Detection of secondary ossification centers by sonography

BACKGROUND: To assess the validity of ultrasonography (US) in detection of secondary ossification centers (SOC) of the hand. Radiography is the standard technique for estimating skeletal bone age with its unwanted harmful effects mostly undesirable in little children. If efficient enough, US could be an appropriate substitute. MATERIALS AND METHODS: Left hand US was performed on 6-60 months children (n = 24, with 29 SOCs for each child in his/her hand and a total of 696 SOCs) referred for wrist radiography and bone age determination during a 4 months period. The presence of SOCs was investigated by US and radiography by two radiologists under blind conditions. RESULTS: US was evaluated 696 SOCs, and 446 SOCs were detected, by US and 436 by radiography without statistically significant difference. The results of US and radiography in detection of SOCs of distal forearm (23 SOCs were detected by both US and radiography) and carpi (87 SOCs) were identical. However, in metacarpi (94 for US, 88 for radiography) and phalanges (242 for US, 238 for radiography) US appeared better. CONCLUSION: On the base of our data, US is at least as effective as radiography in detection of SOCs and therefore can play a role in the skeletal age estimation.