Ramsey N F, Kirkby B S, Van Gelderen P, Berman K F, Duyn J H, Frank J A, Mattay V S, Van Horn J D, Esposito G, Moonen C T, Weinberger D R
Clinical Brain Disorders Branch, National Institute of Mental Health, NIH, Washington, DC 20032, USA.
J Cereb Blood Flow Metab. 1996 Sep;16(5):755-64. doi: 10.1097/00004647-199609000-00001.
Positron emission tomography (PET) functional imaging is based on changes in regional cerebral blood flow (rCBF). Functional magnetic resonance imaging (fMRI) is based on a variety of physiological parameters as well as rCBF. This study is aimed at the cross validation of three-dimensional (3D) fMRI, which is sensitive to changes in blood oxygenation, with oxygen-15-labeled water (H2(15)O) PET. Nine normal subjects repeatedly performed a simple finger opposition task during fMRI scans and during PET scans. Within-subject statistical analysis revealed significant ("activated") signal changes (p < 0.05, Bonferroni corrected for number of voxels) in contralateral primary sensorimotor cortex (PSM) in all subjects with fMRI and with PET. With both methods, 78% of all activated voxels were located in the PSM. Overlap of activated regions occurred in all subjects (mean 43%, SD 26%). The size of the activated regions in PSM with both methods was highly correlated (rho = 0.87, p < 0.01). The mean distance between centers of mass of the activated regions in the PSM for fMRI versus PET was 6.7 mm (SD 3.0 mm). Average magnitude of signal change in activated voxels in this region, expressed as z-values adapted to timeseries, zt, was similar (fMRI 5.5, PET 5.3). Results indicate that positive blood oxygen level-dependent (BOLD) signal changes obtained with 3D principles of echo shifting with a train of observations (PRESTO) fMRI are correlated with rCBF, and that sensitivity of fMRI can equal that of H2(15)O PET.
正电子发射断层扫描（PET）功能成像基于局部脑血流量（rCBF）的变化。功能磁共振成像（fMRI）则基于多种生理参数以及rCBF。本研究旨在对三维（3D）fMRI与用氧 - 15标记水（H2(15)O）PET进行交叉验证，3D fMRI对血液氧合变化敏感。九名正常受试者在fMRI扫描和PET扫描期间反复执行简单的对指任务。受试者内统计分析显示，在所有接受fMRI和PET检查的受试者中，对侧初级感觉运动皮层（PSM）均出现显著（“激活”）信号变化（p < 0.05，经体素数量校正的Bonferroni法）。两种方法均显示，所有激活体素中有78%位于PSM。所有受试者均出现激活区域重叠（平均43%，标准差26%）。两种方法在PSM中激活区域的大小高度相关（rho = 0.87，p < 0.01）。fMRI与PET在PSM中激活区域质心之间的平均距离为6.7毫米（标准差3.0毫米）。该区域激活体素中信号变化的平均幅度，以适应时间序列的z值（zt）表示，两者相似（fMRI为5.5，PET为5.3）。结果表明，采用一系列观察的回波移位三维原理（PRESTO）fMRI获得的正性血氧水平依赖（BOLD）信号变化与rCBF相关，且fMRI的敏感性可与H2(15)O PET相当。
