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Database of normalised computed tomography dose index for retrospective CT dosimetry.
J Radiol Prot. 2014 Jun; 34(2):363-88.JR

Abstract

Volumetric computed tomography dose index (CTDIvol) is an important dose descriptor to reconstruct organ doses for patients combined with the organ dose calculated from computational human phantoms coupled with Monte Carlo transport techniques. CTDIvol can be derived from weighted CTDI (CTDIw) normalised to the tube current-time product (mGy/100 mAs), using knowledge of tube current-time product (mAs), tube potential (kVp), type of CTDI phantoms (head or body), and pitch. The normalised CTDIw is one of the characteristics of a CT scanner but not readily available from the literature. In the current study, we established a comprehensive database of normalised CTDIw values based on multiple data sources: the ImPACT dose survey from the United Kingdom, the CT-Expo dose calculation program, and surveys performed by the US Food and Drug Administration (FDA) and the National Lung Screening Trial (NLST). From the sources, the CTDIw values for a total of 68, 138, 30, and 13 scanner model groups were collected, respectively. The different scanner groups from the four data sources were sorted and merged into 162 scanner groups for eight manufacturers including General Electric (GE), Siemens, Philips, Toshiba, Elscint, Picker, Shimadzu, and Hitachi. To fill in missing CTDI values, a method based on exponential regression analysis was developed based on the existing data. Once the database was completed, two different analyses of data variability were performed. First, we averaged CTDI values for each scanner in the different data sources and analysed the variability of the average CTDI values across the different scanner models within a given manufacturer. Among the four major manufacturers, Toshiba and Philips showed the greatest coefficient of variation (COV) (=standard deviation/mean) for the head and body normalised CTDIw values, 39% and 54%, respectively. Second, the variation across the different data sources was analysed for CT scanners where more than two data sources were involved. The CTDI values for the scanners from Siemens showed the greatest variation across the data sources, being about four times greater than the variation of Toshiba scanners. The established CTDI database will be used for the reconstruction of CTDIvol and then the estimation of individualised organ doses for retrospective patient cohorts in epidemiologic studies.

Authors+Show Affiliations

Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, MD 20852, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Intramural

Language

eng

PubMed ID

24727361

Citation

Lee, Eunah, et al. "Database of Normalised Computed Tomography Dose Index for Retrospective CT Dosimetry." Journal of Radiological Protection : Official Journal of the Society for Radiological Protection, vol. 34, no. 2, 2014, pp. 363-88.
Lee E, Lamart S, Little MP, et al. Database of normalised computed tomography dose index for retrospective CT dosimetry. J Radiol Prot. 2014;34(2):363-88.
Lee, E., Lamart, S., Little, M. P., & Lee, C. (2014). Database of normalised computed tomography dose index for retrospective CT dosimetry. Journal of Radiological Protection : Official Journal of the Society for Radiological Protection, 34(2), 363-88. https://doi.org/10.1088/0952-4746/34/2/363
Lee E, et al. Database of Normalised Computed Tomography Dose Index for Retrospective CT Dosimetry. J Radiol Prot. 2014;34(2):363-88. PubMed PMID: 24727361.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Database of normalised computed tomography dose index for retrospective CT dosimetry. AU - Lee,Eunah, AU - Lamart,Stephanie, AU - Little,Mark P, AU - Lee,Choonsik, Y1 - 2014/04/14/ PY - 2014/4/15/entrez PY - 2014/4/15/pubmed PY - 2015/1/30/medline SP - 363 EP - 88 JF - Journal of radiological protection : official journal of the Society for Radiological Protection JO - J Radiol Prot VL - 34 IS - 2 N2 - Volumetric computed tomography dose index (CTDIvol) is an important dose descriptor to reconstruct organ doses for patients combined with the organ dose calculated from computational human phantoms coupled with Monte Carlo transport techniques. CTDIvol can be derived from weighted CTDI (CTDIw) normalised to the tube current-time product (mGy/100 mAs), using knowledge of tube current-time product (mAs), tube potential (kVp), type of CTDI phantoms (head or body), and pitch. The normalised CTDIw is one of the characteristics of a CT scanner but not readily available from the literature. In the current study, we established a comprehensive database of normalised CTDIw values based on multiple data sources: the ImPACT dose survey from the United Kingdom, the CT-Expo dose calculation program, and surveys performed by the US Food and Drug Administration (FDA) and the National Lung Screening Trial (NLST). From the sources, the CTDIw values for a total of 68, 138, 30, and 13 scanner model groups were collected, respectively. The different scanner groups from the four data sources were sorted and merged into 162 scanner groups for eight manufacturers including General Electric (GE), Siemens, Philips, Toshiba, Elscint, Picker, Shimadzu, and Hitachi. To fill in missing CTDI values, a method based on exponential regression analysis was developed based on the existing data. Once the database was completed, two different analyses of data variability were performed. First, we averaged CTDI values for each scanner in the different data sources and analysed the variability of the average CTDI values across the different scanner models within a given manufacturer. Among the four major manufacturers, Toshiba and Philips showed the greatest coefficient of variation (COV) (=standard deviation/mean) for the head and body normalised CTDIw values, 39% and 54%, respectively. Second, the variation across the different data sources was analysed for CT scanners where more than two data sources were involved. The CTDI values for the scanners from Siemens showed the greatest variation across the data sources, being about four times greater than the variation of Toshiba scanners. The established CTDI database will be used for the reconstruction of CTDIvol and then the estimation of individualised organ doses for retrospective patient cohorts in epidemiologic studies. SN - 1361-6498 UR - https://www.unboundmedicine.com/medline/citation/24727361/Database_of_normalised_computed_tomography_dose_index_for_retrospective_CT_dosimetry_ L2 - https://doi.org/10.1088/0952-4746/34/2/363 DB - PRIME DP - Unbound Medicine ER -