Radiation dose metrics in multidetector computed tomography examinations: A multicentre retrospective study from seven tertiary care hospitals in Kerala, South India

Abstract

Background: Presently, computed tomography (CT) is the most important source of medical radiation exposure. CT radiation doses vary considerably across institutions depending on the protocol and make of equipment. India does not yet have national or region-specific CT diagnostic reference levels. Aim: To evaluate radiation doses of consecutive multidetector CT (MDCT) examinations based on anatomic region, performed in 1 month, collected simultaneously from seven tertiary care hospitals in Kerala. Settings and Design: Descriptive study. Materials and Methods: We collected the CT radiation dose data of examinations from the seven collaborating tertiary care hospitals in Kerala, performed with MDCT scanners of five different makes. The data included anatomic region, number of phases, CT dose index (CTDI_vol), dose-length product (DLP), and effective dose (ED) of each examinations and patient demographic data. Statistical Analysis: We calculated the 25^th, 50^th, and 75^th percentiles of the CTDI_vol, DLP, and ED according to anatomic region. We made descriptive comparisons of these results with corresponding data from other countries. Results: Of 3553 patients, head was the most frequently performed examination (60%), followed by abdomen (19%). For single-phase head examinations, 75^th percentile of CTDI_volwas 68.1 mGy, DLP 1120 mGy-cm, and ED 2.1 mSv. The 75^th percentiles of CTDI_vol, DLP, and ED for single-phase abdomen examinations were 10.6, 509.3, and 7.7, and multiphase examinations were 14.6, 2666.9, and 40.8; single-phase chest examinations were 23.4, 916.7, and 13.38, and multiphase examinations were 19.9, 1737.6, and 25.36; single-phase neck were 24.9, 733.6, and 3.814, and multiphase neck were 24.9, 2076, and 10.79, respectively. Conclusion: This summary CT radiation dose data of most frequently performed anatomical regions could provide a starting point for institutional analysis of CT radiation doses, which in turn leads to meaningful optimization of CT.

Keywords

Achievable dose - CT dose index - diagnostic reference level - diagnostic reference range - dose-length product - effective dose - radiation dose metrics

