Is it possible to have DWI negative despite high T2?

Question

Hi doctor,

I want to know about the vertebral artery dissection. I had a traumatic brain injury (TBI) (with neck trauma too), no loss of consciousness, no amnesia. The computed tomography (CT) was negative. The magnetic resonance (MR) showed T2 hyperintensity in the right lateral medulla (no diffusion-weighted imaging (DWI) was performed). After few days, the MR showed the same even with contrast, DWI negative (is it not weird, DWI negative despite high T2?). In the same month, magnetic resonance angiography (MRA) showed the right vertebral artery very hypoplastic and completely occluded in the intracranial part. The computed tomography angiography (CTA) showed the right vertebral artery in the same situation. What I think is vertebral artery dissection and ischemia in the lateral medulla. For two reasons. 1) vertebral artery blockage can lead to ischemia in the lateral medulla (specifically the intracranial blockage, which I have); 2) Why is DWI negative if T2 is high? I guess because of high active diffusion control adenylate cyclase (ADC), and why is ADC high? What doctors told me: It is nothing to worry about. I do not know if they think my right vertebral artery has always been this way because my posterior cerebral arteries arise mainly from carotids.

Answer 1

Hi,

Welcome to icliniq.com. Thanks for writing to us. There are many variable patterns of the vertebral artery visualization, and the commonest is the vertebral artery of one side is nondominant and shows thin flow or near-complete luminal occlusion. You might be having a non-dominant right vertebral artery. Many times a T2 hyperintensity can be visualized as an isolated and nonspecific finding in the brain if there is no restricted diffusion. Visualization of such an area in the lateral medulla is less common. If there is no restricted diffusion, then it can be a mild area of edema. Regards.