Ultrasound Volume Projection Imaging for Assessment of Scoliosis

Abstract

The standing radiograph is used as a gold standard to diagnose spinal deformity including scoliosis, a medical condition defined as lateral spine curvature > 10°. However, the health concern of X-ray and large inter-observer variation of measurements on X-ray images have significantly restricted its application, particularly for scoliosis screening and close follow-up for adolescent patients. In this study, a radiation-free freehand 3-D ultrasound system was developed for scoliosis assessment using a volume projection imaging method. Based on the obtained coronal view images, two measurement methods were proposed using transverse process and spinous profile as landmarks, respectively. As a reliability study, 36 subjects (age: 30.1 ±14.5; male: 12; female: 24) with different degrees of scoliosis were scanned using the system to test the inter- and intra-observer repeatability. The intra- and inter-observer tests indicated that the new assessment methods were repeatable, with ICC larger than 0.92. Small intra- and inter-observer variations of measuring spine curvature were observed for the two measurement methods (intra-: 1.4 ±1.0° and 1.4 ±1.1°; inter-: 2.2 ±1.6° and 2.5 ±1.6°). The results also showed that the spinal curvature obtained by the new method had good linear correlations with X-ray Cobb's method (R2 = 0.8, p < 0.001, 29 subjects). These results suggested that the ultrasound volume projection imaging method can be a promising approach for the assessment of scoliosis, and further research should be followed up to demonstrate its potential clinical applications for mass screening and curve progression and treatment outcome monitoring of scoliosis patients.

Segmentation of the spinous process and its acoustic shadow in vertebral ultrasound images

“…Potential applications include deformity assessment (Ungi et al, 2014;Cheung et al, 2015;Young et al, 2015), spinal brace adjustment Li et al, 2012) and dense 3D spine surface reconstruction (Nguyen et al, 2015). The current gold standard measure for assessing scoliosis (as well as its progression or the effectiveness of a treatment) is the Cobb angle, measured on postero-anterior X-ray images.…”

A Survey on 3D Ultrasound Reconstruction Techniques

“…The limitation of planar viewing is that there will be possibility to loss of information due to the complex shape of ROI, especially when viewing spinal curvature. Thus, the use of nonplanar volume rendering method can compensate this limitation [31]. Due to its simplicity and the fact that it does not require high computational power, the multiplanar reformatting method is favorable among researchers and practitioners alike to visualize the 3D ultrasound reconstruction.…”

Non-invasive methods of computer vision in the posture evaluation of adolescent idiopathic scoliosis

“…Only two studies used a methodology involving contact with the patient, which was the acquisition of the 3D data using ultrasound systems (Kowalski et al 2014, Cheung et al 2015. The remaining studies used non-contact methods.…”

“…According to Cheung et al (2015), early screening and observation of scoliosis can apparently mitigate the surgical risk. Furthermore, a timely diagnosis of AIS prevents an excessive progression to a pathological postural adaptation.…”

“…non-invasive ways of measuring spine and posture asymmetries, and the methodological procedures for testing the reliability and validity of the instruments used(Cheung et al 2015, Komeili et al 2014, Kowalski et al 2014, Saad et al 2012, Fortin et al 2012, Rankine et al 2012, Weiss & Seibel 2013. One study assessed the time effectiveness of the procedure employed(Weiss & Seibel 2013), and the other six showed the use of non-invasive technologies to attain quantitative and/or qualitative information about trunk asymmetry(Komeili et al 2015, Fortin et al 2013, Sarnadskiy 2012a, 2012b, Aroeira et al 2011.< Insert Figure 2 about here>Quality assessment of the studiesTable 2presents the results of the quality assessment of the studies found according to the QUADAS scale.…”