Magnetic resonance imaging using T1-, T2-, T2*-weighted, FLAIR, DWI with ADC sequences.
Sagittal FLAIR shows high signal in brainstem due to vasogenic edema and tortuous vessels in subarachnoid space. Axial T2 shows increased intensity and slight enlargement of the brainstem due to vasogenic edema with tortuous vessels in the basal cisterns.
Sagittal T1 shows low signal intensity in the brainstem due to vasogenic edema. On axial gradient echo images, there are round foci of absent signal in brainstem as a result of magnetic susceptibility artefacts because of microbleeds due to venous congestion.
Sagittal T2 demonstrates that the brainstem hypersignal continues down to the spinal cord up to segment C6. Tortuous draining vessels are once again seen in both anterior and posterior subarachnoid space, as well as incidental, common in this age, degenerative disk disease.
On DWI and ADC maps, there is no diffusion restriction and therefore no acute ischemia.