Signal Changes in the Brain on Susceptibility-Weighted Imaging Under Reduced Cerebral Blood Flow: A Preliminary Study

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1552-6569.2008.00348.x Byline: Yasutaka Fushimi (1), Yukio Miki (1), Nobuyuki Mori (1), Tsutomu Okada (1), Shin-ichi Urayama (1), Hidenao Fukuyama (1), Kaori Togashi (1) Keywords: Susceptibility-weighted imaging; high-field MRI; hyperventilation Abstract: ABSTRACT OBJECTIVES To reveal the characteristics of susceptibility-weighted imaging (SWI) under low cerebral blood flow (CBF) induced by hyperventilation (HV). MATERIALS AND METHODS 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. RESULTS CBF during HV (CBF.sub.HV) was decreased compared with CBF during NV (CBF.sub.NV) (29.1 [+ or -] 4.6%). FL-GM.sub.HV and OL-GM.sub.HV showed significant signal decreases compared with FL-GM.sub.NV and OL-GM.sub.NV, respectively (P= .018, .017). CV.sub.HV was significantly increased compared with CV.sub.NV (164.1 [+ or -] 29.9%) (P= .00019). CONCLUSIONS 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. Author Affiliation: (1)From the Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan (YF, YM, NM, TO, KT); Department of Radiology, Hikone Municipal Hospital, Hikone, Japan (YF); Department of Radiology, Tenri Hospital, Tenri, Japan (TO); and Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan (SU, HF). Article History: Acceptance: Received August 29, 2008. Accepted for publication October 2, 2008. Article note: Correspondence: Address correspondence to Yukio Miki, MD, PhD, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan. E-mail: mikiy@kuhp.kyoto-u.ac.jp.