Optimization of head computed tomography scan in a tertiary institution in Edo State, South-South Nigeria Dose optimization in head CT

Main Article Content

Chikezie Chukwuemeka Udo
Akintayo Daniel Omojola
Chukwuemeka Christian Nzotta


Objective: The study is aimed at optimizing the existing CT protocol for head scans in a Specialist Teaching Hospital in Edo State with a 16-slice Siemens Somatom Emotion scanner. Also, the study determined the volume computed tomography dose index (CTDIvol) and Dose Length Product (DLP) from the patient's dose profiles. The results from this study were compared with relevant studies.

Materials and Methods: The scanner was used to acquire head CT of 160 patients retrospectively. Also, a locally designed head phantom was used to simulate individual patients using a similar protocol by changing the tube current (mA) and total scan width (TSW) only from the existing protocol.

Results: Percentage dose reduction (PDR) for the CTDIvol and DLP ranged 42.00-46.80% and 37.13-43.54% respectively. The optimized CTDIvol and DLP were lowest compared to studies in the United Kingdom (UK), Italy, India, Ireland, Sudan, Nigeria, European Commission (EC), United States of America (USA) and Japan. Only the DLP for India was lower than our optimized value.

Conclusion: The need to understudy CT configuration is necessary, this will allow end-users to optimize certain parameters in the CT scanner, which will reduce the patient dose without compromising image quality


Download data is not yet available.

Article Details

How to Cite
Udo, C. C., Omojola, A. D., & Nzotta, C. C. (2021). Optimization of head computed tomography scan in a tertiary institution in Edo State, South-South Nigeria. Medical Science and Discovery, 8(4), 225-230. https://doi.org/10.36472/msd.v8i4.521
Research Article


1. Tabari A, Lo Gullo R, Murugan V, Otrakji A, Digumarthy S, Kalra M. Recent Advances in Computed Tomographic Technology: Cardiopulmonary Imaging Applications J Thorac Imaging. 2017; 32 (2):89-100.

2. Ginat DT, Gupta R. Advances in computed tomography imaging technology. Annu Rev Biomed Eng. 2014; 16:431-53.

3. Heidbuchel H, Wittkampf FH, Vano E, Ernst S, Schilling R, Picano E et al. Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures. Europace. 2014:16(7):946-64.

4. Zontar D, Zdesar U, Kuhelj D, Pekarovic D, Skrk D. Estimated collective effective dose to the population from radiological examinations in Slovenia. Radiol Oncol 2015; 49(1): 99-106.

5. Parakh A, Euler A, Szucs-Farkas Z, Schindera ST. Transatlantic Comparison of CT Radiation Doses in the Era of Radiation Dose Tracking Software. AJR Am J Roentgenol 2017; 209:1302-7.

6. Rehani MM, Frush DP, Berris T, Einstein AJ. Patient Radiation Exposure Tracking: Worldwide Programs and Needs—Results from the First IAEA Survey. Eur J Radiol. 2012; 81(10): e968–e976.

7. Bosch de Basea M, Moriña D, Figuerola J, Barber I, Muchart J, Lee C, Cardis E. Subtle excess in lifetime cancer risk related to CT scanning in Spanish young people. Environ Int. 2018; 120:1-10.

8. Power SP, Moloney F, Twomey M, James K, O’Connor OJ, Maher MM. Computed tomography and patient risk: Facts, perceptions and uncertainties. World J Radiol 2016; 8(12): 902-915

9. Rehani MM. Patient radiation exposure and dose tracking: a perspective. Journal of Medical Imaging 4(3), 2017; 031206-1- 031206-8

10. Fisher DR, Fahey FH. Appropriate use of effective dose in radiation protection and risk assessment. Health Phys. 2017; 113(2): 102–109

11. Adejoh T, Nzotta CC, Aronu ME, Dambele MY. Diagnostic reference levels for computed tomography of the head in Anambra State of Nigeria. West Afr J Radiol. 2017; 24: 142-146

12. Chiegwu HU, Bessie EI, Chukwuemeka NC, Ike OSO, Emejulu OA, Chimuanya UD. Increasing radiation doses from computed tomography versus diagnostic reference levels: How compliance are we? BJMMR 2015; 9:1–15.

13. McNitt-Gray MF. AAPM/RSNA Physics Tutorial for Residents: Topics in CT: Radiation dose in CT. RadioGraphics. 2002; 22:1541-1553.

