Usefulness of the FibroScan-AST score by vibration-controlled transient and B-mode ultrasound elastography

Aim: This study aims to investigate the reproducibility of Young's moduli, attenuation coefficients, and FibroScan-AST (FAST) scores obtained via vibration-controlled transient elastography (VCTE) and B-mode ultrasound (US) elastography performed on phantoms and patients with chronic liver disease.
Methods: First, the phantoms were used to confirm the four different attenuation-coefficient values while the two phantoms were used to confirm the Young’s moduli. The FAST scores were obtained via simulations performed using tentative AST settings. The values of the three measured parameters corresponding to VCTE and B-mode US elastography techniques were subsequently compared. Second, 189 patients with chronic liver disease who underwent elastography and liver biopsy were retrospectively reviewed.
Results: The XL probe yields nearly identical attenuation-coefficient and Young’s modulus values as well as FAST scores. For phantom 5, when AST was set to 100 U/L, the corresponding FAST score equaled less than 0.36. However, for phantom 6, an AST value of 50 U/L yielded a FAST score exceeding 0.36. In patients, the area under the curve (AUC) were similar for VCTE (0.846) and US-elastography (0.814) (P=0.251). However, there was data variability in some cases with low AST.
Conclusions: The attenuation coefficient, Young’s modulus, and FAST score can be easily reproduced using different US machines. However, the user must be wary of the false negative results usually obtained when considering low AST values.