PMID- 37056156
OWN - NLM
STAT- MEDLINE
DCOM- 20230417
LR  - 20230420
IS  - 1361-6498 (Electronic)
IS  - 0952-4746 (Linking)
VI  - 43
IP  - 2
DP  - 2023 Apr 14
TI  - Feasibility of size-specific organ-dose estimates based on water equivalent 
      diameter for common head CT examinations: a Monte Carlo study.
LID - 10.1088/1361-6498/acc1f0 [doi]
AB  - Computed tomography dose index (CTDI) is an unreliable dose estimate outside of 
      the standard CTDI phantom diameters (16 and 32 cm). Size-specific dose estimate 
      (SSDE) for head computed tomography (CT) examination was studied in the American 
      Association of Physicists in Medicine Report 293 to provide SSDE coefficient 
      factors based on water equivalent diameter as size metrics. However, it is 
      limited to one protocol and for a fully irradiated organ. This study aimed to 
      evaluate the dependency of normalized organ dose (ND) on water equivalent 
      diameter as a size metric in three common protocols: routine head, paranasal 
      sinus, and temporal bone. CTDI(w)measurements were performed for outlined 
      protocols in the Siemens Emotion 16-slice-configuration scanner. Geant4 
      Application for Tomographic Emission Monte Carlo simulation platform, coupled 
      with ten GSF patient models, was used to estimate organ doses. CT scanner system 
      was modeled. Helical CT scans were simulated using constructor scan parameters 
      and calculated scan lengths of each patient model. Organ doses provided by 
      simulations were normalized to CTDI(vol). The water equivalent diameters (D(w)) 
      of patient models were obtained via relationships betweenD(w)and both effective 
      diameter for a sample of patients' data.NDs received by fully, partially, and 
      non-directly irradiated organs were then reported as a function ofD(w). For fully 
      irradiated organs, brain (R(2)> 0.92), eyes (R(2)> 0.88), and eye lens (R(2)> 
      0.89) correlate well withD(w). For the rest of the results, a poor correlation 
      was observed. For partially irradiated organs, the exception was scalp (R(2)= 
      0.93) in temporal bone CT. For non-directly irradiated organs, the exception was 
      thyroid (R(2)> 0.90) and lungs (R(2)> 0.91) in routine head CT. ND correlates 
      well in routine head CT than other protocols. For the most part, no relationship 
      seems to exist betweenR(2)and scan percentage coverage. The results have revealed 
      additional factors that may influence the ND andD(w)relationship, which explains 
      the need for more studies in the future to investigate the effect of scan 
      conditions and organ anatomy variation.
CI  - (c) 2023 Society for Radiological Protection. Published on behalf of SRP by IOP 
      Publishing Limited. All rights reserved.
FAU - Tahiri, M
AU  - Tahiri M
AUID- ORCID: 0000-0001-6096-7940
AD  - Hassan First University of Settat, High Institute of Health Sciences, Laboratory 
      of Sciences and Health Technologies, Settat, Morocco.
FAU - Benameur, Y
AU  - Benameur Y
AD  - Hassan First University of Settat, High Institute of Health Sciences, Laboratory 
      of Sciences and Health Technologies, Settat, Morocco.
FAU - Mkimel, M
AU  - Mkimel M
AUID- ORCID: 0000-0002-0621-382X
AD  - Hassan First University of Settat, High Institute of Health Sciences, Laboratory 
      of Sciences and Health Technologies, Settat, Morocco.
FAU - El Baydaoui, R
AU  - El Baydaoui R
AD  - Hassan First University of Settat, High Institute of Health Sciences, Laboratory 
      of Sciences and Health Technologies, Settat, Morocco.
FAU - Mesardi, M R
AU  - Mesardi MR
AD  - Hassan First University of Settat, High Institute of Health Sciences, Laboratory 
      of Sciences and Health Technologies, Settat, Morocco.
LA  - eng
PT  - Journal Article
DEP - 20230414
PL  - England
TA  - J Radiol Prot
JT  - Journal of radiological protection : official journal of the Society for 
      Radiological Protection
JID - 8809257
SB  - IM
MH  - Humans
MH  - Radiation Dosage
MH  - *Radiometry/methods
MH  - Monte Carlo Method
MH  - Feasibility Studies
MH  - *Tomography, X-Ray Computed/methods
MH  - Phantoms, Imaging
MH  - Scalp
OTO - NOTNLM
OT  - Monte Carlo
OT  - SSDE
OT  - irradiated organs
OT  - organ dose
OT  - water equivalent diameter
EDAT- 2023/04/15 06:00
MHDA- 2023/04/17 06:41
CRDT- 2023/04/14 01:52
PHST- 2022/11/22 00:00 [received]
PHST- 2023/03/07 00:00 [accepted]
PHST- 2023/04/17 06:41 [medline]
PHST- 2023/04/14 01:52 [entrez]
PHST- 2023/04/15 06:00 [pubmed]
AID - 10.1088/1361-6498/acc1f0 [doi]
PST - epublish
SO  - J Radiol Prot. 2023 Apr 14;43(2). doi: 10.1088/1361-6498/acc1f0.