Computed tomography system and method for orienting detector ring in or on gantry

Abstract

The invention relates to a computed tomography system, comprising an examination region and a static gantry, the gantry comprising an X-ray source and a detector ring, the detector ring surrounding the examination region and at least two detector segments, the computed tomography system being configured in such a way that the X-ray source is arranged in the examination region. The detector ring is arranged such that the position of the detector segments in the axial direction of the detector ring relative to the X-ray source and / or relative to each other is adjustable.

Description

Technical Field

[0001] The invention relates to a computed tomography system and a method for orienting a detector ring in or on a gantry of a computed tomography system.

[0002] Regardless of the grammatical gender of a particular term, persons with male, female, or other gender identities are included. Background Art

[0003] Typically in the prior art, the detector of a computed tomography system (CT system) is arranged in or on the gantry of the CT system. The gantry is usually a short ring-shaped tunnel, in the inner area of ​​which a subject, in particular a patient or a part of a subject, is placed for examination. The detector usually includes electronic components, which are used to convert the detected X-ray beams of the X-ray tube into electronic signals. According to the prior art, the detector or a mechanical device (on which the electronic components of the detector are placed) is usually implemented as a partial sector (for example, more than 45°) and rotates around the subject together with the X-ray tube during CT measurement.

[0004] Here, precise alignment and fixing of the detector are important for obtaining good CT image data. Due to the rotation and the forces generated thereby, the gantry and the mechanism responsible for the rotation must be designed to be very stable and therefore have a correspondingly high weight. The high weight limits the possibilities for using the CT system, for example, usually only stationary use is possible. Summary of the invention

[0005] The object of the present invention is therefore to provide a computed tomography system which can be used flexibly, in particular due to low weight and / or reduced or avoided rotational forces. In addition, it would be desirable to be able to orient the detector of the computed tomography system precisely and as simply as possible.

[0006] This object is achieved by a computed tomography system according to claim 1 and a method according to claim 11. Further features and advantages emerge from the dependent claims, the description and the accompanying figures.

[0007] According to a first aspect of the invention, a computer tomography system is provided, which comprises an examination region and a static gantry, the static gantry comprising a detector ring surrounding the examination region. The detector ring comprises at least two detector segments, wherein the computer tomography system is configured such that the positioning of the detector segments in the axial direction of the detector ring is adjustable. Advantageously, the computer tomography system (CT system) can be implemented relatively narrowly compared to the CT systems commonly seen in the prior art. This can be achieved by virtue of the fact that for the CT examination, a rotation of the detector is not necessary, and preferably also a rotation of the X-ray beam is not necessary, and thus a less stable, lighter structure is achieved. Thus, in addition, the gantry can be implemented narrower. In addition, the CT system according to the invention can relatively easily achieve precise adjustment of the detector. In addition, by providing the detector segments, the replacement of components of the detector can be simplified, and due to the achievable lower weight of the individual detector segments, the replacement of the entire detector can also be facilitated.

[0008] In particular, a computed tomography system is disclosed, comprising an examination region and a stationary gantry, wherein the gantry comprises a detector ring surrounding the examination region, wherein the detector ring comprises at least two detector segments, wherein the computed tomography system is configured such that the positioning of the detector segments in an axial direction of the detector ring is adjustable, in particular relative to one another.

[0009] The term "examination area" is to be understood broadly within the framework of the present invention. Generally, an examination area is an area in which a subject or an object or a part of a subject or an object can be placed in order to examine it with a computed tomography system, in particular to collect image data therefrom. For example, a subject can be a person, in particular a patient, or an animal. For example, an object can be a part of a person or an animal, such as a limb, a trunk, an organ, etc. However, the object can also be any other object, such as any object.

[0010] Preferably, the gantry is arranged around the examination region. The term static gantry is to be understood in particular in contrast to a rotating gantry according to the prior art. The term static here refers to the use in CT measurements. In particular, the gantry is configured such that it does not have to be rotated for the CT measurement, or it is not provided that the gantry is rotated substantially around the examination region during the CT measurement. Furthermore, it is not excluded that the static gantry can also be rotated generally, for example in the unmounted state or during the mounting of the gantry.

