A reduced micro-dose protocol for 3D reconstruction of the spine in children with scoliosis: results of a phantom-based and clinically validated study using stereo-radiography
The aim of this study was to validate the reproducibility of 3D reconstructions of the spine using a new reduced micro-dose protocol.
First, semi-quantitative image analysis was performed using an anthropomorphic child phantom undergoing low-dose biplanar radiography. This analysis was used to establish a “lowest dose” allowing for acceptable visibility of spinal landmarks. Subsequently, a group of 18 scoliotic children, 12 years of age or younger, underwent full-spine biplanar radiography with both micro-dose and the newly defined reduced micro-dose. An intra- and inter-observer reliability study of 3D reconstructions of the spine was performed according to the International Organization for Standardization (ISO)-5725 standard, with three operators.
The reduced micro-dose setting corresponded to a theoretical reduction of radiation dose exposure of approximately 58%. In vivo results showed acceptable intra- and inter-observer reliability (for instance, 3.8° uncertainty on Cobb angle), comparable to previous studies on 3D spine reconstruction reliability and reproducibility based on stereo-radiography.
A new reduced micro-dose protocol offered reliable 3D reconstructions of the spine in patients with mild scoliosis. However, the quality of 3D reconstructions from both reduced micro-dose and micro-dose was inferior to standard-dose protocol on most parameters. Standard-dose protocol remains the option of choice for most accurate assessment and 3D reconstruction of the spine. Still, this new protocol offers a preliminary screening option and a follow-up tool for children with mild scoliosis yielding extremely low radiation and could replace micro-dose protocol for these patients.
• We investigated the reliability of 3D reconstructions of the spine based on a new stereo-radiography protocol reducing radiation dose by 58% compared with established micro-dose imaging protocol.
• The new reduced micro-dose protocol offers a reproducible preliminary screening option and a follow-up tool in the necessarily frequent repeat imaging of children with mild scoliosis yielding extremely low radiation and could replace existing micro-dose protocol for these patients.
• EOS standard-dose protocol remains the option of choice for exact radiographic assessment of scoliosis, offering more exact 3D reproducibility of the spine compared to both micro-dose and the new reduced micro-dose protocols.
KeywordsThree-dimensional imaging Scoliosis Radiation dosage Radiography Reproducibility of results
Adolescent idiopathic scoliosis
As low as reasonable achievable
Apical vertebra rotation
Dose area product
Intra vertebral rotation
International organization for standardization
Torsional index of the spine
Fondation ParisTech BiomecAM chair on subject specific modeling, with the financial support of Société Générale and Covea.
Compliance with ethical standards
The scientific guarantor of this publication is Prof. Raphaël Vialle.
Conflict of interest
Two authors of this manuscript declare relationship with the following company: EOS imaging®, Paris, France (Prof. Raphaël Vialle, consulting fees. Prof. Wafa Skalli, coinventor of the EOS system, with no personal financial benefice (royalties rewarded to research and education)).
Statistics and biometry
No complex statistical methods were necessary for this paper.
Written informed consent was obtained from all subjects (patients) in this study.
Institutional Review Board approval was obtained.
• Prospective validation study with technical notes
• Multicenter study
- 1.Labelle H, Aubin CE, Jackson R, Lenke L, Newton P, Parent S (2011) Seeing the spine in 3D: how will it change what we do? J Pediatr Orthop 31:S37–S45. https://doi.org/10.1097/BPO.0b013e3181fd8801
- 6.Nault ML, Mac-Thiong JM, Roy-Beaudry M et al (2014) Three-dimensional spinal morphology can differentiate between progressive and nonprogressive patients with adolescent idiopathic scoliosis at the initial presentation: a prospective study. Spine (Phila Pa 1976) 39:601–606. https://doi.org/10.1097/BRS.0000000000000284 CrossRefGoogle Scholar
- 7.Levy AR, Goldberg MS, Mayo NE, Hanley JA, Poitras B (1996) Reducing the lifetime risk of cancer from spinal radiographs among people with adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 21:1540–1547. https://doi.org/10.1097/00007632-199607010-00011
- 9.Ronckers CM, Land CE, Miller JS, Stovall M, Lonstein JE, Doody MM (2010) Cancer mortality among women frequently exposed to radiographic examinations for spinal disorders. Radiat Res 174:83–90. https://doi.org/10.1667/RR2022.1
- 10.Simony A, Carreon LY, Jensen KE, Christensen SB, Andersen MO (2015) Incidence of cancer and infertility, in patients treated for adolescent idiopathic scoliosis 25 years prior. Spine J 15:S112. https://doi.org/10.1016/j.spinee.2015.07.076
- 11.Kadoury S, Mandel W, Roy-Beaudry M, Nault ML, Parent S (2017) 3-D morphology prediction of progressive spinal deformities from probabilistic modeling of discriminant manifolds. IEEE Trans Med Imaging 36:1194–1204. https://doi.org/10.1109/TMI.2017.2657225
- 12.Damet J, Fournier P, Monnin P et al (2014) Occupational and patient exposure as well as image quality for full spine examinations with the EOS imaging system occupational and patient exposure as well as image quality for full spine examinations with the EOS imaging system. Med Phys. https://doi.org/10.1118/1.4873333
- 13.Strauss KJ, Kaste SC (2006) ALARA in pediatric interventional and fluoroscopic imaging: striving to keep radiation doses as low as possible during fluoroscopy of pediatric patients-a white paper executive summary. J Am Coll Radiol 3:686–688. https://doi.org/10.1016/j.jacr.2006.04.008 CrossRefPubMedGoogle Scholar
- 14.Humbert L, De Guise JA, Aubert B, Godbout B, Skalli W (2009) 3D reconstruction of the spine from biplanar X-rays using parametric models based on transversal and longitudinal inferences. Med Eng Phys 31:681–687. https://doi.org/10.1016/j.medengphy.2009.01.003
- 15.Ilharreborde B, Steffen JS, Nectoux E et al (2011) Angle measurement reproducibility using EOSThree-dimensional reconstructions in adolescent idiopathic scoliosis treated by posterior instrumentation. Spine (Phila Pa 1976) 36:E1306–E1313. https://doi.org/10.1097/BRS.0b013e3182293548 CrossRefGoogle Scholar
- 16.Courvoisier A, Ilharreborde B, Constantinou B, Aubert B, Vialle R, Skalli W (2013) Evaluation of a three-dimensional reconstruction method of the rib cage of mild scoliotic patients. Spine Deform 1:321–327Google Scholar
- 18.Dose WB, Dose O, Radiation T (2013) ATOM Dosimetry Phantoms. http://www.cirsinc.com/file/Products/701_706/701%20706%20ATOM%20PB%20110615.pdf. Accessed 17 Oct 2018