Effect of Disease Progression on Liver Apparent Diffusion Coefficient Values in a Murine Model of NASH at 11.7 Tesla MRI

Purpose: To evaluate the apparent diffusion coefficient (ADC) values of liver in a murine model of non-alcoholic steatohepatitis using 11.7 Tesla (T) MRI. Materials and Methods: This animal study was IACUC approved. Seventeen male C57BL/6 mice were divided into control (n = 3) and experimental groups (n 14) fed a methionine-deficient choline-deficient (MCD) diet to induce steatohepatitis. Livers underwent ex vivo diffusion-weighted MR imaging and ADC maps were calculated. A pathologist determined subjective scores of steatosis, classified from 0 to 3. Digital image analysis was used to determine percentage areas of steatosis. Graphs comparing ADC to subjective and digital image analysis (DIA) determinations of steatosis were plotted. Results: Subjective assessments of steatosis ranged up to values of 3 and DIA determined areas of steatosis to range up to approximately 16%. ADC values approximated 800 x 10(-6) mm(2)/s (range, 749-811 x 10(-6) mm(2)/s, mean 786 x 10(-6) mm(2)/s) in controls and 500 x 10(-6) mm(2)/s (range, 478-733 x 10(-6) mm(2)/s, mean 625 x 10(-6) mm(2)/s) in experimental mice. Moderate correlation between ADC and subjective scores of steatosis (R = -0.56) was observed. Strong correlation between ADC values and percentage areas of steatosis was between ADC values and percentage areas of steatosis was observed greater (R = -0.81) and very strong correlation was observed with the exclusion of a single outlying data point (R = -0.91). Conclusion: Based on the comparison of ADC values and steatosis determinations by DIA, increasing degrees of steatosis are seen to result in decreased hepatic ADC values.