Study Of Relationship Between ADC Value And Blood Flow Of Rabbit Liver With Diffusion-Weighted Imaging

Objective to investigate the relationship between blood flow and apparent diffusion coefficient (ADC) value, to explore whether a lower blood supply alters this relation and evaluate it quantitatively in healthy rabbit with diffusion weighted imaging (DWI).Method twelve blue-purple rabbits were studied with DWI. All of animals were anesthetized and fastened on wooded anatomic table. Then hepatic artery and portal vein were separated anatomically. According to objective of experiment, hepatic artery and portal vein were blocked respectively and simultaneously. Abdomens of rabbits were banded so that their respirations were restrained. In this experiment, b values were 0,50,200 and 500 respectively. And from which ADC values were calculated on the workstation.Result ADC values were 3.838±0.243, 3.667±0.218, 3.610±0.264 and 2.905±0.251 with b value of 50 when blood flow of liver were 100%,75%,25% and 0 respectively. And ADC values were 3.729±0.159, 3.547±0.183, 3.472±0.167 and 2.723±0.153 with b value of 200 respectively. In according, the percentage of ADC value reduced were 4.6%,6.5% and 25.4%. compare with ADC value calculated physiologically, no significant difference of ADC value were calculated when hepatic artery or portal vein were blocked respectively. But both hepatic artery and portal vein were blocked simultaneously, ADC value become lower and there was asignificant difference statistically (P < 0.05). There were correlation between ADC and blood flow of liver (P < 0.05). And in which the correlation was most significant when blood flow of liver stopped (r = 0.868, P<0.01) .Conclusion 1 Our results demonstrate that a relationship between ADC value and blood flow of liver exists in rabbit liver, ADC value reduced with blood flow of liver decreased. And ADC value can be reduced sharply.2 ADC value reduced by 4.6% and 6.5% only when hepatic artery or portal vein were blocked respectively. The possible reason may be not compensation between hepatic artery and portal vein each other but that sensitivity of DWI was low in detecting blood flow in tissue.3 We used b values of 50, 200 and 500 in our study, and obtained a satisfactory results with b values of 50 and 200 . It could be demonstrated that DWI with a higher b value can be used to evaluate the blood perfusion in microcirculation.