WO2008046781A1 - Medical diagnostic system - Google Patents

Abstract

The invention relates to a medical diagnostic system (2), comprising two measuring systems with one holding device (14, 22) each, at least one positioning device (4, 40) connected to a holding device (14, 22) for positioning the measuring systems, and a common control unit (10), which is designed to position both measuring systems one after the other for performing measurements. The one measuring system is an X-ray measuring system with an X-ray emitter (18) and an X-ray detector (20). The other measuring system is an additional measuring system. Thus measurements with both measuring systems can be performed in one operation. Immediate results can be obtained, such as a medical intervention monitored repeatedly with both measuring systems.

Description

Medical diagnostic system

The invention relates to a medical diagnostic system.

A medical diagnostic system comprises at least one measuring system, which is arranged on a holding device and is positioned by means of a positioning device. Furthermore, a control unit for controlling the positioning device is provided. In recent years, various types of medical diagnostic systems have evolved in medical technology.

In computer tomography (CT), for example, a person to be examined is successively inserted into a gantry by means of a patient couch. In the gantry, an X-ray measuring system comprising an X-ray source and an X-ray detector is movably arranged on its circumference. The gantry is therefore simultaneously the holding and positioning device for the X-ray measuring system. The X-ray measuring system records X-ray images from a variety of different directions. From these X-ray images, a sequence of image information of the body of the person to be examined is generated, which is stored in the form of sectional images. These sectional images can be used later for diagnostic

Be considered as a sequence of images on a display element. By means of a computer-aided processing of several successive sectional images, three-dimensional views are generated on the display element. In these three-dimensional views, anatomical details emerge particularly well, making them particularly well-suited for medical evaluation of anatomical features.

The CT represents anatomical structures in great detail. Its resolution lies in the submillimeter range. However, in a CT cross-sectional image, cancer cells do not look any different from healthy cells, so they are not recognized until so many have accumulated that they form an unusual structure.

Another medical diagnostic system is described in DE 44 36 828 Cl. It has an X-ray measuring system with an X-ray source and an X-ray detector, which are arranged at the ends of a C-arm. The C-bow is carried by another C-bow. Both C-arms together constitute the holding and positioning device for the X-ray measuring system. By means of such a medical diagnostic device, it is possible to produce two-dimensional planar individual recordings in the form of sectional images. In addition, the combined holding and positioning device can also be rotated in the central longitudinal direction so that cross-sectional sequences can also be produced in the manner of a CT. By means of this medical diagnostic system, individual measurements can be carried out quickly. In addition, it is well suited for the implementation of medical interventions. The C-arm holding device for the X-ray measuring system allows almost unhindered access to a person on whom the intervention is to be carried out. A repeated check of the progress of the medical intervention is possible without any problems. In contrast, in a CT, the person often has to be removed from the gantry by means of the patient bed at least a part.

Nuclear medical measurement methods, which are used, for example, in tumor diagnostics, follow a different route of presentation. In this case, a person to be examined is given a special functional contrast agent, a so-called radiopharmaceutical, which accumulates in certain body regions before the examination.

In positron emission tomography (PET), the radiopharmaceutical is a positron emitter, which releases a positron when decayed. This is, for example, a glucose solution whose glucose molecules are labeled with fluorine atoms of the fluoroisotope ¹⁸ F. The radioactively labeled Glucose molecules are incorporated, in particular, by body cells with increased metabolic activity. These regions of increased metabolic activity very often represent an accumulation of cancer cells.

When a positron breaks down, two x-ray quanta are generated which fly away from their point of origin at a 180 ° angle and are registered in a spatially resolved manner by means of two scintillation detectors arranged opposite a holding and positioning device. The measured image information is converted into sectional images. In these sectional images, body regions with an increased metabolic activity can be detected.

In single-photon emission tomography (SPECT), a person to be examined is injected with a gamma emitter into the bloodstream, for example the metastable technetium isotope ^99m Tc, which passes into the ground state with a half-life of 6.01 hours by emitting X-rays. The atoms of the gamma emitter are distributed in the bloodstream of the person. The emitted X-rays are detected in a spatially resolved manner by means of one or two scintillation detectors. The measured image information is converted into sectional images as in PET.

The contrast of the sectional images depends on the perfusion or perfusion of a body region. Thus, a reduced perfusion of the heart muscle (myocardium) can be detected as well as a hyperperfusion of a body region suggestive of a tumor. A minor perfusion of a brain area indicates a brain dysfunction such as Alzheimer's disease or an epileptic disorder. It may also be an indication of a blood clot that, if left untreated, would lead to a stroke.

The sectional images measured by means of PET or SPECT therefore have a very important supportive function in diagnostics. Based on their image information can be the success be immediately understood. Unlike CT, however, PET or SPECT provide much less detailed anatomical information. Their spatial uncertainty is several millimeters. This is disadvantageous in particular when initiating therapeutic measures. Thus, in the case of irradiation therapy with X-ray radiation in the case of an insufficiently accurate localization of a tumor, either healthy body tissue is destroyed during the irradiation or else a tumor is not completely irradiated. In case of surgical removal of the tumor, due to the local blurring of the measurement by means of PET or SPECT, also healthy body tissue must be removed in order to ensure a safe removal of the tumor.

The invention has for its object to provide a medical diagnostic system that provides comprehensive information for the diagnosis of a person.

