Asian Spine J.  2008 Dec;2(2):90-93. 10.4184/asj.2008.2.2.90.

Cobb Angle Measurement of Scoliosis Using Computer Measurement of Digitally Acquired Radiographs: Intraobserver and Interobserver Variability

• Srinivasalu S
• Modi HN
• SMehta S
• Suh SW
• Chen T
• Murun T

• KMID: 1972533
• DOI: http://doi.org/10.4184/asj.2008.2.2.90

Abstract

STUDY DESIGN: We evaluated computer assisted digital measurement of radiographic parameters in patients with idiopathic scoliosis. PURPOSE: To assess the reliability of digital measurements. OVERVIEW OF LITERATURE: Various authors analyzed scoliotic deformities by conventional radiographs, but very few studies have addressed the reliability of digital radiographic measurement using computer software. METHODS: Three independent, blinded observers measured 318 whole spine pre-operative antero-posterior radiograms of children with varying degrees of idiopathic scoliosis. Only one curve per radiograph was measured. Each observer measured the Cobb angle three times with a 1-week gap between each measurement. The computer system, picture archiving and communication system (PACS, PiViewSTAR version 5) was used in all cases. The end vertebrae were pre-selected to avoid this as a potential source of error. The results were statistically analyzed for intraobserver and interobserver reliability and variability. RESULTS: The 95% confidence intervals for intraobserver and interobserver variability were +/-1.30 and +/-1.260, respectively. There was better reliability in larger curves. CONCLUSIONS: Measurement using a digitized system may help to minimize measurement discrepancies by eliminating an intrinsic cause of error.

Keyword

Scoliosis; Digital imaging; Cobb angle; Intraobserver and interobserver variability

MeSH Terms

Child
Computer Systems
Congenital Abnormalities
Humans
Observer Variation
Scoliosis
Software
Spine