Neuroimaging of cerebral venous thrombosis
Abstract
Early and accurate diagnosis of cerebral venous thrombosis (CVT) is possible with the help of computed tomography (CT) scan and magnetic resonance imaging (MRI). Empty Δ sign on postcontrast CT is present in only up to 30% of the cases. The role of CT venography is not yet established, but it is emerging as an effective modality for diagnosis of CVT. T2* MRI sequence is superior to spin echo in detecting CVT and small hemor rhages. MR venography is considered the technique of choice for diagnosis and follow-up of CVT, but in certain cases, MRI could be superior as it shows the thrombus itself and not just the absence of signal as seen on MR venography. Diffusion-weighted imaging is a relatively new MRI technique that is extremely sensitive in detecting acute arterial strokes and can distinguish cytotoxic and vasogenic edema. The presence of hyperintense signal on diffusion-weighted imaging in the occluded veins or sinuses at the time of diagnosis may predict a low rate of vessel recanalization. Contrast angiography should be strongly considered if isolated cortical vein thrombosis is suspected.