title: Reliability of radiographic intervertebral disc height measurement for in vivo rat-tail model.
abstract: Quantification of changes in intervertebral disc height is critical for studying intervertebral disc degeneration. Reliability of disc height measurement is therefore especially important for in vivo studies using animal models of disc degeneration. In this study, the effects of image intensity and percentage of disc width used for disc height measurement from radiographic images were evaluated in a rat-tail model. Radiographs were taken for 10 Sprague-Dawley rats using a standardized protocol. Average disc heights of the caudal 8-9 discs were determined using original and intensity adjusted images with different percentages of disc width. The average disc height was found to be significantly affected by both the image intensity and the percentage of disc width measured. A higher reliability was found in the measurement for image with adjusted intensity and using smaller disc width. Image intensity is suggested to be controlled and the disc width should be taken into account in quantifying the disc height.
authors.affiliation: Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, SAR, PR China.
authors.forename: Alon
authors.initials: A
authors.lastname: Lai
authors.forename: Daniel H K
authors.initials: DH
authors.lastname: Chow
authors.forename: W S
authors.initials: WS
authors.lastname: Siu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Holmes
authors.forename: F H
authors.initials: FH
authors.lastname: Tang
mesh_terms: D000818:Animals; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008297:Male; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013623:Tail / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*