RecruitingDiagnostic testHyperpolarized 13C Pyruvate-MRI and FDG-PET in a Single Exam for the Prognosis of Ischemic CardiomyopathyThis prospective, non-blinded, single-center, translational research study aims to validate a multimodal advanced imaging exam for cardiac viability. The protocol utilizes three distinct imaging modalities: Single Photon Emission Computed Tomography Myocardial Perfusion Imaging (SPECT MPI), 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and Hyperpolarized Carbon-13 (HP-13C) Pyruvate Magnetic Resonance Imaging (MRI). Under this protocol, the SPECT MPI and FDG-PET exams will be used in combination to comprehensively assess myocardial viability. Concurrently, the HP-13C Pyruvate MRI will be utilized to provide additional insights into myocardial metabolism. The study will evaluate healthy volunteers to establish baseline parameters and patients with ischemic cardiomyopathy (ICM) before and after surgical revascularization.