Radiation image recording and read-out apparatus

Claim 1

A radiation image recording and read-out apparatus for use in energy subtraction processing for mamma images, which comprises: i) a conveyance means for conveying a single stimulable phosphor sheet, which is capable of storing a radiation image thereon, along a predetermined path, ii) an image recording section which is located in the vicinity of said path and which is provided with: a) a radiation source, and b) an image recording table, on which the mamma is supported and secured and which is located between said radiation source and part of said path, radiation being produced by said radiation source and caused to pass through the mamma and then to impinge upon said stimulable phosphor sheet, whereby a radiation image of the mamma is stored on said stimulable phosphor sheet, iii) an image read-out section which is located in said path and which is provided with: a) a stimulating ray source for producing stimulating rays, which scan said stimulable phosphor sheet carrying said radiation image stored thereon at said image recording section and which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to the radiation, and b) a photoelectric read-out means for detecting the emitted light and converting it into an image signal. iv) an erasing section which is located in said path and in which, before a next radiation image is stored on said stimulable phosphor sheet after said image signal has been obtained therefrom in said image read-out section, energy remaining on said stimulable phosphor sheet is erased, v) a sheet moving means for moving said stimulable phosphor sheet from said image recording section to said image read-out section and then to said erasing section along said path, said sheet moving means thereafter moving said stimulable phosphor sheet to said image recording section, vi) a radiation change-over means with which the quality of the radiation in said image recording section is changed over between at least two kinds of quality, vii) a control means which operates said sheet moving means in synchronization with the change-over operation of said radiation change-over means, such that two radiation images are sequentially stored with the radiation having different quality on said stimulable phosphor sheet during two image recording operations, and said two radiation images stored with the radiation having different quality during two image recording operations are read out during two image read-out operations in said image read-out section, and viii) an operating section in which image signals, which represent the two radiation images stored with the radiation having different quality and which were detected during the two image read-out operations in said image read-out section, are weighted and then subtracted from each other.