Estimating surface radiation dose from Multidetector CT: Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations

J. J. DeMarco, C. H. Cagnon, D. D. Cody, D. M. Stevens, Cynthia H McCollough, J. O'Daniel, M. F. McNitt-Gray

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Multidetector CT (MDCT) systems offer larger coverage and wider z-axis beams, resulting in larger cone angles. One impact on radiation dose is that while radiation profiles at isocenter are constant when contiguous axial scans are performed, the increased beam divergence from the larger cone angle results in significant surface dose variation. The purpose of this work was to measure the magnitude of this effect. Contiguous axial scans were acquired using an MDCT for two sizes of cylindrical phantoms and an anthropomorphic phantom. Film dosimetry and/or radiation detector measurements were performed on the surface of each phantom. Detailed mathematical models were developed for the MDCT scanner and all phantoms. Monte Carlo simulations of contiguous axial scans were performed for each phantom model. From cylindrical phantoms, film dosimetry at the surface showed differences between peak and valley that reached 50%. From the anthropomorphic phantom, measured values ranged from 7.9 to 16.2 mGy at the phantom surface. Monte Carlo simulations demonstrated these variations in both cylindrical and anthropomorphic phantoms. The magnitude of variation was also related to object size. Even when contiguous axial scans are performed on MDCT, surface radiation profiles show considerable variation. This variation will increase as MDCT cone angles increase and when non-contiguous scans (e.g. pitch > 1) are acquired. The variation is also a function of object size. While average surface doses may remain constant, peak doses may increase, which may be significant for radiation sensitive organs at or near the surface (e.g. breast, thyroid).

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
EditorsM.J. Flynn
Pages102-112
Number of pages11
Volume5745
EditionI
DOIs
StatePublished - 2005
EventMedical Imaging 2005 - Physics of Medical Imaging - San Diego, CA, United States
Duration: Feb 13 2005Feb 15 2005

Other

OtherMedical Imaging 2005 - Physics of Medical Imaging
CountryUnited States
CitySan Diego, CA
Period2/13/052/15/05

Fingerprint

Dosimetry
Cones
Radiation
Radiation detectors
Monte Carlo simulation
Mathematical models

Keywords

  • CT
  • Measurement
  • Multidetector CT
  • Radiation dose
  • X-ray computed tomography

ASJC Scopus subject areas

  • Engineering(all)

Cite this

DeMarco, J. J., Cagnon, C. H., Cody, D. D., Stevens, D. M., McCollough, C. H., O'Daniel, J., & McNitt-Gray, M. F. (2005). Estimating surface radiation dose from Multidetector CT: Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations. In M. J. Flynn (Ed.), Progress in Biomedical Optics and Imaging - Proceedings of SPIE (I ed., Vol. 5745, pp. 102-112). [13] https://doi.org/10.1117/12.595933

Estimating surface radiation dose from Multidetector CT : Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations. / DeMarco, J. J.; Cagnon, C. H.; Cody, D. D.; Stevens, D. M.; McCollough, Cynthia H; O'Daniel, J.; McNitt-Gray, M. F.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. ed. / M.J. Flynn. Vol. 5745 I. ed. 2005. p. 102-112 13.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

DeMarco, JJ, Cagnon, CH, Cody, DD, Stevens, DM, McCollough, CH, O'Daniel, J & McNitt-Gray, MF 2005, Estimating surface radiation dose from Multidetector CT: Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations. in MJ Flynn (ed.), Progress in Biomedical Optics and Imaging - Proceedings of SPIE. I edn, vol. 5745, 13, pp. 102-112, Medical Imaging 2005 - Physics of Medical Imaging, San Diego, CA, United States, 2/13/05. https://doi.org/10.1117/12.595933
DeMarco JJ, Cagnon CH, Cody DD, Stevens DM, McCollough CH, O'Daniel J et al. Estimating surface radiation dose from Multidetector CT: Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations. In Flynn MJ, editor, Progress in Biomedical Optics and Imaging - Proceedings of SPIE. I ed. Vol. 5745. 2005. p. 102-112. 13 https://doi.org/10.1117/12.595933
DeMarco, J. J. ; Cagnon, C. H. ; Cody, D. D. ; Stevens, D. M. ; McCollough, Cynthia H ; O'Daniel, J. ; McNitt-Gray, M. F. / Estimating surface radiation dose from Multidetector CT : Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. editor / M.J. Flynn. Vol. 5745 I. ed. 2005. pp. 102-112
@inproceedings{029bd879be2e4bd9ac3133480da13087,
title = "Estimating surface radiation dose from Multidetector CT: Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations",
abstract = "Multidetector CT (MDCT) systems offer larger coverage and wider z-axis beams, resulting in larger cone angles. One impact on radiation dose is that while radiation profiles at isocenter are constant when contiguous axial scans are performed, the increased beam divergence from the larger cone angle results in significant surface dose variation. The purpose of this work was to measure the magnitude of this effect. Contiguous axial scans were acquired using an MDCT for two sizes of cylindrical phantoms and an anthropomorphic phantom. Film dosimetry and/or radiation detector measurements were performed on the surface of each phantom. Detailed mathematical models were developed for the MDCT scanner and all phantoms. Monte Carlo simulations of contiguous axial scans were performed for each phantom model. From cylindrical phantoms, film dosimetry at the surface showed differences between peak and valley that reached 50{\%}. From the anthropomorphic phantom, measured values ranged from 7.9 to 16.2 mGy at the phantom surface. Monte Carlo simulations demonstrated these variations in both cylindrical and anthropomorphic phantoms. The magnitude of variation was also related to object size. Even when contiguous axial scans are performed on MDCT, surface radiation profiles show considerable variation. This variation will increase as MDCT cone angles increase and when non-contiguous scans (e.g. pitch > 1) are acquired. The variation is also a function of object size. While average surface doses may remain constant, peak doses may increase, which may be significant for radiation sensitive organs at or near the surface (e.g. breast, thyroid).",
keywords = "CT, Measurement, Multidetector CT, Radiation dose, X-ray computed tomography",
author = "DeMarco, {J. J.} and Cagnon, {C. H.} and Cody, {D. D.} and Stevens, {D. M.} and McCollough, {Cynthia H} and J. O'Daniel and McNitt-Gray, {M. F.}",
year = "2005",
doi = "10.1117/12.595933",
language = "English (US)",
volume = "5745",
pages = "102--112",
editor = "M.J. Flynn",
booktitle = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
edition = "I",

