TIA患者脑SPECT血流灌注显像的研究

目的探讨短暂性脑缺血发作(TIA)间歇期的局部脑血流状况.方法用99mTc-ECD对41例TIA患者进行脑SPECT血流灌注显像,分析轻、中及重度低灌注与TIA时的临床神经功能缺损评分及TIA次数的关系,并与同期脑CT结果进行对比分析.结果所有患者的脑SPECT灌注显像均有不同程度的低灌注区域,其中82.9%的患者发现有与症状相关的低灌注区,而脑CT仅显示了31.7%的临床责任病灶,SPECT的敏感性明显高于脑CT(x2=21.983,P＜0.01),且这种差异对脑叶尤其颞叶病灶表现得更明显(x2=31.694,P＜0.01);随着临床神经功能缺损程度的加重及TIA次数的增加,脑SPECT灌注显像低灌注区范围越大.结论SPECT发现的局部低灌注现象可能是以前或正在发生的临床或亚临床脑缺血事件的反映;用SPECT可观察TIA间歇期的脑血流状况,判断TIA的预后并调整治疗.

The changes of cerebral blood flow measured by SPECT in TIA patients

Objective To approach the cerebral perfusion and haemodynamics in symptom-free patients with transient ischaemic attack (TIA). Methods We conducted brain 99 m TC-ECD SPECT and CT studies in 41 TIA patients, and analyzed the relationship between regional cerebral blood flow (rCBF) in different levels of hypoperfusion (mild, middle and severe) and clinical neuron function deficit (CNFD) scores and frequencies of TIA, and compared with coexisting brain CT. Results All patients with TIA episode had shown variable focal hypoperfusion on SPECT, either with or without correlation with TIA symptoms, in which 82.9% of cases had hypoperfusion related with symptoms, but CT only showed 37.1% of lesions related with symptoms. Sensitivity on SPECT was obviously higher than that on CT ( x 2= 21.983 , P< 0.01 ). This difference was much evident in brain lobes, especially in temporal lobe ( x 2= 31.694 , P< 0.01 ). With aggravating of CNFD and increasing of TIA frequencies, the hypoperfusion region became larger. Conclusions Focal hypoperfusion by SPET should not be viewed as clinically insignificant because it probably reflects previous or ongoing clinical and/or subclinical episodes of cerebral ischaemia. SPECT can be used to assess the cerebral blood flow, predict prognosis and regulate treatments in patients with TIA.