MRI-based Quantitative Brain Perfusion Mapping for Sickle Cell Disease

基于 MRI 的镰状细胞病定量脑灌注图

• 批准号: 8618677
• 负责人: Qin Qin
• 金额: $ 15.21万
• 依托单位: HUGO W. MOSER RES INST KENNEDY KRIEGER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-12-20 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8618677
• 关键词: Abnormal Hemoglobins; Accounting; Adolescent; Adult; Affect; Age; Angiography; Blood; Blood Circulation; Blood Transfusion; Bolus Infusion; Brain; Brain Injuries; Cause of Death; Cerebrovascular Circulation; Cerebrum; Characteristics; Child; Childhood; Clinical; Contrast Media; Detection; Disease; Early identification; Etiology; Evaluation; Failure; Focal Neurologic Deficits; Genetic; Goals; Half-Life; Hematocrit procedure; Hematological Disease; Homeostasis; Image; Imaging Techniques; Impairment; Infarction; Ionizing radiation; Label; Longitudinal Studies; Magnetic Resonance Imaging; Maps; Measurement; Measures; Metric; Microvascular Dysfunction; Monitor; Morbidity - disease rate; Oxygen; Patients; Perfusion; Perfusion Weighted MRI; Phase; Population; Positron-Emission Tomography; Predictive Value; Predisposition; Property; Protocols documentation; Radiation; Recording of previous events; Recurrence; Relaxation; Reproducibility; Research; Risk; Risk Factors; Role; Sickle Cell Anemia; Sickle Hemoglobin; Slice; Spin Labels; Stroke; Stroke prevention; Techniques; Testing; Time; Transfusion; Validation; Water; Weight; base; blood flow measurement; cerebral artery; cerebrovascular; clinical efficacy; disability; healthy volunteer; hemodynamics; high risk; improved; mortality; non-invasive monitor; prevent; public health relevance; research study; response; screening; single photon emission computed tomography

DESCRIPTION (provided by applicant): SCD is a genetic blood disorder characterized by abnormal hemoglobin S (HbS) synthesis with sickle cell anemia (SCA) as the most common subtype. Stroke is the most frequent cause of death and long-term disability in both children and adults with SCD. Studies of patients with focal neurologic deficits have revealed abnormalities of both large and small vessels in SCD. Currently, the main clinical screening test is the use of transcranial Doppler (TCD) for neurologically asymptomatic children with SCD. The TCD test has a low positive predictive value and is not effective to screen stroke risk in adult SCD patients. Cerebral blood flow (CBF), a measure of the microvascular perfusion of the brain, has been recognized as a potentially more sensitive and specific indicator of early cerebrovascular impairment in both children and adults with SCD. CBF measurement based on the arterial spin labeling (ASL) MRI technique is promising as it does not require a contrast agent and is free of radiation. However, the existing ASL techniques often acquire 2D multi-slice perfusion-weighted MRI at a single post-labeling delay and, for CBF calculation, make assumptions on a number of parameters that are related to blood properties, such as arterial arrival time (AAT), longitudinal relaxation time (T1) of blood and labeling efficiency. The overall goal of the research proposed is to develop and validate a multi-delay 3D ASL protocol combined with per-subject measurements of blood T1 and labeling efficiency, which provides accurate and reliable perfusion metrics (CBF and AAT) for SCD patients. The measured CBF and AAT are expected to allow detection of both small and large vessel disease simultaneously for SCD. The specific aims of this study is first to develop a comprehensive and fast ASL-based perfusion protocol and demonstrate its reliability and reproducibility in healthy volunteers (Aim 1), then to validate the measured CBF and AAT with phase-contrast MR Angiography (PC-MRA) and dynamic susceptibility contrast (DSC) MRI in a group of SCA patients without a history of stroke (Aim 2), and finally to monitor CBF and AAT in patients with SCD and a history of stroke to explore the association between CBF and AAT and recurrent brain injury (Aim 3).

描述（由申请人提供）：SCD 是一种遗传性血液疾病，其特征是血红蛋白 S (HbS) 合成异常，其中镰状细胞性贫血 (SCA) 是最常见的亚型。中风是导致 SCD 儿童和成人死亡和长期残疾的最常见原因。对局灶性神经功能缺损患者的研究表明，SCD 患者的大血管和小血管均存在异常。目前，主要的临床筛查测试是使用经颅多普勒（TCD）对无神经症状的 SCD 儿童进行筛查。 TCD 测试的阳性预测值较低，不能有效筛查成人 SCD 患者的卒中风险。脑血流量 (CBF) 是大脑微血管灌注的测量指标，已被认为是 SCD 儿童和成人早期脑血管损伤的潜在更敏感和特异的指标。基于动脉自旋标记 (ASL) MRI 技术的 CBF 测量很有前景，因为它不需要造影剂且无辐射。然而，现有的ASL技术通常在单个标记后延迟时获取2D多层灌注加权MRI，并且为了计算CBF，需要对许多与血液特性相关的参数做出假设，例如动脉到达时间（AAT）、血液的纵向弛豫时间（T1）和标记效率。该研究的总体目标是开发和验证多延迟 3D ASL 方案，结合每个受试者的血液 T1 测量和标记效率，为 SCD 患者提供准确可靠的灌注指标（CBF 和 AAT）。测量的 CBF 和 AAT 有望同时检测 SCD 的小血管和大血管疾病。本研究的具体目标是首先开发一种全面、快速的基于 ASL 的灌注方案，并在健康志愿者中证明其可靠性和可重复性（目标 1），然后验证 通过相位对比磁共振血管造影（PC-MRA）和动态磁敏感对比（DSC）MRI测量一组无脑卒中病史的SCA患者的CBF和AAT（目标2），最后监测有脑卒中病史的SCD患者的CBF和AAT，探讨CBF和AAT与复发性脑损伤之间的关系（目标3）。