Susceptibility weighted imaging (SWI) is a specialized MRI sequence that uses magnetic susceptibility differences between tissues to produce high-resolution images. It is exquisitely sensitive to blood products, iron, and calcium — revealing microbleeds that routine sequences miss.
Also called: SWI · Susceptibility weighted imaging
What does SWI detect?
SWI is tuned to substances that disturb the local magnetic field.
- Small hemorrhages and microbleeds
- Venous structures
- Iron accumulation
- Calcifications
- Cavernous malformations
When is SWI used?
SWI aids in the diagnosis and evaluation of traumatic brain injury, stroke, cerebral microangiopathy, and neurodegenerative disease — often adding decisive detail to a standard brain MRI.
How do I prepare?
Standard MRI preparation applies.
Where can I get this exam?
Susceptibility Weighted Imaging is available at seven of our centers — Palm Harbor MRI, Palm Harbor MRI – Wesley Chapel, Highland MRI, Brandon MRI, Bradenton MRI, Venice MRI and Venice MRI – Port Charlotte. One call reaches every location — we will schedule you at whichever has the soonest opening, usually the same week.
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Medically reviewed by the board-certified radiologists of MRI Associates · Updated 2026-08-25