LIVER STEATOSIS ASSESSED BY CONTROLLED ATTENUATION PARAMETER (CAP) MEASURED WITH THE XL PROBE OF THE FIBROSCAN: A PILOT STUDY ASSESSING DIAGNOSTIC ACCURACY

To assess liver steatosis, the controlled attenuation parameter (CAP; giving an estimate of ultrasound attenuation similar to 3.5 MHz) is available with the M probe of the FibroScan. We report on the adaptation of the CAP for the FibroScan XL probe (center frequency 2.5 MHz) without modifying the range of values (100-400 dB/m). CAP validation was successfully performed on Field II simulations and on tissue-mimicking phantoms. In vivo performance was assessed in a cohort of 59 patients spanning the range of steatosis. In vivo reproducibility was good and similar with both probes. The area under receiver operative characteristic curve was equal to 0.83/0.84 and 0.92/0.91 for the M/XL probes to detect > 2% and > 16% liver fat, respectively, as assessed by magnetic resonance imaging. Patients can now be assessed simultaneously for steatosis and fibrosis using the FibroScan, regardless of their morphology. (C) 2016World Federation for Ultrasound in Medicine & Biology.