Publikationsverlauf

Artikel online veröffentlicht:
26. Juli 2021

• References

• 1 Amis Jr ES, Butler PF, Applegate KE, Birnbaum SB, Brateman LF, Hevezi JM. et al. American College of Radiology white paper on radiation dose in medicine. J Am Coll Radiol 2007; 4: 272-84
• 2 Mettler Jr FA, Thomadsen BR, Bhargavan M, Gilley DB, Gray JE, Lipoti JA. et al. Medical radiation exposure in the U.S. in 2006: Preliminary results. Health Phys 2008; 95: 502-7
• 3 Wiest PW, Locken JA, Heintz PH, Mettler Jr FA. CT scanning: A major source of radiation exposure. Semin Ultrasound CT MR 2002; 23: 402-10
• 4 Paolicchi F, Faggioni L, Bastiani L, Molinaro S, Caramella D, Bartolozzi C. Real practice radiation dose and dosimetric impact of radiological staff training in body CT examinations. Insights Imaging 2013; 4: 239-44
• 5 Brenner DJ, Hall EJ. Computed tomography—An increasing source of radiation exposure. N Engl J Med 2007; 357: 2277-84
• 6 American Association of Physicists in Medicine. AAPM Position Statement on Radiation Risks from Medical Imaging Procedures (Policy No. PP 25-B). Available from: http://www.aapm.org/org/policies/details.asp?id=318 and type=PP and current=true. [Last accessed 2017 Aug 08]
• 7 International Electrotechnical Commission. Medical Electrical Equipment. Part 2–44: Particular requirements for the safety of X-ray equipment for computed tomography. 2.1. International Electrotechnical Commission (IEC) Central Office; Geneva, Switzerland: 2002. IEC publication No. 60601–2–44
• 8 Boone JM. The trouble with CTDI 100. Med Phys 2007; 34: 1364-71
• 9 McCollough CH, Primak AN, Braun N, Kofler J, Yu L, Christner J. Strategies for reducing radiation dose in CT. Radiol Clin North Am 2009; 47: 27-40
• 10 1990 Recommendations of the International Commission on Radiological Protection. Ann ICRP 1991; 21: 1-201
• 11 Radiological Protection and Safety in Medicine. ICRP publication 73. Ann ICRP 1996; 26: 1-31
• 12 Rosenstein M. Diagnostic reference levels for medical exposure of patients: ICRP guidance and related ICRU quantities. Health Phys 2008; 95: 528-34
• 13 Vassileva J, Rehani M. Diagnostic reference levels. AJR Am J Roentgenol 2015; 204: W1-3
• 14 Goske MJ, Strauss KJ, Coombs LP, Mandel KE, Towbin AJ, Larson DB. et al. Diagnostic reference ranges for pediatric abdominal CT. Radiology 2013; 268: 208-18
• 15 Livingstone RS, Dinakaran PM. Radiation safety concerns and diagnostic reference levels for computed tomography scanners in Tamil Nadu. J Med Phys 2011; 36: 40-5
• 16 Saravanakumar A, Vaideki K, Govindarajan KN, Jayakumar S. Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India. J Med Phys 2014; 39: 50-5
• 17 Saravanakumar A, Vaideki K, Govindarajan KN, Jayakumar S, Devanand B. Estimation of dose reference levels in computed tomography for select procedures in Kerala, India. J Med Phys 2015; 40: 115-9
• 18 Saravanakumar A, Vaideki K, Govindarajan K, Devanand B, Jayakumar S, Sharma S. Establishment of CT diagnostic reference levels in select procedures in South India. IJRR 2016; 14: 341-7
• 19 The 2007 recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann ICRP 2007; 37: 1-332
• 20 American College of Radiology (ACR). ACRAAPM practice parameter for diagnostic reference levels and achievable doses in medical x-ray imaging. ACR website. http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/Reference_Levels_Diagnostic_Xray.pdf. Published 2013. Amended 2014. [Last accessed on 2017 Aug 27]
• 21 Smith-Bindman R, Moghadassi M, Wilson N, Nelson TR, Boone JM, Cagnon CH. et al. Radiation doses in consecutive CT examinations from five University of California Medical Centers. Radiology 2015; 277: 134-41
• 22 Kanal KM, Butler PF, Sengupta D, Bhargavan-Chatfield M, Coombs LP, Morin RL. US diagnostic reference levels and achievable doses for 10 adult CT examinations. Radiology 2017; 284: 120-33
• 23 Shrimpton PC, Hiller MC, Meeson S, Golding SJ. Doses from computed tomography (CT) examinations in the UK – 2011 review. Public Health England website. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/349188/PHE_CRCE_013.pdf. Published 2014. [Last accessed on 2017 Aug 27]
• 24 Yonekura Y. Diagnostic reference levels based on latest surveys in Japan – Japan DRLs 2015. Japanese Network for Research and Information on Medical Exposure. Medical exposure Research Information Network (J-RIME) website. Available from: http://www.radher.jp/J-RIME/report/DRLhoukokusyoEng.pdf. Published 2015. [Last accessed on 2017 Aug 27]
• 25 Hart D, Hillier MC, Wall BF. National reference doses for common radiographic, fluoroscopic and dental X-ray examinations in the UK. Br J Radiol 2009; 82: 1-12
• 26 Pantos I, Thalassinou S, Argentos S, Kelekis NL, Panayiotakis G, Efstathopoulos EP. Adult patient radiation doses from non-cardiac CT examinations: A review of published results. Br J Radiol 2011; 84: 293-303
• 27 Huda W, Mettler FA. Volume CT dose index and dose-length product displayed during CT: What good are they?. Radiology 2011; 258: 236-42