Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques

AIM: To compare ultrasound-based acoustic structure quantification (ASQ) with established non-invasive techniques for grading and staging fatty liver disease. METHODS: Type 2 diabetic patients at risk of nonalcoholic fatty liver disease (n = 50) and healthy volunteers (n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography (TE), controlled attenuation parameter (CAP), proton magnetic resonance spectroscopy (H-1-MRS; only available for the diabetic cohort), and ASQ. ASQ parameters mode, average and focal disturbance (FD) ratio were compared with: (1) the extent of liver fibrosis estimated from TE and nonalcoholic fatty liver disease (NAFLD) fibrosis scores; and (2) the amount of steatosis, which was classified according to CAP values. RESULTS: Forty-seven diabetic patients (age 67.0 +/- 8.6 years; body mass index 29.4 +/- 4.5 kg/m(2)) with reliable CAP measurements and all controls (age 26.5 +/- 3.2 years; body mass index 22.0 +/- 2.7 kg/m(2)) were included in the analysis. All ASQ parameters showed differences between healthy controls and diabetic patients (p < 0.001, respectively). The ASQ FD ratio (logarithmic) correlated with the CAP (r = -0.81, p < 0.001) and H-1-MRS (r = -0.43, p = 0.004) results. The FD ratio [CAP < 250 dB/m: 107 (102-109), CAP between 250 and 300 dB/m: 106 (102-114); CAP between 300 and 350 dB/m: 105 (100-112), CAP >= 350 dB/m: 102 (99-108)] as well as mode and average parameters, were reduced in cases with advanced steatosis (ANOVA p < 0.05). However, none of the ASQ parameters showed a significant difference in patients with advanced fibrosis, as determined by TE and the NAFLD fibrosis score (p > 0.08, respectively). CONCLUSION: ASQ parameters correlate with steatosis, but not with fibrosis in fatty liver disease. Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies.