Restricted diffusion is an MRI finding where water molecules in tissue are unable to move as freely as expected, producing a bright signal on diffusion-weighted images.
Restricted diffusion is an imaging finding, not a symptom. The clinical picture depends on the underlying condition.
Restricted diffusion in the brain is a classic marker of acute stroke; elsewhere it can suggest abscess, certain tumours, or highly cellular lesions.
Diffusion-weighted imaging (DWI) and its companion ADC map are part of nearly every brain MRI and many body MRIs.
Management depends on the underlying cause — acute stroke care, antibiotics and drainage for abscess, or oncology referral for suspicious masses.
This entry explains the word. If it appeared on your report, the next step is getting that report interpreted for your case.