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CT venography

CT venography is a rapid technique which provides an accurate detailed depiction of the cerebral venous system.

Indications

Rapid diagnosis of cerebral venous thrombosis.

Contraindications

general CT contraindications such as pregnancy, claustrophobia, etc. iodinated contrast contraindications, such as chronic renal failure

Actual procedure will vary depending on institutional protocol/guidelines, but a typical protocol will include:

peripheral venous access (18-20G) in an antecubital vein nonionic contrast material is injected at 4-5 mL/s for a total of 100-120 mL with a 45-second prescanning delay a helical scan is performed by scanning caudally from the calvarial vertex to C1 Data acquisition and analysis

images are analyzed on a dedicated workstation proper evaluation of the dural sinuses indicates proper inspection of the axial thin-section contrast-enhanced source images of a helical CT scan two-dimensional (2D) & three-dimensional (3D) multi-planar images, as well as rendering techniques such as maximum intensity projection (MIP), surface shaded displays (SSD) and volume rendering (VR) in a sagittal, coronal, and oblique planes an essential step in CT venography is the removal of bone from the images, by graded subtraction

Findings

Venous sinus abnormalities dural venous sinus thrombosis thrombosis recanalisation, the sinus shows an irregular appearance with multiple intrasinus channels and dural collateral vessels sinus stenosis or occlusion secondary to tumour invasion (e.g. meningioma) vascular malformations (e.g. AVM, dural arteriovenous fistula or developmental venous anomaly) idiopathic intracranial hypertension: bilateral stenoses of the transverse sinuses, without definitive evidence of current or prior thrombosis Parenchymal abnormalities cerebral parenchymal abnormalities such as hemorrhagic infarction Normal variations

sinus hypoplasia and aplasia arachnoid granulations sinus duplication or fenestration variant anatomy of the sinuses (e.g. occipital sinus or persistent falcine sinus)

ct_venography.txt · Last modified: 2017/08/22 09:14 by administrador