Custom-designed analysis of subtracted computed tomogram angiogram

Subtracted CT angiogram (sCTA) of brain provides both anatomical and functional information of brain circulation. For emergent service of patient, e.g. stroke, integration and automation of the on-line image realignment for motion correction, and functional analyses were required for clinical application. By adapting Analysis of Functional Neuroimage (AFNI, National Institute of Health, USA), Viewit (University of Illinois, USA) and SPM (Statistical Parametric Mapping, Wellcome Department of Cognitive Neurology, UK), a customdesigned image processing demonstrated the evaluation of the motion displacement and functional analyses of tri-phase CTA studies, including precontrast phase, CTA phase and post-contrast phase. With the on-line imaging processing, processing time was about 20 seconds per slice using workstation or PC-Linux platforms. The on-line processing illustrated the potential applications in CTA of skull base and cerebral perfusion using tri-phase CTA technique. Easy implementation of the processing configuration can be applied in the standard clinical environment without additional cost.