Abstract
Objectives
To evaluate four digital intraoral radiographic systems using perceptibility curves (PCs) in a grayscale domain and to clarify the usefulness of this new method.
Methods
Four systems were evaluated, namely the CDR, Dixel, Digora, and Digora Optime. An aluminum phantom with 12 steps was radiographed using all four systems. The mean gray values and their standard deviations were measured for each step as well as the background of the images for each device. The minimum perceptible gray level differences at a given exposure were calculated from the mean gray values and standard deviations, and a PC in the grayscale domain was constructed at each exposure for all devices. The area under the PC was assumed to be the perceptible contrast information at that exposure for each system. By combining the PCs at all exposures for each system, the maximum perceptible contrast information in each system was calculated. The correlation between the perceptible contrast information and the number of perceptible holes by observers at each exposure was examined for all four digital systems.
Results
The Dixel and Digora Optime showed similar PCs, and their minimum perceptible gray level differences were the smallest among the systems. The correlation between the number of perceptible holes and the areas under the PCs at each exposure for the four systems was relatively high (r = 0.92).
Conclusions
The areas under the PCs in a grayscale domain were highly correlated with observer performance. This method can be used to evaluate the image quality of new digital systems.
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References
Stamatakis HC, Yoshiura K, Shi XQ, Welander U, McDavid WD. A simplified method to obtain perceptibility curves for direct dental digital radiography. Dentomaxillofac Radiol. 1999;28:112–5.
Yoshiura K, Kawazu T, Chikui T, Tatsumi M, Tokumori K, Tanaka T, et al. Assessment of image quality in dental radiography, part 2: optimum exposure conditions for detection of small mass changes in 6 intraoral radiography systems. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999;87:123–9.
Yoshiura K, Okamura K, Tokumori K, Nakayama E, Chikui T, Goto TK, et al. Correlation between diagnostic accuracy and perceptibility. Dentomaxillofac Radiol. 2005;34:350–2.
Yoshiura K, Stamatakis H, Shi XQ, Welander U, McDavid WD, Kristoffersen J, et al. The perceptibility curve test applied to direct digital dental radiography. Dentomaxillofac Radiol. 1998;27:131–5.
Yoshiura K, Welander U, McDavid WD, Li G, Shi XQ, Nakayama E, et al. Comparison of the psychophysical properties of various intraoral film and digital systems by means of the perceptibility curve test. Dentomaxillofac Radiol. 2004;33:98–102.
Yoshiura K, Welander U, Li G, Shi XQ, McDavid WD, Kawazu T, et al. Analysis of different approaches to constructing perceptibility curves. Oral Radiol. 2003;19:38–48.
Yoshiura K, Stamatakis HC, Welander U, McDavid WD, Shi XQ, Ban S, et al. Prediction of perceptibility curves of direct digital intraoral radiographic systems. Dentomaxillofac Radiol. 1999;28:224–31.
Okamura K, Yoshiura K, Tatsumi M. Image quality evaluation of intraoral digital imaging system, Digora Optime. Dental Radiol. 2009;49:1–6 (in Japanese).
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Okamura, K., Yoshiura, K., Tatsumi, M. et al. A new method for evaluating perceptible contrast information in digital intraoral radiographic systems. Oral Radiol 27, 98–101 (2011). https://doi.org/10.1007/s11282-011-0068-7
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DOI: https://doi.org/10.1007/s11282-011-0068-7