PMID- 35040673
OWN - NLM
STAT- MEDLINE
DCOM- 20220427
LR  - 20220524
IS  - 1527-1315 (Electronic)
IS  - 0033-8419 (Print)
IS  - 0033-8419 (Linking)
VI  - 303
IP  - 2
DP  - 2022 May
TI  - Dependence of Water-equivalent Diameter and Size-specific Dose Estimates on CT 
      Tube Potential.
PG  - 404-411
LID - 10.1148/radiol.210860 [doi]
AB  - Background The size-specific dose estimate (SSDE) is a patient-focused CT dose 
      metric. However, published size-dependent conversion factors (f(size)) used to 
      calculate SSDE were determined primarily by using phantoms; only eight to 15 
      patient data sets were used, all at 120 kV. Purpose To determine the effect of 
      different tube potentials on the water-equivalent diameter (WED) and SSDE for 
      patient CT scans of the head, chest, and abdomen. Materials and Methods This 
      retrospective study used 250 noncontrast CT scans acquired between March 2013 and 
      June 2017. Bony structures were segmented, and their CT numbers were modified to 
      reflect bone attenuation at 70, 90, 110, 130, and 150 kV. Soft-tissue CT numbers 
      were unchanged because of negligible energy dependence. f(size) was measured in 
      anthropomorphic phantoms for each tube potential and fit to an exponential 
      function. WED and SSDE were determined for each patient at all tube potentials, 
      regression analysis was performed relative to the WED and SSDE at 120 kV, and 
      mean differences relative to 120 kV were calculated. Results In 250 patients 
      (median age, 21.5 years; interquartile range, 44 years; 130 women), WED for all 
      tube potentials was linearly related to the WED at 120 kV in all body regions 
      (R(2) = 0.995-1.000). The effect of tube potential on WED was negligible for 
      torso examinations (Cohen d < 0.05). In the head, a medium effect size was 
      observed at 70 kV; however, the mean absolute difference in WED was small (-0.49 
      cm +/- 0.08 [standard deviation]; P < .001). For commonly used combinations of tube 
      potential and patient size, the mean differences in SSDE at alternative tube 
      potentials relative to SSDE at 120 kV were less than 5%. Conclusion At 
      noncontrast CT, published size-dependent conversion factors accurately determined 
      size-specific dose estimates on 250 patient scans at five tube potentials other 
      than 120 kV. (c) RSNA, 2022 Online supplemental material is available for this 
      article. See also the editorial by Boone in this issue.
FAU - McCollough, Cynthia H
AU  - McCollough CH
AUID- ORCID: 0000-0002-5346-332X
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - McCollough, Shannon L
AU  - McCollough SL
AUID- ORCID: 0000-0002-2768-0435
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Schneider, Justine J
AU  - Schneider JJ
AUID- ORCID: 0000-0002-3519-4752
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Moen, Taylor R
AU  - Moen TR
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Weaver, Jayse M
AU  - Weaver JM
AUID- ORCID: 0000-0002-6123-8878
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Vrieze, Thomas J
AU  - Vrieze TJ
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Yu, Lifeng
AU  - Yu L
AUID- ORCID: 0000-0002-4267-1326
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
FAU - Leng, Shuai
AU  - Leng S
AUID- ORCID: 0000-0002-6453-9481
AD  - From the Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 
      55905.
LA  - eng
GR  - R01 EB017095/EB/NIBIB NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20220118
PL  - United States
TA  - Radiology
JT  - Radiology
JID - 0401260
RN  - 059QF0KO0R (Water)
SB  - IM
CIN - Radiology. 2022 Jan 18;:212801. PMID: 35040681
MH  - Adult
MH  - Female
MH  - Humans
MH  - Male
MH  - Phantoms, Imaging
MH  - Radiation Dosage
MH  - Retrospective Studies
MH  - *Tomography, X-Ray Computed/methods
MH  - *Water
MH  - Young Adult
PMC - PMC9038617
MID - NIHMS1755829
COIS- Disclosures of Conflicts of Interest: C.H.M. Travel support from American 
      Association of Physicists in Medicine (AAPM); president and chair of the Board of 
      the AAPM; vice-president and board member of International Society of CT. S.L.M. 
      No relevant relationships. J.J.S. No relevant relationships. T.R.M. No relevant 
      relationships. J.M.W. No relevant relationships. T.J.V. No relevant 
      relationships. L.Y. No relevant relationships. S.L. No relevant relationships.
EDAT- 2022/01/19 06:00
MHDA- 2022/04/28 06:00
PMCR- 2023/05/01
CRDT- 2022/01/18 12:19
PHST- 2022/01/19 06:00 [pubmed]
PHST- 2022/04/28 06:00 [medline]
PHST- 2022/01/18 12:19 [entrez]
PHST- 2023/05/01 00:00 [pmc-release]
AID - 10.1148/radiol.210860 [doi]
PST - ppublish
SO  - Radiology. 2022 May;303(2):404-411. doi: 10.1148/radiol.210860. Epub 2022 Jan 18.