弥漫性轴索损伤的影像诊断比较

Diffuse axonal injury in closed head injury:imaging findings

目的 :比较CT、常规MR和扩散加权成像 (DWI)对急性、亚急性脑弥漫性轴索损伤 (DAI)的诊断价值。方法 :5 0例患者在脑损伤后 2h～ 2 0d行CT、常规MR及MRDWI ,比较病变在CT、MR各种序列上的表现特点。结果 :5 0例中CT检查阴性者 2 4例 (占 48% ) ,阳性者 2 6例 ,发现DAI病灶 75个。 5 0例在MR各种序列显示病灶 2 40个 ,其中非出血性病灶 182个 ,有 45个病灶在DWI上能观察到而常规MRI无法显示 ,占 2 4.7% ,83个病灶在DWI上信号明显高于T2 WI的病灶 ,占 45 .6% ;出血性病灶 5 8个中 ,有 12个病灶CT显示 ,而在常规MR和DWI上显示不清。结论 :对DAI急性期及亚急性期非出血性病灶的显示 ,MR常规检查比CT敏感 ,MRDWI比常规MRT2 WI敏感 ,统计学差异均有显著性意义 (P <0 .0 1)。非出血性病灶在DWI上的信号强度明显高于常规MRT2 WI ,统计学差异有显著性意义 (P <0 .0 1)。对出血性病灶的显示 ,CT优于常规MRSE序列和MRDWI。

Objective:To compare computed tomography with conventional MR and diffusion-weighted imaging (DWI) in the detection of acute and subacute diffuse axonal head injuries.Methods:Fifty patients were examined within 2h to 20 days after trauma by computed tomography,conventional MRI and T 2 *-weighted echo-plannar sequences.Lesions were identified and compared on all imaging.Results:Twenty-four patients show normality in CT imagings (24/50).Seventy-five lesions were counted by CT imaging in twenty-six patients.Two hundred and forty lesions were counted by the combined use of all MR imaging.The forty-five (24.9%) lesions identified by DWI were not seen on conventional MRI.The signal intensity of eighty three lesions (45.6%) on DWI was higher than that on T 2WI.CT identified twelve hemorrhagic shearing injuries that were invisible on conventional MR and diffusion-weighted imaging (DWI).Conclusion:In the detection of the nonhemorrhagic shearing injuries in acute and subacute diffuse axonal head injuries,conventional MR is more sensitive than computed tomography,DWI is more sensitive than conventional MR because it identifies additional shearing.CT is more sensitive than conventional MR and DWI in the detection of the hemorrhagic shearing injuries.