[0011] The gantry includes a detector ring. This relationship and the term gantry itself can be understood broadly. For example, it can be provided that the detector ring is fastened or mounted on a base frame of the gantry. Preferably, the detector ring is a static detector ring corresponding to a static gantry. In particular, the detector ring is configured to not rotate around the examination area during CT measurement. This has the advantage that less rotational force is generated, whereby the gantry as a whole can be implemented as less solid. Thus, material can be saved and the CT system as a whole can be lighter. Thus, the use possibilities of the CT system can be expanded if necessary, in that less space and / or a less stable arrangement site can be provided. The term "ring" in the term "detector ring" can be understood broadly. For example, the detector ring can have an extension in the radial direction. The detector ring can be a 360° detector ring. Accordingly, the detector ring extends around the entire circumference of a circle. This is advantageous because the X-ray signal can therefore be detected in all radial directions. Alternatively, the detector ring can also be a partial ring. The partial ring does not extend over the entire circumference of the circle. This may be advantageous in order to provide a particularly light or particularly advantageous CT system.The detector ring surrounds the examination region, ie in particular the detector ring is arranged around the examination region.

[0012] The detector ring includes at least two detector segments, preferably at least three detector segments. Each of the detector segments can preferably include one or more detector elements configured to detect X-ray beams. Dividing the detector ring into detector segments can advantageously simplify the handling of the detector ring, for example, in that fewer large parts must be moved during installation. This can also reduce costs during transportation, for example. In addition, modularization can be achieved by dividing into detector segments. For example, a single detector segment can be replaced. In this regard, it is advantageous to use detector segments that are no longer adjustable in the axial direction. For example, the detector ring can include exactly three detector segments. The three detector segments are particularly advantageous not only for relatively simple installation due to the lower weight but also for easy orientation due to the obtained flexibility. Facts have shown that the three detector segments, on the one hand, achieve flexible adjustment of the orientation of the detector segments, and on the other hand, also achieve good stability and organization of the single piece by using not too many segments. However, it is also basically possible that the detector ring includes more than three detector segments or exactly two detector segments.

[0013] The positioning of the detector segments is adjustable in the axial direction of the detector ring. The axial direction is in particular a direction that extends perpendicularly through a circular surface or a partial circular surface formed by the detector ring. The axial direction can correspond to the z-direction of a computed tomography system. For example, the position of individual detector segments in the axial direction can be adjusted individually. Advantageously, the position of the detector ring as a whole and relative to the individual detector segments can thus be adjustable. Adjustment of the entire detector ring can be helpful in order to adjust the positioning relative to one or more X-ray sources. Thus, for example, it can be achieved that the detector ring is located at the focus of the X-ray source. Advantageously, inhomogeneities in the structure of the X-ray source or the frame of the detector ring can be compensated for by adjusting individual segments. Optionally, the orientation of the detector segments can also be adjustable. As a result, even more accurate adjustment of the detector ring is possible. Preferably, the computed tomography system can be configured so that the detector segments are fixable after the axial position adjustment.

[0014] Preferably, the computed tomography system can further comprise a static X-ray source. In particular, the X-ray source can also be annular and can be arranged around the examination area. The X-ray source can have a plurality of X-ray beam generators distributed along a ring shape. The detector ring and the X-ray source can have a common axial direction. Preferably, the annular X-ray source can have a larger diameter than the detector ring, so that the X-ray source is arranged further outside around the examination area than the detector ring in the radial direction. Preferably, the detector ring can be arranged offset relative to the X-ray source in the axial direction. By such a configuration, a particularly small offset of the detector ring relative to the X-ray source can be achieved, whereby (relative to a larger offset) the image quality can be improved.

[0015] According to one embodiment, the detector segments are substantially ring segments, each of which is a partial ring of a detector ring. Ring segments have proven to be particularly practical to handle during installation, replacement and maintenance.

