WO2017081263A1

WO2017081263A1 - X-ray system, rotation unit and method

Info

Publication number: WO2017081263A1
Application number: PCT/EP2016/077448
Authority: WO
Inventors: Michael Salamon; Johannes LEISNER; Carina KREUTNER; Nils REIMS; Thomas SCHLECHTER; Michael BÖHNEL
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2015-11-13
Filing date: 2016-11-11
Publication date: 2017-05-18
Also published as: DE102015222480A1

Abstract

The invention relates to an X-ray system comprising a radiation source, a radiation detector, and a rotation unit arranged between the radiation source and the radiation detector. This rotation unit has at least two receiving devices for at least two objects and is designed to rotate the at least two objects individually about their respective rotational axis. The X-ray system also comprises a calculation unit, which is designed to calculate a reconstruction data set for each object of the at least two objects, during the irradiation of the at least two objects by means of the radiation source and the radiation detector, based on irradiation data determined by the radiation detector.

Description

X-ray system, rotation unit and procedure description

Embodiments of the present invention relate to an X-ray system for determining at least two own reconstruction data sets of at least two objects and to an associated method. Further exemplary embodiments relate to a rotation unit for use with an X-ray system.

X-ray systems, in particular X-ray systems in combination with rotational units are used in computed tomography. The industrial application of computed tomography has meanwhile become an integral part of quality assurance in the manufacturing industry. The previous application is limited, however, especially in high-resolution scans with resolutions below 100 μηη difficult to be scanned test objects, due to the relatively long measurement times, to a random test. An increase in the measurement throughput is already achieved today for easily durchstrahlende test objects made of materials such as plastic or aluminum, by a simultaneous arrangement of multiple test objects in a transmission room. An example of this is illustrated in FIG. 6a or FIG. 6b. FIG. 6 a shows an X-ray system comprising an X-ray tube 12 and an X-ray detector 14, which lies opposite in the direction of radiation (compare beam cone 16 of the X-ray tube 12). The x-ray tube 12 typically behaves like a spot radiator, in which the x-ray radiation is emitted by a radiation outlet 12a. As shown here, the beam cone 16, which in combination with the detector surface / detector width 14 defines the transmission space, starting from the beam outlet 12a, wherein beam cone 16 and beam detector 14 are aligned with each other in such a way that the orthogonality conditions (see dashed solder 16! associated Lotfuß) are met. In the space between the X-ray tube 12 and the X-ray detector 14 or in particular within the beam cone 16, a plurality of test objects p1 to p4 are arranged. These are located on a turntable 18, such as a turntable 18, which rotates about a rotation axis 18r. As a result, the objects p1 to p4 rotate within the beam cone 16 (or transmission space) between the x-ray source and the x-ray detector, as shown in particular by comparison with FIG. 6b.

FIG. 6b shows the X-ray system from FIG. 6a, in which case the rotation unit 18 and thus the four test objects p1 to p4 were rotated by at least 210 °. By means of the rotation about the axis of rotation 18r, the samples p1 to p4 are rotated within the irradiation space 16 and thus irradiated from all directions and imaged on the detector 14. This method is based on the property of computed tomography (CT) to map each test object p1 to p4 located in the measured volume 16 precisely in the reconstructed volume and thus allows a separate analysis of the individual test objects in the entire measurement volume following the measurement and reconstruction. However, the essential limitation of this method of increasing throughput is that the overlaid images cause several test objects, particularly in highly absorbent materials, such as e.g. Iron, the achievable contrast and the radiolabilty are adversely affected. This becomes clear, in particular with regard to FIG. 6b, in which the test objects p1 to p4 are all located on the vertical axis 161. As a result, the transmission length increases from the simple diameter d (see Fig. 6a) to the summed diameter 4 x d (see Fig. 6b). Generally speaking, this means that in some angular positions of the rotary unit 18, the transmission lengths d are superimposed up to n times. Therefore, there is a need for an improved concept.

The object of the present invention is to provide a device and a method for increasing the scan throughput in computer tomography, in particular in the case of highly absorbent objects or in systems with limited X-ray energy. The object is solved by the independent claims. Embodiments of the present invention provide an x-ray system for determining at least two (separate) reconstruction data sets of at least two objects. The system comprises a radiation source, one or more radiation detectors, a rotation unit arranged between the radiation source and the radiation detector and a calculation unit. By means of the radiation source and the radiation detector, at least two objects are simultaneously illuminated. For this purpose, the rotation unit comprises at least two receiving devices for at least two objects and is designed to rotate the at least two objects (by means of the two receiving devices) individually around their own axis of rotation. As a consequence, each object is imaged onto a limited area of the radiation detector during the entire transmission. The calculation unit, which now receives the irradiation data from the radiation detector, now calculates a reconstruction data record based on the irradiation data per object of the at least two objects. Another embodiment relates to a rotation unit for the arrangement between an X-ray source and an X-ray detector with at least two receiving devices for at least two objects. The rotation unit is designed to simultaneously rotate the at least two objects about its own axis of rotation. The rotation unit further comprises a control interface, via which the simultaneous rotation can be controlled by means of a control of an X-ray system.

