Rationale: Despite several decades of research, the exact etiology of adolescent idiopathic scoliosis (AIS) remains unclear. In AIS, spine curvature begins with and progresses during the adolescent growth spurt. Previous studies are only performed on populations with already established scoliosis and normal spinal growth (of bone and IVD tissue) during adolescence has also not been defined. Growth pattern differences may exist between scoliotic and nonscoliotic subjects. Previous studies support the hypothesis that AIS is a spinal deformity that starts with decompensation in the IVD and is linked to sagittal spinal alignment. However, to understand its cause and pathogenic mechanism, the changes to the adolescent spine must be assessed longitudinally during the growth period coinciding with the period prior to and during the onset of AIS. Ideally this should include a cohort who do and do not develop AIS and their assessment must be minimally harmful, without radiation exposure. Certain populations are at increased risk for scoliosis development (i.e. girls with family members with scoliosis and 22q11.2DS patients). New imaging modalities (boneMRI, 3D spinal ultrasound) allow for non-radiographic monitoring of spinal growth.