Neuroradiological features of CVT
| CT + CT venography | MR + MR venography | |
|---|---|---|
| Typical findings | Sinus or vein hyperdensity Dense triangle sign Empty delta sign Cord sign Absence of flow in thrombosed sinuses | 1 week: isointense on T1 and hypointense in T2W images 2 weeks: hyperintense on T1 and T2W images >2 weeks: variable on T1 and T2, hypointense in GRE and SWI DWI hyperintensity Venous wall enhancement Absence of flow in thrombosed sinuses |
| Advantages | Easily available Fast Reduced motion artefact | No ionising radiation exposure No contrast medium required Good visualisation of brain parenchyma Good for detection of cortical and deep cerebral vein thrombosis |
| Disadvantages | Ionising radiation Use of contrast medium Poor detection of small parenchymal abnormalities Low sensitivity in small cortical and deep thrombosis | Time consuming Motion artefact can degrade images Reduced availability Contraindicated in some patients (eg, cardiac devices, medically unstable) |
CVT, cerebral venous thrombosis; DWI, diffusion-weighted imaging; GRE, gradient recalled echo; SWI, susceptibility-weighted imaging; T2W, T2-weighted.