A Novel Classification Method for Mild Adolescent Idiopathic Scoliosis Using 3D Ultrasound Imaging

Abstract Mild adolescent idiopathic scoliosis (AIS), with Cobb For the preliminary study, 90 mild AIS subjects (21 M and 69 F; Age:14.5±1.7 years old; Cobb: 18.2±6.4°) underwent both 3D ultrasound and X-ray scanning on the same day. For each case, a clinician measured Cobbs and denoted major curve as ground truth. Bending Asymmetry Index (BAI) was developed to indicate the presence of a possible structural curve. The curve classification was coded to a modified Lenke classification for mild cases (m-Lenke). The results of 3D ultrasound classification were evaluated with the X-ray. It was shown that 70.1% of the subjects had identical curve classification results and 72.0% had the correct major curve detection. Lumbar-dominated curves had distinctive performance (p=0.91, r=0.91) against others. The study demonstrated the possibility of a 3D ultrasound-based method for mild AIS curve classification. The discrepancies could be partially explained by the limitations of the ultrasound scanning in proximal thoracic region. Subsequent studies will validate the proposed method with a larger cohort.