Use Of Intravoxel Incoherent Motion Diffusion-Weighted Imaging (IVIM-DWI) In Evaluation Of Histological Grades Of Pancreatic Ductal Adenocarcinoma (PDAC)

Objective: To investigate the diagnostic performance of intravoxel incoherent motion(IVIM)parameters in the preoperative grading of pancreatic ductal adenocarcinoma(PDAC).Methods: A total of 28 PDACs who were confirmed by the surgical pathology prospectively enrolled and underwent with routine MR and intravoxel incoherent motion Diffusion-weighted Imaging(IVIM-DWI)examination.The original images of IVIM-DWI were imported into the IMAgen GINE workstation.ROI was manually drawn on three of the largest consecutive lesion slices;The values of ADC,D,D* and f were calculated.Independent Sample t-test was used to evaluate the difference of these parameters of well/moderately differentiated and poorly differentiated PDAC,receiver operating characteristics(ROC)curves were performed to evaluate the diagnostic performance,Spearman correlation analysis was used to determine the correlation between these parameters and histologic grade.Results : Mean D value of well/moderately differentiated PDAC was significantly lower than that of poorly differentiated PDAC(0.550×10-3 mm2/s vs.0.672×10-3mm2/s,P<0.05).Mean ? value of well/moderately differentiated PDAC was significantly higher than that of poorly differentiated PDAC(58.4% vs.40.4%,P<0.05).The area under curve value of ? in differentiating well/moderately differentiated PDAC from poorly differentiated PDAC was slightly higher than that of D(0.961>0.956,P<0.001).a negative correlation was obtained from the D and a positive correlation was obtained from the f(all P<0.05).Conclusion: D and f value of intravoxel incoherent motion Diffusion-weighted Imaging(IVIM-DWI)can be used to evaluate the pathological differentiated grades of PDAC,IVIM-DWI is a promising and non-invasive tool in the preoperative pathological grade of PDAC.