Qiu-Ju LI MD, Presenter: Nothing to Disclose

Jiahui Li MD, Abstract Co-Author: Nothing to Disclose

Bing Yu MD, Abstract Co-Author: Nothing to Disclose

Yu Shi PhD, Abstract Co-Author: Nothing to Disclose

Zhou-She ZHAO, Abstract Co-Author: Nothing to Disclose

Zi-Heng ZHANG, Abstract Co-Author: Nothing to Disclose

Qiyong Guo MD, Abstract Co-Author: Nothing to Disclose

To investigate the relationship between the ADC values and AQP expression, using a multiple b-value(multi-b) diffusion weighted magnetic resonancce imaging(DW MRI),with the histopathological and immunohistochemical tests as gold standard.

24 rodent liver fibrosis models at different fibrotic stages were prepared in male Wistar rat for the experiment through thioacetamide injection thrice a week with another 6 intact as the control group. Both groups were performed MR measurements, on a 3.T scanner, before and after the injection of acetazolamide solution, an typical AQP inhibitor, used to inhibit the AQP1, AQP3 and AQP4 on hepatic tissue. For the MR protocol, besides the conventional T1WI and T2WI , a multi-b DWI was carried out with 18 b values selected from 0 to 4500 s/mm2(low-b: <200 s/mm2, mid-b: 300-1500s/mm2 and high-b: 1700-4500 s/mm2). The obtained multi-b DW images were post-processed through a newly developed tri-exponential model with low-b, mid-b, and high-b ADCs achieved. The output parametric maps were reviewed and analyzed blindly by two experienced observers with no histologic detail informed. The same layer of the harvested lobe were chosen for the routine HE staining, Sirius red staining of collagen, and AQP1 molecular pathology staining to determine the stage of liver fibrosis and the AQP1 expression level. Liver fibrosis was evaluated according to the Metavir scoring system.

The AQP1 expression in the liver endothelial cells significantly increased with aggravation of liver fibrosis from normal to early stage fibrosis. The mean high-b ADC value of S2 was significantly higher than S1, both higher than S0 (P<0.05), which was in accordance with the result of immunohistochemical tests. At S1, the high-b value post inhibitors injection had a significant decrease (>30%), and 20% higher than S2. However, the inhibition tests were negative at S0.

It was demonstrated in this study that the severity of liver fibrosis is positively correlated with the AQP1 expression and the multi-b DW MRI technique was capable to detect the S1 stage liver fibrosis.

AQP multi-b DWI molecular imaging is a promising tool for early diagnosis of liver fibrosis.

LI, Q, Li, J, Yu, B, Shi, Y, ZHAO, Z, ZHANG, Z, Guo, Q, Assessment of Aquaporins Function of Early-stage Liver Fibrosis Using Multi-B Diffusion-weighted MRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010195.html