The invention is therefore based on the finding that, starting from a classical X-ray system consisting of a radiation source and one or more X-ray-sensitive detectors in row or surface construction, it is advantageous to simultaneously scan through several samples or objects in order to increase the scan throughput , wherein instead of the normal CT rotary unit, a so-called simultaneous rotation unit is used, which rotates each sample or each object individually in the X-ray and thereby defines a separate distorted CT beam cone for each sample or object. In this case, both the fluoroscopy and the rotation of the plurality of samples or objects takes place simultaneously. The CT data sets of a plurality of samples or objects recorded simultaneously by means of one or more detectors can be subdivided per image into individual data sets for each object. Through the rotation unit referred to here as a simultaneous rotation unit, it is possible for the objects to lie individually between the radiation source and the radiation detector during the entire transmission and not overlap one another, so that advantageously by means of the simultaneous rotation unit simultaneous computed tomography of highly absorbent objects or by means of weak radiation sources is possible.

As already indicated above, according to exemplary embodiments, the arrangement of the rotation unit or, in particular, the plurality of the recording device for the plurality of objects is such that the plurality of objects lie on rotation about their own axis of rotation within a transmission space passing through the area between the radiation source and the radiation detector is defined. This also applies in particular if the rotation unit comprises more than the two receiving devices for the two objects. In that case, it is then possible for the transmission and rotation of the at least two objects and consequently also the determination of the reconstruction data sets of the at least two objects to take place simultaneously.

According to embodiments, there are two fundamentally different possibilities as to how a rotation unit with at least two or three receiving devices can be designed. According to a first exemplary embodiment, the at least (two) three receiving devices and thus also the at least (two) three objects can be arranged along a line in the irradiation space. Alternatively, it would be conceivable that the at least three recording devices for the at least three objects are arranged along a curved circular arc around the radiation source or in this case the point radiation source (which is typically the case with X-ray sources).

Thus, the radiation source according to embodiments may be a point-shaped radiation source, in which case the detector is designed either flat or curved around the radiation source, so that a conical transmission space is spanned. Here, both alternatives explained above with regard to the arrangement of the recordings or objects (straight or circular arc) are conceivable. According to alternative embodiments, it would also be conceivable that the radiation source is embodied as an omnidirectional radiation source, in which case the radiation detector is a bent radiation detector, so that a transmission zone in the form of a circle segment is spanned. For this embodiment, the rotation unit is predestined with the recordings or objects arranged along a circular point. When using bent radiation detectors, it is also possible to use radiation detectors of a plurality of straight-line segments which are arranged at an angle to one another. According to the further embodiments, an employment of a radiation detector, in which the angle between the individual elements (eg manually or automatically) is adjustable, possible. By the adjustment or generally by the Anwinkelung distortions can be reduced or avoided in particular in the edge region in which no rectilinear mapping takes place. In this case, according to embodiments, the arrangement of the individual units of the radiation detector is selected such that they are arranged along a circular arc around the point-shaped radiation source.

With regard to these distortions can - according to embodiments or for better understanding - the beam cone are divided into main beam and secondary beam. A cone of rays typically comprises a central main cone of radiation and at least two minor cone cones, each object being transilluminated by a cone of rays or by its own cone of rays. Particularly problematic are the Nebenstrahlkegel by distortions can occur. These distortions are either compensated in accordance with the above-described mechanical correction approach with the curved radiation detector (for example, curved such that all secondary beams impinge perpendicularly on the respective unit) or, according to further exemplary embodiments, subsequently corrected mathematically by means of the calculation unit. With regard to the rotation unit, it should be noted that the simultaneous rotation of the individual recording devices and thus also of the individual objects is achieved in that each recording device with a rigidly coupled gear (with the same axis of rotation as the recording device itself) is executed, in which case the gear via a worm wheel each recording device on a common drive shaft, by means of which all recording devices are driven, is engaged. This drive shaft may be rectilinear so as to form a line-like arrangement of the two or more pick-up devices, or may also have a curvature (e.g., by means of hinges) so that the two or more pick-up devices can be arranged along a circular arc (see above). According to further embodiments, each receiving device can be driven by means of its own drive. This variant is particularly suitable for rotation units, in which the two or more receiving devices are arranged along the circular arc.

