Chapter 8. Establishment of a Local Diagnostic Reference Level (LDRL) for Adult Computed Tomography (CT) Scans in Hospitals and Diagnostic Centers in Addis Ababa, Ethiopia


Blein Mulugeta¹, Wondemu Geteye¹, Efrem Mengistu², Yenuse Molla¹, and Ali Beyene¹
¹Department of Medical Radiologic Technology, Addis Ababa University, Ethiopia
²Department of Physics, Dire-Dewa University, Ethiopia

Part of the book: Advances in Health and Disease. Volume 63


Computed tomography (CT) has become the most commonly used medical imaging modality and a powerful clinical tool for the diagnosis and management of patients. However, CT is associated with relatively high radiation doses with a corresponding increased risk of carcinogenesis. The optimization of patient protection in CT requires the application of examination-specific scan protocols. A diagnostic reference level (DRL) is a form of investigation level used as a tool to aid in the optimization of protection in the medical exposure of patients for diagnostic and interventional procedures. There are no studies conducted regarding the establishment of DRL on CT in Addis Ababa, Ethiopia. As a result, the purpose of this study was to establish a local diagnostic reference level and estimation of an effective dose for adult CT in Addis Ababa, Ethiopia. A cross-sectional facility-based study design was used to conduct this prospective study. Common adult CT examinations of the head, chest, and abdomen-pelvic without contrast in five CT centers from December 20, 2019, to March 10, 2020, were studied. A total of 430 patient data was collected. Obtained data were analyzed by descriptive statistics using SPSS version 21.0. The established local diagnostic reference level (LDRL) of the head, chest, and abdominopelvic in dose quantities of Volume Weighted Computed Tomography Dose Index (CTDIvol)(mGy) and dose length product (DLP) ( were 51mGy, 1246; 11.18mGy, and 11.96mGy, 612.59 respectively. The estimated effective dose for head, chest, and abdomen pelvic were 2.6mSv, 5.6mSv, and 9.2mSv respectively. The head DLP and effective dose value were above the recommended value. The scan length and scan protocol used for head scan in the surveyed center was high.

