Absolute Changes in Regional Cerebral Blood Flow in Association with Upright Posture in Humans: An Orthostatic PET Study

Journal of Nuclear Medicine

Yasuomi Ouchi¹  Shuji Nobezawa¹  Masami Futatsubashi¹  Hiroyuki Okada¹  Etsuji Yoshikawa¹ 

[1] Positron Medical Center, Hamamatsu Medical Center, Hamakita; Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Japan Positron Medical Center, Hamamatsu Medical Center, Hamakita; Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Japan Positron Medical Center, Hamamatsu Medical Center, Hamakita; Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita, Japan

关键词: upright posture;    regional cerebral blood flow;    PET;    autoradiographic method;    statistical parametric mapping;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

To determine whether hemodynamic parameters are changed by upright posture in healthy middle-aged humans, absolute values of regional cerebral blood flow (rCBF) were investigated for three different orthostatic conditions. Methods: PET with [15O]H2O and arterial blood sampling were performed on eight middle-aged healthy volunteers while they were sitting passively or standing actively. Absolute rCBF values estimated by the autoradiographic method in regions of interest were compared using ANOVA, and relative changes in rCBF were also analyzed voxel by voxel using statistical parametric mapping (SPM). Results: Physiologic data remained unchanged for different conditions. ANOVA and SPM showed that absolute and relative rCBF levels were significantly elevated in the cerebellar vermis in the standing position compared with those in the supine and sitting positions. In contrast, ANOVA showed that rCBF in the frontal and parietal cortices tended to be lower in the sitting and standing positions than in the supine position. Regression analysis showed that the frontal rCBF measured during standing tended to be inversely correlated with age. Conclusion: The results showed that cerebellar vermis activation was more marked in the standing position than in the sitting or supine positions, indicating that the vermis is a neural substrate for controlling voluntary upright posture. Brain perfusion in the distal internal carotid artery region may be subject to orthostatic postural changes in healthy middle-aged humans.

【 授权许可】

Unknown