Further exemplary embodiments relate to a method for the simultaneous determination of at least two reconstruction data records for at least two objects. The method comprises the steps of: ("1") determining a radiographic data set comprising Transmitted radiographs, wherein in each radiographic image the at least two objects are imaged, which are rotated individually by means of a lying between a radiation source and a radiation detector rotation unit with at least two receiving devices for the at least two objects individually about its own axis of rotation, and extracting the reconstruction data sets. In this case, in step "2a" the reconstruction data set for a first of the at least two objects from the radiographic data set and extracted in step "2b" of the reconstruction data set for a second of the at least two objects from the same radiographic data set. According to further embodiments, this method can be carried out by means of a computer or computer-aided.

Further developments are defined in the subclaims. Embodiments of the invention will be explained with reference to the accompanying drawings. Show it:

Fig. 1 is a schematic block diagram of a basic embodiment of the

X-ray system; a schematic block diagram of an extended embodiment of the X-ray system with a rigid radiation detector; schematic block diagrams of extended embodiments of the X-ray system with bent and / or adjustable X-ray detectors ren; schematic construction drawings of coming in X-ray systems of Figure 1, and 3a used rotary unit according to embodiments. 5a, 5b are schematic construction drawings of a rotary unit used in the X-ray systems of FIGS. 3a and 3b according to embodiments; and

Fig. 6a, 6b, an X-ray system according to the prior art. Before embodiments of the present invention are explained in detail below with reference to the figures, it should be noted that identical elements and structures are provided with the same reference numerals, so that the description of which is mutually applicable or interchangeable.

1 shows an X-ray system 10 with a radiation source 12 and a radiation detector 14, wherein the X-ray tube 12 emits the X-radiation by means of the opening 12a of the same so that the transmission cone 16 is formed. The radiation source 12 may comprise, for example, an X-ray tube, a linear accelerator, a betatron, a radioactive radiation source or in general a spot beam source, wherein the radiation detector 14 is present, for example, in the form of a X-ray sensitive detector in line or plane construction with one or more elements. In the case of a line detector this extends as shown along a leg of the beam cone 16. In the case of a surface detector, this would extend into the depth plane, not shown, so that not only sectional images in the plane of the two-dimensional beam cone 16 can be determined, but also SD Models over all cutting planes of the objects p1 and p2 assuming that the cone of rays 16 is three-dimensional (third dimension not shown).

This transmission cone 16 defines the transmission space or the measuring field and is essentially defined by the opening angle of the opening 12a and the width of the detector 14. Within the transmission space 16, the objects p1 and p2 are arranged substantially parallel to the detector 14 (i.e., not in particular on a common line between the opening 12a and the detector 14) with the aid of the rotation unit 20.

As a result, within the measuring field 16, the plurality of test objects p1 and p2 are arranged next to one another, so that each object p1 and p2 lie alone between the radiation source 12 and a respective region 14p1 or 14p2. As a consequence, when the at least two objects p1 and p2 are irradiated, they are imaged onto the respective area 14p1 or 14p2 independently of the other object p1 / p2. In order to be able to determine computed tomography images of the two objects p1 and p2, the objects p1 and p2 are rotatably supported by the rotation unit, each object p1 and p2 or the associated receptacle 20p1 or 20p2 of the rotation unit 20 for the respective object p1 or p2 about its own axis 21 p1 or 21 p2 is rotated. The up- For example, 20p1 and 20p2 may be turntables that are components of the rotary device 20. According to embodiments, the rotation of the two receiving devices 20p1 and 20p2 and thus the rotation of the objects p1 and p2 takes place simultaneously.

Furthermore, the system 10 comprises a calculation unit (not shown), which is connected to the detector 14 and is designed, based on the sensor signals, ie the radiographic data set, and in particular the sensor signals of the sensor surfaces 14p1 and 14p2 two or more reconstruction data sets for the two or to determine several transmission objects p1 and p2. Because each sample p1 and p2 is rotated about its own axis 21p1 and 21p2, the position of the objects p1 and p2 within the cone 16 does not change or, if at all, only minimally, so advantageously the regions 14p1 and 1 p2, from which the sensor signals for the reconstruction of the two objects p1 and p2 result, are clearly separated from each other, which simplifies the reconstruction. Furthermore, due to the rotation of the objects p1 and p2, each object p1 and p2 is imaged from the transmission directions which extend over the 360 ° rotation, so that the CT reconstruction is possible in the full complement. Due to the fact that the individual radiographic images of the objects p1 and p2 on the detector 14 do not overlap during the rotation by 360 °, each sample p1 and p2 can be detected with the minimum transmission length. Starting from a simultaneous rotation of the objects p1 and p2, a high scan throughput is also achieved.

