Diffusion-weighted MRI for quantification of liver fibrosis: preliminary experience.
OBJECTIVE
The purpose of this study was to evaluate our preliminary experience using diffusion-weighted MRI for quantification of liver fibrosis.


METHODS
Diffusion-weighted MRI with single-shot echo-planar technique at b values of 50, 300, 500, 700, and 1,000 s/mm2 was prospectively performed on 23 patients with chronic hepatitis and on seven healthy volunteers. The apparent diffusion coefficient (ADC) was measured in four locations in the liver. Liver biopsy results (n = 19) were retrospectively reviewed by two hepatopathologists in consensus to determine stage of fibrosis and grade of inflammation. A Mann-Whitney test was used to compare the ADCs between patients classified with respect to having stage 2 or greater versus stage 1 or less fibrosis and stage 3 or greater versus stage or less 2 fibrosis. Receiver operating characteristics analysis was used to assess the performance of ADC in prediction of the presence of stage 2 or greater and stage 3 or greater fibrosis.


RESULTS
Using a b value of 500 s/mm2 and all combined b values, we found significantly lower hepatic ADCs in stage 2 or greater versus stage 1 or less fibrosis and stage 3 or greater versus stage 2 or less fibrosis. The mean ADCs (x 10(-3) mm2/s) with all b values were 1.47 +/- 0.11 (SD) versus 1.65 +/- 0.10 for stage 2 or greater versus stage 1 or less fibrosis (p < 0.001) and 1.44 +/- 0.07 versus 1.66 +/- 0.10 for stage 3 or greater versus stage 2 or less fibrosis (p <0.001). Hepatic ADC was a significant predictor of stage 2 or greater and stage 3 or greater fibrosis, with areas under the curve of 0.896 and 0.896, sensitivity of 83.3% and 88.9%, and specificity of 83.3% and 80.0% (ADC with all b values, 1.54-1.53 x 10(-3) mm2/s or less).


CONCLUSIONS
Diffusion-weighted MRI can be used for prediction of the presence of moderate and advanced liver fibrosis.
Taouli
Bachir
B
New York University Medical Center, MRI, 530 First Ave., New York, NY 10016, USA. bachir.taouli@med.nyu.edu
Tolia
Anuj J
AJ
Losada
Mariela
M
Babb
James S
JS
Chan
Edwin S
ES
Bannan
Michael A
MA
Tobias
Hillel
H
D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index