Dentomaxillofacial Radiology, Vol 20, Issue 4 193-199, Copyright © 1991 by British Institute of Radiology
Automatic analysis of radiographic images: II. Software implementation and testing on bitewing radiographs
D. K. Benn
Department of Community Medicine, University College London.
A prototype, completely automatic image-analysis system for dental bitewing
radiographs was implemented in 'C' on a Unix workstation. A multiple layer
hierarchical image model was created in software for each radiograph using
production rule-based knowledge. The highest model layer formed an
English-like description of anatomical structures including tooth type,
interdental alveolar bone crest margins and spaces. A representation of
spatial relationships between anatomical structures was formed, providing a
method for comparing similar regions of a patient in serial, but not
absolutely standardized, images. In 31 clinical radiographs, the system
automatically identified 93% (193) of all available interdental spaces
which are the key image regions for model creation. Each image required 2
minutes of processing time. The reproducibility of finding 34 interdental
spaces in five films revealed one error. Further work is required to
improve the recognition rate of the interdental regions towards 100% and to
develop automatic comparisons between areas of change (disease?) in serial
films.
