• liver stiffness
• chronic liver disease
• Share Wave Elastography

Aim of this study was to evaluate the reproducibility and diagnostic accuracy of "real time" Shear Wave Elastography in the measurement of liver stiffness in patients with chronic viral hepatitis B and C and in a group of healthy volunteers. A consecutive series of patients with chronic viral hepatitis B and C and a group of healthy volunteers were evaluated. Patients with chronic liver disease underwent liver biopsy. The degree of liver fibrosis was assessed according to the METAVIR "score system". Measurements of liver stiffness were performed by an experienced radiologist (observer 1) and two less experienced radiologists (observers 2 and 3). Measurements were made by each observer in least three different points of liver parenchyma. In each patient, were acquired 12 consecutive measurements for a total time acquisition of about 5-10 minutes per patient by using iU22 ultrasond system (Philips Medical Systems) with a dedicated convex probe. The degree of liver stiffness measured in kPa was recorded and displayed automatically at the end of each measurement. The results of the "real time" Shear Wave Elastography evaluation, corresponding to the average of 12 measurements, were displayed at the end of each measuremet. They evaluated 57 patients with chronic liver disease and 37 healthy volunteers (50 males and 44 females, aged between 19 and 80 years). The average value of the measurements were of 9.7 kPa in patients with chronic liver disease and 5.5 kPa in the group of healthy volunteers. The "real time" Shear Wave Elastography measurements showed a good correlation with the results of the biopsy relatively to the stage of fibrosis (p <0.001). An excellent reproducibility was observed in measurements between the three observers (ICC, 0.85; 95% confidence interval: 0.70 to 0.94). In conclusion, the "real time" Shear Wave
Elastosography showed to be a reproducible method and accurate in measuring the stiffness of the liver parenchyma in patients with chronic liver desease and in the group of healthy volunteers. Healthy volunteers showed significantly lower values with respect to patients with chronic liver desease.