14. Al-Mahrooqi KMS. The Optimisation of Routine Paediatric CT Scanning Protocols. Faculty of Science and Engineering Department of Medical Radiation Sciences. Curtin University, [Thesis]. 2015

15. Nuyts J, De Man B, Dupont P, Defrise M, Suetens P, Mortelmans L. Iterative reconstruction for helical CT: a simulation study. Phys Med Biol. 1998; 43(4):729–737

16. Elbakri IA, Fessler JA. Statistical image reconstruction for polyenergetic X-ray computed tomography. IEEE Trans Med Imaging. 2002; 21(2):89–99.

17. Lasio GM, Whiting BR, Williamson JF. Statistical reconstruction for x-ray computed tomography using energy-integrating detectors. Phys Med Biol. 2007; 52(8):2247–2266.

18. Thibault JB, Sauer KD, Bouman CA, Hsieh J. A three-dimensional statistical approach to improved image quality for multislice helical CT. Med Phys. 2007; 34(11):4526–4544.

19. Frush DP, Donnelly LF, Rosen NS. Computed tomography and radiation risks: What pediatric health care providers should know. Pediatrics. 2003; 112:951-957.

20. Cohnen M, Fischer H, Hamacher J, Lins E, Kötter R, Mödder U. CT of the head by use of reduced current and kilovoltage: relationship between image quality and dose reduction. AJNR Am J Neuroradiol. 2000 Oct; 21(9):1654-60.

21. Sodickson A. Strategies for Reducing Radiation Exposure from Multidetector Computed Tomography in the Acute Care Setting. Canadian Association of Radiologists Journal. 2013; 64: 119e129

22. Sulagaesuan C, Saksobhavivat N, Asavaphatiboon S, Kaewlai R. Reducing emergency CT radiation doses with simple techniques: A quality initiative project J Med Imaging Radiat Oncol. 2016; 60: 23–34.

23. Baskan O, Erol C, Ozbek H, Paksoy Y. Effect of radiation dose reduction on image quality in adult head CT with noise-suppressing reconstruction system with a 256 slice MDCT. J Appl Clin Med Phys. 2015; 16: 5360

24. Shrimpton PC, Jansen JT, Harrison JD. Updated estimates of typical effective doses for common CT examinations in the UK following the 2011 national review. Br J Radiol. 2016; 89 (1057):20150346.

25. Palorini F, Origgi D, Granata C , Matranga D, Salerno S. Adult exposure from MDCT including multiphase studies: first Italian nationwide survey. Eur Radiol. 2013; 24(2):469-83.

26. 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

27. Foley SJ, Mcentee MF, Rainford LA. Establishment of CT diagnostic reference levels in Ireland. Br J Radiol. 2012; 85:1390–1397.

28. Suliman II, Abdalla SE, Ahmed NA, Galal MA, Salih I. Survey of computed tomography technique and radiation dose in Sudanese hospitals. Eur J Radiol. 2011; 80(3):e544-51.

29. Ekpo EU, Adejoh T, Akwo JD, Emeka OC, Modu AA, Abba M, et al. Diagnostic reference levels for common computed tomography (CT) examinations: results from the first Nigerian nationwide dose survey. J. Radiol. Prot. 2018; 38:525–535

30. European Commission. Medical Radiation Exposure of the European Population (Part2). Radiation Protection No 180. Luxemburg: Publications Office of the European Union. 2014

31. Kanal K M, Butler PF, Sengupta D, Bhargavan-Chatfield M., Coombs LP, Morin RL. United States Diagnostic Reference Levels and Achievable Doses for 10 Adult CT Examinations. J Rad 2017; 284:120-133.

32. Medical Information Research Information Network (JRIME). Diagnostic Reference Levels Based on Latest Surveys in Japan 2015. Available from: http://www.radher.jp/J-RIME/report/DRLhoukokusyoEng.pdf. 2015, Nov 10.

33. Akpochafor MO, Omojola AD, Adeneye SO, Ekpo V, Adedewe NA, Adedokun AR, Adewa DJ, Aweda MA, Ekpo MA. Computed tomography dose reference level for non-contrast and contrast examination in 13 CT facilities in South-West Nigeria. PJR. 2018; 4: 285-293

34. Akpochafor M, Adeneye SO, Ololade Kehinde1, Omojola AD, Oluwafemi A, Nusirat A, Aderonke A, Aweda MA, Bright Aboyewa O. Development of Computed Tomography Head and Body Phantom for Organ Dosimetry. Iran J Med Phys 2019; 16:8-14.