[0016] According to one embodiment, the detector segments each comprise a substrate and at least one functional unit having a detector element, which is fastened or can be fastened to the substrate and can be removed from the substrate. The substrate can be substantially partially annular. Viewed in the axial direction, the substrate can define the shape of the exterior of the detector segment by its own shape. Advantageously, a particularly good modular and flexible configuration of the detector ring can be achieved by means of the substrate. Here, the term substrate can be understood broadly. In particular, the substrate does not have to be flat, but can have a structured surface. For example, the substrate can have devices for receiving and / or fastening functional units. Advantageously, the substrate can make it possible to remove a single functional unit having a detector element, for example for maintenance or replacement, without changing the general orientation of the detector segment due to the substrate remaining in a mounted and oriented state.

[0017] According to one embodiment, the computer tomography system includes a guide rail, which extends substantially in the axial direction and can guide the deviation of the detector segment in the axial direction. For example, the detector segment can be plugged into the guide rail and / or can be plugged into the guide rail. Optionally, the detector segment can include one or more through holes, and the guide rail is guided and / or can be guided via the through holes. Optionally, the detector segment can be placed on the guide rail and / or can be placed on the guide rail. The guide rail can make the movement of the detector segment easier. For example, manual movement can be achieved with little force through the guide rail. The guide rail can be removably fastened or can be fastened to the rack. Advantageously, the guide rail can therefore be used, for example, for installation or maintenance and then removed to prevent interference with the guide rail during normal operation. Alternatively, the guide rail can be permanently arranged on the computer tomography system, especially on the rack. Advantageously, the permanent existence of the guide rail, for example, the maintenance or replacement of the detector segment can be promoted in this way: the guide rail does not have to be installed first.

[0018] According to one embodiment, replaceable spacers are provided between the detector segments and the frame, or the base of the frame, so that the positioning of the detector segments in the axial direction of the detector ring can be adjusted by the spacers. The term spacer can be understood broadly within the framework of the present invention. Spacers can describe any such device: the device is suitable for ensuring the spacing between the base of the frame and the corresponding detector segment. For example, the spacer can be a compensation plate. For example, the spacer can be a shim. The shim can also be defined as a washer and / or an adjustment plate. Advantageously, the spacer can adjust the spacing in the axial direction between the focus of the X-ray source and the scanning plane of the detector ring or the detector element. For example, it can be provided that the detector ring or a single detector segment is loosened and moved in the axial direction on the guide rail as described here. Thereafter, a new spacer can be installed on the frame, and the detector ring or the detector segment can be moved back in the axial direction again until the detector ring or the detector segment contacts the spacer. Therefore, the adjustment of the detector ring can be carried out particularly accurately and quickly. Thus, additional manual adjustment steps that may otherwise be necessary can be omitted. Furthermore, spacers are a particularly inexpensive option for adjusting the detector segments in the axial direction. Optionally, it can be provided that spacers, in particular washers, are used to tension at least one of the detector segments, in particular at least one of the base plates, in order to compensate for the shape of the respective detector segment. This is particularly advantageous in the case of thermally induced deformations.

[0019] According to one embodiment, the spacer is produced from a metal-containing material, in particular steel. The properties of metals can be particularly well suited for use as spacers. For example, in the case of operation-dependent heating, the heat release of the detector can be improved by metals. In particular, steel can provide a good combination of flexibility and stability in manufacturing. However, other materials can also be conceivable for the spacer as an option.

[0020] According to one embodiment, the spacer is an elongated compensating plate. Preferably, the spacer is oriented such that the longitudinal extension of the compensating plate corresponds essentially to the radial direction. By orienting the longitudinal extension of the spacer in the radial direction, it is possible to particularly effectively change or, if necessary, correct the flatness of the detector ring.

[0021] According to one embodiment, the frame comprises a fastening device for fixing the spacer. The fastening device can simplify and / or reliably realize the installation of the spacer. The fastening device can include, for example, a screw hole. The fastening device can include, for example, a slot for inserting the spacer. The fastening device can include, for example, a click and release mechanism. The frame can include a plurality of fastening devices for a plurality of spacers per detector segment.

