SPECT Imaging for Detecting Coronary Artery Disease and Determining Prognosis by Noninvasive Assessment of Myocardial Perfusion and Myocardial Viability
SPECT Imaging for Detecting Coronary Artery Disease and Determining Prognosis by Noninvasive Assessment of Myocardial Perfusion and Myocardial Viability
复制标题
DOI：
10.1007/s12265-011-9290-2
复制
发表时间：
2011-08-01
影响因子：
3.4
通讯作者：
Heede, Ruth C.
中科院分区：
文献类型：
--
作者：
Beller, George A.;Heede, Ruth C.
对心肌细胞中一价阳离子的主动和被动转运机制的基本知识导致了利用伽马相机或正电子发射断层扫描(PET)成像技术对钾、铊、Rb和氨的放射性同位素在体内无创评估局部心肌灌注和活性方面的应用研究。随后，与线粒体膜结合的~(99m)Tc标记异腈(Sestamibi和Tetrofosmin)在单光子发射断层扫描(SPECT)中作为一种优良的显像剂应运而生。当这些显像剂中的任何一种在运动或药物应激时被静脉注射时，心肌示踪剂摄取的缺陷要么是局部血流储备异常，要么是反映冠状动脉疾病(CAD)的心肌瘢痕。负荷SPECT或PET心肌灌注成像的主要临床指征是检测引起胸痛的冠心病，并进行危险分层以预测预后。正常负荷心肌灌注扫描的患者预后良好，未来的年死亡率为1.0%，或非致命性心肌梗死。缺血灌注缺陷(在负荷图像上可见的缺陷，但在静息图像上有所改善)的范围和严重程度越大，后续随访期间的死亡率或梗死率就越高。静息显像单独用于测定冠心病合并严重左心功能不全患者的心肌存活性。与正常摄取的心肌节段相比，心肌节段血管重建术比药物治疗有更好的长期结果，因为药物治疗可以增强左心功能并改善存活率。SPECT成像的其他应用包括评估心脏交感神经功能，评估健康和疾病中的心肌代谢，以及冠状动脉粥样硬化和心肌干细胞治疗的分子成像。
Basic knowledge of active and passive transport mechanisms for concentrating monovalent cations in myocardial cells led to the investigation of the application of radioisotopes of potassium, thallium, rubidium, and ammonia to the in vivo noninvasive assessment of regional myocardial perfusion and viability utilizing gamma camera or positron emission tomographic (PET) imaging technology. Subsequently, technetium-99m (Tc-99m)-labeled isonitriles (sestamibi and tetrofosmin), which bind to mitochondrial membranes, emerged as superior imaging agents with single photon emission tomography (SPECT) imaging. When any of these imaging agents are injected intravenously during either exercise or pharmacologic stress, myocardial defects in tracer uptake represent either abnormal regional flow reserve or myocardial scar reflecting of coronary artery disease (CAD). The major clinical indications for stress SPECT or PET myocardial perfusion imaging are for detection of CAD as the cause of chest pain and risk stratification for prognostication. Patients with normal stress myocardial perfusion scans have an excellent prognosis with < 1.0% annual rate future annual death or nonfatal infarction. The greater the extent and severity of ischemic perfusion defects (defects seen on stress images but improve on resting images), the greater the subsequent death or infarction rate during follow-up. Rest imaging alone is performed for determination of myocardial viability in patients with CAD and severe left ventricular dysfunction. Myocardial segments showing > 50% uptake compared to normal uptake have a better long-term outcome with revascularization than with medical therapy with enhanced left ventricular function and improved survival. Other applications of SPECT imaging include the evaluation of cardiac sympathetic function, assessment of myocardial metabolism in health and disease, and molecular imaging of coronary atherosclerosis and myocardial stem cell therapy.