Validation of automatic bone age rating in children with precocious and early puberty.

BACKGROUND AND AIMS: Manual bone age (BA) rating in precocious puberty (PP) is associated with considerable rater variability. The aim was to evaluate a new method for automated Greulich and Pyle (GP) BA determination in children with PP.

METHODS: Seven hundred forty-one archived X-rays from 13 boys and 103 girls with PP or early puberty of various etiologies (age range at time of X-ray, 0.3-14.8 years; mean BA advancement, 2.3 years) were rated. Automatic rating (BoneXpert BA, or BXBA) was compared with the original manual GP rating (manual BA, or ManBA). X-rays where BXBA deviated from ManBA by more than 1.5 years were rerated by three raters, and the average was formed (ReferenceBA).

RESULTS: All 741 X-rays, except nine (three images had poor quality and six were from children with a chronological age younger than 1.5 years), were analyzed automatically. The mean difference of BXBA-ManBA was -0.19 years; the SD of the differences was 0.76 years (95% confidence interval 0.72-0.80). ReferenceBA was determined for 41 images. A discrepancy from ReferenceBA greater 1.5 years was found in four images against BXBA and in 10 images against ManBA.

CONCLUSION: Automated BA is efficient and reliable in children with PP.