Computer-implemented method for operating an x-ray device, and x-ray device
An X-ray device has a stand, a support arm, a mount and a C-arm, on which are arranged, opposing one another, an X-ray generator and an X-ray detector. The support arm is coupled to the stand at one end such that it can rotate about a first axis of rotation for the creation of a first degree of freedom of movement and the mount is coupled to the support arm at the other end such that it can rotate about a second axis of rotation for the creation of a second degree of freedom of movement. The first axis of rotation, the second axis of rotation and a central beam of the X-ray generator intersect at one point in all positions of the support arm and of the mount.
1 . A computer-implemented method for operating an X-ray device for acquiring projection images of an acquisition region of a patient, the method comprising:
acquiring the projection images along a lateral trajectory, three-dimensional with respect to a reference plane, of an X-ray generator encompassing the patient laterally with respect to a longitudinal direction of the patient, for a coverage of a projection angle range of at least 200° with respect to the reference plane, wherein
the X-ray device includes a stand, a support arm, a mount and a C-arm, on which are arranged, opposing one another, the X-ray generator and an X-ray detector,
the support arm is coupled to the stand at one end such that it can rotate about a first axis of rotation for creation of a first degree of freedom of movement and the mount is coupled to the support arm at another end such that it can rotate about a second axis of rotation for creation of a second degree of freedom of movement, so that the first axis of rotation, the second axis of rotation and a central beam of the X-ray generator intersect at one point in all positions of the support arm and of the mount,
the C-arm is further displaceably mounted in a guide of the mount for creation of a third degree of freedom of movement,
each of the first degree of freedom of movement, the second degree of freedom of movement, and the third degree of freedom of movement is assigned an actuator that can be activated by a control device of the X-ray device, and
the lateral trajectory uses all three degrees of freedom of movement such that the C-arm is positioned laterally next to the patient along an entire lateral trajectory with respect to the longitudinal direction of the patient or of a patient couch on which the patient is positioned.
2 . The method of claim 1 , furthering comprising:
determining the lateral trajectory using at least one of,
an optimization procedure while maintaining a safe distance from the patient, or
components of the X-ray device as a boundary condition, so that they come to lie as close as possible to an ideal trajectory in the reference plane.
3 . The method of claim 2 , wherein at least one of the ideal trajectory is a partial circular path or a vertical plane is used as the reference plane.
4 . The method of claim 2 , wherein at least one of,
at least a maximum angular deviation of the central beam from the reference plane is specified as a further boundary condition, the maximum angular deviation being from 10 to 20°, or
a minimum angular deviation is specified as an optimization target.
5 . The method of claim 2 , further comprising:
determining patient-specific expansion information, wherein the optimization procedure is based on the patient-specific expansion information.
6 . The method of claim 1 , further comprising:
extending the projection angle range for an acquisition of further projection images for a reduction of artifacts in a subsequent reconstruction beyond a reference angle range to be covered.
7 . The method of claim 6 , wherein the extending extends the projection angle range compared to the reference angle range by 2 to 10°.
8 . The method of claim 1 , wherein at least one of
the first axis of rotation is inclined by 1 to 20° compared to a horizontal,
a travel range about the first axis of rotation is 140 to 160°,
the travel range about the second axis of rotation is 300 to 320°, in particular 310°, or
the travel range due to displacement of the C-arm in the mount is 140 to 160°.
9 . The method of claim 1 , wherein the X-ray detector is mounted such that it can rotate via a further actuator, which can be activated by the control device, about a detector axis of rotation parallel to the central beam, in particular corresponding thereto, wherein during the lateral trajectory the control device activates the further actuator such that the X-ray detector assumes a specified orientation for the projection images.
10 . The method of claim 1 , wherein the acquisition region is at least one of an abdominal region or a hip region.
11 . The method of claim 1 , wherein the stand is floor-mounted.
12 . The method of claim 1 , wherein the movement along the lateral trajectory takes place at a speed of at least 40° per second.
13 . An X-ray device comprising:
an X-ray generator;
an X-ray detector;
a stand;
a support arm;
a mount; and
a C-arm, the stand, the support arm, the mount and the C-arm-C are being arranged on, opposing one another, the X-ray generator and the X-ray detector, wherein the support arm is coupled to the stand at one end such that it can rotate about a first axis of rotation for creation of a first degree of freedom of movement and the mount is coupled to the support arm at another end such that it can rotate about a second axis of rotation for creation of a second degree of freedom of movement, such that the first axis of rotation, the second axis of rotation and a central beam of the X-ray generator intersect at one point in all positions of the support arm and of the mount, and wherein the C-arm is further displaceably mounted in a guide of the mount for creation of a third degree of freedom, wherein each of the degrees of freedom is assigned an actuator that can be activated by a control device of the X-ray device, wherein the control device is configured to cause the X-ray device to perform the method of claim 1 .
14 . The method of claim 3 , wherein at least one of,
at least a maximum angular deviation of the central beam from the reference plane is specified as a further boundary condition, the maximum angular deviation being from 10 to 20°, or
a minimum angular deviation is specified as an optimization target.
15 . The method of claim 3 , further comprising:
determining patient-specific expansion information, wherein the optimization procedure is based on the patient-specific expansion information.
16 . The method of claim 15 , further comprising:
extending the projection angle range for an acquisition of further projection images for a reduction of artifacts in a subsequent reconstruction beyond a reference angle range to be covered.
17 . The method of claim 16 , wherein the extending extends the projection angle range compared to the reference angle range by 2 to 10°.
18 . The method of claim 3 , wherein at least one of
the first axis of rotation is inclined by 1 to 20° compared to a horizontal,
a travel range about the first axis of rotation is 140 to 160°,
the travel range about the second axis of rotation is 300 to 320°, in particular 310°, or
the travel range due to displacement of the C-arm in the mount is 140 to 160°.