DETECTION OF HYPOXIA IN SICKLE CELL ANEMIA BY BOLD MRI

通过大胆 MRI 检测镰状细胞性贫血中的缺氧

• 批准号: 6593862
• 负责人: Mary E Fabry
• 金额: $ 17.52万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-20 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6593862
• 关键词: bioimaging /biomedical imaging; blood vessel occlusion; clinical research; diagnosis design /evaluation; functional magnetic resonance imaging; human subject; hypoxia; microcirculation; oxygen tension; sickle cell anemia; sickle cell crisis

(Adapted from Applicant's Abstract) Treatment of sickle cell painful crisis has suffered from a lack of objective criteria for detecting progression of crisis and use in evaluating treatment protocols. To date, MRI of painful crisis has yielded results which are intriguing but difficult to evaluate. Detection of hypoxia in regions with acute pain may yield a useable marker. The technology for in vivo observation of blood perfusion and tissue oxygenation by blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) has matured into a sensitive technique an can be applied to these problems. The investigators will test the hypothesis that painful crisis of the limbs is accompanied by areas of blood hypoxia due to partial obstruction of the circulation which can be detected by BOLD MRI. The investigators also test the hypothesis that the stereotypical repetition of painful crisis as the same sight might be the consequence of congenital or acquired alteration (by previous crises or other effects) in the microcirculation that predispose to repeat crises in the same site. The investigators will also examine the hypothesis that HU will reduce the extent of the area affected and/or the degree of blood hypoxia in areas prone to crisis. The investigators have demonstrated in transgenic mice expressing the BetaS-globin gene that BOLD-MRI can detect the presence of high levels of deoxy hemoglobin (blood hypoxia) in tissues such as the medulla of the kidney which have been shown to have very low oxygen tension by other means. Highly deoxygenated sickle cell blood is at risk of polymer formation and the microcirculation is a risk of vaso- occlusion. The investigators propose here to use BOLD-MRI to detect blood deoxygenation in adult patients with sickle cell painful crisis. A goal of these studies to separate acute, ongoing events during sickle cell painful crisis from the results of previous episodes of ischemia. Previous approaches to detection of pathological changes occurring during the course of sickle cell painful crisis such as 99mTc bone scans and MRI are too sensitive to the presence of old infarcts to allow detection of new infarcts without prior baseline studies. If successful, this approach may allow the unique visualization of poorly perfused regions without reference to baseline studies.

镰状细胞疼痛的治疗(改编自申请者摘要) 危机因缺乏客观的检测标准而受到影响 危象进展及在评估治疗方案中的应用。到目前为止， 痛苦危机的核磁共振成像结果耐人寻味，但 很难评估。检测到急性疼痛区域的缺氧可能 拿出一个可用的记号笔。活体血液观察技术 依赖血氧水平的灌流和组织氧合(BOLD) 磁共振成像(MRI)已经成熟为一种敏感的技术和 可以应用于这些问题。调查人员将测试 假说四肢疼痛的危象伴随着 血液循环部分阻塞所致的血液缺氧，可 被大胆的核磁共振检测到。研究人员还测试了一种假设，即 痛苦危机的刻板印象的重复，因为同样的场景可能是 先天或后天改变的后果(由以前的危机或 其他影响)在微循环中，容易在 同样的网站。调查人员还将检验胡士泰的假设 会减少受影响区域的范围和/或血液的程度 容易发生危机的地区的缺氧。调查人员已经在 BOLD-MRI可检测到表达β-珠蛋白基因的转基因小鼠 组织中存在高水平的脱氧血红蛋白(血液缺氧) 例如肾脏的髓质，已经被证明是非常低的 氧分压通过其他方式。高度脱氧的镰状细胞血液在 聚合物形成和微循环的风险是血管形成的风险 遮挡。研究人员建议在这里使用BOLD-MRI来检测血液 成人镰状细胞疼痛危象患者的脱氧治疗。目标是 这些研究旨在分离镰状细胞疼痛期间的急性、持续事件 从之前的脑缺血发作的结果来看，这是一种危机。上一首 检测疾病发生过程中病理变化的方法 镰状细胞疼痛危象的病程，如99mTc骨扫描和磁共振成像 对陈旧性梗死的存在过于敏感，不能检测到新的 在没有事先基线研究的情况下发生梗塞。如果成功，这种方法可能会 允许以独特的方式显示灌注度较低的区域 参考基线研究。