Value of pre-intervention CT perfusion imaging in acute ischemic stroke prognosis

Noninvasive imaging plays an important role in acute stroke towards diagnosis and ongoing management of patients. Systemic thrombolysis and endovascular thrombectomy (EVT) are proven treatments currently used in standards of care in acute stroke settings. The role of computed tomography angiography (CTA) in selecting patients with large vessel occlusion for EVT is well established. However, the value of CT perfusion (CTP) imaging in predicting outcomes after stroke remains ambiguous. This article critically evaluates the value of multimodal CT imaging in early diagnosis and prognosis of acute ischemic stroke with a focus on the role of CTP in delineating tissue characteristics, patient selection, and outcomes after reperfusion therapy. Insights on various technical and clinical considerations relevant to CTP applications in acute ischemic stroke, recommendations for existing workflow, and future areas of research are discussed

Diagnostic and prognostic utility of computed tomography perfusion imaging in posterior circulation acute ischemic stroke : a systematic review and meta-analysis

Background: Computed tomography perfusion (CTP) imaging could be useful in the diagnosis of posterior circulation stroke (PCS) and in identifying patients who are likely to experience favorable outcomes following reperfusion therapy. The current study sought to investigate the diagnostic and prognostic capability of CTP in acute ischemic PCS by performing a systematic review and meta-analysis. Methods: Medline/PubMed and the Cochrane Library were searched using the terms: “posterior circulation”, “CT perfusion”, “acute stroke”, and “reperfusion therapy”. The following studies were included: (1) patients aged 18 years or above; (2) patients diagnosed with PCS; and (3) studies with good methodological design. Pooled sensitivity (SENS), specificity (SPEC), and area under the curve (AUC), computed using the summary receiver operating characteristic (SROC) curves, were used to determine diagnostic/prognostic capability. Results: Out of 14 studies included, a meta-analysis investigating diagnostic accuracy of CTP was performed on nine studies. Meta-analysis demonstrated comparable diagnostic accuracy of CTP to non-contrast computed tomography (NCCT) (AUCCTP: 0.90 [95% CI 0.87–0.92] vs. AUCNCCT: 0.96 [95% CI 0.94–0.97]); however, with higher pooled sensitivity (SENSCTP: 72% [95% CI 57%–83%] vs. SENSNCCT: 25% [95% CI 17%–35%]) and lower specificity (SPECCTP: 90% [95% CI 83%–94%] vs. SPECNCCT: 96% [95% CI 95%–98%]) than NCCT. Meta-analysis to determine prognostic capability of CTP could not be performed. Conclusions: CTP has limited diagnostic utility in acute ischemic PCS, albeit with superior diagnostic sensitivity and inferior diagnostic specificity to NCCT. Further prospective trials are required to validate the prognostic capability of CTP-derived parameters in PCS