Using ultrasound imaging to identify landmarks in vertebra models to assess spinal deformity.

Scoliosis is a type of spinal deformity that commonly develops in adolescents. Cobb angle, using the most tilted vertebrae, is the gold standard to assess scoliosis on radiographs. However, regularly taking radiographs introduces harmful ionizing radiation to patients, thus non-ionizing radiation methods have been explored for many years. Ultrasound has been proposed as one of the non-ionizing radiation methods to measure the deformity. This research was divided into two studies: 1) to investigate the reliability and repeatability of a new proposed method to measure Cobb angle; 2) to determine if landmarks can be identified from ultrasound images to measure curvature of spine. Based on the two studies, the feasibility of using ultrasound images to assess spinal deformity will be determined. Thirty-nine radiographs were used in the first study. The new method agreed well with the traditional Cobb method with intraclass correlation coefficient (ICC) value greater than 0.7 in different severity groups, and the average angle difference was 1.6° ± 3.1°. The second study showed laminae and transverse processes could be recognized from ultrasound images. The difference of the width of the laminae between the phantom and the ultrasound image was 0.3 mm. Therefore, it is feasible to use the proposed method and the laminae from the ultrasound images to assess the severity of scoliosis.