From static to dynamic SPECT/CT: A systematic review of clinical applications and perspectives.

BACKGROUND: Single Photon Emission Computed Tomography (SPECT) is a cornerstone of functional nuclear medicine imaging, traditionally providing static three-dimensional representations of radiotracer distribution. The emergence of 4D SPECT has introduced the temporal dimension to SPECT, enabling the quantification of physiological parameters such as perfusion, uptake, and clearance rates. This systematic review aims to synthesize current evidence on dynamic SPECT principles, clinical applications and perspectives across major organ systems. METHODS: A systematic literature review was conducted according to the PRISMA guidelines. The PubMed database was searched over a 30-year period up to 2026 using "dynamic" and "SPECT," supplemented by specific searches in cardiac imaging including "SPECT" and "myocardial blood flow." All references were imported into the Rayyan web platform for duplicate removal and structured screening. Of the 1,029 studies initially identified, 807 were excluded. The remaining 222 studies were assessed in full text to identify relevant works addressing dynamic SPECT acquisition, reconstruction methods, and clinical applications. RESULTS: Dynamic SPECT has been explored in several domains, primarily cardiology and nephrology. Cardiac dynamic SPECT enables absolute myocardial blood flow quantification comparable to PET, while renal applications allow the assessment of cortical function and excretory dynamics. Advances in cadmium-zinc-telluride (CZT) detector technology, reconstruction algorithms, and motion-compensated acquisitions have been key to improving temporal and spatial resolution. CONCLUSIONS: Dynamic SPECT/CT represents a major evolution toward quantitative nuclear imaging, bridging the gap between traditional static SPECT and PET kinetics. Continued technological refinement and standardization are essential to establish its role in routine clinical practice.