Original scientific paper
Intraoral Computer-Assisted Microdensitometric Study
Jurica Krhen
Dubravka Knezović-Zlatarić
Pavel Kobler
Asja Čelebić
Ognjen Milat
Adil Džubur
Abstract
The precision of a method of microdensitometry on digitized images, using six step copper stepwedge (SW), was studied. Two retroalveolar radiographs were made for each of the six examined patients. Lynotype-Hell (8-bit, 300DPI) transparent scanner was used to scan the radiographs. All the images were, prior to the measurements, inverted. The digitized radiographs were saved in the Issa-program for archiving radiographs, while the optical density (OD) was measured by using software Scion image for 6 steps of the SW and 7 regions of interest (ROI). The gray levels (GLs) were converted into the ODs for both images by formula OD = -log Ii /255, where Ii = measured intensity. ODs of each step of the SW were correlated with the copper thickness of the related step and the regression formula was thus derived from the relationship of the OD and the actual thickness of the related step through the third degree polynomial function. The results revealed that the method detects mineral bone changes, i.e. OD changes, which surpass more than 7% of density on the images.
Keywords
microdensitometry; bone structure; retroalveolar radiograph
Hrčak ID:
11412
URI
Publication date:
15.9.2001.
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