SWI
Pronunciation: S-W-I
Also written as: SWI — susceptibility-weighted imaging
Susceptibility-weighted imaging sequence that enhances visualization of venous structures and blood products by exploiting magnetic susceptibility differences.
Full Definition
Susceptibility-weighted imaging (SWI) is an advanced MRI technique that combines magnitude and phase information to create high-resolution images with enhanced contrast for structures containing blood products, calcifications, or venous vasculature. The sequence is particularly sensitive to deoxyhemoglobin, hemosiderin, and other paramagnetic substances, making it valuable for detecting microbleeds, cavernous malformations, and venous abnormalities that may be invisible on conventional sequences. SWI is increasingly used in clinical protocols for traumatic brain injury, stroke evaluation, and tumor characterization where detection of hemorrhagic components is critical for diagnosis and treatment planning.
Usage
Usage note: Always define the acronym on first use in clinical reports; some institutions prefer the full term for clarity.
In Context
- "SWI revealed multiple punctate microhemorrhages consistent with diffuse axonal injury." — Trauma imaging report
- "The imaging protocol should include SWI to evaluate for occult vascular malformations." — Clinical imaging requisition