High-resolution dynamic angiography using flat-panel volume CT: feasibility demonstration for neuro and lower limb vascular applications.

Abstract

This paper evaluates a prototype flat-panel volume CT (fpVCT) for dynamic in vivo imaging in a variety of neurovascular and lower limb applications. Dynamic CTA was performed on 12 patients (neuro = 8, lower limb = 4) using an fpVCT with 120 kVp, 50 mA, rotation time varying from 8 to 19 s, and field of view of 25 × 25 × 18 cm(3). Four-dimensional data sets (i.e. 3D images over time) were reconstructed and reviewed. Dynamic CTA demonstrated sufficient spatio-temporal resolution to elucidate first-pass and recirculation dynamics of contrast bolus through neurovasclaur pathologies and phasic blood flow though lower-limb vasculature and grafts. The high spatial resolution of fpVCT resulted in reduced partial volume and metal beam-hardening artefacts. This facilitated assessment of vascular lumen in the presence of calcified plaque and evaluation of fractures, especially in the presence of fixation hardware. Evaluation of arteriovenous malformation using dynamic fpVCT angiography was of limited utility. Dynamic CTA using fpVCT can visualize time-varying phenomena in neuro and lower limb vascular applications and has suffcient diagnostic imaging quality to evaluate a number of pathologies affecting these regions. • CTA using fpVCT has sufficient spatial and temporal resolution to study phasic blood flow. • CTA using fpVCT reveals recurrence of aneurysms even after clipping/coiling. • fpVCT has reduced partial volume and metal beam-hardening artefacts. • fpVCT can show vessel lumen in the presence of calcified plaque. • CTA using fpVCT can demonstrate vascular supply to transplanted grafts.