Detection of simulated osteoporosis in dog alveolar bone with the use of digital subtraction

Abstract

The purpose of this in vitro study was to examine radiographic changes in dog alveolar bone during simulated osteoporosis (decalcification) and to determine the minimal amount of generalized bone loss that can be detected under optimal radiographic conditions with the use of digital subtraction. Five samples of dog maxillary alveolus were progressively decalcified at timed intervals with 0.1 N hydrochloric acid solutions. The percentage of calcium lost during each interval was quantified with calcium assays. Sets of four radiographs from each sample were exposed at 30 kVp and 50 kVp initially and after each decalcification interval. The radiographs were digitized and bone profiles (scan lines) were generated between images of lead markers. To suppress contaminating image noise each set of four profiles were superimposed and averaged on a pixel-by-pixel basis. The averaged profile from each stage of decalcification was subtracted from the averaged initial profile on a pixel-by-pixel basis, the mean profile intensity change for each decalcification stage calculated, and this mean change compared to the initial mean intensity to yield the percentage mean profile intensity change for each sample for each decalcification stage. Statistical analysis was performed with repeated measures analysis of variance. Results indicate that generalized decalcification of less than 7.5% was detected in all samples of dog maxillae with exposures of 30 kVp and that generalized decalcification of less than 19% was detected with exposures of 50 kVp.