Fig. 2. Comparison of user-determined radiation dose in pediatric cardiothoracic CT with tube current modulation in two groups.
A. CT scout image shows slice position (horizontal orange line) of axial CT image for determination of CTDIvol that was entered after scan range adjustment (transparent purple rectangle) in group 1. B. CT scout image shows slice position (horizontal orange line) of axial CT image for determination of CTDIvol that was entered with minimal longitudinal range at same position (transparent purple rectangle) in group 2. C. In group 2, scan range was subsequently extended longitudinally (arrows) to full scan range (transparent purple rectangle) of cardiothoracic CT scanning. As result, initially entered CTDIvol value with minimal longitudinal range was automatically changed to new value after scan range adjustment, based on body attenuation information obtained from CT scout image in group 2. Of note, both arms are raised up on CT scout image in both cases.