Abstract
The noise equivalent quanta (NE Q) and detective quantum efficiency (DQE) of an FCR-101 computed radiqi plc system (Fuji Photo Film Co., Ltd., Japan) with two different versions (types II and III) of ST (for standard applications) imaging plates were measured. The NEQ and DQE of the system excluding the display part were calculated as functions of incident exposure and spatial frequency. Both of them were obtained from the gradient of the digital characteri stic curve relating the pixel value to the retive x-ray intensity, the presampling modulation transfer function, and the digital Wiener spectrum of the FCR system. Compared to the type II, the type III showed an insignificant change in spatial-resolution properties but a significant improvement in noise, including luminescence noise and structure noise. The improvement of type III in noise properties gave a better NEQ and DQE. It is confirmed that types II and III of HR (for mammography and bone radiography) plates have the same trend as that of ST plates.
