Ultrasound Imaging of Spinal Vertebrae to Study Scoliosis

Abstract

Scoliosis is a musculoskeletal disorder manifested as a three-dimensional spinal deformity. It affects 2% -3% of the adolescent population. The conventional method to diagnose scoliosis is to measure the Cobb angle from posteroanterior radiograph. Since radiation exposure is not desirable for patients, other non-ionizing methods have been explored. Among all the non-ionization methods, ultrasound (US) is a potential cost-effective method. However, our understanding of US interaction with the vertebrae or the spine is limited. The purpose of this study was to demonstrate the ability of US to identify bony landmarks for measuring spinal deformity. This study used a phased array US system with a 5 MHz transducer and a position encoder. In-vitro experiment on a cadaver vertebra and a pilot clinical study were carried out. The in-vitro experimental results showed that the lamina and spinous process were strong reflectors from the single vertebra. Less than 4% of error occurred on the dimension measurements. The pilot study was performed on a healthy subject and a scoliotic patient. The results indicated the lamina and spinous process could be identified and the curvature of the spine could be estimated using the reflectors. The difference of the curvature angle of the spine measured from the radiograph and the US images was 2˚. These results have illustrated that US is a promising tool to measure curvature of spinal deformity and study scoliosis.

Reliability of the axial vertebral rotation measurements of adolescent idiopathic scoliosis using the center of lamina method on ultrasound images: in vitro and in vivo study

“…As shown in Fig. 2a, the laminae, which were strong reflection points (around the two lowest points of the ''W-shape'') due to a strong reflection signal from the lamina area [17], were used to assess the AVR. A line was drawn through the centers of the left and right laminae and the angle formed between this line and the reference horizontal level indicated the AVR angle.…”

“…However, both teams acquired data while subjects were in the prone position, which affected the spinal deformity assessment. Recently, Chen et al [16,17] validated that upright ultrasound spine images could be obtained and the center of lamina (COL) method using the ultrasound images provided both Cobb angle and AVR measurements. The Cobb angle validation studies were reported [18,19].…”

Excitation of ultrasonic Lamb waves using a phased array system with two array probes: Phantom and in vitro bone studies

“…The recorded echoes are stored, 183 delayed, and then summed to produce an ultrasound signal. The 184 scanner was previously used to study scoliosis [22]. 185 The two array probes used are the 16-element (2.25L16) and 186 64-element (2.25L64) array probes with a central frequency of 187 2.25 MHz (Fig.…”

Ultrasound-assisted brace casting for adolescent idiopathic scoliosis, IRSSD Best research paper 2014

“…To measure the coronal curvature on the ultrasound image, the centers of laminae (COL) method introduced by Chen et al [19,20] was applied. The centers of laminae at the end vertebra levels were manually selected on the coronal plane of the ultrasound image.…”