X-ray apparatus with component positioning coordinated with radio-opaque objects in examination room

[0001] 1. Field of the Invention

[0002] The present invention concerns an x-ray acquisition apparatus of the type having a spatially adjustable x-ray detector, a spatially adjustable x-ray source, and a control unit with which the x-ray source can be aligned to the x-ray detector.

[0003] 2. Description of the Prior Art

[0004] An x-ray acquisition apparatus of this type is known from DE 196 11 705 B4. In the x-ray acquisition apparatus described there, the x-ray source can be aligned relative to the x-ray detector that can be adjusted three-dimensionally in space. This known x-ray acquisition apparatus does not take into account the position of radio-opaque objects that are located in the room (such as perhaps a patient bed that may be located in the beam path). After every positioning of the x-ray detector, therefore, the user must ascertain whether a radio-opaque object is located in the beam path. This assessment represents an additional time expenditure and is not always reliably possible, so that incorrect (flawed) exposures can be created.

[0005] An object of the present invention is to provide an x-ray acquisition apparatus of the aforementioned type in which the desired x-ray imaging (data acquisition) result can be completed in a shorter amount of time.

[0006] This object is achieved by an x-ray acquisition apparatus according to the invention having a spatially adjustable x-ray detector, a spatially adjustable source, and a control unit with which the x-ray source can be aligned relative to the x-ray detector, and wherein the control unit takes into account the position of radio-opaque objects located in the room and, before an x-ray acquisition, emit a signal if and when a radio-opaque object is located in the beam path.

[0007] As used herein, “radio-opaque object” means an object that strongly absorbs x-ray radiation to an extent that relevant information about the subject to be imaged is lost.

[0008] By means of the signal that is emitted as an output from the control unit when a radio-opaque object is located in the beam path, the user is presented in a simple manner with the possibility to change the position of the x-ray detector before an x-ray acquisition is initiated. Incorrect exposures due to radio-opaque objects that are located in the beam path are thereby reliably avoided and the desired x-ray imaging result can be acquired in a shorter amount of time.

[0009] In one embodiment, the x-ray detector is manually supported on a mounting device such that the x-ray detector can be adjusted (displaced) three-dimensionally in space. The x-ray source is supported on a further mounting device such that it can be adjusted as well.

[0010] At least one sensor with which a detected position of the x-ray detector can be transmitted to the control unit can be located on the x-ray detector. The control unit determines a control signal for the x-ray source with which the x-ray source can be automatically aligned relative to the x-ray detector.

[0011] In another embodiment, the position or positions of radio-opaque objects (such as, for example, the position of an operating table) are stored in the control unit and those positions can be compared with the position of the beam path.

[0012] The use of further sensors that are attached to the radio-opaque objects is advantageous. The positions of the radio-opaque objects are determined via these sensors and transmitted to the control unit. The position of movable radio-opaque objects during movement thereof thus can also be taken into account.

[0013] In a preferred embodiment of the invention, the x-ray acquisition apparatus has a collimator that is controllable via the control unit such that the radiation field of the x-ray source is limited and matched to the size of the x-ray detector. The manual set-up step in which the collimator is adjusted is thus omitted. The acquisition can be executed without time delay.

[0014] The position detection of the x-ray detector can be implemented using acoustic and/or, optical and/or electromagnetic sensors.

[0015] The mounting device on which x-ray source is mounted preferably is equipped with a collision detection system so that collisions with objects or people are avoided during movement of the x-ray source towards the x-ray detector.

[0016] In another embodiment, a further signal can be generated that informs the user if and when the x-ray source cannot be aligned relative to the x-ray detector, for example when an object prevents the alignment of the x-ray source relative to the x-ray detector. In this case, the user is informed by the further signal so that he or she can take measures in order to correct the problem, perhaps by removal of the interfering object or by a repositioning of the x-ray detector.

[0017] The x-ray acquisition apparatus is appropriately equipped with a control unit that is executed as a computer. In addition to its functions, the computer can produce tomosynthesis images or 3D image reconstructions from a number of exposures of the subject from different positions. Naturally, however, separate computers or computer modules can be used to perform the respective functions of control and image generation.

[0018] The mounting device of the x-ray source and/or of the x-ray detector can be a robot arm with six degrees of freedom. Such a robot allows a large freedom of movement with a space-saving design.

[0020] The drawing shows a ceiling-mounted x-ray detector 1 that can be three-dimensionally adjusted in space with a manually adjustable mounting arm 3 with six degrees of freedom. Sensors 5 are located on the x-ray detector 1 that supply signals to a control unit 7 that calculates therefrom the spatial position of the x-ray detector 1. An x-ray source 9 is adjustable in a motorized manner in space by a robot arm 11 with six degrees of freedom and is aligned relative to the x-ray detector 1 by control signals from the control unit 7. The spatial positions of radio-opaque objects such as, for example, radio-opaque parts 13 of the operating table 15 are stored in the control unit 7. If a radio-opaque object 13 is located in the beam path 17 (as is shown in the drawing), a signal that informs the user about this situation is output by the control unit 7. The user can thereupon reposition the x-ray detector 1.

[0021] A collimator 19 is located on the x-ray source 9 that is automatically controlled by the control unit. 7 to adjust the aperture angle of the beam path 17 to match the x-ray detector 1. A high image performance can be realized by a fixed installation of the x-ray acquisition apparatus.

[0022] A collision detection system 21 is located on the x-ray source 9 that avoids collision of the x-ray source with people or objects during the motorized alignment of the x-ray source 9. If the x-ray source 9 cannot be aligned relative on the x-ray detector 1 (because, for example, an object prevents this), a further signal is output that informs the user about this situation. The x-ray detector 1 can thereupon be repositioned.

[0023] In the exemplary embodiment, the control unit 7 is fashioned as a computer. Since the spatial position of the x-ray detector 1 is detected during an acquisition of image data, three-dimensional image reconstructions and tomosynthesis images can be produced from a number of exposures from different directions. The produced images can be shown to the user at monitors that are hung from the ceiling or are located on a monitor cart.

[0024] Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.