Monitoring of Curve Progression in Patients with Adolescent Idiopathic Scoliosis Using 3-D Ultrasound

Abstract

ObjectiveTo investigate whether 3D ultrasound can provide comparable results to conventional X-ray examination in assessing curve progression in AIS patients. Methods136 AIS subjects (42 males and 94 females; 10-18 years of age, mean of 14.1 ± 1.9 years) with different severities of scoliosis (Cobb angle ranged from 10-85 degrees, mean of 24.3 ± 14.4 degrees) were included. Each subject underwent bi-planar low-dose X-ray EOS® and 3D ultrasound system scanning with the same posture on the same date. Subjects underwent the second assessment at routine clinical follow-up. Manual measurement of scoliotic curvature on ultrasound coronal projection images and posterior-anterior radiographs were presented as ultrasound curve angle (UCA) and radiographic Cobb angle (RCA), respectively. RCA and UCA increments of five degrees or more represented a scoliosis progression detected by X-ray assessment and 3D ultrasound assessment, respectively. ResultsThe sensitivity and specificity for UCA measurement for detecting scoliosis progression were 0.93 and 0.90, respectively. The negative likelihood ratio of the diagnostic test for scoliosis progression by the 3D ultrasound imaging system was 0.08. ConclusionThe 3D ultrasound imaging method is a valid technique to detect coronal curve progression as compared to conventional radiography in follow-up of AIS. Substituting conventional radiography by 3D ultrasound is effective in reducing the radiation dose to be suffered by AIS patients during their follow-up examinations.