Assessment of scoliosis in adolescence and adults by 3-D ultrasound imaging: a pilot study

Abstract

Objective To assess scoliosis in adolescence and adults by three-dimensional (3-D) ultrasound imaging. Methods A commercial available ultrasound instrument with a magnetic sensor system was used for long distance 3-D ultrasound imaging.Specific phantoms were imaged to evaluate the precision of this imaging system. Twenty healthy adults and 20 patients with scoliosis were imaged by 3-D ultrasonography and radiography. The deformity angle of the patients with scoliosis was measured on the reconstructed coronal plane (C plane) of 3-D ultrasound imaging. The relevance between the curvature measured by ultrasound and the Cobb angles originated by radiography were evaluated. Results There was no significant difference between the angles of the phantom measured by the 3-D ultrasound imaging system and that measured by an angle gauge (P=0.479). The transverse process, vertebral arch and acoustic shadow of the central spinous process of spines in healthy adults can be displayed on the reconstructed C plane by 3-D ultrasound imaging. The morphology of scoliosis in all the twenty patients can be observed on the reconstructed C planes (multi-layers) by 3-D ultrasound imaging, which accorded well with that observed on radiograph. In 9 patients, part of the spinal segment could not be totally displayed on one single coronal plane and no additional measurement was carried out. In 11 patients, all the segments of the spine could be clearly displayed on a single coronal plane and the curvature of scoliosis was then measured. There were no significant differences between the angle measured on 3-D ultrasound imaging and the Cobb angle measured on radiograph(P=0.974) and the two measurement methods have high correlation(r=0.991, P<0.000 1). Conclusions The commercial available 3-D ultrasound imaging system applied in this study offers a viable method to assess scoliosis in adolescence and adults in a reliable and radiation-free manner. Key words: Ultrasonography, three-dimensional; Scoliosis; Magnetic induction