Interobserver variability in the detection of cerebral venous thrombosis using CT venography with matched mask bone elimination

Abstract

Objectives Computed tomography venography (CTV) has proven to be a reliable imaging method in the evaluation of cerebral venous thrombosis with good correlation to magnetic resonance (MR) imaging and digital subtraction angiography (DSA). It is fast and widely accessible, especially in the emergency setting. For better visualization of vascular structures bone is often removed from the images. The purpose of this study was to evaluate the quality of a fully automatic bone removal method, matched mask bone elimination (MMBE), and to assess the interobserver variability of the CTV technique. Patients and methods Fifty patients with clinical suspicion of cerebral venous thrombosis underwent multislice CTV with MMBE post-processing. Axial source images and maximum intensity projections were retrospectively evaluated by two neuroradiologists for quality of bone removal and for the presence or absence of thrombosis in nine dural sinuses and five deep cerebral veins. A per sinus/vein and a per patient analysis (thrombosis in at least one sinus or vein) was performed and interobserver agreement was assessed. Results Both observers considered bone removal good in all patients (100%). Interobserver agreement per patient was excellent ( κ = 0.83), with a full agreement in 47 of 50 patients (94%). The interobserver agreement per sinus or vein was good ( κ = 0.76), with a full agreement in 679 of 700 sinuses or veins (97%). Conclusion CTV aided with MMBE is a robust technique for visualization of the intracranial venous circulation, removing bone effectively. CTV has high interobserver agreement for presence or absence of cerebral venous thrombosis.