At this point, it should be noted that, according to further exemplary embodiments, a reduction of the beam energy of the radiation source 12 without sacrificing reconstructability and contrast during the reconstruction would be possible, depending on the minimum radiation length achieved. In order to further increase the scan throughput, it would be useful, instead of the two samples p1 and p2, a plurality of samples, e.g. To arrange the samples p1 to p4 within the cone 16, as will be explained with reference to FIG. 2.

Fig. 2 shows the X-ray system 10 of FIG. 1, wherein within the cone 16 just four samples p1 to p4 are arranged or positioned by means of the rotation unit 20, that all four samples p1 to p4 to their own axis of rotation 21 p1 to 21 Turn p4. The corresponding object receptacles or turntables for the objects p1 to p4 of the rotary unit 20 are mechanically or electrically coupled to one another. It should again be noted at this point that all samples p1 to p4 are arranged within the beam cone 16 so that their projection images 14p1 to 14p4 do not overlap on the detector. In detail, the beam cone 16 here comprises four so-called secondary beam cone 16p1 to 16p4. In other words, this means that the beam cone 16 is divided into a plurality of distorted secondary beam cone 16p1 to 16p4, wherein the tube and detector detection takes place simultaneously.

These sub-beams 16p1 to 16p4 are not evenly sliced, as compared to the beam cone 16 or a main beam cone that would extend along the solder 161, since the beam direction (compare α, β, γ and δ) in comparison to the beam direction Lot of the solder 161 are angled. This results in geometric distortions, which are corrected according to further embodiments.

Therefore, it makes sense to individually treat the raw data generated in the secondary beam cones 16p1 to 16p4 generated in this way in the reconstruction and optionally to subject it to a special correction in order to achieve the orthogonality conditions required for the SD computer tomography reconstruction, not only for the main beam cone. but also for the secondary beam cone 16p1 to 16p4 to meet. The beam cone 16p1 to 16p4, which is individually distorted in each data record, is backscaled by the computing unit (not shown) to a non-distorted beam cone, ie comparable to a central main beam cone, in order then to achieve an artifact-free reconstruction of each individual test object p1 to p4 , The method explained here on the basis of the system 10 'is suitable for all computed tomography applications from high-resolution computer tomographs to high-energy computed tomographs with line or flat-panel detectors, in which the object or objects p1 to p4 occupies only a limited area of the beam cone 16 and Simultaneous detection of several placed on a centrally rotating unit test objects due to the summed wall thicknesses and the material-specific absorption properties is not possible or only with limited quality.

According to further exemplary embodiments, the rotary unit 20, which was shown here as a rotary unit 20 running parallel to the detector surface 14, can also be radially curved. Here, "radially curved" means that the receptacles for the objects p1 to p10 are arranged radially around the beam exit point 12a, so that the center each turntable is equidistant from the beam exit point. In the special case of a high magnification V »1, this modality is particularly useful. As an alternative to the computational correction of the distorted secondary beams 16p1 to 16p4, the detector surface 14 can be bent, so that the geometrical distortions in the secondary beams 16p1 to 16p4 are avoided, as will now be shown with reference to FIG. 3a. 3a shows an X-ray system 10 'with a radiation source 12 which emits the cone of rays 16 with the four secondary beam cones 16p1 to 16p4 within which the objects P1 to P4 are arranged. The objects p1 to p4 are positioned by means of the rotation unit 20. In the X-ray system 10 ', the detector 1' is curved around the radiation outlet 12a, as shown here, consisting of four units 14a 'to 14c'. This detector 14, referred to as a MULUX detector, has the advantage that the elements 14a 'to 14c' are always aligned, ie at a given distance between the detector 14 'and the radiation source 12, orthogonally with respect to the secondary beam cones 16p1 to 16p4.

This variant represents an alternative to the computer-aided reduction of artifacts, which leads to a hardware-side change to an increase in quality over conventional computed tomography arrays. By means of the method described here with reference to FIG. 10 ', each sample p1 to p4 is detected in such a way that a strong change in the magnification, due to a sample location that is decentralized to the center of rotation, can be avoided between the individual angular positions. As a result, the size of the projected image projected on the projector 14p1 to 14p4 remains constant and thus allows an advantageous collimation of the relative field of view on the detector 14 '. This in turn allows a significant increase in image quality by reducing stray beam artifacts. The method further allows for applications that rely on a very highly collimated field of view, such as for 3D contour measurement of massive objects, such as cylinder heads, a significant increase in throughput at the usually running over several hours measuring time. With reference to Fig. 3b, another embodiment of an X-ray system 10 "will now be explained in which the scan throughput can be further increased an X-ray system 10 "with an X-ray tube 12", for example an altered radiation source, namely a so-called panoramic emitter. The radiation source 16 'is listed as an all-round radiator, eg with a circle segment of 210 ° around the opening 12a or more. The MULIX detector 14 "is also shown as arcuate around this sector with an opening angle of 210 ° .In this exemplary embodiment, the mulex detector 14" comprises 12 objects which are angled relative to one another for the total of 12 secondary beam cones 16p1 to 16p12 which the 12 objects p1 to p12 can be transmitted through. In this embodiment, the objects p1 to p12 are arranged in a circular arc around the beam opening 12a. The arrangement is effected by means of the rotation unit 20 ". This rotation unit 20" here comprises the 12 object receptacles or turntables which are individually rotatable about a respective axis of rotation. By means of the wide-angle X-ray tube 12 "with, for example, a so-called Panoramatarget and using a scalable X-ray detector 14", the throughput can be maximized. According to alternative embodiments, it would also be possible to arrange the objects and consequently also the rotation unit 20 "corresponding to a full circle, in which case a fully circular X-ray detector 14" is used. Even with such a 360 ° arrangement, which can be referred to as a multi-cone arrangement, a single X-ray source 12 ", which spans the 360 ° X-ray beam, would be sufficient, so that the usually unused beam cone region can be optimally utilized for highly absorbent objects and as a result the throughput can be further increased.

Referring now to Figs. 4a-e, the rotation unit 20 will now be explained in detail and in particular with regard to the rotation mechanism.

FIG. 4 a shows a plan view of the rotation unit 20, while FIG. 4 b illustrates a side sectional view of the same. FIGS. 4c-f individually illustrate the object receptacle 20p1 (in this case turntable), wherein FIG. 4c illustrates the plan view of the rotary divider 20p1, FIG. 4d the section through turntable with associated gear as a side view, and FIG. 4e the associated side illustration. 4f shows a three-dimensional view of the gear wheel of the turntable 20p1 in combination with the drive shaft 16. As already explained, the rotation unit 20 comprises five rotatable object receptacles 20p1 to 20p5. These five rotatable object receivers 20p1 to 20p5 (turntable) protrude on a first side of the rotation unit 20, or to be specific, of the housing 24 thereof. As can be seen in particular from FIG. 4d, a gear 25p1 to 25p5 is provided on the opposite side of the turntables 20p1 to 20p5, rigidly coupled by means of a shaft 24w. Optionally, in the space between the gear 25p1 and the object receptacle 20p1 in the region of the shaft 24w is mounted rotatably relative to the housing 24 (see reference numeral 24I, which indicates a corresponding ball bearing).

Starting from the arrangement of FIGS. 4a and 4b, it is apparent that all five gears 25p1 to 25p5 and thus also the respective receptacles 20p1 to 20p5 (equidistant) are located in a row. The gears 25p1 to 25p5 and thus the rotatable object receivers 20p1 to 20p5 are driven via a common drive shaft 26, which in turn can be brought into rotation by means of the electric drive 27. The drive shaft 26 is arranged perpendicular to the respective axis of rotation with respect to the shaft 24w (cf bearing 24!) Of the respective receptacles 20p1 to 20p5, which defines the respective "own" rotation axis of the receptacles 20p1 to 20p5 For coupling between the gearwheels 25p1 to 25p5 with the drive shaft 26, the drive shaft 26 has so-called worm gears 28p1 to 28p5 The engagement of the worm wheel 28p1 with the gear 25p1 is illustrated with reference to Fig. 4f It should be noted that the gear 25p1 by means of a Versch robbery (screw and The individual worm gears 28p1 to 28p5 may optionally include couplings 29k by means of which the drive shaft 26 is segmented into segments and / or bearings 29I for supporting the drive shaft 26 may be provided opposite the housing 24. In this case, the bearings 29I (eg fixed bearing in FIG Combined with floating bearing) preferably but not necessarily, arranged such that each engagement region between gear 25p1 and worm wheel 28p1 by a left-side and a right-side bearing 29I relative to the housing 24 is supported. The same applies to the supports of the clutches 29k.

