DE102011088392B4 - X-ray machine - Google Patents

Abstract

An X-ray machine, comprising a C-arm rotatable about a fulcrum and having an X-ray source and an X-ray detector mounted thereon, characterized in that the C-arm (4, 14) is rotatable along a circular path which, as viewed in FIG Circumferential direction of the C-arm (4, 14), seen in the middle of the C-arm (4, 14) in the radial direction near the inside of the C-arm (4, 14) and at the outer ends of the C-arm ( 4, 14) extends in the radial direction in the vicinity of the outside of the C-arm (4, 14) so that an X-ray central beam (7) extending from the X-ray source (5) to the X-ray detector (6) is independent of the instantaneous rotational position of the C -Bogens (4) always through the pivot point (3) of the C-arm (4).

Description

The invention relates to an X-ray machine with a C-arm, which is mounted on a holder and rotatable about a pivot point, on which an X-ray source and an X-ray detector are arranged.

With such X-ray machines, 3D images of the body part are reconstructed from a series of 2D projections of a body part of a patient recorded at different projection angles.

The prerequisite for 3D imaging is usually an isocentric C-arm that rotates in an orbital motion about a fixed pivot point (rotation axis). Isocentricity is characterized by the fact that the X-ray central beam always passes through the fulcrum. However, isocentric C-arms have disadvantages in terms of mass distribution and because of their relatively high weight, therefore non-isocentric C-arms which are "shorter" than an isocentric C-arm are often used for two-dimensional imaging.

In the DE 100 03 524 A1 For example, an X-ray machine is proposed in which a series of 2D projections of a phantom is made in a calibration mode in order to record 2D projections from the positions of the C-arm determined during calibration, from which a 3D image data record is generated.

In the DE 10 2008 062 030 A1 It is explained that in an X-ray machine with a non-isocentric C-arm, the imaging area of an object is encircled in an elliptical orbit, whereby the volume range of the object is significantly restricted. If this disadvantage is to be avoided, make horizontal and vertical shifts of the C-arm.

DE 101 53 787 B4 discloses an X-ray diagnostic device with a C-arm, which is guided in a horizontally and vertically adjustable holder.

Out DE 199 61 094 A1 An X-ray device with a C-arm is known, which is displaceable via a manual handle in a holder.

Out DE 10 2010 021 657 A1 a C-arm is known, which is mounted on guide rollers, which is mounted at an angle of preferably about 45 ° relative to its cross-sectional sides along the edges of a holding device, movable.

The invention has for its object to provide an X-ray machine with a non-isocentric C-arm, which is suitable for 3D imaging.

To solve this problem is provided according to the invention in an X-ray machine of the type mentioned that the C-arm is rotatable along a circular path, as seen in the circumferential direction of the C-arm, seen in the center of the C-arm in the radial direction in the vicinity the inside of the C-arm and at the outer ends of the C-arm in the radial direction in the vicinity of the outside of the C-arm, so that extending from the X-ray source to the X-ray detector X-ray beam always independent of the current rotational position of the C-arm passes through the pivot point of the C-arm.

With conventional X-ray machines, 3D imaging can only be performed if the X-ray machine has an isocentric C-arm, but these C-arms are significantly larger and heavier than non-isocentric C-arms due to the necessary counterbalance.

The invention is based on the recognition that three-dimensional imaging can also take place with a non-isocentric C-arm by rotating it along a specific circular path, which differs from the circular segment shape of the C-arm. In particular, it is necessary that the radius of the circular path for the rotation of the C-arm is greater than the radius of the C-arm, the radius of the circular path must correspond to the sum of the radius of the C-arm plus half the width of the X-ray detector. If these geometric requirements are met, the X-ray central beam always passes through the pivot point of the C-arm. Under this condition, a 3D image can subsequently be generated from a plurality of 2D images recorded at different projection angles, at the same time the weight compensation is ensured.

In the X-ray apparatus according to the invention, it is preferred that the C-arm is attached to the holder by means of a roller guide. The roller guide allows a precisely controllable rotation and positioning of the C-arm relative to the support of the X-ray machine.

In the X-ray apparatus according to the invention, the roller guide may comprise an undercut groove in which a component of the holder is received. In this embodiment, the C-arm surrounds the component of the holder, whereby a mechanically particularly stable construction is given.

