초록/요약

Introduction: Global and regional sympathetic activity in the heart can be evaluated using [I-123]meta-iodobenzylguanidine ([I-123]mIBG) imaging. However, [I-123]mIBG is associated with low image spatial resolution and sensitivity in cardiac imaging. We investigated the capability of an F-18-labeled mIBG derivative, meta-(3-[F-18]fluoropropyl)benzylguanidine ([F-18]mFPBG), for identifying ischemic and viable myocardium in a rat model of myocardial infarction. Materials and Methods: The ex vivo biodistribution and in vivo metabolic stability of [F-18]mFPBG were investigated in Sprague-Dawley rats. Selective cardiac adrenergic activation was confirmed via a blocking experiment involving pretreatment with desipramine (2 mg kg(-1)), followed by the administration of [F-18]mFPBG. Imaging properties of [F-18]mFPBG were compared with those of traditional cardiac imaging radiotracers ([I-123]mIBG and [Tc-99m]MIBI) in a rat model of myocardial infarction. Non-invasive image-based measurements of infarct sizes were then compared with histological findings by using Bland-Altman analysis. Results: The differences in infarct sizes determined using histological analysis and [F-18]mFPBG PET were -2.55 +/- 4.99% (range: -12.33 to 7.22), -2.35 +/- 3.32% (range: -8.87 to 4.16), and -3.15 +/- 6.16% (range: -15.24 to 8.93) at 5, 20, and 40 min, respectively. Furthermore, [F-18]mFPBG PET was superior to traditional imaging methods in assessing the degree of ischemia in areas of myocardial infarction, as well as the actual infarct size. Conclusion: Compared to [I-123]mIBG, [F-18]mFPBG showed improved spatial resolution and sensitivity in a rat model of myocardial infarction. This result suggested that [F-18]mFPBG is a promising cardiac PET imaging agent for potential diagnostic application in PET cardiology. (C) 2018 Elsevier Inc. All rights reserved.