A novel flow dynamics study of the intracranial veins using whole brain 4D-CTA.

Abstract

PURPOSE\nThe flow dynamics of the intracranial venous channels are fundamentally important for understanding intracranial physiology and pathophysiology. However, the method clinically applicable to the evaluation of the flow dynamics of the intracranial venous system has not been well described in the literature. Here, we developed a new method to evaluate intracranial venous flow direction and velocity using 4D-CTA. The aim of the current study was to verify the accuracy and validity of 4D-CTA in a clinical setting.\n\n\nMETHODS\nWe retrospectively analyzed 97 veins from 26 patients (16 cases of arteriovenous shunt disease, nine intracranial tumor cases, and one cerebral aneurysm case) who underwent both 4D-CTA and conventional digital subtraction angiography (DSA). Using 4D-CTA, we analyzed the time-density curve with gamma distribution extrapolation and obtained the direction of the flow and flow velocity of each vein. The direction of the flow in 4D-CTA was also collated with that obtained using conventional DSA to verify the experimental method.\n\n\nRESULTS\nThe direction of the flow determined by 4D-CTA was consistent with that of conventional DSA in 94.8% of cases. The average venous flow velocity was 64.3 mm/s and 81.8 mm/s, respectively, in the antegrade and retrograde channels affected by arteriovenous shunts.\n\n\nCONCLUSIONS\nThe current flow analysis using 4D-CTA enabled us to evaluate the direction and velocity of intracranial venous flow. Aside from some limitations, the current method is reliable and its potential for application in clinical settings is promising.