Initial study of biexponential model of intravoxel incoherent motion magnetic resonance imaging in evaluation of the liver fibrosis.

Abstract

The diagnosis of liver fibrosis is a difficult task at any time using conventional clinical imaging. Intravoxel incoherent motion (IVIM) can be used to investigate both diffusion and perfusion changes in tissues. This study was designed to determine the value of IVIM in the diagnosis and staging of liver fibrosis. IVIM examinations were performed on a GE 3.0T MR scanner in 25 patients with liver fibrosis and 25 healthy volunteers as the control group. Patients with liver fibrosis diagnosis were confirmed by pathology and staged on a scale of F0-4. The standard ADC values and the values of a biexponential model (slow ADC (Dslow), fast ADC (Dfast) and fraction of fast ADC (FF)) were measured in three liver regions per person. The mean standard ADC values, Dslow values, Dfast values and FF values from the study group were compared among the right posterior hepatic lobe, right anterior hepatic lobe and medial segment of the left lobe. Receiver Operating Characteristic (ROC) curves and independent-samples t-tests were used to calculate the mean standard ADC values, Dslow values, Dfast values and FF values from the study group and the control group. Spearman rho correlation analysis was used for the stage of liver fibrosis. The liver fibrosis stages between the groups F0-1 and F2-4, the groups F0-2 and F3-4 were compared. Among the liver fibrosis, there was no significant difference in the mean standard ADC values, Dslow values, Dfast values, and FF values obtained from the right posterior hepatic lobe, right anterior hepatic lobe and medial segment of the left lobe. Using ROC analysis, the Area Under the Curve (AUC) values of standard ADC, Dslow, Dfast, FF were all between 0.7 to 0.9. The mean standard ADC values, Dslow values, Dfast values and FF values of the liver in the study group were significantly lower than the values in the control group (P < 0.05). As the stage of the fibrosis increased, the values decreased by Spearman rho correlation analysis. The mean values (standard ADC, Dslow, Dfast, and FF) of liver fibrosis stages between the groups F0-1 and F2-4, the groups F0-2 and F3-4 showed significant differences (P < 0.05). IVIM can reflect the conditions of perfusion and diffusion in liver fibrosis and thus distinguish between normal liver and liver fibrosis. The IVIM technique may serve as a valuable tool for detecting and characterizing liver fibrosis, and monitoring its progression in a noninvasive manner.