CT脑组织血流灌注成像方法的研究

The preliminary study of CT perfusion methods in intra-axial ischemic disease

目的 探讨CT灌注成像方法在颅脑疾病诊断中的初步临床应用。方法 采用SiemensPlus 4和PerfusionCT/VA 10A扫描灌注系统 ,对 8例进行常规扫描 ,然后选定基底节区层面做快速注药后的动态CT检查 ,对比剂为优维显 3 0 0 ( 3 0 0mgI/ml) ,注射速度 10ml/s ,剂量 5 0ml,经高压注射器注射的同时进行扫描 ,共扫描 3 2层。经后处理获得一系列反映不同时相的脑血流灌注图 ,然后进行综合分析。结果 4例正常脑血流灌注图清晰 ,脑灰白质交界分明、对称 ,染色均匀 ;2例缺血灌注图经伪彩染色后 ,病灶显示更加直观、清晰 ;2例肿瘤灌注图显示单发转移瘤异常供血血管、水肿区和过度灌注区。结论 快速注射对比剂和选用上矢状窦为参照血管计算脑血容量是获得高质量灌注图像的保证 ,为实现CT脑组织血流灌注的定量研究提供了新的方法。

Objective To evaluate the appl ication of CT perfusion in intra-axia l disease. Methods By applying a nuclear medicine data processi ng technique to the time-density data obtained from dynamic CT, cerebral tissue perfusion was p e rformed in 8 cases, 4 with normal findings, 2 with ischemic cerebrovascular dise ase, and 2 with gliomas. Cerebral blood perfusion maps was created and analyzed, absolute regional cerebral blood volume, regional cerebral blood flow, and mean transit time were determined and analyzed as well. Results Wit h regard to var ious degrees of perfusion impairment within the ischemic territory, thus giving rise to a very heterogenous appearance. As a rule, the center of a lesion usuall y representing the core of ischemia showed marked reduction of blood flow. At th e outer margin of a tumor area, the reduction of CBF and CBV was often less pron ounced, indicating some residual flow via collaterals, as was confirmed by the b olus delay on the time to peak time. Conclusion In the near fut ure, functional imaging techniques should have a major impact on therapeutic decision-making i n acute stroke patients, perfusion CT may be recommended even now for emergency applications in daily patient care due to its practicability.