MRI三维动脉自旋标记法对TIA的诊断价值

目的本研究拟运用MRI三维动脉自选标记法(3D-ASL),结合DWI及时间飞跃法MRA(3DTOF-MRA),探讨3D-ASL在TIA的诊断、血流灌注评估等方面的应用价值,为临床超早期诊断、治疗提供更多的理论依据。方法发病24 h内的TIA患者13例,入院时进行常规MRI、DWI、3D-TOF-MRA及3D-ASL扫描。观察所有患者MRA图,分析颅内血管及颈内动脉有无狭窄及异常,比较DWI所示梗死面积(SDWI)和全脑血流量(CBF)图上灌注异常面积(SASL)的差异,分别计算DWI和3D-ASL对TIA患者的检出率,并结合MRA分析造成脑组织血流灌注异常的原因。对于DWI阴性但ASL灌注异常,且MRA(或CTA)显示血管狭窄的患者,计算病灶侧和对侧相应区域的CBF值的比值(rCBF),比较rCBF与入院时(发病24 h内)的NIHSS、Glasgow昏迷评分量表(GCS)、mRS及神经内科临床评分量表(ABCD2)评分、患者发病时间以及一过性脑缺血症状发作持续时间有无相关性,并且比较分析rCBF值与MRA(或CTA)所示血管直径狭窄程度的相关性。结果(1)SASL>SDWI:13例TIA患者中,11例DWI未发现病灶,即SDWI=0,而SASL>0,且显示灌注减低;2例DWI阳性,但病灶面积仍SASL>SDWI。(2)3D-ASL对TIA的检出率明显高于DWI:DWI对TIA患者病灶的检出率为15%;3D-ASL对TIA患者病灶的检出率为69%。(3)rCBF与入院时(发病24 h内)的NIHSS、GCS、mRS及ABCD2评分的分值均无相关性;rCBF与患者发病时间及一过性脑缺血症状发作持续时间无相关性;rCBF值与MRA(或CTA)所示血管直径狭窄程度呈负相关关系(rs=-0.697,P=0.011)。结论3DASL与DWI相比,对TIA的诊断敏感性较高。及早行3D-ASL检查,并与DWI、MRA等序列联合应用,能更早发现灌注异常,并初步提示责任血管狭窄程度,为临床治疗提供科学依据。

Diagnostic value of MRI three-dimensional arterial spin labeling for TIA

Objective This study intends to use MRI three-dimensional arterial spin labeling(3D-ASL)technology,combined with time to flight MRA(3D-TOF-MRA)and DWI,to explore the application value of 3DASL in the diagnosis of TIA and the evaluation of blood perfusion,in order to provide more theoretical basis for the super-early clinical diagnosis and treatment.Methods Choose 13 patients of Transient ischemic attack(TIA)within 24 h,the routine MRI,DWI,3D-TOF-MRA and 3D-ASL scan were performed on admission.Compare the difference between the area of infarct on DWI(SDWI)and the perfusion anomaly area on cerebral blood flow(CBF)chart(SASL),calculating the detection rates of DWI and 3D-ASL for patients with TIA respectively,and to analysis the causes of abnormal cerebral blood perfusion Combineding with MRA.For patients with DWI negative but ASL perfusion abnormality,and MRA(or CTA)showing vascular stenosis,calculate the ratio of CBF values of the lesion side and the corresponding area on the opposite side(rCBF).The correlation between rCBF and NIHSS,Glasgow coma scale(GCS),mRS and Neurology clinical rating scale(ABCD2)score at admission(within 24 h of onset),time of onset and duration of transient ischemic symptoms was compared.The correlation between rCBF value and the degree of vascular diameter stenosis shown in MRA(or CTA)was also analyzed.Results(1)SASL>SDWI:Among the 13 patients with TIA,no lesions were found in 11 cases of DWI,SDWI=0,but SASL>0,and it shows that the perfusion is reduced;2 cases of DWI are positive,but the lesion area was SASL>SDWI.(2)The detection rate of 3DASL for TIA is significantly higher than that of DWI:The detection rate of DWI for patients with TIA is 15%,the detection rate of ASL for patients with TIA is 69%.(3)rCBF was not correlated with NIHSS score,GCS score,mRS score and ABCD2 score on admission(within 24 h of onset);rCBF was not correlated with the onset time of patients and the duration of transient ischemic symptoms;rCBF value was moderately negatively correlated with the degree of vascular diameter stenosis shown in MRA(or CTA)(rs=-0.697,P=0.011).Conclusions Compared with DWI,3D-ASL is more sensitive to the diagnosis of TIA.Early 3D-ASL examination and combined application with DWI,MRA and other sequences can detect perfusion abnormalities earlier,and preliminarily indicate the degree of responsible vascular stenosis,providing scientific basis for clinical treatment.