LIEM THANH LE, LINH HONG BUI, NHAT THONG LE, HAI THANH PHAN
MEDIC MEDICAL CENTER, HCMC, VIETNAM
Purpose: To compare acoustic radiation force impulse imaging (ARFI) with transient elastography (TE) and tests of serologic markers for assessing whether ARFI can substitute TE technique in non-invasive liver fibrosis evaluation.
Materials and methods: All subjects agree to join the study, which is completely free of charge, and the local ethics committee approves the research. ARFI causes displacement in liver tissue which propagates shear wave, was recorded in units of meters per second. All 554 cases (353 male, 201 female) (including 366 cases of chronic viral hepatitis B, C and control group=188 cases), age from to 85 yo (mean = 44+/-13.2), BMI =14.8 to 32.4 (mean=22.06+/-2.85) were examined by 2 sonologists performing ARFI and TE techniques, and tested serologic markers in the same day. ARFI values are compared to TE values by MedCalc statistical software, and serologic markers tests are the standard reference.
Results: Results of ARFI and TE technique are close correlattion with statistical significance of fibrosis staging (correlative coefficient r = 0.83 with P smaller than 0.0001, 95% CI = 0.804-0.855). The shear wave velocity means of ARFI range from 0.79 to 3.53 m/s (see table V0-V4) and there are statistical differences between V0-V4 with t<0.05, p<0.0001. Values of TE, from 2.2 to 75kPa. Close clinical agreement between FibroScan F4 and ARFI V4 for cirrhosis, kappa=0.8.
With the regressive equation y = 0.9458 + 0.04266 x (where x = FS and y = VS), we propose a fibrosis staging of ARFI and TE as follows:
Conclusions: ARFI in liver fibrosis assessment in chronic viral hepatitis has accurate diagnosis which is in close correlation with TE in the present study of 554 cases. With advantages of ACUSON S2000, ARFI techniques (not blinded in ROI, not limited in the obese patient and ascites, convenient operation) may substitute for TE of FibroScan.