Optimisation of paediatrics computed radiography for full spine curvature measurements using a phantom: a pilot study

Sa dos Reis, Claudia; Ndlovu, J.; Serrenho, C.; Akhtar, I.; de Haan, S.; Garcia, J.; de Linde, D.; Thorskog, M.; Franco, L.; Lanca, C.; Hogg, P.

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Access Status

Open access

Authors

Sa dos Reis, Claudia

Ndlovu, J.

Serrenho, C.

Akhtar, I.

de Haan, S.

Garcia, J.

de Linde, D.

Thorskog, M.

Franco, L.

Lanca, C.

Hogg, P.

Date

2014

Type

Book Chapter

Metadata

Show full item record

Citation

Sa dos Reis, C. and Ndlovu, J. and Serrenho, C. and Akhtar, I. and de Haan, S. and Garcia, J. and de Linde, D. et al. 2014. Optimisation of paediatrics computed radiography for full spine curvature measurements using a phantom: a pilot study. In adiation dose and image quality optimisation in medical imaging, 43-51. Lisboa.

Source Title

adiation dose and image quality optimisation in medical imaging

Additional URLs

http://usir.salford.ac.uk/34439/

ISBN

978-1-907842-60-3

School

Department of Medical Radiation Sciences

Remarks

This open access article is distributed under the Creative Commons license http://creativecommons.org/licenses/by-nc-sa/

URI

http://hdl.handle.net/20.500.11937/44243

Collection

Curtin Research Publications

Abstract

Aim: Optimise a set of exposure factors, with the lowest effective dose, to delineate spinal curvature with the modified Cobb method in a full spine using computed radiography (CR) for a 5-year-old paediatric anthropomorphic phantom. Methods: Images were acquired by varying a set of parameters: positions (antero-posterior (AP), posteroanterior (PA) and lateral), kilo-voltage peak (kVp) (66-90), source-to-image distance (SID) (150 to 200cm), broad focus and the use of a grid (grid in/out) to analyse the impact on E and image quality (IQ). IQ was analysed applying two approaches: objective [contrast-to-noise-ratio/(CNR] and perceptual, using 5 observers. Monte-Carlo modelling was used for dose estimation. Cohen’s Kappa coefficient was used to calculate inter-observer-variability. The angle was measured using Cobb’s method on lateral projections under different imaging conditions. Results: PA promoted the lowest effective dose (0.013 mSv) compared to AP (0.048 mSv) and lateral (0.025 mSv). The exposure parameters that allowed lower dose were 200cm SID, 90 kVp, broad focus and grid out for paediatrics using an Agfa CR system. Thirty-seven images were assessed for IQ and thirty-two were classified adequate. Cobb angle measurements varied between 16°±2.9 and 19.9°±0.9. Conclusion: Cobb angle measurements can be performed using the lowest dose with a low contrast-tonoise ratio. The variation on measurements for this was ±2.9° and this is within the range of acceptable clinical error without impact on clinical diagnosis. Further work is recommended on improvement to the sample size and a more robust perceptual IQ assessment protocol for observers.