Comparison of Radiation Dose Estimates and Scan Performance in Pediatric High-Resolution Thoracic CT for Volumetric 320-Detector Row, Helical 64-Detector Row, and Noncontiguous Axial Scan Acquisitions Daniel J. Podberesky, MD, Erin Angel, PhD, Terry T. Yoshizumi, PhD, Greta Toncheva, MS, Shelia R. Salisbury, PhD, Alan S. Brody, MD, Christopher Alsip, RT, Alessandra Barelli, John C. Egelhoff, DO, Colin Anderson-Evans, BS, Giao B. Nguyen, MS, David Dow, MD, Donald P. Frush, MD Rationale and Objectives: Efforts to decrease radiation exposure during pediatric high-resolution thoracic computed tomography (HRCT), while maintaining diagnostic image quality, are imperative. The objective of this investigation was to compare organ doses and scan performance for pediatric HRCT using volume, helical, and noncontiguous axial acquisitions. Materials and Methods: Thoracic organ doses were measured using 20 metal oxide semiconductor field-effect transistor dosimeters. Mean and median organ doses and scan durations were determined and compared for three acquisition modes in a 5-year-old anthropomorphic phantom using similar clinical pediatric scan parameters. Image noise was measured and compared in identical regions within the thorax. Results: There was a significantly lower dose in lung (1.8 vs 2.7 mGy, P < .02) and thymus (2.3 vs 2.7 mGy, P < .02) between volume and noncontiguous axial modes and in lung (1.8 vs 2.3 mGy, P < .02), breast (1.8 vs 2.6 mGy, P < .02), and thymus (2.3 vs 2.4 mGy, P < .02) between volume and helical modes. There was a significantly lower median image noise for volume compared to helical and axial modes in lung (55.6 vs 79.3 and 70.7) and soft tissue (76.0 vs 111.3 and 89.9). Scan times for volume, helical, and noncontiguous axial acquisitions were 0.35, 3.9, and 24.5 seconds, respectively. Conclusion: Volumetric HRCT provides an opportunity for thoracic organ dose and image noise reduction, at significantly faster scanning speeds, which may benefit pediatric patients undergoing surveillance studies for diffuse lung disease. Key Words: Respiratory system; volumetric computed tomography; pediatrics; radiation dosimetry. ªAUR, 2013 Acad Radiol 2013; 20:1152–1161 From the Cincinnati Children’s Hospital Medical Center, Department of Radiology, 3333 Burnet Avenue, MLC 5031 (D.J.P., A.S.B., C.A.), and Center for Epidemiology and Biostatistics, Cincinnati, OH 45229 (S.R.S.); Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710 (D. P. F.); Phoenix Children’s Hospital Department of Radiology, 1919 East Thomas Road, Phoenix, AZ 85016 (J.C.E.); Toshiba America Medical Systems, Tustin, CA (E.A., A.B.); Radiation Safety Division (T.T.Y., G.T., C.A.-E., G.B.N.), Duke University Medical Center, Durham, NC; and College of Medicine, University of Cincinnati, Cincinnati, OH (D.D). Received December 25, 2012; accepted May 21, 2013. All of the authors contributed substantially to this manuscript in the three ICMJE categories. Conflicts of interest: The Department of Radiology at Cincinnati Children’s Hospital receives research support from Toshiba America Medical Systems. Dr Podberesky is a member of the Toshiba professional speaker’s bureau. The other authors have no relevant conflicts of interest. Dr Angel and Ms Barelli are employees of Toshiba America Medical Systems. All data was analyzed and controlled by authors who were not employed by Toshiba. Address correspondence to: D.J.P. e-mail: daniel.podberesky@cchmc.org ªAUR, 2013 http://dx.doi.org/10.1016/j.acra.2013.05.013 1152