Radiation Dose Optimization during Temporal Bone CT Examination Using One-Shot Axial Volumetric Acquisition

Document Type : Original Paper


1 Laboratory of Electronic Systems, Information Processing, Mechanics and Energetics, Faculty of Sciences , University Ibn Tofail Kenitra, Kenitra, Morocco

2 Hassan First University of Settat, High Institute of Health Sciences, Laboratory of Sciences and Health Technologies, Settat, Morocco

3 Departement of Physics, Laboratory of High Energy Physics, Modelling and Simulation, Faculty of Science, Mohammed V Agdal University, Rabat, Kingdom of Morocco


Introduction: The optimization of radiation exposure when exploring small and complex anatomical structures is the most important issue for temporal bone CT. The objective of this study is to use single-shot volume acquisition in order to minimize the dose and compare the obtained image quality to a conventional helical technique. 
Material and Methods: Twenty patients (8 males, 12 females) were scanned using the 135kVp single-shot volume mode (VMCT135-kVp) whereas other twenty patients (9 males, 11 females) were examined using the 120kVp helical mode (HMCT120-kVp). A physician-interpreter evaluated the subjective conspicuity of 53 structures in the temporal bone on a 5-point scale using multiplanar reconstruction (MPR). In addition, the image noise in both techniques was quantified by analyzing it in three different regions of interest (ROIs). Radiation dose reduction was noted and compared with literature-based effective dose dosimetry data.
Results: The mean dose-length-product (DLP) for the VMCT135-kVp was (69.6±2.5 mGy.cm), which was significantly lower (p<0.001), compared to (186.4±4.3 mGy.cm) for HMCT120-kVp. Similarly, the effective dose (0.15±0.01 mSv) for VMCT135-kVp was reduced by approximately 61.5% relative to (0.39±0.05 mSv) for HMCT120-kVp. In contrast, there was no significant difference in the image noise average between the two protocols (p> 0.05). Indeed, the overall analysis of the 53 anatomic structures revealed no differences between the two protocols, and most anatomic structures were identified.
Conclusion: For temporal bone, the VMCT135-kVp scan significantly reduces radiation exposure compared to the HMCT120-kVp. The obtained dose was lower compared to the literature-based protocol while maintaining image visualization quality.


