Performance and reliability assessment of a lower dose, task-based scoliosis radiography protocol in pediatric patients.

backgroundFollow-up scoliosis radiographs are performed to assess the degree of spinal curvature and skeletal maturity, which can be done at lower radiation exposures than those in standard-dose radiography.

objectiveDescribe and evaluate a protocol that reduced the radiation in follow-up frontal-view scoliosis radiographs. MATERIALS AND

methodsWe implemented a postero-anterior lower dose modified-technique for scoliosis radiography with task-based definition of adequate image quality and use of technique charts based on target exposure index and patient's height and weight. We subsequently retrospectively evaluated 40 consecutive patients who underwent a follow-up radiograph using the modified-technique after an initial standard-technique radiograph. We evaluated comparisons of proportions for subjective assessment with chi-squared tests, and agreements of reader's scores with intraclass correlation coefficients and Bland-Altman plots. We determined incident air kerma, exposure index, deviation index/standard deviation, dose-area product (DAP), and effective dose for each radiograph. We set statistical significance at P<0.05.

resultsForty patients (65% female), aged 4-17 years. Median effective dose was reduced from 39 to 10 µSv (P<0.001), incident air kerma from 139 to 29 µSv (P<0.001), and DAP from 266 to 55 mGy*cm

conclusionSubstantial dose reduction on follow-up scoliosis imaging with existing radiography units is achievable through task-based definition of adequate image quality and tailoring of radiation to each patient's height and weight, while still allowing for reliable assessment and reproducible measurements.