Abstract
Nuclear imaging has established itself as a front-runner for the early diagnosis of coronary artery disease (CAD), owing to its non-invasive capabilities to assess myocardial perfusion, ischemia, and microvascular dysfunction. Early and accurate detection of CAD is crucial in improving patient outcomes, as timely intervention can significantly reduce the risk of major adverse cardiac events (MACE) such as heart attacks and strokes. Among the available nuclear imaging techniques, Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) stand out as highly effective modalities. When these techniques are combined with computed tomography (CT), they offer a comprehensive evaluation of both cardiac function and anatomy, which is critical for precise diagnosis. SPECT and PET, in conjunction with CT, provide unique advantages of visualizing myocardial blood flow and identifying ischemic areas and scar tissue with high sensitivity and specificity. PET, in particular, provides superior spatial resolution and quantification of myocardial perfusion compared to SPECT, making it a preferred choice in many clinical settings. Additionally, PET provides valuable information on myocardial viability and metabolic activity, which helps clinicians make informed decisions on revascularization or other therapeutic interventions. This review aims to evaluate and compare nuclear imaging modalities - SPECT, PET, and hybrid SPECT/CT and PET/CT - for the early detection and risk stratification of coronary artery disease (CAD). Recent advancements in nuclear imaging technology have further enhanced diagnostic capabilities, for instance, improvements in hardware, software, and radiotracers have resulted in higher image quality, faster acquisition times, and lower radiation doses, contributing to better risk stratification, enabling earlier diagnosis of CAD, and facilitating personalized treatment plans, thereby reducing the incidence of MACE in high-risk populations.