DESIGN OF FUNCTIONAL BRAIN MAPPING STUDIES WITH PET AND O15-WATER

使用 PET 和 O15-水进行脑功能图谱研究的设计

• 批准号: 5201148
• 负责人: P HERSCOVITCH
• 金额: --
• 依托单位: CLINICAL CENTER
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5201148
• 关键词: brain mapping; human subject; neurophysiology; neuropsychological tests; positron emission tomography; radionuclides

PET with oxygen-15 water is widely used to determine regional cerebral blood flow (rCBF) changes in functional brain mapping experiments. We and others have shown that when rCBF changes during scan data collection, the measured flow is very close to the flow value at the start of the scan, rather than being a time-average of the flow during the scan. This may have implications for the design of mapping studies which involve two or more components, e.g., a learning or practice phase, and a recall or execution phase. If the phases are performed without attention to when the scan starts, the rCBF maps may reflect a combination of the two phases. If they are coordinated with the scan start, the images may reflect the task phases, permitting one to determine which brain regions are involved in each phase. This hypothesis was tested with a visual memory task which alternated between a 30 sec encoding phase when subjects viewed slides of unfamiliar faces, and a 30 sec recognition phase when they indicated whether they had previously seen faces presented to them. Eleven normal control subjects were studied on the Scanditronix PC2O48-I5B tomograph. Injection of 0-15 water and task onset were coordinated so that subjects performed one of the task phases during the first 20 sec of the scan. The data were analyzed using Statistical Parametric Mapping software. Direct comparison of scans starting in encoding phase with scans starting with recognition showed dramatic differences, with relatively higher rCBF during encoding in the frontal, temporal and parietal regions, more on the left. Comparison of scans starting with each phase to control tasks (a face matching task and a sensorimotor control) demonstrated substantial differences in the patterns of activation. These experimental results were consistent with simulation studies of step changes in rCBF occurring at various times in relation to the start of the scan. Thus both simulations and experimental data demonstrated that the first 15- 20 sec after bolus arrival and scan start determine the observed rCBF response in an activation task. This study provides a strategy for designing functional brain mapping experiments to determine which brain regions are involved in the components of a more complex task.

氧-15水PET被广泛用于确定局部脑 脑血流（rCBF）的变化。我们和 其他人已经表明，当rCBF在扫描数据收集期间改变时， 测量的流量非常接近扫描开始时的流量值， 而不是扫描期间的流量的时间平均。这可能 对涉及两个或两个以上的绘图研究的设计有影响， 更多的组件，例如，一个学习或实践阶段，一个回忆或 执行阶段。如果在执行阶段时不注意 当扫描开始时，rCBF图可以反映两个阶段的组合。如果 它们与扫描开始相协调，图像可以反映任务 阶段，允许一个人确定哪些大脑区域参与 每个阶段。 这一假设进行了测试与视觉记忆任务，交替 当受试者观看不熟悉的幻灯片时， 面部，以及30秒的识别阶段，当他们表明他们是否有 以前见过的面孔呈现在他们面前。11名正常对照受试者 在Scanditronix PC 2 O 48-I5 B断层扫描仪上进行研究。注射0-15 水和任务的开始是协调的，这样受试者就可以完成以下任务之一： 在扫描的前20秒期间任务阶段。对数据进行 使用统计参数映射软件进行分析。直接比较 从编码阶段开始的扫描与从识别阶段开始的扫描 在编码过程中，rCBF相对较高， 在额叶颞叶和顶叶区域，更多的是在左边。 从每个阶段开始的扫描比较，以控制任务（面部 匹配任务和感觉运动控制）表现出实质性的 激活模式的差异。这些实验结果是 与rCBF发生阶跃变化的模拟研究一致， 与扫描开始相关的各种时间。 因此，模拟和实验数据都表明， 15-推注到达和扫描开始后20秒确定观察到的rCBF 在激活任务中的响应。这项研究提供了一个战略， 设计功能性大脑绘图实验来确定 区域参与更复杂任务的组成部分。