Rauscher Alexander, Sedlacik Jan, Barth Markus, Haacke E Mark, Reichenbach Jürgen R
Institute for Diagnostic and Interventional Radiology, Friedrich Schiller University, Jena, Germany.
Magn Reson Med. 2005 Jul;54(1):87-95. doi: 10.1002/mrm.20520.
Susceptibility weighted imaging (SWI) is a BOLD-sensitive method for visualizing anatomical features such as small cerebral veins in high detail. The purpose of this study was to evaluate high-resolution SWI in combination with a modulation of blood oxygenation by breathing of air, carbogen, and oxygen and to directly visualize the effects of changing blood oxygenation on the magnetic field inside and around venous blood vessels. Signal changes associated with the response to carbogen and oxygen breathing were evaluated in different anatomic regions in healthy volunteers and in two patients with brain tumors. In the magnitude images inhalation of carbogen led to significant signal intensity changes ranging from +4.4 +/- 1.9% to +9.5 +/- 1.4% in gray matter and no significant changes in thalamus, putamen, and white matter. During oxygen breathing mean signal changes were smaller than during carbogen breathing. The method is capable of producing high-resolution functional maps of BOLD response to carbogen and oxygen breathing as well as high-resolution images of venous vasculature. Its sensitivity to changes in blood oxygenation was demonstrated by in vivo visualization of the BOLD effect via phase imaging.
磁敏感加权成像（SWI）是一种对血氧水平依赖（BOLD）敏感的方法，能够高分辨率地显示诸如脑小静脉等解剖结构特征。本研究的目的是评估高分辨率SWI结合空气、卡波金和氧气呼吸对血液氧合的调节作用，并直接观察血液氧合变化对静脉血管内外磁场的影响。在健康志愿者和两名脑肿瘤患者的不同解剖区域，评估了与卡波金和氧气呼吸反应相关的信号变化。在幅度图像中，吸入卡波金导致灰质信号强度显著变化，范围从+4.4±1.9%到+9.5±1.4%，而丘脑、壳核和白质无显著变化。在氧气呼吸期间，平均信号变化小于卡波金呼吸期间。该方法能够生成对卡波金和氧气呼吸的BOLD反应的高分辨率功能图以及静脉血管系统的高分辨率图像。通过相位成像在体内可视化BOLD效应，证明了其对血液氧合变化的敏感性。
