Springer Online Journal Archives 1860-2000
Abstract Radiographic information on the imaging plate was read with a pixel size of 50 μm×50 μm and recorded with 100 μm×100 μm. Various frequency-enhanced images were produced by an unsharp masking process that can maximize the spatial frequency enhancement at 0.25, 0.50, 1.00, 2.00, and 4.00 cycles/mm. Using these images, the effect of frequency enhancement processing for the X-ray diagnosis of normal anatomical structures and simulated bone changes on intraoral computed radiography was investigated. The imaging conditions under which the most valuable radiographic images for diagnosis of normal anatomical structures were obtained was a frequency type that diminished the low level density area, a non-linear gradation and an enhancement rank of 4 at the spatial frequency of 2.00 cycles/mm. These iamges projected a higher image quality than conventional periapical films. In addition, the intraoral computed radiography had equivalent or better ability to detect fine-simulated bone changes compared to conventional periapical films. These findings suggest that the spatial frequency enhancement area needed to obtain images with significant diagnostic value, equivalent to or better than conventional periapical film images, is 2.00 cycles/mm in intraoral computed radiography, with maximal spatial resolution of 5.00 cycles/mm.
Type of Medium: