IJCS | Volume 33, Nº4, July and August 2020

396 Figure 3 – A. 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET) whole body and fused PET/Computed tomography of the heart at baseline and follow-up of a 39-year-old male presenting with episodic complete heart block and sinus node dysfunction. The patient had dual chamber cardioverter defibrillator implantation and was diagnosed with cardiac and systemic sarcoidosis. Treatment with low-dose prednisone and methotrexate was initiated. Scan 1 . Whole-body findings: cluster of FDG-avid, tiny nodules in the right lung (SUVmax=6.94), bilateral hilar adenopathy (SUVmax=6.4), bilateral supraclavicular lymph node, multiple foci of increased FDG activity in the liver and spleen and prominent lymph node in the porta hepatis. Cardiac findings: four areas of increased FDG uptake correlating with regions of reduced myocardial perfusion on rest imaging (basal inferolateral wall, basal inferoseptal wall, basal to mid-anterior wall, apical lateral wall and apex). Follow-up of seven months afterwards ( Scan 2 ): Whole-body: Interval reduction in the degree of metabolic activity of all the previous findings. Cardiac findings: no active inflammatory process in the myocardium. Regions of scar in the mid-anterior wall, mid-to- apical inferolateral wall and apex. B. Baseline study with rubidium-82 (top line) and 18F-FDG (bottom line) in short axis, horizontal long axis and vertical long axis, showing the perfusion-metabolism mismatch pattern in the basal inferolateral wall, basal inferoseptal wall, basal to mid-anterior wall, apical lateral wall and apex PET imaging has proven to be useful in predicting treatment response, not onlyby reductionof inflammation but also by improvement of LV function. Osborne et al. 54 evaluated the relationship between the reduction in myocardial inflammation measured by FDG uptake and the improvement in LV ejection fraction. 54 They assessed 23 patients with serial PET scans (median of four per patient) and quantified the maximum SUV and volume of tissue with inflammation to assess the extension and intensity of FDG uptake for each study performed. The median time between the first and the last scan was two years. Most of the patients (91%) were treated with corticosteroids, and 83%had ICDs. Therewas a significant inverse linear relationship between maximum SUV and ejection fraction (EF) with an expected increase in EF of 7.9% per SUV reduction of 10g/mL by longitudinal regressionmodel (p=.008). On the volume-based analysis, EF increased 2.1% per 100 cm 3 decrease in volume of Wiefels et al. 18F-FDG PET/CT and cardiac sarcoidosis Int J Cardiovasc Sci. 2020; 33(4):389-400 Review Article