The Role of CT Perfusion in the Evaluation and Management of Acute Ischemic Stroke-A Systematic Review.

BACKGROUND: CT perfusion (CTP) is increasingly used in the evaluation of acute ischemic stroke (AIS) and may complement non-contrast CT (NCCT) and CT angiography (CTA). This review aimed to assess the role of CTP in patient selection for reperfusion therapy, its prognostic value, and the influence of technical factors, collateral assessment, and post-processing software. METHODS: A literature search of PubMed, DOAJ, and Google Scholar (2014-2025) identified 119 articles; after screening, 39 met inclusion criteria. Only studies on adult AIS patients investigated with CTP were included. Data were synthesized across eight thematic categories: core/penumbra estimation, prognosis, treatment selection, collateral assessment, software validation, technical parameters, reliability, and safety. RESULTS: CTP improved identification of infarct core, penumbra, and collateral status, aiding patient selection for endovascular therapy, particularly beyond 6 h. Limitations included variability in tissue thresholds, "ghost infarct core," and differences across software. Technical advances, such as "one-stop-shop" protocols and low-kV acquisition, reduced treatment delays and radiation. Reliability studies showed CTP to be less accurate than diffusion-weighted MRI, while safety analyses confirmed a low risk of contrast-induced nephropathy. CONCLUSIONS: CTP enhances patient stratification and outcome prediction, supporting individualized treatment strategies. Standardization of protocols and validation of software remain necessary before CTP can serve as a reliable alternative to MRI-DWI.