In summary, with reference to the rotation unit 20 from FIGS. 4a-f, it can be stated that it can be used as a rotation unit in the exemplary embodiments from FIGS. 1 and 2 as well as 3a. In addition, it should be noted that here in FIGS. 4f of five object recordings 20p1 to 20p5 is assumed. In such a case, according to further exemplary embodiments, the mean object receptacle, that is to say 20p3, would lie in the main beam cone, so that for this correction as a rule no compensation for the geometrically induced distortions becomes necessary.

5a shows the rotation unit 20 ", which can be used in the embodiment of Fig. 3b, but also for the embodiments of Figs 1, 2 and 3a, The rotation unit 20" also has the five object receptacles 20p1 to 20p5, wherein These are arranged on a circular arc. The synchronous drive of the same takes place, as explained with reference to FIGS. 4a-f, by means of a common drive segment 26 "subdivided into segments, which here is designed as couplings curved by means of the universal joints 29k". These joints 29k "have the task of connecting the individual shaft segments to each other in a rotary manner The joints 29k" are always located between two gears 25p1 to 25p5, the remaining elements, e.g. Bearing 29I, worm wheel 28p1 to 28p5 and drive 27 are substantially identical to the embodiment of Fig. A-f.

Referring to Fig. 5b, a further variant of the bent rotary unit 20 "'for use in the embodiment of Fig. 3b or an embodiment of Figs, 1, 2 and 3a is explained. wherein each object receptacle 20p1 to 20p5 only individual, not mechanically coupled (perpendicular to the respective axis of rotation arranged) drive shaft segments 26 '"are provided. Instead of the couplings, each drive shaft 26 "'is rotated by means of its own drive 27", so that the same functionality as the curved rotation unit 20 "can be realized as a result 20p5 are no longer mechanically coupled with respect to their rotation, according to further embodiments, the synchronization of the rotation of the individual object receptacles 20p1 to 20p5 is now carried out electrically, namely by the individual drives 27 '"being driven simultaneously.

In the above embodiments of the rotation unit 20, 20 "and 20"', the drive 27 is usually controlled by the control of the X-ray system. For this purpose, an interface, such as the interface of the motor 27 is then provided in the respective rotation unit 20, 20 "and 20"'. It should be noted at this point that, even if in the above embodiments, the drive of the individual object receptacles 28p1 to 28p5 at the example game of a gear worm-wheel combination has been explained, in which a conversion of the rotation takes place by 90 °, the realization is not limited thereto. Thus, according to further embodiments, the mechanical synchronization can take place in that all gears 25p1 are driven by means of a common toothed belt. Alternatively, it would also be conceivable that, according to further embodiments, each object receptacle 20p1 to 20p5 (turntable) is driven directly by its own drive unit, wherein the synchronization is again effected electrically.

As already indicated above, the compensation of geometrically induced distortions can be done either mathematically or by angling the individual elements of the radiation detector. In this case, the elements can also be designed to be adjustable relative to one another in accordance with further exemplary embodiments, so that, depending on the prevailing requirements, another orbit radius along which the elements of the radiation detector are arranged is adjustable. Starting from the situation as shown in FIG. 2, the units 14a ', 14b', 14c ', 14d' of FIG. 3a are now arranged in such a way until the angles α, β, γ and δ are all at right angles , The alignment of all elements 14a 'to 14d' can be done jointly or individually, namely such that for each Nebenstrahlkegeii 16p1 to 16p4 compliance with the Orthogonalitätsbedingungen is guaranteed. For realization, reference is made to DE 102012208305 A1, in which rather different embodiments for realizing the partial curvature in the segments or modules is described.

Even if the above exemplary embodiments were explained in particular with reference to the devices, it should be pointed out that, in accordance with further exemplary embodiments, the corresponding method is provided for determining or for simultaneously determining a plurality of reconstruction data sets for a plurality of objects. The method comprises the steps

Determining a radiographic data set of the at least two objects, which are rotated individually by means of a lying between a radiation source and a radiation detector rotation unit with at least two receiving devices for the at least two objects each about its own axis of rotation;

Extracting the reconstruction data set for a first of the at least two objects from the radiographic data set; and Extracting a second reconstruction data set for a second of the at least two objects from the radiographic data set.

Although some aspects have been described in the context of a device, it will be understood that these aspects also constitute a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method steps may be performed by a hardware device (or using a hardware device). Apparatus), such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some or more of the most important method steps may be performed by such an apparatus.

Depending on particular implementation requirements, embodiments of the invention may be implemented in hardware or in software. The implementation may be performed using a digital storage medium, such as a floppy disk, a DVD, a Blu-ray Disc, a CD, a ROM, a PROM, an EPROM, an EEPROM or FLASH memory, a hard disk, or other magnetic disk or optical memory are stored on the electronically readable control signals that can cooperate with a programmable computer system or cooperate such that the respective method is performed. Therefore, the digital storage medium can be computer readable.

