The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

Xiang Li; Ehsan Samei; W. Paul Segars; Erik K. Paulson; Donald P. Frush

doi:10.1117/12.878616

The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

Xiang Li, Ehsan Samei, W. Paul Segars, Erik K. Paulson, Donald P. Frush

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

2 Scopus citations

Abstract

The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, each covering an entire region of the body (e.g., head, neck, chest, abdomen and/or pelvis). Similar conversion coefficients, however, do not exist for examinations that cover a single organ or a sub-region of the body, as in the case of a multi-phase liver examination. In this study, we extended the DLP-to-effective dose conversion coefficient (k factor) to a wide range of body CT protocols and derived the corresponding DLP-to-cancer risk conversion coefficient (q factor). An extended cardiactorso (XCAT) computational model was used, which represented a reference adult male patient. A range of body CT protocols used in clinical practice were categorized based on anatomical regions examined into 10 protocol classes. A validated Monte Carlo program was used to estimate the organ dose associated with each protocol class. Assuming the reference model to be 20 years old, effective dose and risk index (an index of the total risk for cancer incidence) were then calculated and normalized by DLP to obtain the k and q factors. The k and q factors varied across protocol classes; the coefficients of variation were 28% and 9%, respectively. The small variation exhibited by the q factor suggested the feasibility of universal q factors for a wide range of body CT protocols.

Original language	English (US)
Title of host publication	Medical Imaging 2011
Subtitle of host publication	Physics of Medical Imaging
DOIs	https://doi.org/10.1117/12.878616
State	Published - 2011
Event	Medical Imaging 2011: Physics of Medical Imaging - Lake Buena Vista, FL, United States Duration: Feb 13 2011 → Feb 17 2011

Publication series

Name	Progress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume	7961
ISSN (Print)	1605-7422

Other

Other	Medical Imaging 2011: Physics of Medical Imaging
Country/Territory	United States
City	Lake Buena Vista, FL
Period	2/13/11 → 2/17/11

Keywords

CT
Monte Carlo
cancer risk
computed tomography
conversion coefficients
dose-length product
effective dose
organ dose

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Atomic and Molecular Physics, and Optics
Biomaterials
Radiology Nuclear Medicine and imaging

Access to Document

10.1117/12.878616

Cite this

Li, X, Samei, E, Segars, WP, Paulson, EK & Frush, DP 2011, The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols. in Medical Imaging 2011: Physics of Medical Imaging., 79612A, Progress in Biomedical Optics and Imaging - Proceedings of SPIE, vol. 7961, Medical Imaging 2011: Physics of Medical Imaging, Lake Buena Vista, FL, United States, 2/13/11. https://doi.org/10.1117/12.878616

@inproceedings{022909cadf8a441ba4cb55965b29e664,

title = "The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols",

abstract = "The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, each covering an entire region of the body (e.g., head, neck, chest, abdomen and/or pelvis). Similar conversion coefficients, however, do not exist for examinations that cover a single organ or a sub-region of the body, as in the case of a multi-phase liver examination. In this study, we extended the DLP-to-effective dose conversion coefficient (k factor) to a wide range of body CT protocols and derived the corresponding DLP-to-cancer risk conversion coefficient (q factor). An extended cardiactorso (XCAT) computational model was used, which represented a reference adult male patient. A range of body CT protocols used in clinical practice were categorized based on anatomical regions examined into 10 protocol classes. A validated Monte Carlo program was used to estimate the organ dose associated with each protocol class. Assuming the reference model to be 20 years old, effective dose and risk index (an index of the total risk for cancer incidence) were then calculated and normalized by DLP to obtain the k and q factors. The k and q factors varied across protocol classes; the coefficients of variation were 28% and 9%, respectively. The small variation exhibited by the q factor suggested the feasibility of universal q factors for a wide range of body CT protocols.",

keywords = "CT, Monte Carlo, cancer risk, computed tomography, conversion coefficients, dose-length product, effective dose, organ dose",

author = "Xiang Li and Ehsan Samei and Segars, {W. Paul} and Paulson, {Erik K.} and Frush, {Donald P.}",

year = "2011",

doi = "10.1117/12.878616",

language = "English (US)",

isbn = "9780819485038",

series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",

booktitle = "Medical Imaging 2011",

}

TY - GEN

T1 - The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

AU - Li, Xiang

AU - Samei, Ehsan

AU - Segars, W. Paul

AU - Paulson, Erik K.

AU - Frush, Donald P.

PY - 2011

Y1 - 2011

N2 - The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, each covering an entire region of the body (e.g., head, neck, chest, abdomen and/or pelvis). Similar conversion coefficients, however, do not exist for examinations that cover a single organ or a sub-region of the body, as in the case of a multi-phase liver examination. In this study, we extended the DLP-to-effective dose conversion coefficient (k factor) to a wide range of body CT protocols and derived the corresponding DLP-to-cancer risk conversion coefficient (q factor). An extended cardiactorso (XCAT) computational model was used, which represented a reference adult male patient. A range of body CT protocols used in clinical practice were categorized based on anatomical regions examined into 10 protocol classes. A validated Monte Carlo program was used to estimate the organ dose associated with each protocol class. Assuming the reference model to be 20 years old, effective dose and risk index (an index of the total risk for cancer incidence) were then calculated and normalized by DLP to obtain the k and q factors. The k and q factors varied across protocol classes; the coefficients of variation were 28% and 9%, respectively. The small variation exhibited by the q factor suggested the feasibility of universal q factors for a wide range of body CT protocols.

AB - The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, each covering an entire region of the body (e.g., head, neck, chest, abdomen and/or pelvis). Similar conversion coefficients, however, do not exist for examinations that cover a single organ or a sub-region of the body, as in the case of a multi-phase liver examination. In this study, we extended the DLP-to-effective dose conversion coefficient (k factor) to a wide range of body CT protocols and derived the corresponding DLP-to-cancer risk conversion coefficient (q factor). An extended cardiactorso (XCAT) computational model was used, which represented a reference adult male patient. A range of body CT protocols used in clinical practice were categorized based on anatomical regions examined into 10 protocol classes. A validated Monte Carlo program was used to estimate the organ dose associated with each protocol class. Assuming the reference model to be 20 years old, effective dose and risk index (an index of the total risk for cancer incidence) were then calculated and normalized by DLP to obtain the k and q factors. The k and q factors varied across protocol classes; the coefficients of variation were 28% and 9%, respectively. The small variation exhibited by the q factor suggested the feasibility of universal q factors for a wide range of body CT protocols.

KW - CT

KW - Monte Carlo

KW - cancer risk

KW - computed tomography

KW - conversion coefficients

KW - dose-length product

KW - effective dose

KW - organ dose

UR - http://www.scopus.com/inward/record.url?scp=79955761047&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79955761047&partnerID=8YFLogxK

U2 - 10.1117/12.878616

DO - 10.1117/12.878616

M3 - Conference contribution

AN - SCOPUS:79955761047

SN - 9780819485038

T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE

BT - Medical Imaging 2011

T2 - Medical Imaging 2011: Physics of Medical Imaging

Y2 - 13 February 2011 through 17 February 2011

ER -

The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

Abstract

Publication series

Other

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this