[0022] According to one embodiment, at least two spacers are provided for each detector segment. Advantageously, a plurality of spacers allows a particularly good adjustment of the orientation of the detector segment. Particularly advantageously, 3 to 5 compensating sheets, preferably 4 compensating sheets, can be provided per detector segment. This number of compensating sheets also allows a stable mounting of the detector segment, a good variability of the orientation of the detector segment and a clear effort when mounting the compensating sheets.

[0023] According to one embodiment, the computed tomography system comprises a set of spacers with different thicknesses. By means of the set of spacers, the axial position of the detector ring or the detector segments can be adjusted or changed relatively quickly and easily. The change of the axial position can be carried out, for example, simply by replacing or replenishing the spacers.

[0024] For example, the spacers can be provided in a graduation of 0.01 to 0.5 mm, preferably in a graduation of 0.05 to 0.2 mm. Graduations in this range can be particularly useful for adjusting the positioning of the detector ring, in that on the one hand, precise adjustment is achieved, but on the other hand, not too many spacers are required.

[0025] According to one embodiment, the computed tomography system comprises at least one motor, which is configured to adjust the positioning of at least one of the detector segments in the axial direction. The computed tomography system may comprise a plurality of motors, each of which is configured to adjust the positioning of at least one of the detector segments in the axial direction. The at least one motor, optionally a plurality of motors, may be configured to adjust the positioning of a plurality of, preferably all, of the detector segments in the axial direction. Advantageously, an automatic adjustment of the axial position of the detector segment may be achieved by the motor. Here, the detector segment may be mounted on a guide device as described here and / or may be guided on the guide device. Advantageously, the motor may be configured to achieve a substantially stepless adjustment of the axial position. Here, “substantially stepless” may be understood within the framework of an accuracy that is structurally determined and possible due to other limitations, such as, for example, meaningful cost utilization expenditures, with which a certain accuracy can be achieved. The motor may be provided without the use of spacers. Optionally, the spacers may be combined with the motor as described here. For example, the spacers may achieve additional positional stability, while the motor may simultaneously achieve an automatic movement of the detector ring. Motors may be a fast and easy to operate solution for movement of the detector segments.

[0026] According to one embodiment, the motor is a linear drive and / or a spindle drive. The guide device may optionally have a thread. The motor may include a shaft driving the thread, so that a movement in the axial direction of the detector segment can be achieved by rotating the thread. The motor may be arranged on the detector ring and / or the detector segment. The linear drive may include a linear unit and a servo motor, wherein the linear unit is driven by the servo motor. The linear unit may be a guide device or equivalent to a guide device. The detector segment may be arranged directly on the linear unit.

[0027] According to one embodiment, the computed tomography system is configured to detect deviations from the positioning of the detector ring classified as ideal by means of a sensor device. Advantageously, the sensor device can be used to automatically determine whether the position of the detector ring or the detector segment should be adjusted. The sensor device can be particularly advantageously combined with a motor. Thus, a fully automatic movement and adjustment of the axial position of the detector ring or the detector segment can be achieved. The sensor device can include, for example, one or more distance sensors. For example, at least one distance sensor can be fastened to at least one detector segment and / or to a base frame of the rack. At least one distance sensor can be configured to determine the distance between the detector segment and the base frame of the rack. The sensor device used can be a measuring sensor device of the computed tomography system itself. For example, the computed tomography system can be configured to detect deviations from the positioning of the detector ring classified as ideal based on measurement data, in particular based on CT image data and / or X-ray image data. If the detector ring is not at the focus of the X-ray source, that is, especially offset in the axial direction, this usually leads to a deterioration of the image quality. The computer tomography system can be configured to infer, based on the image quality of the computer tomography measurement or X-ray measurement, whether there is a deviation from the position of the detector ring that is classified as ideal. Advantageously, the position determination can be achieved by the measurement based on the CT data without the need for additional sensors. For example, it can be provided that the CT data are determined within the framework of a test measurement. Optionally, the computer tomography system can be configured to check the deviation of the position of the detector ring or the detector segments based on the CT data obtained during normal operation. The check can also be transferred to an external monitoring unit.

