The Significance Of Diffusion Tensor Imaging And Susceptibility Weighted Imaging In Diffuse Axonal Injury

Part ⅠObjective To investigate the significance of Diffusion Tensor Imaging (DTI) in acute Diffuse Axonal Injury(DAI).Methods21acute DAI patients and10volunteers are examined using Diffusion Tensor Imaging. The FA values of5regions of interest are measured:the ROIs are genu of the corpus callosum, splenium of the corpus callosum, anterior limb of the internal capsule, posterior limb of the internal capsule and external capsule. Compare the FA value between the DAI group and control group, and correlate the FA value of the experimental group with the clinical Glasgow Coma Score(GCS).Results The cerebral white matter fibers, which are high intensity, can be clearly revealed in FA maps, injuried parts are local low intensity. The FA value of DAI group(0.562±0.042) is statistical lower than control group(0.609±0.045). And the FA value is medium positive correlated with GCS in DAI group(r=0.508).3D-DTT showed the injuried fibers were lost the normal shape.Conclusion Compare to CT and conventional MR, DTI can be more sensitive to find the white matter lesion of DAI. The change of fractional anisotropy can be used to assess the condition of the patient, predict the prognosis of patients.Part ⅡObjective To investigate the significance of Susceptibility Weighted Imaging(SWI) in diagnosis of hemorrhagic lesions associated with DAI.Methods19acute or subacute DAI patients are examined using SWI and conventional MRI sequence. To compare the sensitivity of SWI with T2WI in detecting lesions, and correlate the number of lesions with initial GCS.Results The number of lesions detected was101,128and538respectively on T1WI, T2WI and SWI. The number of lesions detected by SWI is statistical more than conventional sequence (Z=-3.764, P<0.01). The number of lesions in SWI of the19patients is negatively correlated markedly with GCS(r=-0.746, P<0.01).Conclusion SWI can be more completely to display hemorrhagic lesions associated with DAI and be better estimated condition and the outcome of patients.Part ⅢObjective To investigate the significance of Susceptibility Weighted Imaging(SWI) in combination with Diffusion Tensor Imaging(DTI) in diagnosis of acute and subacute Diffuse Axonal Injury.Methods19acute or subacute DAI patients are examined using SWI> DTI and conventional MRI sequence. To oberve and compare the lesions on each sequence. To correlate the number of lesions with initial glasgow coma score(GCS).Results The number of lesions detected was128,279,538and589respectively on T2WI, DTI, SWI and SWI in combination with DTI. The number of lesions detected by SWI in combination with DTI is statistical more than SWI (Z=-3.193, P≤0.01), DTI (Z=-3.551, P≤0.01) and T2WI (Z=-3.725, P≤0.01). The number of lesions detected by SWI in combination with DTI is negatively correlated markedly with GCS(r=-0.775, P^0.01) and the correlation is better than SWI, DTI. The number of lesions detected by T2WI is correlated unmarkedly with GCS.Conclusion Combination of SWI and DTI can be more complete to display DAI lesions than SWI or DTI and can be better estimated condition and the outcome of patients. In addition,3D-DTT may visual dispaly the injuried fibers.