Normalized CT dose index of the CT scanners used in the National Lung Screening Trial

Dianna D. Cody, Hyun Jung Kim, Christopher H. Cagnon, Frederick J. Larke, Michael M. McNitt-Gray, Randell L. Kruger, Michael J. Flynn, J Anthony Seibert, Philip F. Judy, Xizeng Wu

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

OBJECTIVE. The National Lung Screening Trial includes 33 participating institutions that performed 75,133 lung cancer screening CT examinations for 26,724 subjects during 2002-2007. For trial quality assurance reasons, CT radiation dose measurement data were collected from all MDCT scanners used in the trial. MATERIALS AND METHODS. A total of 247 measurements on 96 MDCT scanners were collected using a standard CT dose index (CTDI) measurement protocol. The scan parameters used in the measurements (tube voltage, milliampere-seconds [mAs], and detector-channel configuration) were set according to trial protocol for average size subjects. The normalized weighted CT dose index (CTDIw) (computed as CTDIw/mAs) obtained from each trial-participating scanner was tabulated. RESULTS. We found a statistically significant difference in normalized CT dose index among CT scanner manufacturers, likely as a result of design differences, such as filtration, bow-tie design, and geometry. Our findings also indicated a statistically significant difference in normalized CT dose index among CT scanner models from the same manufacturer (e.g., GE Healthcare, Siemens Healthcare, and Philips Healthcare). We also found a statistically significant difference in normalized CT dose index among all models and all manufacturers; furthermore, we found a statistically significant difference in normalized CT dose index among CT scanners from all manufacturers when we compared scanners with four or eight data channels to those with 16, 32, or 64 channels, suggesting that more complex scanners have improved dose efficiency. CONCLUSION. Average normalized CT dose index values varied by a factor of almost two for all scanners from all manufacturers. This study was focused on machine-specific normalized CT dose index; patient dose and image quality were not addressed.

Original languageEnglish (US)
Pages (from-to)1539-1546
Number of pages8
JournalAmerican Journal of Roentgenology
Volume194
Issue number6
DOIs
StatePublished - Jun 2010

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Delivery of Health Care
Lung
Clinical Protocols
Early Detection of Cancer
Lung Neoplasms
Radiation

Keywords

  • CT dose measurements
  • CT radiation dose
  • Lung cancer screening
  • MDCT dose

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Medicine(all)

Cite this

Cody, D. D., Kim, H. J., Cagnon, C. H., Larke, F. J., McNitt-Gray, M. M., Kruger, R. L., ... Wu, X. (2010). Normalized CT dose index of the CT scanners used in the National Lung Screening Trial. American Journal of Roentgenology, 194(6), 1539-1546. https://doi.org/10.2214/AJR.09.3268

Normalized CT dose index of the CT scanners used in the National Lung Screening Trial. / Cody, Dianna D.; Kim, Hyun Jung; Cagnon, Christopher H.; Larke, Frederick J.; McNitt-Gray, Michael M.; Kruger, Randell L.; Flynn, Michael J.; Seibert, J Anthony; Judy, Philip F.; Wu, Xizeng.

In: American Journal of Roentgenology, Vol. 194, No. 6, 06.2010, p. 1539-1546.

Research output: Contribution to journalArticle

Cody, DD, Kim, HJ, Cagnon, CH, Larke, FJ, McNitt-Gray, MM, Kruger, RL, Flynn, MJ, Seibert, JA, Judy, PF & Wu, X 2010, 'Normalized CT dose index of the CT scanners used in the National Lung Screening Trial', American Journal of Roentgenology, vol. 194, no. 6, pp. 1539-1546. https://doi.org/10.2214/AJR.09.3268
Cody DD, Kim HJ, Cagnon CH, Larke FJ, McNitt-Gray MM, Kruger RL et al. Normalized CT dose index of the CT scanners used in the National Lung Screening Trial. American Journal of Roentgenology. 2010 Jun;194(6):1539-1546. https://doi.org/10.2214/AJR.09.3268
Cody, Dianna D. ; Kim, Hyun Jung ; Cagnon, Christopher H. ; Larke, Frederick J. ; McNitt-Gray, Michael M. ; Kruger, Randell L. ; Flynn, Michael J. ; Seibert, J Anthony ; Judy, Philip F. ; Wu, Xizeng. / Normalized CT dose index of the CT scanners used in the National Lung Screening Trial. In: American Journal of Roentgenology. 2010 ; Vol. 194, No. 6. pp. 1539-1546.
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abstract = "OBJECTIVE. The National Lung Screening Trial includes 33 participating institutions that performed 75,133 lung cancer screening CT examinations for 26,724 subjects during 2002-2007. For trial quality assurance reasons, CT radiation dose measurement data were collected from all MDCT scanners used in the trial. MATERIALS AND METHODS. A total of 247 measurements on 96 MDCT scanners were collected using a standard CT dose index (CTDI) measurement protocol. The scan parameters used in the measurements (tube voltage, milliampere-seconds [mAs], and detector-channel configuration) were set according to trial protocol for average size subjects. The normalized weighted CT dose index (CTDIw) (computed as CTDIw/mAs) obtained from each trial-participating scanner was tabulated. RESULTS. We found a statistically significant difference in normalized CT dose index among CT scanner manufacturers, likely as a result of design differences, such as filtration, bow-tie design, and geometry. Our findings also indicated a statistically significant difference in normalized CT dose index among CT scanner models from the same manufacturer (e.g., GE Healthcare, Siemens Healthcare, and Philips Healthcare). We also found a statistically significant difference in normalized CT dose index among all models and all manufacturers; furthermore, we found a statistically significant difference in normalized CT dose index among CT scanners from all manufacturers when we compared scanners with four or eight data channels to those with 16, 32, or 64 channels, suggesting that more complex scanners have improved dose efficiency. CONCLUSION. Average normalized CT dose index values varied by a factor of almost two for all scanners from all manufacturers. This study was focused on machine-specific normalized CT dose index; patient dose and image quality were not addressed.",
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