MSCT venography finds cerebral thromboses

Digital subtraction angiography was traditionally considered the best modality for diagnosing CVT. The procedure's invasive nature, however, coupled with an associated risk of cerebrovascular complications, has led to its increasing replacement by MR imaging, and especially MR venography.2 But MR has a number of its own drawbacks. Several studies have reported limited accuracy of MR venography in the diagnosis of CVT.1,3,4 MR scanners are not generally available 24/7, yet a significant proportion of CVT patients will present to the emergency room during on-call hours and require urgent evaluation. Many of these patients are unable to lie motionless for the duration of an MR examination. Reduced access can also become a problem when dealing with critically ill patients suffering from cerebral venous occlusions.3 The optimum diagnostic method for CVT should have high spatial resolution of the cerebral veins, short examination time, and maximum patient access. Advanced CT technology may address these needs. Multislice CT is becoming more common in clinical practice. It's unrivaled spatial and temporal resolution makes it possible to acquire isotropic voxels and to reformat data sets in any desired plane. Large volumes can be acquired within a short time with no resolution loss.5 MSCT has reduced posterior fossa artifacts in brain scans significantly.6 Both arteries and veins can be covered intracerebrally with a single-bolus, monophasic protocol.7,8 The entire supra-aortic, cervicocranial vasculature can be imaged on a 16-slice CT scanner with a single bolus in 12 seconds.9 We have found that MSCT angiography of the brain is possible even in uncooperative patients, given scan times of four to 12 seconds. Patient access is almost unlimited during most parts of the imaging protocol.