SPATIAL ATTENTION AFFECT BRAIN ACTIVITY IN HUMAN PRIMARY VISUAL CORTEX

空间注意力影响人类初级视觉皮层的大脑活动

• 批准号: 6123026
• 负责人: SUNIL P GANDHI
• 金额: $ 0.07万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6123026
• 关键词: bioimaging /biomedical imaging; biomedical resource; magnetic resonance imaging; radiology; technology /technique

Introduction: The ability to localize and differentiate between hypoxic and well-oxygenated tumors in vivo may aid in the staging of treatment and affect the choice of therapeutic agent. This potentially can be achieved through the use of magnetic resonance spectroscopy (MRS) to measure the relative concentrations of two molecules 1)lactate - a marker for non-oxidative glycolysis, and 2) choline - when enhanced, a marker for active tumor. To assess metastatic neck nodes resulting from primary occurances of squamous cell carcinoma, we have implemented a new J-difference editing scheme using band selective inversion with gradient dephasing (BASING) which was developed for water suppression and lactate rephasing. BASING applied to lactate editing is unique in that the four benefits are provided: 1) singlet suppression with resilience to B1-scaling errors, 2) easy incorporation into localization sequences such as point resolved spectroscopy (PRESS) 3) arbitrary echo times for TE >= 1/J, and 4) RF pulses with steep transition bands that are required to maintain visibility of the choline resonance. Methods: Data were collected from 8 patients and volunteers with the following scan parameters: TR = 2s, TE = 144 ms, number of acquisitions = 256. A 4-element head, neck and cervical phased-array coil (MRI Devices Corp., Waukesha, WI.) operating in receive-only mode was used to maximize coverage and the SNR. To achieve robust separation of lactate from the singlets, a novel phase regularization algorithm, which compensated for phase and frequency variations between successive excitations, was developed. Results: Data from the neck muscle of a normal volunteer showed that a lipid suppression factor of over 1000 was achievable with use of the phase regularization algorithm. The spectra from the neck tumor nodes demonstrated variable amounts of choline and lactate detected. However, the two spectra with the most lactate and choline had median pO2 values of approximately 0.7 mm Hg which is highly suggestive of hypoxia Conclusions: We have demonstrated the use of a new MRS technique capable of detecting both choline and lactate resonances in vivo in head and neck tumors. This has not previously been accomplished and may offer a noninvasive means of differentiating between necrosis, hypoxic and well-oxygenated tumors.

简介：本地化和区分 体内缺氧和氧合良好的肿瘤可能有助于分期 治疗和影响治疗剂的选择。 这 通过使用磁共振 光谱（MRS）测量两种物质的相对浓度 分子1）乳酸盐-非氧化糖酵解的标志物，和2） 胆碱-当增强时，是活跃肿瘤的标志物。 评估 原发鳞状细胞癌引起的转移性颈淋巴结 细胞癌，我们实施了一种新的J-差异编辑方案， 使用具有梯度失相（BASING）的带选择性反转， 是为水抑制和乳酸复相而开发的。 基础 应用于乳酸编辑是独特的，因为四个好处是 提供：1）具有对B1-缩放的弹性的单线态抑制 错误，2）容易并入定位序列， 点分辨光谱（PRESS）3）TE >=的任意回波时间 1/J，以及4）要求具有陡峭过渡带的RF脉冲， 保持胆碱共振的可见性。 方法：资料来源： 采集自8名患者和志愿者，扫描如下 参数：TR = 2s，TE = 144 ms，采集次数= 256。 一 4-元件头、颈和颈部相控阵线圈（MRI设备 公司名称：沃基沙，威斯康星州）在只接收模式下运行， 最大化覆盖范围和SNR。 为了实现稳健的分离， lactate乳酸from the singlets单态，a novel新phase相位regularization正则化algorithm算法， 其补偿了相位和频率变化， 连续的激励，是发达国家。 结果：颈部数据 正常志愿者的肌肉显示， 使用相位正则化可以实现超过1000个 算法 颈部肿瘤结节的光谱显示 检测到不同量的胆碱和乳酸盐。 但两 具有最多乳酸盐和胆碱的光谱的中位pO 2值为 约0.7 mm Hg，高度提示缺氧 结论：我们已经证明了一种新的MRS技术的使用 能够在体内检测胆碱和乳酸共振， 头颈部肿瘤 这是以前没有实现过的， 可以提供一种非侵入性的方法来区分坏死， 缺氧和氧合良好的肿瘤。