Findings
- Markedly increased extent of T2/FLAIR signal hyperintensity throughout the left frontal and parietal lobes extending into the posterior limb of the left internal capsule and ventrolateral left thalamus
- No associated enhancement or restricted diffusion (though diffusion images are degraded by artifact)
- Mild associated mass effect without midline shift, herniation, or hydrocephalus
- Additional T2/FLAIR hyperintense lesions involving the bilateral cerebral hemispheres, pons, and middle cerebellar peduncles are similar in appearance
- No evidence of acute infarct or hemorrhage
Diagnosis
Immune reconstitution inflammatory syndrome (IRIS)
Sample Report
Markedly increased extent of T2/FLAIR signal hyperintensity without enhancement throughout the left frontal and parietal lobes extending into the posterior limb of the left internal capsule and ventrolateral left thalamus, which given abruptness of change most likely represents immune reconstitution inflammatory syndrome (IRIS) in this patient on treatment for multiple sclerosis.
Additional T2/FLAIR hyperintense lesions involving the bilateral cerebral hemispheres, pons, and middle cerebellar peduncles are similar in appearance, consistent with chronic demyelinating lesions.
Mild associated mass effect without midline shift, herniation, or hydrocephalus.
No evidence of acute infarct or hemorrhage.
Discussion
References