Abstract:
The heart failure epidemic continues to rise with coronary artery disease as one of its main causes. Novel concepts for risk stratification to guide the referring cardiologist towards revascularization procedures are of significant value. Myocardial perfusion imaging using single-photon emission computed tomography (SPECT) agents has demonstrated high accuracy for the detection of clinically relevant stenoses. With positron emission tomography (PET) becoming more widely available, mainly due to its diagnostic performance in oncology, perfusion imaging with that modality is more practical than in the past and overcomes existing limitations of SPECT MPI. Advantages of PET include more reliable quantification of absolute myocardial blood flow, the routine use of computed tomography for attenuation correction, a higher spatiotemporal resolution and a higher count sensitivity. Current PET radiotracers such as rubidium-82 (half-life, 76 s), oxygen-15 water (2 min) or nitrogen-13 ammonia (10 min) are labeled with radionuclides with very short half-lives, necessitating that stress imaging is performed under pharmacological vasodilator stress instead of exercise testing. However, with the introduction of novel 18F-labeled MPI PET radiotracers (half-life, 110 min), the intrinsic advantages of PET can be combined with exercise testing. Additional advantages of those radiotracers include, but are not limited to: potentially improved cost-effectiveness due to the use of pre-existing delivery systems and superior imaging qualities, mainly due to the shortest positron range among available PET MPI probes. In the present review, widely used PET MPI radiotracers will be reviewed and potential novel 18F-labeled perfusion radiotracers will be discussed.
摘要:
心力衰竭流行持续上升,冠状动脉疾病是其主要原因之一。风险分层的新概念可指导转诊的心脏病专家进行血运重建手术,具有重要价值。使用单光子发射计算机断层扫描(SPECT)试剂的心肌灌注成像已证明可检测临床相关狭窄。随着正电子发射断层扫描(PET)变得越来越广泛,主要是由于其在肿瘤学中的诊断性能,使用该模式的灌注成像比过去更实用,并且克服了SPECTMPI的现有局限性。PET的优点包括更可靠的绝对心肌血流量的定量,常规使用计算机断层扫描进行衰减校正,更高的时空分辨率和更高的计数灵敏度。目前的PET放射性示踪剂,如铷-82(半衰期,76秒),氧-15水(2分钟)或氮-13氨(10分钟)用半衰期非常短的放射性核素标记,需要在药理学血管扩张剂压力下进行压力成像,而不是运动测试。然而,随着新型18F标记的MPIPET放射性示踪剂(半衰期,110分钟),PET的内在优势可以与运动测试相结合。这些放射性示踪剂的其他优点包括,但不限于:由于使用现有的输送系统和卓越的成像质量,可能提高成本效益,主要是由于在可用的PETMPI探针中最短的正电子范围。在本次审查中,将审查广泛使用的PETMPI放射性示踪剂,并讨论潜在的新型18F标记的灌注放射性示踪剂。