| Object:By using the exponential model of intravoxel incoherent motion(IVIM)to investigate the differences between high and low grade gliomas of diffusion and perfusion,then compare with DWI and 3D-PCASL technology,to explore the application of IVIM in preperative grading of gliomas.Methods:1.38 cases of gliomas(20 males,18 females),age range:9-72,with an average of 44.5 years,19 high grade and 19 low grade.2.All patients was underwent conversional MRI(T1-FLAIR,T2 WI,T2-FLAIR,DWI),then the IVIM-DWI?3D-PCASL and enhancement.3.IVIM-DWI used exponential model soft ware to get three species parameter images of slow diffusion coefficient D(slow ADC)?fast diffusion coefficient D*(fast ADC)and the fractional perfusion-related volume f value(fraction of fast ADC);Conversional MRI soft ware to get the diffusion coefficient ADC images;3D-PCASL soft ware to get the cerebral blood flow(CBF)images.4.Measurment of tumor material(avoid necrotic or cystic,vascular and mass fringe),combined with the multi-faceted enhanced T1 WI image,select the maximum signal or obvious reinforcement,manully drawing inrerested region in the area of the largest and upper and lower adjacent level,The tumor blood flow(TBF)as well as the ADC?D?D*and f values were separately determined.Repeated 3 times,take the mean value respective,size of each region of interest(ROI)is about 50mm2.5.All parameter values recorded as mean±standard deviation(x±s):(1)Compare all parameters of IVIM?converntional DWI and 3D-PCASL between high and low grade gliomas groups,and two independent-samples t test or corrected t test was used;(2)Correlation of tumor material analyzed by pearson and Spearman,the parameters such as D?D*?f,respectively and corresponds to the ADC?TBF values,if had significant correlation,writtend a scatter chart and analysed the relationship;(3)Allparameters value between high and low-grade gliomas,if statistically significant,writtend a ROC curve and then calculated the area under the curve(AUC),found the best classificantion threshold?sensitivity and specificity.Results1.Clinical pathology results:(1)I Grade:2 Astrocytoma?1 Pilomyxoid astrocytoma;(2)II Grade:12 Astrocytoma?1 Oligodendroglioma?1 Pleomorphic xanthoastrocytoma?1 Ependymoma?1 Diffuse astrocytomas;(3)III Grade:7 Astrocytoma?1 Anaplastic astrocytoma;(4)IV Grade:3 Astrocytoma?8 Glioblastoma?2.Conversional MRI analysis:(1)DWI:HGG:Same or low signal were 3 cases,High signal were 16 cases;LGG:Same or low signal were 17 cases,High signal were 2 cases.(2)MRI scan:HGG:cyst formation or necrosis were 13 cases,Hemorrhagic were 7cases,Calcification were 4 cases,Mass effect and peritumoral edema were 15 cases;LGG:cyst formation or necrosis were 2 cases,Hemorrhagic were 0cases,Calcification were 0 cases,Mass effect and peritumoral edema were 5 cases.(3)Contrast enhancement scan:HGG:No contrast were 0 cases,Light contrast were 1 cases,Medium contrast were 8 cases,Markedly contrast were 10 cases;LGG:No contrast were 7 cases,Light contrast were 9 cases,Medium contrast were 3 cases,Markedly contrast were 0 cases.3.Conversional MRI?IVIM?3D-PCASL,independent-samples t test display:(1)Average ADC?D?f values of HGG material were significantly lower than the LGG,a statistically significant difference(P<0.05).(2)Average D*?TBF value of HGG material was significantly higher than the LGG,a statistically significant difference(P<0.05).4.Correlation of two variabless between IVIM and Conventional DWI?ASL:(1)All patients tumor material absolutely average ADC value was positively correlated with D?f value(P<0.05),and has no correlation with the D* value.(2)All patients tumor material absolutely average TBF value was positively correlated with D* value,and was negatively correlated with D?f value(P<0.05).5.Scatter chart analysis display:(1)D value was positively correlated with ADC value,the correlation coefficient is 0.984.(2)f value was positively correlated with ADC value,the correlation coefficient is0.664.(3)D*value was positively correlated with TBF value,the correlation coefficient is 0.416.(4)f value was negatively correlated with TBF value,the correlation coefficient is?0.446.6.ROC curve analysis display:(1)Az of ADC is 0.816,threshold value is 0.98,with sensitivity(89.5%)and specificity(68.4%).(2)Az of D is 0.801,threshold value is 0.793,with sensitivity(84.2%)and specificity(63.2%).(3)Az of f is 0.767,threshold value is 0.411,with sensitivity(73.7%)and specificity(73.7%).(4)Az of TBF is 0.981,threshold value is 51.55,with sensitivity(94.7%)and specificity(94.7%).(5)Az of D* is 0.747,threshold value is 3.27,with sensitivity(78.9%)and specificity(73.7%).Conclusion:The exponential model of intravoxel incoherent motion(IVIM)with highmagnetic field(3.0T)MR system can get the diffusion and perfusion informations of gliomas,when the D value is 0.793×10-3mm2/s and the D* value is3.27×10-3mm2/s,we can investigate the differences between HGG and LGG,and the f shows images very well.Three parameters can be non-invasive,comprehensive assessment of preoperative grading of gliomas,and provide a reference for further surgery. |
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