A RAPID Checklist: Understanding Pitfalls and Artifacts in Stroke

Ischemic stroke is a leading cause of morbidity and mortality worldwide. In the acute setting, neuroimaging plays a critical role in determining management and outcome. Noncontrast head CT is initially used to identify hemorrhage and large areas of ischemia that preclude thrombolysis and thrombectomy. In patients who present between 6 and 24 hours after last known well, CTA and CTP are useful tools to select those who may benefit from mechanical thrombectomy. The utility of CTP lies in its ability to identify irreversibly infarcted tissue (core infarct) and distinguish it from potentially salvageable tissue (penumbra). Radiologists and clinicians need to understand this imaging technique and its major pitfalls to avoid interpretation mistakes.Learning Objective: To describe the basic principles of CTP acquisition, propose a short and practical checklist for interpreting automated CTP scans obtained with a commercially available and widely used program, and review its main pitfalls and artifacts