Integrating study for clinical imaging of cerebral functions and hemodynamic parameters.

为探讨脑血管病变与脑血流动力学改变的关系，应用PET技术测定慢性脑血管病（CVD）患者局部脑血流量（rCBF）和氧代谢率（CMRO_2）。对<15>104名患有主要脑动脉狭窄闭塞性疾病的患者（平均年龄=61.0±14.0岁）在基线和乙酰唑胺（ACZ）注射后10分钟进行了10-水PET研究，以评估rCBF的局部变化。所有患者还接受了<15>使用稳态法的^ O-gas PET研究，以测量总脑血容量（CBV）、氧提取分数（OEF）和CMRO_2。他们被评估为痛苦的灌注（II期缺血）定义的升高和残余血管舒张能力。ACZ诱导的rCBF增加%的平均值在所有CVD患者的两个半球都是显著的，尽管有一个亚组的患者显示出ACZ诱导的rCBF增加显著减少。 ...更多信息 d半球。在受影响的皮质区域的绝对OEF与rCBF的%变化不相关，而在同一地区的OEF的不对称指数表现出弱相关性。16例患者的OEF显著增加，其中7例（43.8%）显示ACZ试验评估的血管储备显著降低。在受累半球rCBF增加减少的31例患者中，仅7例患者（22.6%）在同一区域显示OEF增加。对ACZ注射的rCBF反应降低与CVD患者的痛苦灌注不一定相关。在慢性血流动力学损害的临界期，这两个血流动力学参数是不等效的。我们还提出了一个新的参数动脉脑灌注压（CPPa）定义的rCBF的动脉毛细血管血容量（V_0）的比值，用于评估脑循环受损。在40例原发性血管闭塞性疾病患者中，约一半患者表现出受累脑区血管舒张能力的降低。在这个严重受损的脑循环组中，中风与ACZ试验中CPPa的降低显著相关。基于PET研究的这些发现，设计了用于评估受损脑循环的MRI研究，并且PET和MRI结果之间具有良好的相关性。我们也将同样的方法应用于SPECT研究。少

To investigate relationship between pathological vascular change and hemodynamic alteration in the brain, regional cerebral blood flow (rCBF) and metabolic rate of oxygen (CMRO_2) were measured in patients with chronic cerebrovascular disease (CVD) using PET. ^<15>O-water PET studies were performed in 104 patients with major cerebral arterial stenoocclusive disease (mean age=61.0±14.0 y) at baseline and 10 min after the acetazolamide (ACZ) injection to evaluate regional changes in rCBF. All patients also underwent ^<15>O-gas PET studies using the steady-state method to measure total cerebral blood volume (CBV), oxygen extraction fraction (OEF) and CMRO_2. They were evaluated misery perfusion (stage II ischemia) defined by elevation of and residual vasodilatory capacity. The mean of % increase in rCBF induced by ACZ was significant in both hemispheres of all patients with CVD although there was a subgroup of patients who showed a significant reduction of the rCBF increase in the affecte … More d hemisphere. The absolute OEF in the affected cortical regions was not correlated with % change in rCBF, whereas asymmetry index of OEF in the same regions showed a weak correlation. Sixteen patients had cerebral regions with a significant increase in OEF, and 7 of them (43.8 %) showed a significant decrease in vascular reserve evaluated by the ACZ test. Of the 31 patients who had a reduction of rCBF increase in the affected hemisphere, only 7 patients (22.6 %) showed an OEF increase in the same region. The reduced rCBF response to the ACZ injection is not necessarily associated with misery perfusion in patients with CVD. The two hemodynamic parameters were not equivalent in the critical stage of chronic hemodynamic impairment. We also proposed a new parameter of arterial cerebral perfusion pressure (CPPa) defined by the ratio of rCBF to arterial-to-capillary blood volume (V_0) for assessment of impaired cerebral circulation. In 40 patients with severer vasoocclusiove disease, about half of them showed a reduction of vasodilatory capacity in the affected cerebral territories. In this severely impaired cerebral circulation group, strokes were significantly associated with reduction of CPPa in the ACZ test. Based on these findings from PET studies, MRI studies for evaluation of impaired cerebral circulation were designed and an excellent correlation was obtained between results from PET and MRI. We also applied the same methods to SPECT studies. Less