Keywords: CT, CTDIvol (mGy), DLP (, LDRLs


[1] Ghonge N. Computed tomography in the 21st century: current status & future
prospects. J. Int. Med. Sci. Acad. (JIMSA). 2013;26(1):35-42.
[2] Carinci F, Massi Benedetti M, Klazinga N, Uccioli L. Lower extremity amputation
rates in people with diabetes as an indicator of health systems performance. A
critical appraisal of the data collection 2000–2011 by the Organization for Economic
Cooperation and Development (OECD). Acta diabetologica. 2016;53(5):825-32.
[3] Bercovich E, Javitt M C. Medical imaging: from roentgen to the digital revolution,
and beyond. Rambam Maimonides medical journal. 2018;9(4).
[4] Foley S J, McEntee M F, Rainford L A. Establishment of CT diagnostic reference
levels in Ireland. The British journal of radiology. 2012;85(1018):1390-7.
[5] Moifo B, Tapouh J R M, Guena M N, Ndah T N, Samba R N, Simo A. Diagnostic
reference levels of adults CT-scan imaging in Cameroon: a pilot study of four
commonest CT-protocols in five radiology Departments. Open Journal of Medical
Imaging. 2017;7(01):1.
[6] Charles M W. ICRP Publication 103: Recommendations of the ICRP. Oxford
University Press; 2008.
[7] Mundi A. Abdullahi, H. Shittu, D. Joseph, AbdulJamiu Aribisala, Peter Eshiett, I.
Richard, Goriya Kpaku. Diagnostic reference level for adult brain computed
tomography scans: A case study of a tertiary health care center in Nigeria. IOSR
Journal of dental and medical sciences. 2015;14(1):66-75.
[8] Thorne M. ICRP publication 60: 1990 recommendations of the international
commission on radiological protection: Annals of the ICRP, 21 (1–3), 1991.
Pergamon; 1992.
[9] Bosmans H, Damilakis J, Ducou le Pointe H, Foley S J. Radiation protection no.
185 European guidelines on diagnostic reference levels for paediatric imaging.
[10] Vañó E, D L Miller, C J Martin, M M Rehani, K Kang, M Rosenstein, P Ortiz López, S Mattsson,
R Padovani, A Rogers. ICRP publication 135: diagnostic
reference levels in medical imaging. Annals of the ICRP. 2017;46(1):1-144.
[11] Mathie M J, Coster A C, Lovell N H, Celler B G. Accelerometry: providing an
integrated, practical method for long-term, ambulatory monitoring of human
movement. Physiological measurement. 2004;25(2):R1.
[12] Goergen S, Revell A, Walker C. Computed Tomography (CT). Inside Radiology
Retrieved March. 2009;2:2016.
[13] Cantatore A, Müller P. Introduction to computed tomography. Kgs Lyngby: DTU
Mechanical Engineering. 2011.
[14] Bartscher M, Hilpert U, Goebbels J, Weidemann G. Enhancement and proof of
accuracy of industrial computed tomography (CT) measurements. CIRP annals.
[15] Menzel H, Schibilla H, Teunen D. European guidelines on quality criteria for
computed tomography. Luxembourg: European Commission. 2000;16262.
[16] McNitt-Gray MF. AAPM/RSNA physics tutorial for residents: topics in CT:
radiation dose in CT. Radiographics. 2002;22(6):1541-53.
[17] Abdulkadir M. Determination of computed tomography diagnostic reference levels
in North-Central Nigeria: University of Ghana; 2015.
[18] Lee C. How to estimate effective dose for CT patients. European Radiology.
[19] Alsafi K. Radiation protection in x-ray computed tomography: Literature review.
Int. J. Radiol. Imaging Technol. 2016;2:1-5.
[20] Huda W. Radiation doses and risks in chest computed tomography examinations.
Proceedings of the American Thoracic Society. 2007;4(4):316-20.
[21] Lewis M. Radiation dose issues in multi-slice CT sccaning. ImPACT technology
update. 2005.
[22] Livingstone R S, Dinakaran P M. Radiation safety concerns and diagnostic reference
levels for computed tomography scanners in Tamil Nadu. Journal of medical
physics/Association of Medical Physicists of India. 2011;36(1):40.
[23] Jessen K, Panzer W, Shrimpton P, Bongartzm G, Geleijns J, Golding S. EUR 16262:
European guidelines on quality criteria for computed tomography. Luxembourg:
Office for Official Publications of the European Communities. 2000.
[24] Wardlaw G, Martel N. Canadian computed tomography survey: national diagnostic
reference levels: sci-thur pm–colourful interactions: highlights 07. Med Phys.
[25] Simantirakis, G., C. J. Hourdakis, S. Economides, I. Kaisas, M. Kalathaki, C.
Koukorava, G. Manousaridis. Diagnostic reference levels and patient doses in
computed tomography examinations in Greece. Radiation protection dosimetry.
[26] Smith-Bindman, Rebecca, Michelle Moghadassi, Nicole Wilson, Thomas R.
Nelson, John M. Boone, Christopher H. Cagnon, Robert Gould. Radiation doses in
consecutive CT examinations from five University of California Medical Centers.
Radiology. 2015;277(1):134-41.
[27] Salama, Dina Husseiny, Jenia Vassileva, Gamal Mahdaly, Mona Shawki, Ahmad
Salama, Debbie Gilley, and Madan Mohan Rehani. Establishing national diagnostic
reference levels (DRLs) for computed tomography in Egypt. Physica medica.
[28] Korir G K, Wambani J S, Korir I K, Tries M A, Boen P K. National diagnostic
reference level initiative for computed tomography examinations in Kenya.
Radiation protection dosimetry. 2016;168(2):242-52.
[29] Ekpo, Ernest U, Thomas Adejoh, Judith D Akwo, Owujekwe C Emeka, Ali A Modu,
Mohammed Abba, Kudirat A Adesina, David O Omiyi, and Uche H Chiegwu.
Diagnostic reference levels for common computed tomography (CT) examinations:
results from the first Nigerian nationwide dose survey. Journal of radiological
protection. 2018;38(2):525.
[30] Safety P. Radiation Dose in X-Ray and CT Exams. American College of Radiology
and Radiological Society of North America (April 2012). 2012.


Publish with Nova Science Publishers

We publish over 800 titles annually by leading researchers from around the world. Submit a Book Proposal Now!