A medical ultrasound system and a 4.0 MHz convex probe with a built-in positioning system were used. The positioning system is essential to reconstruct the 3D image. Three different types of spine were scanned: i) two Sawbones spine phantoms: one was a normal spine without any vertebral rotation and the other was set as a moderate curve with certain vertebral rotation, ii) a non-scolitotic spine from a 33-year-old male healthy volunteer and iii) a scoliotic spine from a 16-year-old female AIS patient with right thoracic (14°) and left lumbar (21°). The phantoms were scanned from T6 to L5, and the subjects were from T1 to L5 in standing positions.
After acquisition, the 3D ultrasound data was fed to an in-house developed program. To accelerate the reconstruction process, the program first eliminated the overlapping data. The manual determination of region of interest followed to further eliminate unnecessary information. The median filter was then applied to reduce the noise. The voxel-based approach was used to perform the volume formation. Smoothing was the last step before volume rendering. This proposed method was first applied to the reconstruction of 3D spine.