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Erschienen in:
01.11.2011 | Original Article
Reduced myocardial 18F-FDG uptake after calcium channel blocker administration. Initial observation for a potential new method to improve plaque detection
Erschienen in: European Journal of Nuclear Medicine and Molecular Imaging | Ausgabe 11/2011
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Purpose
Physiological glucose uptake by the myocardium may hamper visualization of coronary atherosclerotic plaques in 18F-FDG PET studies. Intracellular myocardial calcium relates to glucose influx. We assessed whether administration of a calcium channel blocker such as verapamil could decrease myocardial 18F-FDG uptake in mice.
Methods
Experiments were conducted on ten male C57BL/6JOlaHsd mice. The mice were studied by 18F-FDG PET/CT under basal conditions and after a single administration of verapamil injected 1 h prior to 18F-FDG administration at doses of 1 mg/kg (group A, n = 5) and 20 mg/kg (group B, n = 5). PET scanning was started 60 min after injection of 18F-FDG employing a dedicated small-animal PET/CT system (ARGUS-CT). In each mouse, post-verapamil PET images were coregistered with the basal PET images. Volumetric regions of interest (VOI) were drawn on the basal study containing the myocardium of the whole left ventricle and quantitatively compared with the same VOI applied to the post-verapamil scan. The SUVmean was used to express the mean myocardial 18F-FDG uptake. The relative coefficient of variation (RV) between the basal and post-verapamil conditions was calculated.
Results
Verapamil administration decreased myocardial 18F-FDG uptake in all animals. The median (range) SUVmean values in group A were 2.6 (1.6–4.1) under basal conditions and 1.7 (1.1–2.9) after verapamil administration (p = 0.043), and in group B were 1.6 (1.3–2.0) under basal conditions and 1.0 (0.9–1.4) after verapamil administration (p = 0.043). The median (range) RV values were −31% (−5%, −50%) in group A, and −37% (−10%, −51%) in group B (p = 0.6).
Conclusion
In this animal model there was a significant reduction in 18F-FDG uptake in the myocardium following verapamil administration. This type of intervention could facilitate the definition of coronary atherosclerotic plaque inflammation on 18F-FDG PET scans.