}

TY - GEN

T1 - Estimating surface radiation dose from Multidetector CT

T2 - Cylindrical phantoms, Anthropomorphic phantoms and Monte Carlo Simulations

AU - DeMarco, J. J.

AU - Cagnon, C. H.

AU - Cody, D. D.

AU - Stevens, D. M.

AU - McCollough, Cynthia H

AU - O'Daniel, J.

AU - McNitt-Gray, M. F.

PY - 2005

Y1 - 2005

N2 - Multidetector CT (MDCT) systems offer larger coverage and wider z-axis beams, resulting in larger cone angles. One impact on radiation dose is that while radiation profiles at isocenter are constant when contiguous axial scans are performed, the increased beam divergence from the larger cone angle results in significant surface dose variation. The purpose of this work was to measure the magnitude of this effect. Contiguous axial scans were acquired using an MDCT for two sizes of cylindrical phantoms and an anthropomorphic phantom. Film dosimetry and/or radiation detector measurements were performed on the surface of each phantom. Detailed mathematical models were developed for the MDCT scanner and all phantoms. Monte Carlo simulations of contiguous axial scans were performed for each phantom model. From cylindrical phantoms, film dosimetry at the surface showed differences between peak and valley that reached 50%. From the anthropomorphic phantom, measured values ranged from 7.9 to 16.2 mGy at the phantom surface. Monte Carlo simulations demonstrated these variations in both cylindrical and anthropomorphic phantoms. The magnitude of variation was also related to object size. Even when contiguous axial scans are performed on MDCT, surface radiation profiles show considerable variation. This variation will increase as MDCT cone angles increase and when non-contiguous scans (e.g. pitch > 1) are acquired. The variation is also a function of object size. While average surface doses may remain constant, peak doses may increase, which may be significant for radiation sensitive organs at or near the surface (e.g. breast, thyroid).

AB - Multidetector CT (MDCT) systems offer larger coverage and wider z-axis beams, resulting in larger cone angles. One impact on radiation dose is that while radiation profiles at isocenter are constant when contiguous axial scans are performed, the increased beam divergence from the larger cone angle results in significant surface dose variation. The purpose of this work was to measure the magnitude of this effect. Contiguous axial scans were acquired using an MDCT for two sizes of cylindrical phantoms and an anthropomorphic phantom. Film dosimetry and/or radiation detector measurements were performed on the surface of each phantom. Detailed mathematical models were developed for the MDCT scanner and all phantoms. Monte Carlo simulations of contiguous axial scans were performed for each phantom model. From cylindrical phantoms, film dosimetry at the surface showed differences between peak and valley that reached 50%. From the anthropomorphic phantom, measured values ranged from 7.9 to 16.2 mGy at the phantom surface. Monte Carlo simulations demonstrated these variations in both cylindrical and anthropomorphic phantoms. The magnitude of variation was also related to object size. Even when contiguous axial scans are performed on MDCT, surface radiation profiles show considerable variation. This variation will increase as MDCT cone angles increase and when non-contiguous scans (e.g. pitch > 1) are acquired. The variation is also a function of object size. While average surface doses may remain constant, peak doses may increase, which may be significant for radiation sensitive organs at or near the surface (e.g. breast, thyroid).

KW - CT

KW - Measurement

KW - Multidetector CT

KW - Radiation dose

KW - X-ray computed tomography

UR - http://www.scopus.com/inward/record.url?scp=23844535237&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=23844535237&partnerID=8YFLogxK

U2 - 10.1117/12.595933

DO - 10.1117/12.595933

M3 - Conference contribution

AN - SCOPUS:23844535237

VL - 5745

SP - 102

EP - 112

BT - Progress in Biomedical Optics and Imaging - Proceedings of SPIE

A2 - Flynn, M.J.

ER -