Beller G A
Department of Medicine, University of Virginia Health Sciences Center, Charlottesville 22908.
Circulation. 1991 Sep;84(3 Suppl):I1-6.
Myocardial thallium-201 (Tl-201) imaging performed in conjunction with exercise stress has enhanced the accuracy of detecting coronary artery disease among patients with chest pain. Sensitivity and specificity of qualitative visual Tl-201 scintigraphy for detection of coronary artery disease average 84% and 87%, respectively. Quantitative analysis of planar Tl-201 scintigrams has yielded sensitivity and specificity in the 90% range. Single photon emission computed tomographic imaging is associated with even higher sensitivity but with specificity in the 82-85% range. Perfusion defects representing ischemia can now be distinguished from scar by demonstration of delayed Tl-201 redistribution or enhanced uptake after reinjection of a second dose of Tl-201. Stenoses of the left circumflex coronary artery are less easily detected than lesions of the right and left anterior descending coronary arteries. False-positive Tl-201 perfusion defects may occur as a result of attenuation artifacts, most often caused by overlying breast tissue or by a high left hemidiaphragm. Patient motion during acquisition of single photon emission computed tomographic images results in artifactual defects on reconstruction. Abnormal Tl-201 uptake has been noted in patients with 1) left bundle branch block and normal coronary arteries, 2) hypertrophic cardiomyopathy, and 3) progressive systemic sclerosis.
与运动负荷试验相结合进行的心肌铊-201（Tl-201）显像提高了胸痛患者冠状动脉疾病检测的准确性。定性视觉Tl-201闪烁显像检测冠状动脉疾病的敏感性和特异性分别平均为84%和87%。平面Tl-201闪烁图的定量分析得出的敏感性和特异性在90%左右。单光子发射计算机断层显像的敏感性更高，但特异性在82%至85%之间。通过显示延迟的Tl-201再分布或再次注射第二剂Tl-201后摄取增强，现在可以将代表缺血的灌注缺损与瘢痕区分开来。左旋支冠状动脉狭窄比右冠状动脉和左前降支冠状动脉病变更难检测到。Tl-201灌注缺损假阳性可能由于衰减伪影导致，最常见的原因是覆盖的乳腺组织或高位左半膈肌。在采集单光子发射计算机断层图像期间患者的运动导致重建时出现伪影缺损。在患有以下疾病的患者中已注意到Tl-201摄取异常：1）左束支传导阻滞且冠状动脉正常；2）肥厚型心肌病；3）进行性系统性硬化症。
