SCANNING X-RAY IMAGING DEVICE WITH VARIABLE SHIELD PLATES AND METHOD FOR OPERATING SAME

摘要

A scanning X-ray imaging device (100) is proposed. The device may be specifically adapted for mammography applications. The device comprises an X-ray source (110), an X-ray line detector (150), a field limiter arrangement (170) and an observation volume (135). The field limiter arrangement (170) comprises at least two variable shield plates (174, 175) enclosing an opening (176) and a displacing mechanism (177). The shield plates may be displaced with respect to a centre axis of an X-ray beam (115) by means of the displacing mechanism such as to vary at least one of a cross-section and a location of the opening (176) between the field plates (174, 175) through which at least a part of the X-ray beam (115) is transmitted. The shield plates may be displaced independently from each other by means of the displacing mechanism (177). Such device (100) may be operated to perform a scanning motion such as to scan at least portions of the X-ray beam through a region of interest within the observation volume (135) and, at the same time, control the displacing mechanism (177) such that the opening (176) between the field plates (174, 175) is first successively opened to a larger cross-section and then successively closed again to a smaller cross-section during the scanning motion. Thereby, an X-ray dose level and an X-ray exposure time may be kept constant throughout an image acquisition procedure and an overall dose level may be minimized.

主权项

1. A scanning X-ray imaging device comprising:
an X-ray source; an X-ray line detector; a field limiter arrangement; an observation volume; wherein the X-ray source is adapted to emit an X-ray beam towards the X-ray line detector; a moving mechanism coupled to at least one of the X-ray source and the X-ray line detector, the moving mechanism adapted to perform a scanning motion such as to scan at least portions of the X-ray beam through a region of interest within the observation volume; wherein the observation volume is arranged between the X-ray source and the X-ray line detector; wherein the field limiter arrangement is arranged between the X-ray source and the observation volume; wherein the field limiter arrangement comprises at least two variable shield plates and a displacing mechanism; wherein the shield plates may be displaced with respect to the center axis of the x-ray beam by means of the displacing mechanism such as to vary at least one of a cross section and a location of an opening between the field plates through which at least a part of the X-ray beam is transmitted; and wherein the shield plates may be displaced independently from each other by means of the displacing mechanism; wherein the independent displacing of the shield plates controlled by the displacing mechanism such that the opening between the shield plates is first successively opened to a larger cross section and then successively closed again to a smaller cross section during the scanning motion.