Intravoxel Incoherent Motion Diffusion Weighted Imaging In Differential Diagnosis Vertebral Metastases And Hemangiomas

Objective:This study investigated the value of intravoxel incoherent motion（IVIM）diffusion weighted imaging in differential diagnosis of vertebral metastases and hemangiomas（including typical and atypical hemangiomas）,and compared its diagnostic efficacy with traditional DWI.Methods:A total 16 patients with vertebral metastasis and 15 patients with hemangioma which were confirmed by clinical follow-up or pathology were collected from the First Affiliated Hospital of China Medical University.Conventional MR imaging and IVIM-DWI imaging were acquired at 3.0T MR scanner on the lesion sites,the b values were:0,30,50,100,150,200,400,600,800,1000 mm ²/s.Two radiologists with more than 3 years of experience in imaging diagnosis outline the appropriate area of interest（ROI）.The IVIM post-processing software was used to obtain the the standard ADC,true diffusion coefficient[D],pseudodiffusion coefficient[D*],and perfusion fraction[f].All IVIM-DWI parameters between vertebral metastases and hemangiomas were analyzed by using t test,α=0.05 was used as the test level,and the difference was statistically significant at P<0.01.The receiver operating characteristic curve（ROC）was used to compare the diagnostic efficiencies of each parameter on vertebral metastases and hemangiomas.Results:1、The standard ADC values of the metastatic tumor group and the hemangioma group is respectively:（0.60±0.16）×10^-3mm²/s,（1.19±0.31）×10^-3mm²/s,the metastatic tumor group standard ADC values is significantly lower than the hemangioma group,statistically significant differences between them（t=6.66,P<0.01）;D values of the metastatic tumor group and the hemangioma group is respectively:（0.36±0.13）×10^-3mm²/s,（0.69±0.18）×10^-3mm²/s,the metastatic tumor group D values is significantly lower than the hemangioma group,statistically significant differences between them（t=5.71,P<0.01）.2、The D*values of the metastatic tumor group and the hemangioma group is respectively:（1.29±0.85）×10^-3mm²/s、（1.46±1.04）×10^-3mm²/s,there were no significant differences between them（t=0.48,P=0.629）,The f values of the metastatic tumor group and the hemangioma group is respectively:（0.34±0.15）%、（0.45±1.20）%,there were no significant differences between them（t=1.13,P=0.275）.3、The areas under the ROC curves of standard ADC and D were 0.921、0.925,respective.For distinguishing the vertebral metastases and hemangiomas,the specificity and sensitivity of D were86.7%、93.7%.The diagnostic threshold was 0.549×10^-3mm²/s.Conclusion:Vertebral metastases have lower standard ADC and D values than vertebral hemangiomas.IVIM-DWI can quantitatively evaluate the diffusion and perfusion characteristics of the two lesions.Therefore,IVIM-DWI has higher differential diagnostic value between vertebral metastases and vertebral hemangiomas;moreover the diagnostic efficiency,sensitivity and specificity of D value are more higher.It is of great value for differential diagnosis of vertebral lesions.