Watabe Tadashi, Shimosegawa Eku, Kato Hiroki, Isohashi Kayako, Ishibashi Mana, Hatazawa Jun
Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Suita, Japan,
Neurosci Bull. 2014 Oct;30(5):857-62. doi: 10.1007/s12264-013-1458-0. Epub 2014 Aug 1.
Local cerebral perfusion pressure (CPP) is a primary factor controlling cerebral circulation and previous studies have indicated that the ratio of cerebral blood flow (CBF) to cerebral blood volume (CBV) can be used as an index of the local CPP. In this study, we investigated whether the CBF/CBV ratio differs among different brain structures under physiological conditions, by means of (15)O positron emission tomography. Nine healthy volunteers (5 men and 4 women; mean age, 47.0 ± 1.2 years) were studied by H2 (15)O bolus injection for CBF measurement and by C(15)O inhalation for CBV measurement. The CBF/CBV ratio maps were created by dividing the CBF images by the CBV images after anatomical normalization. Regions of interest were placed on the CBF/CBV maps and comparing the regions. The mean CBF/CBV ratio was highest in the cerebellum (19.3 ± 5.2/min), followed by the putamen (18.2 ± 3.9), pons (16.4 ± 4.6), thalamus (14.5 ± 3.3), cerebral cortices (13.2 ± 2.4), and centrum semiovale (11.5 ± 2.1). The cerebellum and putamen showed significantly higher CBF/CBV ratios than the cerebral cortices and centrum semiovale. We created maps of the CBF/CBV ratio in normal volunteers and demonstrated higher CBF/CBV ratios in the cerebellum and putamen than in the cerebral cortices and deep cerebral white matter. The CBF/CBV may reflect the local CPP and should be studied in hemodynamically compromised patients and in patients with risk factors for small-artery diseases of the brain.
局部脑灌注压（CPP）是控制脑循环的主要因素，先前的研究表明，脑血流量（CBF）与脑血容量（CBV）的比值可作为局部CPP的指标。在本研究中，我们通过（15）O正电子发射断层扫描研究了在生理条件下不同脑结构之间的CBF/CBV比值是否存在差异。对9名健康志愿者（5名男性和4名女性；平均年龄47.0±1.2岁）进行了研究，通过静脉注射H2（15）O测量CBF，通过吸入C（15）O测量CBV。在进行解剖学归一化后，将CBF图像除以CBV图像，创建CBF/CBV比值图。在CBF/CBV图上放置感兴趣区域并比较这些区域。CBF/CBV平均比值在小脑最高（19.3±5.2/分钟），其次是壳核（18.2±3.9）、脑桥（16.4±4.6）、丘脑（14.5±3.3）、大脑皮质（13.2±2.4）和半卵圆中心（11.5±2.1）。小脑和壳核的CBF/CBV比值显著高于大脑皮质和半卵圆中心。我们创建了正常志愿者的CBF/CBV比值图，并证明小脑和壳核的CBF/CBV比值高于大脑皮质和深部脑白质。CBF/CBV可能反映局部CPP，应在血流动力学受损的患者以及有脑小动脉疾病危险因素的患者中进行研究。
