TY - JOUR
T1 - Assessment of image quality in dental radiography, part 1
AU - Yoshiura, Kazunori
AU - Kawazu, Toshiyuki
AU - Chikui, Tohru
AU - Tatsumi, Masato
AU - Tokumori, Kenji
AU - Tanaka, Takemasa
AU - Kanda, Shigenobu
N1 - Funding Information:
This work was supported in part through a Grant-in-Aid for Scientific Research (C) from the Japanese Ministry of Education, Science and Culture.
PY - 1999
Y1 - 1999
N2 - Objective. The purpose of this study was to describe and validate an image-quality phantom to be used in dental radiography for comparison of film and digitally acquired images. Study design. An aluminum block of 12 steps, with 7 holes in each step, was covered by acrylic blocks. This phantom was radiographed with Kodak Ultra-speed and Ektaspeed Plus films at 70, 65, and 60 kVp with the whole exposure range available. All together, 50 dental films were randomly sequenced and presented to 7 observers. The average number of perceptible holes from all steps was plotted against exposure for each tube voltage and film type, generating a modified perceptibility curve. The tentative optimum exposure level was determined from perceptibility curves in each experimental condition and compared with that determined by means of the standard aluminum stepwedge and the preset time of the x-ray machine. The density range of this phantom at the optimum exposure was compared with that of clinical dental radiographs. Validity of the phantom was evaluated according to the optimum exposure level from the modified perceptibility curves and the overall density range. Finally, the average maximum numbers of perceptible holes at the tentative optimum exposure level were compared for each tube voltage and film type. The statistical test used was a 2-way factorial analysis of variance. Results. The exposure at the perceptibility curve peak approximated that obtained by means of the standard aluminum stepwedge and the time preset by the manufacturer. The overall density range at the perceptibility curve peak covered the clinical density range for each tube voltage and film type. There were no statistically significant differences between film types or among tube voltages. Conclusions. The x-ray attenuation range for this phantom seemed to approximate clinical conditions. In addition, differences in image quality could be quantitatively evaluated by means of the number of the holes seen in the phantom.
AB - Objective. The purpose of this study was to describe and validate an image-quality phantom to be used in dental radiography for comparison of film and digitally acquired images. Study design. An aluminum block of 12 steps, with 7 holes in each step, was covered by acrylic blocks. This phantom was radiographed with Kodak Ultra-speed and Ektaspeed Plus films at 70, 65, and 60 kVp with the whole exposure range available. All together, 50 dental films were randomly sequenced and presented to 7 observers. The average number of perceptible holes from all steps was plotted against exposure for each tube voltage and film type, generating a modified perceptibility curve. The tentative optimum exposure level was determined from perceptibility curves in each experimental condition and compared with that determined by means of the standard aluminum stepwedge and the preset time of the x-ray machine. The density range of this phantom at the optimum exposure was compared with that of clinical dental radiographs. Validity of the phantom was evaluated according to the optimum exposure level from the modified perceptibility curves and the overall density range. Finally, the average maximum numbers of perceptible holes at the tentative optimum exposure level were compared for each tube voltage and film type. The statistical test used was a 2-way factorial analysis of variance. Results. The exposure at the perceptibility curve peak approximated that obtained by means of the standard aluminum stepwedge and the time preset by the manufacturer. The overall density range at the perceptibility curve peak covered the clinical density range for each tube voltage and film type. There were no statistically significant differences between film types or among tube voltages. Conclusions. The x-ray attenuation range for this phantom seemed to approximate clinical conditions. In addition, differences in image quality could be quantitatively evaluated by means of the number of the holes seen in the phantom.
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U2 - 10.1016/S1079-2104(99)70304-5
DO - 10.1016/S1079-2104(99)70304-5
M3 - Article
C2 - 9927090
AN - SCOPUS:0032618303
SN - 1079-2104
VL - 87
SP - 115
EP - 122
JO - Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics
JF - Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics
IS - 1
ER -