Evaluation of Low-Dose 3D Skull CT Images in Craniosynostosis

Document Type : Original Paper


1 Medical imaging research center, Shiraz university of medical sciences, Shiraz, Iran

2 Department of Radiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz 7134845794, Iran.

3 Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012. INDIA

4 Retired Scientist from Indian Institute of Astrophysics, present affiliation: Ongil, 79 D3, Sivaya Nagar, Reddiyur Alagapuram, Salem 636004. India.

5 Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran


Introduction: Computed Tomography (CT) is nowadays used widely to differentiate normal brain cranium sutures from abnormal ones in pediatric patients with the aim of early treatment. This study tried to develop a low-dose CT protocol with the acceptable image quality of skull bone in order to evaluate craniosynostosis.
Material and Methods: In this study a cranium bone of human cadaver was scanned with standard and reduced dose protocols. Two radiologists verified the quality of skull bone images acquired from the protocol in which there had been 60% dose reduction to scan pediatric patients. The quality of low dose protocol of three dimensional (3D) CT images of skull bone of 57 pediatric subjects suspected of craniosynostosis were compared with standard-dose skull CT images of 44 patients of the same age range. Volume CT dose index (CTDIvol), dose-length product (DLP), and effective dose (ED) were used to evaluate CT dose protocols. The comparison was made by two sample t-test.
Results: Mean and standard deviations of CTDIvol, DLP, and ED of standard and reduced doses were 12.4±2.7 mGy, 191.5±54 mGy.cm, 1.94±0.58 mSv and 5.4±0.2 mGy, 85±9 mGy.cm, 0.77±0.17 mSv, respectively, which had statistically significant difference (α=0.05). The quality of skull bone views obtained from low-dose CT protocol were found to be as good as in standard dose. 
Conclusion: Standard-dose 3D CT protocol of skull bone can be replaced by a 60%-reduced-dose 3D CT protocol with comparable image quality in pediatric patients suspected of craniosynostosis.


Main Subjects

  1. Ernst CW, Hulstaert TL, Belsack D, Buls N, Gompel GV, Nieboer KH, et al. Dedicated sub 0.1 mSv 3DCT using MBIR in children with suspected craniosynostosis: quality assessment. European Radiology. 2016 Mar;26(3):892-9.
  2. Kirmi O, Steven JLo, Johnson D, Anslow P. Craniosynostosis: A Radiological and Surgical Perspective. Seminars in Ultrasound, CT and MRI. 2009;30:492-512.
  3. Kim HJ, Roh HG, Lee IW. Craniosynostosis : Updates in Radiologic Diagnosis. Journal of Korean Neurosurgical Society. 2016 May;59(3):219.
  4. Pearce MS, Salotti JA, Little MP, McHugh K, Lee C, Kim KP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukemia and brain tumors: a retrospective cohort study. The Lancet. 2012 Aug 4;380(9840):499-505.
  5. Ryan PM, et al. Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction. Journal of Neurosurgery Pediatrics PED. 2013 Oct 1;12(4):406-10.
  6. Hamada N. Ionizing radiation sensitivity of the ocular lens and its dose rate dependence. International Journal of Radiation Biology. 2017 Oct 3;93(10):1024-34.
  7. Han MA, Kim JH. Diagnostic X-Ray Exposure and Thyroid Cancer Risk: Systematic Review and Meta-Analysis. Thyroid. 2018 Feb 1;28(2):220-8.
  8. Lai CWK, Cheung HY, Chan TP, Wong TH. Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield. Radioprotection. 2015 Jan 1;50(3):195-201.
  9. Fabritius G, Brix G, Nekolla E, Klein S, Popp HD, Meyer M, Glatting G, et al. Cumulative radiation exposure from imaging procedures and associated lifetime cancer risk for patients with lymphoma. Scientific reports. 2016 Oct 17;6(1):1-9.
  10. Kaasalainen T, Palmu K, Lampinen A, Reijonen V, Leikola J, Kivisaari R, et al. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction.  Pediatric radiology. 2015 Sep;45(10):1544-53.
  11. Montoya JC, Eckel LJ, DeLone DR, Kotsenas AL, Diehn FE, Yu L, et al. Low-Dose CT for Craniosynostosis: Preserving Diagnostic Benefit with Substantial Radiation Dose Reduction. American Journal of Neuroradiology. 2017 Apr 1;38(4):672-7.
  12. Morton RP, Reynolds RM, Ramakrishna R, Levitt MR, Hopper RA, Lee A, et al. Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction: clinical article. Journal of Neurosurgery: Pediatrics. 2013 Oct 1;12(4):406-10.
  13. Deak PD, Smal Y, Kalender WA. Multisection CT protocols: sex- and age-specific conversion factors used to determine effective dose from dose-length product. Radiology, 2010 Oct;257(1):158-66.
  14. Bushberg JT, Leidholdt EM, Boone JM. The Essential Physics of Medical Imaging. 2002, Philadelphia, USA: Williams & Wilkins.
  15. Danil WW. Biostatistics: Afoundation for analysis in the health sciences, 7th edition. 1999, New York, United States: John Wiley & Sons, Inc.
  16. Nagayama, Y, Oda S, Nakaura T, Tsuji A, Urata J, Furusawa M, et al. Radiation Dose Reduction at Pediatric CT: Use of Low Tube Voltage and Iterative Reconstruction. Radiographics. 2018 Sep;38(5):1421-40.
  17. Reid J, Gamberoni J, Dong F, Davros W. Optimization of kVp and mAs for pediatric low-dose simulated abdominal CT: is it best to base parameter selection on object circumference? American Journal of Roentgenology. 2010 Oct;195(4):1015-20.
  18. Sodickson A, Baeyens PF, Andriole KP, Prevedello LM, Nawfel RD, Hanson R, et al. Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology. 2009 Apr;251(1):175-84.
  19. Chaparian A, Zarchi HK. Assessment of radiation-induced cancer risk to patients undergoing computed tomography angiography scans. International Journal of Radiation Research. 2018;16(1):107-15.
  20. Mahmoodi M, Chaparian A. Organ doses, effective dose, and cancer risk from coronary CT angiography examinations. American Journal of Roentgenology. 2020 May;214(5):1131-6.
  21. Karimizarchi H, Chaparian A. Estimating risk of exposure induced cancer death in patients undergoing computed tomography pulmonary angiography. Radioprotection. 2017 Apr 1;52(2):81-6.
  22. Ogbole GI. Radiation dose in paediatric computed tomography: risks and benefits. Annals of Ibadan postgraduate medicine. 2010;8 (2):118-26.