Thus, some embodiments according to the invention include a data carrier having electronically readable control signals capable of interacting with a programmable computer system to perform one of the methods described herein.

In general, embodiments of the present invention may be implemented as a computer program product with program code, where the program code is effective. perform one of the procedures when the computer program product runs on a computer. The program code can also be stored, for example, on a machine-readable carrier.

Other embodiments include the computer program for performing any of the methods described herein, wherein the computer program is stored on a machine-readable medium.

In other words, an exemplary embodiment of the method according to the invention is thus a computer program which has program code for carrying out one of the methods described herein when the computer program runs on a computer.

A further embodiment of the inventive method is thus a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program is recorded for carrying out one of the methods described herein.

A further embodiment of the method according to the invention is thus a data stream or a sequence of signals, which represent the computer program for performing one of the methods described herein. The data stream or the sequence of signals may be configured, for example, to be transferred via a data communication connection, for example via the Internet. Another embodiment includes a processing device, such as a computer or a programmable logic device, that is configured or adapted to perform one of the methods described herein.

Another embodiment includes a computer on which the computer program is installed to perform one of the methods described herein.

Another embodiment according to the invention comprises a device or system adapted to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission can be done for example electronically or optically. The receiver may be, for example, a computer, a mobile device, a storage device, or a similar device. be direction. For example, the device or system may include a file server for transmitting the computer program to the recipient.

In some embodiments, a programmable logic device (eg, a field programmable gate array, an FPGA) may be used to perform some or all of the functionality of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor to perform one of the methods described herein. In general, in some embodiments, the methods are performed by any hardware device. This may be a universal hardware such as a computer processor (CPU) or hardware specific to the process, such as an ASIC.

The embodiments described above are merely illustrative of the principles of the present invention. It will be understood that modifications and variations of the arrangements and details described herein will be apparent to others of ordinary skill in the art. Therefore, it is intended that the invention be limited only by the scope of the appended claims and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

claims

X-ray system (10, 10 ', 10 ") having the following features: a radiation source (12, 12"); a radiation detector (14, 14 ', 14 ") arranged between the radiation source (12, 12") and the radiation detector (14, 14', 14 "), comprising at least two rotation units (20, 20", 20 "') Receiving devices (20p1 -20p12) for at least two objects (p1 -p12) and configured to rotate the at least two objects (p1 -p12) individually about their own axis of rotation (21 p1-21 p5) and a calculation unit, which is formed when the at least two objects (p1-p12) are irradiated by means of the radiation source (12, 12 ") and the radiation detector (14, 14 ', 14") on the basis of radiographic data determined by the radiation detector (14, 14'). , 14 "), each object (p1-p12) of the at least two objects (p1-p12) to calculate a reconstruction data set.

X-ray system (10, 10 ', 10 ") according to claim 1, wherein the rotation unit (20, 20", 20 "') is arranged such that upon rotation of the objects (p1-p12) about its own axis of rotation (21 p1 -21 p5) the objects (p1-p12) lie within a transmission space defined by the area between the radiation source (12, 12 ") and the radiation detector (14, 14 ', 14").

X-ray system (10, 10 ', 10 ") according to claim 1 or 2, wherein the rotation unit (20, 20", 20 "') at least three receiving devices (20p1-20p12) for at least three objects (p1 -p12), the along a line in the transmission space (16) are arranged.

An X-ray system (10, 10 ', 10 ") according to claim 1 or 2, wherein said radiation source (12, 12") is a spot beam source and said rotation unit (20, 20 ", 20"') comprises at least three pickups (20p1 -20p12) for comprises at least three objects (p1-p12) arranged along a curved arc around the point source.

5. X-ray system (10, 10 ', 10 ") according to one of the preceding claims, wherein the radiation and the rotation of the at least two objects (p1-p12) and the determination of the reconstruction data sets of the at least two objects (p1 -p12) occur simultaneously.

6. X-ray system (10, 10 ', 10' ') according to one of the preceding claims, wherein the radiation source (12, 12 ") is a point-shaped radiation source (12, 12") and wherein the radiation detector (14, 14', 14 ") a planar or curved radiation detector (14, 14 ', 14 ") is, so that a conical radiation space (16) is spanned.

7. X-ray system (10, 10 ', 10' ') according to one of claims 1 to 5, wherein the radiation source (12, 12 ") is a Rundumstrahlenquelle and wherein the Strahlende- detector (14, 14', 14") is a curved beam detector (14, 14 ', 14 ") is, so that a circular segment-shaped transmission space (16) is spanned.

