PMID- 36626827
OWN - NLM
STAT- MEDLINE
DCOM- 20230123
LR  - 20230320
IS  - 1361-6498 (Electronic)
IS  - 0952-4746 (Linking)
VI  - 43
IP  - 1
DP  - 2023 Jan 20
TI  - Dose reference level based on size-specific dose estimate (SSDE) and feasibility 
      of deriving effective body diameter using tube current and time product (mAs) for 
      adult chest and abdomen computed tomography (CT) procedures.
LID - 10.1088/1361-6498/acb1bf [doi]
AB  - This study aimed to establish dose reference level (NDRLSSDE) based on 
      size-specific dose estimate (SSDE) derived using effective diameter (Deff) for 
      adult chest and abdomen computed tomography (CT) procedures and to explore the 
      feasibility of drivingDeffusing the product of tube current and time (mAs). In 
      this retrospective study, dose data, scan parameters and patient body dimensions 
      at the mid-slice level from 14 CT units (out of 63 total) were extracted. 
      Additionally, the mAs values of the axial slice at the samez-location where the 
      diameter measurements were made (mAs(z)) were recorded. Pearson's correlation (r) 
      analysis was used to determine the relationship ofDeffwith patient BMI, weight, 
      and mAs(z). The NDRLSSDEfor the chest and abdomen were 9.72 mGy and 13.4 mGy, 
      respectively. The BMI and body weight were less correlated (r= 0.24 andr= 0.33, 
      respectively) withDeff. The correlation between mAs(z)andDeffwas considerably 
      strong (r= 0.78) and can be used to predictDeffaccurately. The absolute dose 
      differences between SSDEs calculated using the AAPM-204 method and mAs(z)was less 
      than 1.1 mGy (15%). Therefore, mAs(z)is an efficient parameter to deriveDeff. 
      Further, the direct conversion factors to estimate SSDEs at different locations 
      along thez-direction in the scan region from corresponding mAs and CTDIvolwere 
      calculated. The NDRLSSDEsuggested in the present study can be used as a reference 
      for size-dependent dose optimisation in Sri Lanka, and existing NDRL based on 
      CTDIvolunderestimate the average adult CT dose by 36.0% and 39.7% for chest and 
      abdomen regions respectively. The results show that using mAs(z)to determine SSDE 
      is a simple and practical approach with an accuracy of 95% and 85% for abdomen 
      and chest scans, respectively. However, the obtained linear relationship 
      betweenDeffand mAs is highly dependent on the ATCM technique and the 
      user-determined noise levels of the scanning protocol. Finally, the phantom study 
      resulted in the strongest correlation (r= 0.99) between theDwzand mAs(z), and the 
      prediction of patient size would be more precise thanDeffmethod.
CI  - (c) 2023 Society for Radiological Protection. Published on behalf of SRP by IOP 
      Publishing Limited. All rights reserved.
FAU - Amalaraj, T
AU  - Amalaraj T
AD  - Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka.
FAU - Jeyasugiththan, Jeyasingam
AU  - Jeyasugiththan J
AUID- ORCID: 0000-0003-2896-3768
AD  - Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka.
FAU - Satharasinghe, Duminda
AU  - Satharasinghe D
AUID- ORCID: 0000-0002-0269-2659
AD  - Department of Nuclear Science, University of Colombo, Colombo, Sri Lanka.
FAU - Pallewatte, A S
AU  - Pallewatte AS
AD  - Department of Radiology, National Hospital of Sri Lanka, Colombo, Sri Lanka.
LA  - eng
PT  - Journal Article
DEP - 20230120
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  - Adult
MH  - Radiation Dosage
MH  - Retrospective Studies
MH  - Feasibility Studies
MH  - *Abdomen/diagnostic imaging
MH  - *Tomography, X-Ray Computed/methods
OTO - NOTNLM
OT  - computed tomography (CT)
OT  - dose reference level (DRL)
OT  - effective diameter
OT  - mAs
OT  - size-specific dose estimate (SSDE)
EDAT- 2023/01/11 06:00
MHDA- 2023/01/24 06:00
CRDT- 2023/01/10 17:32
PHST- 2022/09/04 00:00 [received]
PHST- 2023/01/10 00:00 [accepted]
PHST- 2023/01/11 06:00 [pubmed]
PHST- 2023/01/24 06:00 [medline]
PHST- 2023/01/10 17:32 [entrez]
AID - 10.1088/1361-6498/acb1bf [doi]
PST - epublish
SO  - J Radiol Prot. 2023 Jan 20;43(1). doi: 10.1088/1361-6498/acb1bf.