Advances in Single-Photon Emission Computed Tomography: Hardware, Software, and Myocardial Flow Reserve Novel PET Applications and Radiotracers for Imaging Cardiovascular Pathophysiology Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification Artificial Intelligence in Nuclear Cardiology Stress-First Myocardial Perfusion Imaging Obtaining a Coronary Artery Calcium Score with Myocardial Perfusion Imaging Clinical Value of Positron Emission Tomography Myocardial Perfusion Imaging and Blood Flow Quantification What Is New in Risk Assessment in Nuclear Cardiology? Radionuclide Assessment of Sarcoidosis Current Status of Radionuclide Imaging of Transthyretin Cardiac Amyloidosis Radionuclide Imaging of Infective Endocarditis Positron Emission Tomography Imaging in Vasculitis Radionuclide Imaging of Heart-Brain Connections