susceptibility-weighted imaging
Also written as: SWI — Susceptibility-Weighted Imaging
MRI sequence highly sensitive to blood products, calcifications, and iron deposits using magnetic susceptibility differences.
Full Definition
Susceptibility-weighted imaging (SWI) is a specialized MRI sequence that exploits magnetic susceptibility differences between tissues to enhance visualization of venous structures, microbleeds, and iron deposition. This technique is exquisitely sensitive to deoxygenated blood, making it superior to conventional sequences for detecting cerebral microhemorrhages, cavernous malformations, and traumatic axonal injury. SWI is also valuable for assessing venous anatomy and pathology, including developmental venous anomalies and cerebral venous thrombosis.
In Context
- "SWI revealed multiple cortical microhemorrhages consistent with cerebral amyloid angiopathy." — Dementia workup report
- "Susceptibility-weighted imaging demonstrated prominent venous structures and several punctate hypointensities." — Traumatic brain injury assessment