Nondiseased liver stiffness measured by shear wave elastography: a pilot study.

Abstract

OBJECTIVES: The purpose of this study was to investigate the value of liver

stiffness in patients without liver disease using shear wave elastography and to

determine the liver stiffness threshold value for identifying patients with

chronic liver diseases. METHODS: A total of 150 patients who underwent liver

sonography coupled with shear wave elastography were enrolled. On the basis of

clinical and pathologic criteria, they were assigned to 1 of 2 groups:

nondiseased liver (n = 97) and noncirrhotic chronic liver disease (n = 53). Liver

stiffness was measured in the right liver, and the median value of 10

measurements was calculated. Both mean and median values in the nondiseased liver

group were compared with those in the noncirrhotic chronic liver disease group.

To validate this comparison, liver stiffness of the patients who underwent liver

biopsy revealing either no fibrosis (fibrosis score F0; n = 5) or substantial

fibrosis (F2; n = 14) was also investigated and compared. To determine the

optimal threshold value for determining chronic liver disease, a receiver

operating characteristic curve analysis was performed. RESULTS: The mean liver

stiffness value in the nondiseased liver group was 5.4 kPa. In the noncirrhotic

chronic liver disease group, the mean value was 8.1 kPa. Differences between the

nondiseased liver and both noncirrhotic chronic liver disease groups were

statistically significant (P < .001). The optimal liver stiffness threshold value

for discriminating nondiseased liver from noncirrhotic chronic liver disease was

6.9 kPa. The sensitivity using this threshold was 94%. In the biopsy-proven

patients, the mean liver stiffness values were 6.0 kPa in the F0 group and 9.9

kPa in the F2 group. CONCLUSIONS: The range of liver stiffness in patients with

nondiseased liver and the optimal threshold value for discriminating these

patients from those with chronic liver disease were identified.