On the routine MR sequences that we did, we could see acute
ischemic lesions. We see them very well on the diffusion images,
where acute ischemic lesions usually appear with high signal
intensity and restricted diffusion. However, the etiology of these
lesions cannot be derived from these images.
An area of restricted diffusion was seen in the anterior cerebral
artery territory and we concluded it was an ischemic lesion. On
MR angiography we can just see if there is stenosis or vessel
occlusion, but it does not provide us information on the etiology
of this kind of lesion.
So, we decided to perform Black Blood imaging. The presence
and the pattern of vessel wall enhancement on Black Blood
imaging, can help us to determine the etiology of the lesion.
Many studies have shown that Black Blood imaging can help
differentiate vasculitis from other causes of vasculopathy, such as
atherosclerosis, with a high specificity [1-3]. In an atherosclerotic
lesion, vessel wall thickening and enhancement are usually eccentric,
while in vasculitis the wall thickening and enhancement are usually
concentric, homogenous, and in a long portion of the vessel.
Furthermore, this imaging can also be used for the follow-up
of patients whenever their treatment is installed in order to
determine the efficacy of a particular treatment.
In this case the Black Blood imaging helped us to suggest the
diagnosis of HIV-related brain vasculitis.