Using Radiation-free Ultrasound for Screening Scoliosis Among School Children in Hong Kong to Reduce Unnecessary X-ray Exposure

In the scoliosis screening program of the Student Health Service (SHS), Department of Health (DH), in Hong Kong, more than 50% of screened school children prescribed with x-ray examination basing on the screening protocol did not have Cobb angle greater than the referral threshold of 20°; ie they did not need specialist referral and thus were subjected to unnecessary x-ray exposure. Our primary objective is to determine whether a new radiation-free ultrasound system could identify subjects with Cobb angle greater than the referral threshold of 20° thus avoiding unnecessary x-rays in the referral workflow. The secondary objective is to evaluate if Angle of Trunk Rotation (ATR) can further increase the accuracy of ultrasound assessment.