CONTROLLED ATTENUATION PARAMETER (CAP): A NOVEL VCTE™ GUIDED ULTRASONIC ATTENUATION MEASUREMENT FOR THE EVALUATION OF HEPATIC STEATOSIS: PRELIMINARY STUDY AND VALIDATION IN A COHORT OF PATIENTS WITH CHRONIC LIVER DISEASE FROM VARIOUS CAUSES

There is a need for noninvasive methods to detect liver steatosis, which can be a factor of liver fibrosis progression. This work aims to evaluate a novel ultrasonic controlled attenuation parameter (CAP) devised to target, specifically, liver steatosis using a sophisticated process based on vibration control transient elastography (VCTE (TM)). CAP was first validated as an estimate of ultrasonic attenuation at 3.5 MHz using Field II simulations and tissue-mimicking phantoms. Performance of the CAP was then appraised on 115 patients, taking the histological grade of steatosis as reference. CAP was significantly correlated to steatosis (Spearman p = 0.81, p < 10(-16)). Area under receiver operative characteristic (ROC) curve (AUC) was equal to 0.91 and 0.95 for the detection of more than 10% and 33% of steatosis, respectively. Furthermore, results show that CAP can efficiently separate several steatosis grades. These promising results suggest that CAP is a noninvasive, immediate, objective and efficient method to detect and quantify steatosis. (E-mail: magali.sasso@echosens.com) (C) 2010 World Federation for Ultrasound in Medicine & Biology.