Measurement of cerebral circulation times using dynamic whole-brain CT-angiography: feasibility and initial experience

The objective of the study was to use 320-detector row 4D CT angiography (CTA) for measuring cerebral circulation times (CCT) and to assess early venous drainage (EVD) and shortening of CCT in arteriovenous malformations (AVM) and to compare with DSA. CCT of 12 physiological patients and five AVM patients were acquired using a 4D CTA protocol by recording cerebrovascular bolus passage time. In the AVM patients EVD time (EVDT) was measured. Identical measurements were performed on DSA for the AVM patients. It was found that the physiological CCTs were 5.8 ± 1.4 s (M ± SD). EVD was seen in all AVMs and resulted in a shortened CCT of 3.4 ± 1.1 s ( p = 0.01). There was no significant difference for CCT and EVDT values derived from DSA and 4D CTA. Thus, the CCTs can be measured non-invasively using clinical 4D CTA. Early venous drainage with shortened CCTs was observed by 4D CTA in all five patients with AVMs.