Multiple (*20) bilateral ovoid, periventricular and callososeptal T2 hyperintense, T1 hypointense lesions are demonstrated. The lesions are perpendicularly orientated to the ventricles. A right frontal juxtacortical
lesion is also seen. There is moderate surrounding adjacent FLAIR / T2 high signal. Some of these are T1 hypointense. Several, however not all of these lesions demonstrate contrast enhancement.
A moderate to large area of right parietal cortical abnormality is seen, with oedema / T2 high signal and associated vasogenic oedema involving cortex and underlying white matter. There is vivid contrast enhancement within this region along with diffusion restriction (correspondingly low on ADC map) that mainly involves cortex. There is minimal mass effect for the degree of signal abnormality.
While some of the periventricular lesions have well-defined ovoid lesions surrounded by a more ill-defined confluent T2 "halo", these lesions do not demonstrate definite concentric ring pattern characteristic of Balo's type MS. Some small brainstem T2 hyperintense lesions may also be present.
No hemorrhage on EPI (not shown). No venous sinus thrombosis seen in non dedicated imaging. MRA has no findings suspicious for vasculitis. Regions of high signal corresponding to the areas of T2 FLAIR parenchymal hyperintensity and not with corresponding T1 hyperintensity are present, unusual but thought most likely to be related to magnetization transfer effect. No increase in cerebral blood volume.
MR Spectroscopy demonstrates elevated creatine:choline and lactate in the right parietal signal abnormality. Voxels placed in bilateral periventricular T2 hyperintense foci demonstrate elevated creatine:choline and mildly elevated lactate.
Overall MRI finding favour demyelination with a tumefactive plaque in the right parietal region and multiple smaller active plaques elsewhere-- particularly consider ADEM or MS variants (such as Marburg's). CNS lymphoma or cerebral vasculitis are differentials. Dual pathology (e.g. subacute infarct of the occipital lobe) not excluded.