FIELD: physics.
SUBSTANCE: system contains an X-ray source; an image detector; a monitor; an input device configured to provide coordinates relating to the X-ray image displayed on the monitor; a controller coupled to the input device, wherein the controller is configured to determine, at least, one research area (RA) on the displayed image based on coordinates provided by the said input device; a collimator configured to expose different patient areas to different radiation levels in accordance with a specific research area (RA); an image processing unit coupled to the detector and the monitor, wherein the image processing unit is configured to process the image fixed by the collimator by correcting, at least, one portion of the image that is outside of one RA in accordance with previously acquired data containing a portion of the image, which was in one former RA, using the tone correction function.
EFFECT: increasing the accuracy of tone correction based on the previously obtained data.
7 cl, 33 dwg, 5 tbl
