Korean J Oral Maxillofac Radiol.  2000 Jun;30(2):101-108.

Assessment of the Measurement Method of the Bone Mineral Density on Cu-Equivalent Image

• Kim JD

Abstract

PURPOSE: The effects of step numbers of copper wedge and exposure on the coefficient of determination(r2) of the conversion equation to Cu-equivalent image and on the Cu-equivalent value(mmCu) and it's coefficient of variation measured at each copper step and the mandibular premolar area were evaluated. METHOD: Digital image analyzing system consisted of scanner, personal computer, and a stepwedge with 10 steps of 0.03mm copper in thickness as reference material was prepared for quantitative assessment of the bone mineral density. NIH image program was used for analyzing images.
RESULTS
The film having moderately high film density showed the discrepancy between the real thickness and the measured Cu-equivalent value of each copper step. The Cu-equivalent image was dependent on the determinational coefficient of the conversion equation than the coefficient of variance of the measured value.
CONCLUSION
Obtaining conversion equation with high coefficient of determination and proper film exposure are supposed to be neccessary for quantitative assessment of bone density. Multiple steps in the range of the corresponding copper thickness to the bone density of the area to be measured should be prepared.

Keyword

Cu-equivalent image; method; bone density; coefficient; determination

MeSH Terms

Bicuspid
Bone Density*
Copper
Microcomputers
Copper