A further development of the invention provides that the groove is arranged in the C-arm in the middle of the C-arm near the inside of the C-arm and at the outer ends of the C-arm in the vicinity of the outside of the C-arm is. The position of the groove in the thickness direction of the C-arm is thus variable, this variable position of the groove is a consequence of the fact that the C-arm and the circular path, along which the C-arm is movable, have a different radius. The thickness of the C-arm, ie its extension in the thickness direction (radial direction) is chosen so that the guide or the groove in the middle of the C-arm is inside and at the outer ends of the C-arm outside.

In order to improve the handling of the X-ray device according to the invention, it may be provided that the C-arm is weight-balanced. Due to the weight compensation moments are reduced or. eliminated, which otherwise would have to be counteracted by other measures. In this connection it can be provided that the C-arm has recesses near its outer ends. In this way, a mass reduction is achieved, which has a positive effect in terms of the required drive energy.

In the case of the X-ray device according to the invention, the weight compensation can be designed so that the recesses adjoin the groove, in particular the recesses can be provided in the thickness direction next to the groove, wherein a recess is shorter than the groove.

• 1 ein erfindungsgemäßes Röntgengerät;
• 2 das Röntgengerät von Fig-. 1 in einer zweiten Stellung;
• 3 das Röntgengerät von 1 in einer dritten Stellung;
• 4 den C-Bogen des erfindungsgemäßen Röntgengeräts mit dargestelltem Röntgenzentralstrahl;
• 5 bis 7 Querschnitte des in 1 zeigten C-Bogens; und
• 8 bis 9 Querschnitte des C-Bogens eines weiteren Ausführungsbeispiels.

Further advantages and details of the invention will be explained below with reference to an embodiment with reference to the drawings. The drawings are schematic representations and show:

• 1 an inventive X-ray device;
• 2 the X-ray machine of Fig-. 1 in a second position;
• 3 the x-ray machine of 1 in a third position;
• 4 the C-arm of the X-ray device according to the invention with represented Röntgengenentralstrahl;
• 5 to 7 Cross sections of in 1 showed C-bows; and
• 8th to 9 Cross sections of the C-arm of another embodiment.

This in 1 shown X-ray machine 1 includes one on a bracket 2 attached to a pivot point 3 (Rotation axis) rotatable C-arm 4 at which an X-ray source 5 and an x-ray detector 6 are arranged. An x-ray central beam 7 extends from the X-ray source 5 to the X-ray detector 6 ,

The C-arm 4 is on the bracket 2 by means of a roller guide, not shown 8th attached. By turning the C-arm 4 Different positions can be approached to create a 2D image acquisition of an examination subject. The individual 2D image recordings can then be used to create a 3D image acquisition.

2 shows the x-ray machine 1 after a rotation of the C-arm 4 from the in 1 shown position in a clockwise direction, in a similar way 3 the x-ray machine 1 after a pivoting of the C-arm 4 from the in 1 shown position counterclockwise. It can be seen that the x-ray central beam 7 regardless of the current position of the C-arm 4 always through the pivot 3 of the C-arm 4 runs. The X-ray machine 1 thus has the same property as an X-ray machine with an isocentric C-arm. Because of its shape, the C-arm is 4 of the X-ray machine 1 Non-isocentric, however, is achieved by a special design of the guide, that the Röntgendentralstrahl 7 always through the pivot 3 of the C-arm 4 runs. Therefore, individual, in different positions of the C-arm 4 captured 2D images are then used to create a 3D image capture.

4 shows that the central X-ray beam 7 always, ie independent of the position of the C-arm 4 through the pivot 3 Thus, a non-isocentric C-arm can be used instead of an isocentric C-arm. However, the non-isocentric arc has advantages in weight as compared to an isocentric C-arm.

