Introduction The Coronary Artery (CA) rest period in the cardiac cycle varies substantially from patient to patient [Wang 1999]. The cross-correlations between images of consecutive heart phases may be used to characterize the cardiac motion, and an optimal acquisition window could be automatically identified [Nehrke 2003]. For selecting an optimal data acquisition window, an automated placing of a Region of Interest (ROI) without user interaction was implemented, and yielded similar result compared to the visual assessment [Jahnke 2005; Maruyama 2007). Combined with user interaction in placing an ROI, the semiautomated approach was developed [Uneno 2009]. However, accurate identification of an ROI still needs to be enhanced.