Computer aided vertebral visualization and analysis: a methodology using the sand rat, a small animal model of disc degeneration.
BACKGROUND
The purpose of this study is to present an automated system that analyzes digitized x-ray images of small animal spines identifying the effects of disc degeneration. The age-related disc and spine degeneration that occurs in the sand rat (Psammomys obesus) has previously been documented radiologically; selected representative radiographs with age-related changes were used here to develop computer-assisted vertebral visualization/analysis techniques. Techniques presented here have the potential to produce quantitative algorithms that create more accurate and informative measurements in a time efficient manner.


METHODS
Signal and image processing techniques were applied to digitized spine x-ray images the spine was segmented, and orientation and curvature determined. The image was segmented based on orientation changes of the spine; edge detection was performed to define vertebral boundaries. Once vertebrae were identified, a number of measures were introduced and calculated to retrieve information on the vertebral separation/orientation and sclerosis.


RESULTS
A method is described which produces computer-generated quantitative measurements of vertebrae and disc spaces. Six sand rat spine radiographs illustrate applications of this technique. Results showed that this method can successfully automate calculation and analysis of vertebral length, vertebral spacing, vertebral angle, and can score sclerosis. Techniques also provide quantitative means to explore the relation between age and vertebral shape.


CONCLUSIONS
This method provides a computationally efficient system to analyze spinal changes during aging. Techniques can be used to automate the quantitative processing of vertebral radiographic images and may be applicable to human and other animal radiologic models of the aging/degenerating spine.
Wilson
Christy
C
University of North Carolina at Charlotte, 9201 University City Blvd Charlotte, NC 28223, USA. chrwilso@uncc.edu
Brown
Darien
D
Najarian
Kayvan
K
Hanley
Edward N
EN
Gruber
Helen E
HE
D000375:Aging / Q000473:pathology; D000818:Animals; D004195:Disease Models, Animal; D005849:Gerbillinae; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000473:pathology*; D010865:Pilot Projects; D011859:Radiography; D013122:Spinal Diseases / Q000000981:diagnostic imaging*