Below is the guide of the C-arm 4 on the bracket 2 explained. In 1 is on the C-arm 4 a circle segment 9 represented, which indicates the position of a groove, by means of the C-arm 4 on the bracket 2 is guided. In 1 you realize that the circle segment 9 in the middle of the C-bow 4 near the inside runs. At the outer ends of the C-arm 4 at which the X-ray source 5 and the X-ray detector 6 are arranged, the circle segment runs 9 near the outside of the C-arm 4 ,

Below is on the 5 - 7 Reference is made in those sectional views of the C-arm 4 are shown. 5 shows a section along the line V - V of 4 , shows accordingly 6 a section along the line VI - VI and 7 a section along the line VII - VII of 4 ,

The in 5 shown cross-section of the C-arm 4 is substantially C-shaped, parallel to a central portion 10 of the C-arm 4 is an undercut groove 11 provided in the assembled state, a roller guide is arranged through which the C-arm 4 on the bracket 2 is rotatably mounted. In 5 is the undercut groove 11 the middle section 10 adjacent.

6 shows a section of the C-arm 4 along the line VI - VI. The undercut groove 11 is identical to the one in 5 shown undercut groove, however, there is the undercut groove 11 at the in 6 illustrated section at another position, namely approximately in the middle. Accordingly, the middle section 12 wider than the corresponding middle section 10 in 5 ,

7 shows a section of the C-arm 4 along the line VII - VII. The undercut groove 11 is located there near the outside, accordingly, the middle section 13 wider than the corresponding middle section 12 in 6 ,

Due to the different radial position of the groove 11 the effect is achieved that the x-ray source 5 , the X-ray detector 6 and thus the X-ray central beam 7 always through the pivot point 3 of the C-arm 4 run, although the circular segment-shaped C-arm 4 has a smaller radius than the rotational movement. Due to the variable position of the roller guide in the C-arm 4 becomes the rotation of the non-isocentric C-arm 4 converted into an isocentric rotation. How best in 1 can be seen, the movement corresponds to a rotation along a circular path whose radius is the sum of the radius of the C-arm and the half-width of the X-ray detector 6 equivalent.

The 8th . 9 and 10 show cross sections of a C-arm 14 a second embodiment, each at the same positions as in the 5 - 7 are shown cuts. The C-arm 14 has an optimized weight distribution.

The in 8th shown C-arm 8th corresponds in terms of its shape to the cross section of 5 shown C-arm 4 , In 9 you realize that the C-arm 14 a recess 15 that is between the groove 11 and the middle section 16 of the C-arm 14 is trained. The essentially rectangular recess 15 is shorter than the groove 11 , Through the recess 15 reduces the mass of the C-arm 14 and thus the occurring torques.

In 10 you finally realize that the recess 15 near the outer ends of the C-arm 14 has a greater width than in the 9 cross section shown. Through the recess 15 becomes the total weight of the C-arm 14 reduced, whereby the handling and the drive is facilitated.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims (8)

An X-ray machine, comprising a C-arm rotatable about a fulcrum and having an X-ray source and an X-ray detector mounted thereon, characterized in that the C-arm (4, 14) is rotatable along a circular path which, as viewed in FIG Circumferential direction of the C-arm (4, 14), seen in the middle of the C-arm (4, 14) in the radial direction near the inside of the C-arm (4, 14) and at the outer ends of the C-arm ( 4, 14) extends in the radial direction in the vicinity of the outside of the C-arm (4, 14) so that an X-ray central beam (7) extending from the X-ray source (5) to the X-ray detector (6) is independent of the instantaneous rotational position of the C -Bogens (4) always through the pivot point (3) of the C-arm (4). X-ray device after Claim 1 , characterized in that the C-arm (4, 14) is formed substantially circular segment-shaped. X-ray device after Claim 1 or 2 , characterized in that the C-arm (4, 14) by means of a roller guide (8) on the holder (2) is mounted. X-ray device after Claim 3 , characterized in that the roller guide (8) comprises an undercut groove (11) in which a component of the holder (2) is accommodated. X-ray device after Claim 4 characterized in that the groove (11) in the C-arm (4, 14) in the middle of the C-arm (4, 14) near the inside of the C-arm (4, 14) and to the outer Ends of the C-arm (4, 14) in the vicinity of the outside of the C-arm (4, 14) is arranged. X-ray apparatus according to one of the preceding claims, characterized in that the C-arm (4, 14) is weight-balanced. X-ray apparatus according to one of the preceding claims, characterized in that the C-arm (4, 14) has at least one recess (15) in the vicinity of its outer ends. X-ray apparatus according to one of the preceding claims, characterized in that the recess (15) adjoins the groove (11).

Images