8. X-ray system (10, 10 ', 10 ") according to one of the preceding claims, wherein from the radiation source (12, 12") to the radiation detector (14, 14', 14 "), a central main beam and at least two secondary beams (16p1 -16p4 ) are emitted which strike different detector surfaces (14p1 - 14p4) of the radiation detector (14, 14 ', 14 ") and / or different detector elements (14a'-14c') of the radiation detector (14, 14 ', 14") An X-ray system (10, 10 ', 10 ") according to claim 8, wherein one of the at least two objects (p1-p12) is separated by a sub-beam (16p1 -16p4) and the other of the at least two objects (p1-p12) by a main beam or another secondary beam (16p1 -16p4) are illuminated. 10. X-ray system (10, 10 ', 10' ') according to claim 8 or 9, wherein the main beam, in contrast to the secondary beams (16p1-16p4) has an isosceles shape.

X-ray system (10, 10 ', 10 ") according to one of claims 8 to 10, wherein the calculation unit is designed to correct geometrically induced distortions in the secondary beams (16p1 -16p4).

12. X-ray system (10, 10 ', 10' ') according to one of the preceding claims, wherein the radiation detector comprises two or more units, wherein two directly adjacent units form an angle of s 180 °.

13. X-ray system (10, 10 ', 10 ") according to claim 12, wherein the angle between the two directly adjacent units manually and / or electrically variable by means of an adjusting mechanism.

The x-ray system (10, 10 ', 10 ") of claim 13, wherein the adjustment mechanism is configured to align the two or more units along a circular arc of adjustable radius.

X-ray system (10, 10 ', 10 ") according to one of claims 12 to 14, wherein the radiation detector (14, 14', 14") has two or more units (14a'-14d '), two directly adjacent units ( 14a'-14d ') include an angle of s 180 °, and wherein the angle between the adjacent units is selected to avoid and / or reduce geometrically induced distortions in the sub-beam (16p1 -16p4).

An X-ray system (10, 10 ', 10 ") according to claim 15, wherein the angle of the two or more units (14a'-14d') is chosen such that the main beam and / or sub-beams (16p1 -16p4) are related to the respective unit (14a'-14d ') to strike vertically.

Rotation unit (20, 20 ", 20"') with at least two receiving devices (20p1 - 20p12) for at least two objects (p1-p12), wherein the rotation unit (20, 20 ", 20"') is formed around the at least two Objects (p1-p12) simultaneously rotate about their own axis of rotation (21 p1-2p4), and wherein the rotation unit (20, 20 ", 20"') comprises a control interface, via which the simultaneous rotation by means of a control of an X-ray system ( 10, 10 ', 10 "), comprising a radiation source (12, 12") and a radiation detector (14, 14', 14 "), is controllable. The rotation unit (20, 20 ", 20"') according to claim 17, wherein the at least two receiving devices (20p1 -20p12) each comprise a rigidly coupled gear (25p1-25p5), and wherein the at least two gearwheels (25p1-25p5) of at least two picking devices (20p1-20p12) are engaged with two worms (28p1 -28p5) rotatable by a common axis (26, 26 ") to simultaneously rotate the at least two picking devices (20p1-20p12).

The rotation unit (20, 20 ", 20" ') according to claim 18, wherein the rotation unit (20, 20 ", 20"') comprises at least three pickup devices (20p1 -20p12) arranged along a curved arc, each one rigidly coupled Gearwheel (25p1 -25p5), and wherein the at least three gears of the at least three pickup devices (20p1 -20p12) are engaged with three worms (28p1 -28p5) rotatable by a common curved axis (26 ") the at least three recording devices (20p1 -20p12) simultaneously rotate, or which are each rotated simultaneously via a separate drive (27).

Method for the simultaneous determination of at least two reconstruction data sets for at least two objects (p1-p12), comprising the following steps:

Determining a radiographic data set from the at least two objects (p1 -p12), which are located by means of a rotation unit (20, 20 ", 20" ') lying between a radiation source (12, 12 ") and a radiation detector (14, 14', 14"). with at least two receiving devices (20p1 -20p12) for the at least two objects (p1 -p12) each individually rotated about its own axis of rotation (21 p1 -21 p5);

Extracting the reconstruction data set for a first of the at least two objects (p1-p12) from the radiographic data set; and

Extracting a second reconstruction data set for a second of the at least two objects (p1-p12) from the radiographic data set. A computer program comprising program code for carrying out the method of claim 20 when the program is run on a computer.