Advent of advanced imaging technology and better neuro-interventional equipment have resulted in timely diagnosis and effective treatment for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, objective clinicoradiologic correlate to identify appropriate candidates and their respective clinical outcome is largely unknown. The purpose of the study is to develop and test a new interactive decision-making support tool to predict severity of AIS prior to thrombectomy using CT perfusion imaging protocol. CT image data of 30 AIS patients with LVO assessed radiologically for their eligibility to undergo mechanical thrombectomy were retrospectively collected and analyzed in this study. First, a computer-aided scheme automatically categorizes images into multiple sequences followed by indexing each slice to specified brain location. Next, consecutive mapping is used for accurate brain region segmentation from skull. The brain is then split into left and right hemispheres, followed by detecting blood in each hemisphere. Additionally, visual tools including segmentation, blood correction, select sequence and index analyzer are implemented for deeper analysis. Last, comparison between blood-volume in each hemisphere over the sequences is made to observe wash-in and wash-out rate of blood flow to assess the extent of damaged and “at risk” brain tissue. By integrating computer-aided scheme into a user graphic interface, the study builds a unique image feature analysis and visualization tool to observe and quantify the delayed or reduced blood flow (brain “at-risk” to develop AIS) in the corresponding hemisphere, which has potential to assist radiologists to quickly visualize and more accurately assess extent of AIS.