Evaluation of acoustic radiation force impulse elastography for fibrosis staging of chronic liver disease: a pilot study.
BACKGROUND
Acoustic radiation force impulse (ARFI) is a new technology integrated into conventional B-mode ultrasonography. ARFI is used to evaluate tissue stiffness in several organs, but this method has not been applied for liver fibrosis.


OBJECTIVE
The aim of this study was to determine whether ARFI elastography is useful for the evaluation of liver fibrosis.


METHODS
This study enrolled 55 consecutive patients with chronic liver disease who underwent a liver biopsy for histological assessment of liver fibrosis by the Metavir scoring system. Liver stiffness of the 55 patients and 25 healthy volunteers was evaluated by ARFI elastography and was expressed as the shear wave velocity. Cut-off values were determined using receiver-operating characteristic (ROC) curves.


RESULTS
Histological liver fibrosis was evaluated by Metavir scoring; F0: six cases, F1: 14 cases, F2: nine cases, F3: nine cases and F4: 17 cases. Liver stiffness determined by ARFI elastography was correlated with histological liver fibrosis (P<0.0001). The areas under the ROC curves were 0.94 (95% confidence intervals, 0.87-0.99) for F2-F4, 0.94 (0.88-0.99) for F3-F4 and 0.96 (0.91-1.01) for F4. The cut-off values of the shear wave velocity were as follows: >1.34 m/s for F2-F4 (sensitivity 91.4%, specificity 80%); >1.44 m/s for F3-F4 (sensitivity 96.2%, specificity 79.3%); and >1.80 m/s for F4 (sensitivity 94.1%, specificity 86.8%).


CONCLUSIONS
Ultrasonic ARFI elastography is a novel, non-invasive and reliable method for the assessment of liver fibrosis in patients with chronic liver disease.
Takahashi
Hirokazu
H
Department of Internal Medicine, Saga Medical School, Nabeshima, Saga, Japan.
Ono
Naofumi
N
Eguchi
Yuichiro
Y
Eguchi
Takahisa
T
Kitajima
Yoichiro
Y
Kawaguchi
Yasunori
Y
Nakashita
Shunya
S
Ozaki
Iwata
I
Mizuta
Toshihiko
T
Toda
Shuji
S
Kudo
Sho
S
Miyoshi
Atsushi
A
Miyazaki
Kohji
K
Fujimoto
Kazuma
K
D000368:Aged; D001707:Biopsy, Needle; D016022:Case-Control Studies; D002908:Chronic Disease; D016001:Confidence Intervals; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008107:Liver Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index