP and AC in detecting ≥S1 (0.93 vs. 0.93, P=0.956) and ≥S2 (0.94 vs. 0.94, P=0.769) (C, D). However, the AUROC of AC from ATI for detecting ≥S3 was significantly higher than that of CAP from TE (0.94 vs. 0.87, P=0.047) (E).

Fig. 3.. Box-and-whisker plots showing liver stiffness (A) from transient elastography (TE) and (B) from two-dimensional shear wave elastography (2D-SWE) according to the stage of liver fibrosis.

The box represents the interquartile range (25th-75th percentile), and the middle line represents the median value of liver stiffness from (A) TE and (B) 2D-SWE. Graphs show the area under the receiver operating characteristic curve of TE and 2D-SWE for diagnosing steatosis grade ≥F1 (C), ≥F2 (D), ≥F3 (E), and F4 (F). There was no significant difference between TE and 2D-SWE in all fibrosis stages; ≥F1 (0.94 vs. 0.89, P=0.107), ≥F2 (0.89 vs. 0.90, P=0.644), ≥F3 (0.91 vs. 0.90, P=0.703), and ≥F4 (0.88 vs. 0.92, P=0.209).