Multiscale image processing and antiscatter grids in digital radiography.
Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.
Lo
Winnie Y
WY
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA. wylo@ucdavis.edu
Hornof
William J
WJ
Zwingenberger
Allison L
AL
Robertson
Ian D
ID
D000818:Animals; D004285:Dogs; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods* / Q000592:standards*; D011860:Radiography, Abdominal / Q000295:instrumentation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods / Q000592:standards / Q000662:veterinary*; D012542:Scattering, Radiation