Ohnishi T, Nakano S, Yano T, Hoshi H, Jinnouchi S, Nagamachi S, Flores L, Watanabe K, Yokogami K, Ohta H
Department of Radiology, Junwakai Memorial Hospital, Komatsu, Japan.
AJNR Am J Neuroradiol. 1996 Apr;17(4):631-7.
To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging.
Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT).
In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas.
Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.
通过乙酰唑胺激发试验，利用磁共振成像（MRI）的敏感性加权梯度回波序列，研究健康受试者和慢性闭塞性脑血管病患者的脑血管舒张能力。
8例慢性闭塞性脑血管病患者和4名健康志愿者，在静脉注射1000mg乙酰唑胺前后，接受敏感性加权磁共振成像检查。在解剖图像上定义的几个感兴趣区域，测量信号强度随时间的变化。所有慢性闭塞性脑血管病患者，还采用单光子发射计算机断层扫描（SPECT）评估乙酰唑胺激发试验和静息状态下的局部脑血流量。
在健康志愿者中，乙酰唑胺注射后3至4分钟信号强度开始增加，随后10分钟内持续升高。给药后效应持续约45分钟。在慢性闭塞性脑血管病患者中，SPECT图像上血管舒张能力正常的闭塞区域，敏感性加权磁共振图像上的信号变化与非闭塞区域无差异。在那些反映血管舒张能力下降的患者中，乙酰唑胺给药后，磁共振图像上信号变化的百分比低于正常灌注区域。
敏感性加权磁共振成像为评估血管舒张能力提供了一种替代方法。
