Myocardial blood flow quantification with 82-Rubidium PET/CT for the diagnosis of cardiac sarcoidosis

Introduction. - Cardiac sarcoidosis (CS) is one of the leading causes of morbi-mortality in sarcoidosis. Its diagnosis still remains challenging. 82-Rubidium PET/CT is being widely used as myocardial perfusion imaging (MPI) in CS. However, myocardial blood flow (MBF) quantification has not yet been studied. The aim of the study was to evaluate the additional value of MBF quantification for the diagnosis of CS. Materials and method. - Thirty-seven patients have been included (47.7 +/- 12.2 years; left ventricular ejection fraction = 50.6 +/- 7.8 %) with a histological proven diagnosis of sarcoidosis and suspicion of CS in this multicenter prospective study. Cardiac involvement was confirmed or excluded by a multidisciplinary team (MDT). All patients underwent a 82-Rubidium rest-stress PET MPI. MDT decision was compared with visual analysis, MBF quantification and combined analysis (visual analysis followed by MBF quantification) of PET imaging. Combined analysis was performed only for doubtful PET imaging. Results. - Thirty-two PET imaging have been considered. Based on MDT decisions, 11 patients had a cardiac involvement, 21 had not. Visual analysis yielded 90.9 % sensitivity and 90.5 % specificity. The difference between MBF of patients with CS and healthy patients was not statistically significant. Combined analysis yielded 100 % sensitivity and 81 % specificity. Conclusion. - 82-Rubidium PET seems to be useful tool for the diagnosis of CS with high sensibility and specificity. MBF quantification could increase the sensibility of PET imaging, without losing specificity. (C) 2015 Elsevier Masson SAS. All rights reserved.