[0028] According to one embodiment, the computer tomography system comprises an X-ray source and an aperture for the X-ray source, wherein the computer tomography system is configured so that the positioning of the aperture in the axial direction of the detector ring is adjustable. The aperture can in particular include aperture segments. The adjustability of the aperture and / or the aperture segments can be set similarly to the adjustability described with respect to the detector ring or the detector segment. For example, aperture spacers can be provided to adjust the axial position of the aperture. The aperture spacers can be implemented similarly to the characteristics of the spacers of the detector segments. Therefore, advantageously, the positioning of the aperture can be adjusted in the same manner as the positioning of the detector ring. Basically, a computer tomography system with an adjustable aperture but without a detector ring as described here can also be envisioned. That is, the adjustable aperture can be implemented independently of the adjustable detector ring and vice versa.

[0029] A further aspect of the invention is a method for orienting a detector ring in or on a gantry of a computed tomography system, wherein the detector ring comprises at least two detector segments, wherein the gantry comprises an X-ray source, wherein the method comprises the following steps:

[0030] (a) obtaining a measurement indicating the current position of the detector segment;

[0031] (b) determining whether there is a deviation in the axial direction according to which the current positioning of the detector segment deviates from the ideal positioning;

[0032] (c) Adjusting the positioning of the detector segments in the axial direction, in particular relative to the X-ray source and / or relative to each other, for which the deviation is determined.

[0033] All advantages and features of the computed tomography system can be transferred analogously to the method and vice versa.

[0034] The measured values ​​can be determined using a sensor system. For example, the measured values ​​can be determined using at least one distance sensor. According to one embodiment, a distance sensor is used on the frame and the detector segment in order to obtain the measured values ​​in the form of distance measurement data, wherein the position is determined based on the distance measurement data. This can be a simple possibility to directly determine the position.

[0035] According to one embodiment, the deviation is determined in such a way that an X-ray recording, in particular a computed tomography recording, is performed to obtain measurement values ​​in the form of at least one X-ray image, and it is determined whether an image error occurs in the at least one X-ray image, which image error can be traced back to the positioning of the detector ring. The measurement value can be a CT measurement value and / or X-ray data measured with a computed tomography system. Therefore, the CT measurement value and / or X-ray data can indicate the current positioning in such a way that a deviation from the focal position of the detector segment can lead to a deterioration in the image quality. The deviation of the positioning in the axial direction of the detector segment can be determined based on the properties of the CT measurement value and / or X-ray data (for example, reduced image quality). Therefore, advantageously, the determination of the deviation can be achieved without the use of additional sensor devices. Further advantageously, it is possible to directly take into account the influence of the positioning. Therefore, this variant does not depend on whether the position estimated as ideal is actually ideal, but can directly find an optimized or improved position within the framework of the accuracy used based on the image quality.

[0036] Adjustment of the positioning may be performed manually by the user. The computed tomography system may request the user to make adjustments to the positioning by notification. Alternatively, adjustment of the positioning may be initiated automatically by the computed tomography system.

[0037] According to one embodiment, in order to adjust the positioning, the detector segments are moved in the axial direction on at least one guide rail respectively. Optionally, before the adjustment, at least one guide rail can be installed on the frame respectively. After the adjustment, at least one guide rail can be removed again. Alternatively, the guide rail can be permanently installed on the frame. The movement of the detector segment can be set manually by the user. Alternatively, the movement of the detector segment can be set automatically, especially by a motor. Before adjusting the positioning, at least one fastening device that releases the adjusted detector segment can be provided. The fastening device can fasten at least one detector segment to the frame respectively, especially to the base frame of the frame. For example, the fastening device can be a fastening device as described here. After adjusting the positioning, the fastening device can be fastened again.

