Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
J Neuroimaging. 2010 Jul;20(3):255-9. doi: 10.1111/j.1552-6569.2008.00348.x. Epub 2009 Jan 30.
To reveal the characteristics of susceptibility-weighted imaging (SWI) under low cerebral blood flow (CBF) induced by hyperventilation (HV).
This study was approved by the institutional review board. Informed consent was obtained. Six healthy volunteers (5 men, 1 woman; mean age, 29 years; range, 24-33 years) underwent SWI and arterial spin labeling perfusion imaging under normal ventilation (NV) and HV at 3.0 T. Regions of interest (ROIs) were placed on gray matter (GM) and white matter (WM) of the frontal lobe (FL) and occipital lobe (OL). Intensities of ROIs were compared between NV and HV. Contrast of veins compared with adjacent cerebral parenchyma (CV) was also compared between NV and HV.
CBF during HV (CBF(HV)) was decreased compared with CBF during NV (CBF(NV)) (29.1 +/- 4.6%). FL-GM(HV) and OL-GM(HV) showed significant signal decreases compared with FL-GM(NV) and OL-GM(NV), respectively (P= .018, .017). CV(HV) was significantly increased compared with CV(NV) (164.1 +/- 29.9%) (P= .00019).
SWI sensitively reflects HV-induced decreases in CBF. The present results might assist in the interpretation of SWI in clinical practice, since CBF decreases might also influence signal changes on SWI.
揭示高通气（HV）引起的脑血流量（CBF）降低时磁敏感加权成像（SWI）的特点。
本研究经机构审查委员会批准，所有志愿者均签署了知情同意书。6 名健康志愿者（5 男 1 女；平均年龄 29 岁；范围 24-33 岁）在 3.0T 磁共振扫描仪上分别行正常通气（NV）和 HV 下的 SWI 和动脉自旋标记灌注成像。在额（FL）和枕（OL）叶的灰质（GM）和白质（WM）上设置感兴趣区（ROI）。比较 NV 和 HV 下 ROI 的强度。比较 NV 和 HV 下静脉与相邻脑实质的对比（CV）。
HV 期间的 CBF（CBF（HV））较 NV 期间的 CBF（CBF（NV））降低（29.1 +/- 4.6%）。FL-GM（HV）和 OL-GM（HV）与相应的 FL-GM（NV）和 OL-GM（NV）相比，信号明显降低（P=.018，.017）。CV（HV）较 CV（NV）显著增加（164.1 +/- 29.9%）（P=.00019）。
SWI 敏感地反映了 HV 引起的 CBF 降低。本研究结果可能有助于 SWI 在临床实践中的解释，因为 CBF 降低也可能影响 SWI 上的信号变化。
