11C-4DST PET/CT Imaging of Cardiac Sarcoidosis: Comparison With 18F-FDG and Cardiac MRI. 
A 75-year-old woman with a history of sarcoidosis presenting with low cardiac output and complete right bundle-branch block underwent 4'-[methyl-C]-thiothymidine (4DST) PET/CT after cardiac MRI and FDG PET/CT for the evaluation of suspected cardiac sarcoidosis (CS) before treatment.  Cardiac MRI revealed late gadolinium enhancement on the anterior-to-lateral and posterior wall, indicating CS.  FDG uptake was shown on the anterior-to-lateral wall, but not on the posterior wall.  In contrast, 4DST uptake was demonstrated on both anterior-to-lateral and posterior walls.  Use of 4DST appears promising for detecting CS without dietary restriction, due to the lack of physiological uptake in myocardium.