[0038] According to one embodiment, spacers are used between the frame and the detector segments in order to compensate for deviations of the detector segments. The spacers may be spacers as described herein. Deviations may be compensated by selecting from a group of different spacers. For example, a first spacer may be adjusted by other spacers, different from the first spacer, in order to compensate. The spacers may be different, in particular in terms of their thickness. Optionally, the positioning and / or orientation of the detector segments relative to each other may be compensated by the spacers. Optionally, the detector segments, in particular the substrate, are tensioned by screwing the spacers and at least one detector segment, in particular the substrate of at least one detector segment. The tensioning may be performed to compensate for unevenness of the detector segments, in particular the substrate. This may be advantageous, for example, in the case of thermally induced warping. The substrate may be a substrate as described herein.

[0039] According to one embodiment, the spacer is fixed with at least one fastening means, in particular one or more screws. The spacer can be fixed independently of the fixation of the detector segment. This can simplify the installation, in that the spacer can be firmly fixed when the detector segment moves. Alternatively, the spacer can be fixed together with the corresponding detector segment by at least one common fastening means. Therefore, advantageously, fewer fastening means can be required.

[0040] According to one embodiment, the detector segment is moved in the axial direction by a motor for adjusting the positioning. The motor can be, for example, a linear drive and / or a spindle drive. Advantageously, an automatic adjustment of the positioning can thus be carried out without the user having to manually move the detector segment. A substantially stepless adjustment of the axial position can be provided by the motor.

[0041] Unless expressly stated otherwise, all embodiments described here can be combined with one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Hereinafter, some embodiments are described with reference to the accompanying drawings.

[0043] Figure 1 A computer tomography system according to an embodiment of the present invention is shown.

[0044] Figure 2 A base frame of a gantry of a computed tomography system according to one embodiment of the present invention is shown.

[0045] Figure 3 An exploded view of a gantry of a computed tomography system according to an embodiment of the present invention is shown,

[0046] Figure 4 FIG. 1 shows a gantry of a computed tomography system according to one embodiment of the present invention, in which two of the three detector segments are installed.

[0047] Figure 5 It is shown that according to the present invention and Figure 4 a corresponding gantry of a computed tomography system of the same embodiment shown in , in which all three detector segments of the detector ring are mounted,

[0048] Figure 6 FIG. 1 shows a gantry of a computed tomography system according to one embodiment of the present invention with a detector segment installed, the detector segment being moved away from the gantry,

[0049] Figure 7 shows a gantry of a computed tomography system according to one embodiment of the present invention with a detector segment installed, the detector segment being moved closer to the gantry, and

[0050] Figure 8 A flow chart of a method for aligning a detector ring in or on a gantry of a computed tomography system is shown according to one specific embodiment of the present invention. DETAILED DESCRIPTION

[0051] Figure 1 The computer tomography system according to one embodiment of the present invention is shown. The computer tomography system comprises a stationary gantry 4 having a detector ring 6, which surrounds an examination area 2 (here, due to the stereoscopic view, the inside cannot be directly seen, see Figure 2The detector ring 6 includes at least two detector segments 7, which cannot be seen here due to the stereoscopic view, but can be seen in some of the embodiments shown below. The computer tomography system is configured so that the positioning of the detector segments 7 in the axial direction of the detector ring 6 is adjustable, and the axial direction corresponds to the z-direction here. A replaceable spacer 11 is provided between the detector segment 7 and the frame 4, so that the positioning of the detector segment 7 (the detector segments combined to produce the detector ring 6) in the axial direction (z-direction) of the detector ring 6 can be adjusted by the spacer 11. Viewed in the z-direction, an X-ray source R and an aperture for the X-ray source R are provided on the other side of the frame 4 opposite to the detector ring 6. Optionally, in addition, the computer tomography system can be configured so that the positioning of the aperture in the axial direction (z-direction) of the detector ring 6 is adjustable.

[0052] Figure 2 The base of a gantry 4 according to one embodiment of the invention is shown. The gantry 4 comprises fastening means 12, in this case screw holes and slots, for fastening spacers 11. Alternatively, other fastening means 12, such as click and release mechanisms, can also be provided. An examination area 2 is arranged centrally in the gantry 4, in which, for example, a patient can be placed.