Main Subjects

  1. Guberina N, Dietrich U, Arweiler-Harbeck D, Forsting M, Ringelstein A. Comparison of radiation doses imparted during 128-, 256-, 384-multislice CT-scanners and cone beam computed tomography for intra-and perioperative cochlear implant assessment. American journal of otolaryngology. 2017 Nov 1;38(6):649-53.
  2. Chen JY, Mafee MF. Computed tomography imaging technique and normal computed tomography anatomy of the temporal bone. Operative Techniques in Otolaryngology-Head and Neck Surgery. 2014 Mar 1;25(1):3-12.
  3. Jackler RK, Parker DA. Radiographic differential diagnosis of petrous apex lesions. Otology & Neurotology. 1992 Nov 1;13(6):561-74.
  4. Basraoui D, Elatiqi K, Jalal H. computed tomography of the petrous bone: Particularities in children. Advances in Molecular Imaging. 2018 May 29;8(2):15-24.
  5. Nauer CB, Zubler C, Weisstanner C, Stieger C, Senn P, Arnold A. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality. Neuroradiology. 2012 Mar;54:247-54.
  6. Meyer M, Haubenreisser H, Raupach R, Schmidt B, Lietzmann F, Leidecker C, et al. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging. European radiology. 2015 Jan;25:178-85.
  7. Unlu E, Okur N, Acay MB, Kacar E, Ozdinc S, Balcik C, et al. The prevalence of incidentally detected idiopathic misty mesentery on multidetector computed tomography: can obesity be the triggering cause?. Canadian Association of Radiologists' Journal. 2016 Aug;67(3):212-7.
  8. International Commission on Radiological Protection. Recommendations of the ICRP. ICRP publication 26. Ann. ICRP. 1977;1(3).
  9. van der Molen AJ, Geleijns J. Overranging in multisection CT: quantification and relative contribution to dose—comparison of four 16-section CT scanners. Radiology. 2007 Jan;242(1):208-16.
  10. Christner JA, Zavaletta VA, Eusemann CD, Walz-Flannigan AI, McCollough CH. Dose reduction in helical CT: dynamically adjustable z-axis X-ray beam collimation. American journal of roentgenology. 2010 Jan;194(1):W49-55.
  11. Schilham A, van der Molen AJ, Prokop M, de Jong HW. Overranging at multisection CT: an underestimated source of excess radiation exposure. Radiographics. 2010 Jul;30(4):1057-67.
  12. Cody DD, Mahesh M. Technologic advances in multidetector CT with a focus on cardiac imaging. Radiographics. 2007 Nov;27(6):1829-37.
  13. Bauknecht HC, Siebert E, Dannenberg A, Bohner G, Jach C, Diekmann S, et al. Image quality and radiation exposure in 320-row temporal bone computed tomography. Dentomaxillofacial Radiology. 2010 May;39(4):199-206.
  14. Tada A, Sato S, Masaoka Y, Kanazawa S. Imaging of the temporal bone in children using low‐dose 320‐row area detector computed tomography. Journal of Medical Imaging and Radiation Oncology. 2017 Aug;61(4):489-93.
  15. Podberesky DJ, Angel E, Yoshizumi TT, Toncheva G, Salisbury SR, Brody AS, et al. Comparison of radiation dose estimates and scan performance in pediatric high-resolution thoracic CT for volumetric 320-detector row, helical 64-detector row, and noncontiguous axial scan acquisitions. Academic Radiology. 2013 Sep 1;20(9):1152-61.
  16. Jafari S, Karimi M, Khosravi H, Goodarzi R, Pourkaveh M. Establishment of diagnostic reference levels for computed tomography scanning in hamadan. Journal of Biomedical Physics & Engineering. 2020 Dec;10(6):792.
  17. Muhammad NA, Kayun Z, Abu Hassan H, Wong JH, Ng KH, Karim MK. Evaluation of organ dose and image quality metrics of pediatric CT chest-abdomen-pelvis (CAP) examination: an anthropomorphic phantom study. Applied Sciences. 2021 Feb 25;11(5):2047.
  18. Niu YT, Mehta D, Zhang ZR, Zhang YX, Liu YF, Kang TL, Xian JF, Wang ZC. Radiation dose reduction in temporal bone CT with iterative reconstruction technique. American journal of neuroradiology. 2012 Jun 1;33(6):1020-6.
  19. Lutz J, Jäger V, Hempel MJ, Srivastav S, Reiser M, Jäger L. Delineation of temporal bone anatomy: feasibility of low-dose 64-row CT in regard to image quality. European radiology. 2007 Oct;17:2638-45.
  20. Schwab SA, Eberle S, Adamietz B, Kuefner MA, Kramer M, Uder M, and et al. Comparison of 128-section single-shot technique with conventional spiral multisection CT for imaging of the temporal bone. American Journal of Neuroradiology. 2012 Apr 1;33(4):E55-60.
  21. Nauer CB, Rieke A, Zubler C, Candreia C, Arnold A, Senn P. Low-dose temporal bone CT in infants and young children: effective dose and image quality. American journal of neuroradiology. 2011 Sep 1;32(8):1375-80.
  22. Kim CR, Jeon JY. Radiation dose and image conspicuity comparison between conventional 120 kVp and 150 kVp with spectral beam shaping for temporal bone CT. European Journal of Radiology. 2018 May 1;102:68-73.
  23. Noto D, Funama Y, Kitajima M, Utsunomiya D, Oda S, Yamashita Y. Optimizing radiation dose by varying age at pediatric temporal bone CT. Journal of applied clinical medical physics. 2015 Jan;16(1):311-8.
  24. Bauknecht HC, Siebert E, Dannenberg A, Bohner G, Jach C, Diekmann S, and et al. Image quality and radiation exposure in 320-row temporal bone computed tomography. Dentomaxillofacial Radiology. 2010 May;39(4):199-206.
  25. Kaste SC, Young CW, Holmes TP, Baker DK. Effect of helical CT on the frequency of sedation in pediatric patients. AJR. American journal of roentgenology. 1997 Apr;168(4):1001-3.
  26. Husstedt HW, Prokop M, Dietrich B, Becker H. Low-dose high-resolution CT of the petrous bone. Journal of Neuroradiology= Journal de Neuroradiologie. 2000 Jun 1;27(2):87-92.