Image based simulation of the low dose computed tomography images suggests 13 mAs 120 kV suitability for non-syndromic craniosynostosis diagnosis without iterative reconstruction algorithms.

OBJECTIVES: The aim of this study was to simulate low dose paediatric head CT images with different noise levels corresponding to various tube current time product values and assess simulated image suitability in non-syndromic craniosynostosis diagnostics. METHOD: 29 paediatric patients who underwent head CT examinations for cranial deformity were enrolled in the study. The low dose CT images, corresponding to 120 kV and 120 mAs, 100 mAs, 80 mAs, 50 mAs and 13 mAs settings, were synthesised by adding noise to original data. Three researchers evaluated suitability for diagnostics of original and simulated images by using questionnaire assessing image suitability. RESULT: 174 separate cases (containing 1 axial and 1 3D image) were evaluated. Percentage of images evaluated as suitable for diagnosis were 98.9% on original images, 100% on 120 mAs, 100% on 100 mAs, 97.1% on 80 mAs, 96.6% on 50 mAs and 96% on 13 mAs. CONCLUSIONS: Images registered with 120 kV 13 mAs can be used to diagnose non-syndromic craniosynostosis with statistically same accuracy as with standard protocol and correspond to decrease of effective dose from 4.98 mSv to 0.33 mSv (median values).