[0053] Figure 3 FIG. 4 shows an exploded view of a gantry 4 of a computed tomography system according to one embodiment of the present invention. The base frame of the gantry 4 substantially corresponds to Figure 2 The rack 4 shown in . In addition, here, spacers 11, detector rings 6 and electronic modules 13 for detector elements of detector segments 7 are provided. Preferably, the spacers 11 can be made of a metal-containing material, in particular steel. For example, the spacers 11 can be a plate, which can be fixed to the fastening device 12 by screws. In this embodiment, the spacers 11 are elongated compensating plates, the longitudinal extension of which extends essentially in the radial direction. A group of spacers 11 with different thicknesses can be provided, which can be replaced separately as required. For example, the thickness graduation can be, for example, 0.1 mm. During operation, the detector ring 6 can be covered to the outside by a protective plate 14.

[0054] Figure 4 A gantry 4 of a computed tomography system according to one specific embodiment of the present invention is shown, in which two of the three detector segments 7 are installed.

[0055] Figure 5A corresponding frame 4 of a computed tomography system according to the same embodiment of the present invention is shown, in which all three detector segments 7 of a detector ring 6 are installed. In order to better see the inside, the protective plate 14 is omitted in this illustration. The detector segments 7 are basically ring segments, which respectively form partial rings of the detector ring 6. Each of the detector segments 7 comprises a base plate 8 and two functional units 9 with detector elements, which are fastened to the base plate 8 and can be removed from the base plate 8. In addition, an electronic component module 13 for controlling and reading out the detector elements is arranged on each functional unit 9. The base plate 8 is also constructed in a substantially partially annular shape. In this embodiment, four spacers 11 are respectively provided for each of the detector segments 7 or for each base plate 8.

[0056] Figure 6 and 7 The gantry 4 of the computed tomography system according to one embodiment of the present invention is shown in each case when the detector segment 7 is installed or moved. Figure 7 In FIG. 4 , the detector segment 7 is moved closer to the housing 4 and the positioning of the detector segment 6 is determined by the spacers 11 between the housing 4 and the detector segment 7. In particular, the spacers 11 provided for the further detector segments 7 can be seen. Figure 6 In the embodiment of the present invention, the detector segment 7 is moved away from the frame 4 on the guide rails 10 so that the spacers 11 of the detector segment 7 can be replaced in order to adjust the positioning of the detector segment 7 in the axial direction of the detector ring 6. The guide rails 10 extend essentially in the axial direction and they are used to guide the movement of the detector segment 7. Optionally, the computed tomography system can include a motor (for example, placed at 15), which is configured to adjust the positioning of at least the detector segment 7 in the axial direction. The motor can be a spindle drive and the guide rail 10 can be a threaded rod, which is used for the movement caused by the motor. The guide rail 10 can be removable. If the guide rail 10 is not arranged to be removable, which may be advantageous in particular in the version with a motor, it is advantageous to configure the guide rail 10 to be slightly shorter to avoid that the guide rail 10 protrudes. In the version with a motor, the spacers 11 can also be omitted and the positioning of the detector segment 7 can only be adjusted by the motor.

[0057] Figure 8A flow chart of a method for orienting a detector ring 6 in a gantry 4 or on a gantry 4 of a computed tomography system according to one embodiment of the present invention is shown. In this case, the detector ring 6 comprises at least two detector segments 7. In a first step 101 of the method, a measured value is determined, which indicates the current position of the detector segment 7. For example, the measured value can be determined by means of a sensor device. The sensor device can comprise, for example, one or more distance sensors that determine distance measurement data. Alternatively or additionally, the CT measurement sensor device itself can be used in that an X-ray recording, in particular a computed tomography image, is performed in order to obtain measured values ​​in the form of at least one X-ray image and / or CT data. In a further step 102, it is determined whether there is a deviation in the axial direction, according to which the current position of the detector segment 7 deviates from the ideal position. For example, the position or the deviation can be determined based on the distance measurement data determined by the distance sensor. Alternatively or additionally, the deviation can be determined by determining whether there is an image error in the measured X-ray image and / or the measured CT data, which image error can be traced back to the position of the detector ring 6. In a further step 103, once the deviation is determined, the positioning of one or more detector segments 7 in the axial direction of the detector segment 7 is adjusted. To adjust the positioning, the detector segment 7 can optionally be moved in the axial direction on the guide rail 10. Additionally or alternatively, the detector segment 7 can be moved in the axial direction by a motor to adjust the positioning.

