What is the differential for this lesion?
A lesion with intrinsic high T1, low T2 (with blooming) and no enhancement suggest that it is mostly composed of blood / haemorrhage. As such differentials include a vascular malformation (e.g. cavernous haemangioma) or a very haemorrhagic tumour (metastasis or primary tumour).
How can you distinguish between the two?
If the patient is asymptomatic or surgical evacuation is not thought to improve symptoms then followup will probably help, however evacuation of the clot and biopsy of any abnormal tissue is often required and will allow for a diagnosis to be made in most instances.
MRI of the spine demonstrates an intramedullary lesion which intrinsic high T1 signal and no convincing enhancement. It is surrounded by very low signal on T2 weighted images, which demonstrates blooming on gradient echo.