Findings
Brain:
The signal intensity of the brain parenchyma is normal. Gradient echo scans show no evidence of hemorrhage. The diffusion-weighted imaging shows restricted diffusion in the central aspect of the splenium of the corpus callosum. No other areas of restricted diffusion are identified.There are no post gadolinium enhanced images.
MRA of the brain:
Both vertebral arteries, the basilar artery and both carotid arteries are patent. The right anterior inferior cerebellar artery is not seen. There are no areas of vascular stenosis or aneurysm formation.
MR venographic images without contrast show nonvisualization of the entirety of the left transverse sinus. The superior sagittal sinus, straight sinus, and right transverse sinus are normal in appearance. There is an arachnoid granulation seen on T2-weighted scans which is indenting the left transverse sinus.
Impressions
Focal area of restricted diffusion in the splenium of the corpus callosum. The likely etiology is nutritional given the patient’s gastric bypass surgery and poor alimentation (akin to Marchiafava Bignami syndrome). This can also be seen in patients with seizures or epileptic drug changes as well as after trauma, demyelination, or even ischemia (given her antiphospholipid antibody status). Clinical correlation is required. The remainder of the brain is normal.