Claims

1. A computer tomography system comprising an examination area (2) and a static gantry (4), The frame (4) comprises an X-ray source (R) and a detector ring (6); wherein the detector ring (6) surrounds the examination region (2) and comprises at least two detector segments (7); The computed tomography system is configured such that the positioning of the detector segments (7) in the axial direction of the detector ring (6) relative to the X-ray source (R) and / or relative to each other is adjustable.

2. The computer tomography system according to claim 1, The detector segments (7) each comprise a base plate (8) and at least one functional unit (9) having a detector element which is fastened or can be fastened to the base plate (8) and can be removed from the base plate (8).

3. A computer tomography system according to any one of the preceding claims, The computed tomography system comprises a guide rail (10) which extends substantially in the axial direction and by which the movement of the detector segment (7) in the axial direction can be guided.

4. The computer tomography system according to any one of the preceding claims, A replaceable spacer (11) is arranged between the detector segment (7) and the frame (4), so that the positioning of the detector segment (7) in the axial direction of the detector ring (6) can be adjusted by the spacer (11).

5. The computer tomography system according to claim 4, The frame (4) comprises a fastening device (12) for fixing the spacer (11).

6. The computer tomography system according to any one of claims 4 to 5, At least two spacers (11) are provided for each of the detector segments (7).

7. A computer tomography system according to any one of the preceding claims, The computed tomography system comprises at least one motor, which is configured to adjust the positioning of at least one of the detector segments (7) in the axial direction.

8. The computer tomography system according to claim 7, The motor is a linear drive and / or a spindle drive.

9. The computer tomography system according to any one of the preceding claims, The computed tomography system is configured to detect deviations from a classified ideal positioning of the detector ring (6) by means of a sensor system.

10. The computer tomography system according to any one of the preceding claims, wherein the computer tomography system comprises an aperture for the X-ray source (R); The computer tomography system is further configured such that the positioning of the aperture in the axial direction of the detector ring (6) relative to the X-ray source (R) is adjustable.

11. A method for orienting a detector ring (6) in or on a gantry (4) of a computed tomography system, wherein the detector ring (6) comprises, in particular, at least two detector segments (7), wherein the method comprises the following steps: (a) determining measured values, which indicate the current positioning of the detector ring, in particular of the detector segments (7); (b) determining whether there is a deviation in the axial direction, according to which the current positioning of the detector ring, in particular of the detector segment (7), deviates from an ideal positioning; (c) For the detector ring, in particular the detector segment, whose deviation has been determined, adjusting the positioning of the detector ring, in particular the detector segment (7) in the axial direction.

12. The method according to claim 11, A spacer (11) is used between the frame (4) and the detector segment (7) in order to compensate for the deflection of the detector segment (7).

13. The method according to any one of claims 11 to 12, In order to adjust the positioning, the detector segment (7) is moved in the axial direction by a motor.

14. The method according to any one of claims 11 to 13, The deviation is determined by carrying out an X-ray recording, in particular a computed tomography recording, to obtain measured values ​​in the form of at least one X-ray image and determining whether image errors occur in the at least one X-ray image, which image errors can be traced back to the positioning of the detector ring (6).

15. The method according to any one of claims 11 to 14, Therein, distance sensors are used on the frame (4) and the detector segment (7) in order to obtain measured values ​​in the form of distance measurement data, wherein the positioning is determined based on the distance measurement data.

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