TISSUE VIABILITY IN STROKE BY SODIUM MR IMAGING

钠中风的组织活力 MR 成像

• 批准号: 6351911
• 负责人: KEITH R. THULBORN
• 金额: $ 24.63万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-20 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6351911
• 关键词: Macaca mulatta; acute disease /disorder; angiography; apoptosis; bioimaging /biomedical imaging; biomarker; blood volume; cell population study; cytotoxicity; diffusion; disease /disorder model; fibrinolysis; histopathology; homeostasis; magnetic resonance imaging; necrosis; pathologic process; plasminogen activator; prognosis; reperfusion; sodium; sodium ion; stroke; terminal nick end labeling

Tissue sodium concentration (TSC), as measured by sodium imaging, will be correlated with diffusion (apparent diffusion coefficient, ADC) and perfusion (relative cerebral blood volume, rCBV; tissue transit time, TTT; arrival time, TA) from proton MRI over the first 12 hours of embolic stroke in a non-human primate model. These quantitative MR imaging parameters will be correlated with histological markers of tissue status including TTC, H&E and TUNEL staining. The goal is to establish if TSC an be used as a measure of tissue viability in assessment of acute stroke. Early intervention with thrombolysis enhances the clinical outcome if the tissue is still viable. As reperfusion of infarcted tissue increases the risk of adverse hemorrhage, the FDA approves a limited window of acceptable risk-benefit ratio of 3 hours from the onset of neurological symptoms in a non-hemorrhagic stroke. A rapid method for assessment of tissue viability in this setting would aid in tailoring clinical management to the pathophysiology of each patient. The central hypothesis is that there is a critical increase in TSC due to loss of sodium ion homeostasis in a region of restricted diffusion (reduced ADC) that indicates a significant loss of tissue viability in stroke. An acute embolic stroke model in a non-human primate is used to determine if a critical threshold of TSC defines tissue viability during the natural progression of stroke thereby predicting recovery following reperfusion after thrombolysis with recombinant tissue plasminogen activator (rt-PA) This animal model is required to establish the magnitude and rate of change of TSC in a well-controlled setting that can be applied in the clinical setting. Other proton MRI parameters used clinically in stroke are water diffusion and perfusion. The same comprehensive, yet efficient MRI protocol as I have used in MRI examinations of both acute and sub-acute stroke patients, allows TSC, ADC and blood pool perfusion parameters or rCBV, TTT and TA to be correlated in this acute stroke model and compared to histological parameters of necrosis and apoptosis. The novel twisted projection imaging acquisition produces high quality, high-resolution sodium images while echo-planar imaging is used for diffusion and perfusion imaging. A dual-frequency, dual-quadrature, 23NA/1H RF coil ensures co-registration of images and maps in minimum time without moving the subject. This well-controlled animal model examines if there is a critical TSC threshold that accurately predicts tissue viability as part of this comprehensive MR imaging protocol being used for clinical management of acute stroke.

通过钠成像测量的组织钠浓度（TSC）将与扩散（明显的扩散系数，ADC）和灌注（相对脑血容量，RCBV；组织传输时间，TTT；到达；到达时间，TA，TA）与Proton MRI的最初12个小时的胚芽中，在非纤维型模型中。这些定量的MR成像参数将与组织状态的组织学标记（包括TTC，H＆E和Tunel染色）相关。目的是确定TSC是否被用作评估急性中风的组织生存能力的量度。如果组织仍然可行，溶栓的早期干预会增强临床结果。 随着梗塞组织的再灌注增加了出血的风险，FDA批准了从非毛发性中风中神经系统症状开始后3小时可接受的风险效益比率有限的窗口。在这种情况下评估组织生存能力的一种快速方法将有助于根据每个患者的病理生理学调整临床管理。中心假设是，由于限制扩散（减少ADC）的钠离子稳态丧失，TSC的急剧增加，这表明中风中组织生存能力显着丧失。使用非人类灵长类动物中的急性栓塞中风模型来确定TSC的临界阈值是否在中风的自然进展过程中定义了组织生存力，从而预测了通过重组组织纤维蛋白原激活剂（RT-PA）在临床范围内进行TSC设置的幅度和速度的速度，从而预测了通过重组组织纤维蛋白原激活剂（RT-PA）进行重组组织的恢复。中风临床中使用的其他质子MRI参数是水的扩散和灌注。与我在急性和亚急性中风患者的MRI检查中使用的全面但有效的MRI方案相同，与在这种急性中风模型中相关，与Necrisosic and poptosis的组织学参数相比，TSC，ADC和血液池灌注参数或RCBV，TTT和TA可以与之相关。新颖的扭曲投影成像采集产生高质量的高分辨率钠图像，而回声平面成像用于扩散和灌注成像。双频，双重分数，23NA/1H RF线圈可确保在最短时间内共同注册图像和地图，而不会移动受试者。 这种控制良好的动物模型检查了是否存在关键的TSC阈值，可以准确预测组织生存力，这是该全面的MR成像协议的一部分，用于急性中风的临床管理。