Image-receptor performance: a comparison of Trophy RVG UI sensor and Kodak Ektaspeed Plus film.
Objective. This study compares the physical characteristics of the RVG UI sensor (RVG) with Ektaspeed Plus film.


METHODS
Dose-response curves were generated for film and for each of 6 available RVG modes. An aluminum step-wedge was used to evaluate exposure latitude. Spatial resolution was assessed by using a line-pair test tool. Latitude and resolution were assessed by observers for both modalities. The RVG was further characterized by its modulation transfer function.


RESULTS
Exposure latitude was equal for film and RVG in the periodontal mode. Other gray scale modes demonstrated much lower latitude. The average maximum resolution was 15.3 line-pairs per millimeter (lp/mm) for RVG in high-resolution mode, 10.5 lp/mm for RVG in low-resolution mode, and 20 lp/mm for film (P <.0001). Modulation transfer function measurements supported the subjective assessments.


CONCLUSIONS
In periodontal mode, the RVG UI sensor demonstrates exposure latitude similar to that of Ektaspeed Plus film. Film images exhibit significantly higher spatial resolution than the RVG images acquired in high-resolution mode.
Ludlow
J
J
Department of Diagnostic Sciences and General Dentistry, University of North Carolina at Chapel Hill, USA. jbl@email.unc.edu
Mol
A
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D000704:Analysis of Variance; D003748:Dental Equipment; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D015588:Observer Variation; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D014962:X-Ray Film