The Value Of Intravoxel Incoherent Motion Diffusion-weighted Imaging In Differentialting Benign And Malignant Lung Lesions

Objective:To explore the value of multiple b value diffusion weighted imaging based on IVIM bi-exponential model for differentiating benign and malignant lung lesions.Methods: We collected patients who do chest CT examination found pulmonary nodules or masses in the radiology department of our hospital in June 2015 to January 2016.All of the cases make chest MRI examination in a week, and within two weeks received a pathological diagnosis. All cases were performed CT plain scan and enhancement,magnetic resonance IVIM-DWI and traditional DWI examination. MRI exam were used 8-element body phase array coil. MRI exam sequences were included the following :axial T1 weighted imaging, axial and coronal T2 fat suppression weighted imaging, coronal T2 weighted imaging, axial multiple-b and mono-b diffusion weighted MRI scan.IVIM-DWI bi-exponential model and traditional single b value DWI parameters are measured with GE AW4.6 workstation post-processingsoftware. The visually identified vessels, cystic and necrotic areas were excluded in selection of ROI. Three areas of interest are taken from the level with the largest solid component, and measuring their average value.Date analyze was used SPSS 20.0 statistical software.And independent t-test was used to compare the values from the pulmonary benign and malignant lesions in terms of the parameters calculated from IVIM. Using receiver operating characteristic(ROC) analysis parameters and calculate the area under the curve to evaluate the diagnosis efficiency of the parameters.Results: 30 cases were collected eventually, including 20 cases malignant and 10 cases benign.All patients were pathologically confirmed within two weeks after MRI exam. We were obtained that a significant reduction of D value and ADC value in malignant group than in benign group by statistical analysis, while D* value and f value were have no significant difference between the two groups. The diagnostic efficiency of D value is higher than that of ADC value. The area under the ROC curve for D value(0.930) was the largest. When the cutoff value was selected as 1.0400×10-3mm2/s, the sensitivity, specificity, accuracy,NPV and PPV value of diagnosing malignant lesions were 0.944,0.750,0.833,0.900 and 0.850.Conclusions: 1、IVIM-DWI have a certain value in differentiation of benign and malignant lung lesions, and D value derived fromIVIM-DWI have the highest diagnosis efficiency。2 、 The ADC value derived from traditional DWI also have a certain value in differentiation of benign and malignant lung lesions and its diagnosis efficiency is slightly below the D value derived from IVIM-DWI.