Technical note: Acquisition of CT models for radiotherapy applications with reduced tube heating

The potential for changing computed tomography (CT) protocols to provide da ta sets that generate high quality digitally reconstructed radiographs (DRR s) from scans with very low tube currents is demonstrated. DRRs were genera ted from CT data acquired with slice thickness of 1, 3, and 5 mm, using hig h current to reduce noise in axial images. These DRRs were compared to one generated from a CT scan acquired using I mm aperture and very low (10 mA) current. The DRR generated via this technique is comparable to that generat ed with high current and I mm aperture, and higher resolution than from the 3 and 5 mm CT scans. (C) 2001 American Association of Physicists in Medici ne.