Dose is not always what it seems

Where very misleading values can result from volume CT dose index and dose length product

J Anthony Seibert, John M Boone, Sandra L. Wootton-Gorges, Ramit Lamba

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Purpose The volume CT dose index (CTDIvol) and the dose-length product, commonly reported for examinations performed on clinical CT scanners, should not be used as surrogates for patient dose. This is because significant under or overestimates of these actual values can occur when there is a mismatch between the actual body size of the patient and the 16 cm or 32 cm diameter CTDIvol phantoms. This mismatch can be exacerbated in pediatric body examinations because of the fact that some manufacturers use the large diameter phantom while other manufacturers use the small diameter phantom as the CTDIvol reference phantom. Method A clinical example is described for a pediatric patient with a 4-fold difference in CTDIvol between a presurgical CT examination and a postsurgical CT examination, even though the actual dose absorbed by the patient was about the same. Using methods published by the American Association of Physicists in Medicine, we calculated the size-specific dose estimate (SSDE), and compared the estimated measurement of dose using the SSDE with the CTDIvol. Results Using SSDE significantly reduced the discrepancy in radiation dose estimates of CTDI vol in the clinical study, and allowed dose estimate comparisons between scanners to be more meaningful. Conclusions Radiation dose estimates are more accurate when using the SSDE metric in lieu of the CTDIvol metric for reporting and comparing patient dose indices.

Original languageEnglish (US)
Pages (from-to)233-237
Number of pages5
JournalJournal of the American College of Radiology
Volume11
Issue number3
DOIs
StatePublished - 2014

Fingerprint

Cone-Beam Computed Tomography
Radiation
Pediatrics
Body Size
Medicine

Keywords

  • Pediatric CT dose
  • size-specific dose estimate (SSDE)

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

@article{23ddb7eb1758416fbf28fef19fb85f58,
title = "Dose is not always what it seems: Where very misleading values can result from volume CT dose index and dose length product",
abstract = "Purpose The volume CT dose index (CTDIvol) and the dose-length product, commonly reported for examinations performed on clinical CT scanners, should not be used as surrogates for patient dose. This is because significant under or overestimates of these actual values can occur when there is a mismatch between the actual body size of the patient and the 16 cm or 32 cm diameter CTDIvol phantoms. This mismatch can be exacerbated in pediatric body examinations because of the fact that some manufacturers use the large diameter phantom while other manufacturers use the small diameter phantom as the CTDIvol reference phantom. Method A clinical example is described for a pediatric patient with a 4-fold difference in CTDIvol between a presurgical CT examination and a postsurgical CT examination, even though the actual dose absorbed by the patient was about the same. Using methods published by the American Association of Physicists in Medicine, we calculated the size-specific dose estimate (SSDE), and compared the estimated measurement of dose using the SSDE with the CTDIvol. Results Using SSDE significantly reduced the discrepancy in radiation dose estimates of CTDI vol in the clinical study, and allowed dose estimate comparisons between scanners to be more meaningful. Conclusions Radiation dose estimates are more accurate when using the SSDE metric in lieu of the CTDIvol metric for reporting and comparing patient dose indices.",
keywords = "Pediatric CT dose, size-specific dose estimate (SSDE)",
author = "Seibert, {J Anthony} and Boone, {John M} and Wootton-Gorges, {Sandra L.} and Ramit Lamba",
year = "2014",
doi = "10.1016/j.jacr.2013.10.010",
language = "English (US)",
volume = "11",
pages = "233--237",
journal = "Journal of the American College of Radiology",
issn = "1558-349X",
publisher = "Elsevier BV",
number = "3",

}

TY - JOUR

T1 - Dose is not always what it seems

T2 - Where very misleading values can result from volume CT dose index and dose length product

AU - Seibert, J Anthony

AU - Boone, John M

AU - Wootton-Gorges, Sandra L.

AU - Lamba, Ramit

PY - 2014

Y1 - 2014

N2 - Purpose The volume CT dose index (CTDIvol) and the dose-length product, commonly reported for examinations performed on clinical CT scanners, should not be used as surrogates for patient dose. This is because significant under or overestimates of these actual values can occur when there is a mismatch between the actual body size of the patient and the 16 cm or 32 cm diameter CTDIvol phantoms. This mismatch can be exacerbated in pediatric body examinations because of the fact that some manufacturers use the large diameter phantom while other manufacturers use the small diameter phantom as the CTDIvol reference phantom. Method A clinical example is described for a pediatric patient with a 4-fold difference in CTDIvol between a presurgical CT examination and a postsurgical CT examination, even though the actual dose absorbed by the patient was about the same. Using methods published by the American Association of Physicists in Medicine, we calculated the size-specific dose estimate (SSDE), and compared the estimated measurement of dose using the SSDE with the CTDIvol. Results Using SSDE significantly reduced the discrepancy in radiation dose estimates of CTDI vol in the clinical study, and allowed dose estimate comparisons between scanners to be more meaningful. Conclusions Radiation dose estimates are more accurate when using the SSDE metric in lieu of the CTDIvol metric for reporting and comparing patient dose indices.

AB - Purpose The volume CT dose index (CTDIvol) and the dose-length product, commonly reported for examinations performed on clinical CT scanners, should not be used as surrogates for patient dose. This is because significant under or overestimates of these actual values can occur when there is a mismatch between the actual body size of the patient and the 16 cm or 32 cm diameter CTDIvol phantoms. This mismatch can be exacerbated in pediatric body examinations because of the fact that some manufacturers use the large diameter phantom while other manufacturers use the small diameter phantom as the CTDIvol reference phantom. Method A clinical example is described for a pediatric patient with a 4-fold difference in CTDIvol between a presurgical CT examination and a postsurgical CT examination, even though the actual dose absorbed by the patient was about the same. Using methods published by the American Association of Physicists in Medicine, we calculated the size-specific dose estimate (SSDE), and compared the estimated measurement of dose using the SSDE with the CTDIvol. Results Using SSDE significantly reduced the discrepancy in radiation dose estimates of CTDI vol in the clinical study, and allowed dose estimate comparisons between scanners to be more meaningful. Conclusions Radiation dose estimates are more accurate when using the SSDE metric in lieu of the CTDIvol metric for reporting and comparing patient dose indices.

KW - Pediatric CT dose

KW - size-specific dose estimate (SSDE)

UR - http://www.scopus.com/inward/record.url?scp=84895481539&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84895481539&partnerID=8YFLogxK

U2 - 10.1016/j.jacr.2013.10.010

DO - 10.1016/j.jacr.2013.10.010

M3 - Article

VL - 11

SP - 233

EP - 237

JO - Journal of the American College of Radiology

JF - Journal of the American College of Radiology

SN - 1558-349X

IS - 3

ER -