2018 Volume 36 Issue 1 Pages 32-35
CT perfusion (CTP) by 4D-CT is commonly used in diagnosis of cerebral ischemia. However, CTP maps potentially vary depending on commercial CTP software. Therefore, this paper proposed a computerized detection method for cerebral ischemic region from 4D-CT. Cross-sectional images with basal ganglia were determined, and then adaptive partial median filter (APMF) which was an edge-preserving-smoothing filter was implemented. A mask image was subtracted from the APMF images to identify blood-vessel regions with contrast agent. Region of interests (ROIs) were placed on the subtracted images for symmetric comparison of blood vessel's area. If blood vessel's areas in the corresponding ROIs were significantly different, the ROI with smaller blood vessel's area was determined as ischemic region. In comparison with CTP maps, the proposed method was able to detect several ischemic regions and distinguish affected side and healthy side. Therefore, it would be useful for ischemic diagnosis in 4D-CT.
