Functional Circulation Time, rCBV and rCBF Images by Angio-CT in the Assessment of Altered Carotid Canalization

Abstract

A conventional Angio-CT sequence was used to generate functional perfusional images by applying particular models to the contrast first pass curves. We calculated the first mathematical moment of monitored time-DH curves from the injection time and applied to the sequence the multiple time graph analysis described by Patlak. The former provides regional an Arm-Brain circulation time (rABCT) image, the latter two images, one related to vascular volume Vv, the other to the blood brain barrier permeability Ki. The Vv and rABCT images were subsequently uitilized to derive the rCBF image (ND-rCBF). The rABCT, Vv and rCBF images were analyzed in a group of 48 patients with angiographically detected unilateral altered carotid canalization of various degrees and clinical pictures. Direct detection was possible in 37 out of 48 cases and a strong suggestion was derived in the remaining cases. Analysis of rABCT provided the maximal rate of detection and allowed us to derive haemodynamic considerations. Assessment of distribution of rABCT changes and Vv analysis discriminated fairly well between patients with relatively mild and severe clinical pictures.