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.

（改编自申请人摘要）镰状细胞性疼痛的治疗 由于缺乏客观的标准来检测危机， 危机的进展和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已经产生了有趣的结果， 难以评估。检测急性疼痛区域的缺氧可能 产生可用的标记。血液在体观察技术 血氧水平依赖性灌注和组织氧合（BOLD） 磁共振成像（MRI）已经成熟为一种敏感的技术， 可以应用于这些问题。调查人员将测试 假设四肢疼痛危机伴随着区域 由于循环的部分阻塞而导致的血液缺氧， 通过BOLD MRI检测。调查人员还测试了假设， 刻板重复的痛苦危机，因为同样的景象可能是 先天性或后天性改变的后果（由以前的危机或 其他影响）在微循环中， 同一个网站。调查人员还将检验胡锦涛的假设， 将减少受影响区域的范围和/或血液的程度， 在容易发生危机的地区缺氧。调查人员已经证明， 表达β S-珠蛋白基因的转基因小鼠，BOLD-MRI可以检测到 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，其已经显示具有非常低的 氧分压通过其他方式。高度脱氧的镰状细胞血在 聚合物形成的风险和微循环是血管的风险， 闭塞研究人员在这里建议使用BOLD-MRI来检测血液 镰状细胞疼痛危象成人患者的脱氧。的目标 这些研究将镰状细胞疼痛期间的急性持续事件 危机的结果，以前的缺血发作。先前 检测在治疗期间发生的病理变化的方法 镰状细胞疼痛危象的过程，如99 mTc骨扫描和MRI， 对旧梗塞的存在太敏感而不能检测新梗塞 既往无基线研究的梗死。如果成功，这种方法可能 允许灌注不良区域的独特可视化， 参考基线研究。