This object is achieved according to the invention by a medical diagnostic system according to claim 1. For this purpose, the diagnostic system has two measuring systems, each with a holding device. Furthermore, at least one positioning device is connected to one of the holding devices for positioning the measuring systems. The medical diagnostic system includes a control unit configured to sequentially position both measurement systems to perform measurements. The first measuring system is an X-ray measuring system which comprises at least one X-ray emitter and one X-ray detector.

However, the X-ray measuring system can also have two or more X-ray sources and two or more X-ray detectors corresponding to these X-ray sources. At the same time, image information can thus be obtained from various points of view, which is extremely advantageous, in particular, when carrying out a medical intervention.

The at least one positioning device is expediently designed so that the most flexible positioning possible. tion of the holding device can be reached with the measuring system arranged on this. For this purpose, the positioning device is designed in the manner of a positioning robot and has, for example, a swivel arm and one or more rotatable elements. The use of such positioning robots has proven itself in the industry for a long time. Positioning robots of this type have a high positioning accuracy and a high repetition accuracy when the same measuring position is approached again.

The possibility of exact control of the measuring position is of particular importance in the present case, so that identical measuring positions can be repeatedly and repeatably used for comparative measurements with both measuring systems for carrying out a measurement. Thus, two different types of image data sets of the same body region are available for the diagnosis. Thus, supplementary image information of the two measuring systems can be assigned to one another in a location-specific manner.

The positioning robot may have a fixed location on which it is positioned by means of a stand. But it can also be guided in addition and, for example, have a rail guide.

Thus, in addition to the measurement with the X-ray measuring system, further image information can be obtained promptly by the further measuring system, by means of which a medical diagnosis can be produced more precisely or a medical intervention can be carried out more precisely.

It is therefore not necessary to carry out measurements with two different medical diagnostic systems. Thus, there are no waiting times for a test result. Due to the acquisition of image information with both measuring systems from the same point of view, the risk of a false diagnosis is reduced since the image information of a body region can be viewed from the same perspective and Different projections of image information can not distort the findings.

By dividing the functionality into a positioning device and into a holding device, a modular construction is also possible. An arbitrary holding device can be coupled to such a positioning device provided that the coupling element of the positioning device and the coupling element of the holding device correspond to one another. Expensive special developments, as required in the case of combined positioning and holding devices, can therefore be avoided. Rather, a positioning device with structurally different, adapted to the application situation holding devices in the manner of a modular system can be fitted.

The further measuring system is preferably a nuclear medicine measuring system. In particular, the nuclear medicine measuring system is a positron emission tomograph (PET) with two scintillation detectors or a single photon emission tomograph (SPECT) with one or two scintillation detectors.

This makes it possible to record a tumor particularly well with SPECT or PET. By means of the X-ray measuring system, which provides a significantly better spatial resolution in the image display, a medical intervention on such a tumor, in particular a closing of the blood vessels supplying the tumor or a burning out of the tumor, can be carried out immediately after its detection. The result of this medical intervention is immediately comprehensible in a new measurement by means of the nuclear medicine measuring system. Multiple switching between an X-ray measuring system and a nuclear medicine measuring system, which often has to be carried out even on account of the utilization of the corresponding individual medical diagnostic systems in a clinic or a doctor's office on different days, can thus be omitted. A treatment of a patient th is thus very quickly feasible. Thus, such medical interventions can be carried out significantly more cost-effectively than is possible on the conventional treatment path using two spatially separate medical diagnostic systems.

The medical intervention can be further optimized by the use of special radiopharmaceuticals, which on the one hand accumulate particularly fast in the body at sites with a high metabolic activity, but on the other hand are also rapidly and residue-free degradable. In this case, it is possible in particular to use tracers which are selectively coupled to an organ to be detected. These tracers allow the perfusion of an organ to be detected. Thus, a lack of perfusion in a heart or a hyperperfusion of tumor tissue is detectable.

In addition, the X-ray measuring system or the nuclear-medical measuring system can also be used alone, so that possibly only a medical diagnostic system has to be purchased where the acquisition of two medical diagnostic systems would have been necessary in the past.

In another variant, the further measuring system is a biopsy system. In this case, the exact location for taking a tissue sample is previously determined by the X-ray measurement system.

In a further variant, the further measuring system is an optical imaging system for molecular imaging, such as, for example, a fluorescence microscope. By means of a fluorescence microscope, similar to a PET or SPECT, sites of high metabolic activity can be detected which have been previously labeled with a fluorescent substance and which in particular indicate a tumor. A medical intervention, in particular the removal of a tumor, is carried out by means of the optical imaging system and monitored immediately afterwards by means of the X-ray measuring system. In another variant, the further measuring system is a surgical microscope, by means of which a medical intervention in the millimeter or submillimeter range can be carried out. Again, the medical intervention is carried out step by step and controlled over and over again by means of the X-ray measuring system.

All other measuring systems listed provide additional information on the measurements of the X-ray measuring system, which makes it possible to make a medical diagnosis more precisely or to carry out a medical intervention more precisely and faster than just with the image information of the X-ray measuring system alone.

The holding device can be designed as a C-arm, as it is already used in conventional X-ray measuring systems. Such a C-arm has a high mobility. In addition, due to its design, it allows a virtually free accessibility of a person on whom a medical intervention is to be carried out. However, the holding device may also have an L-shape, as used in conventional SPECT systems, or be designed differently. When choosing a suitable holding device, it is expedient to orientate oneself on hitherto used and proven geometries for such holding devices, in order to avoid a completely new development with a corresponding expense.

If the X-ray measuring system comprises two or more X-ray sources and two or more X-ray detectors, the holding device for the X-ray measuring system can also be designed as a double C-arm.

The at least one positioning device expediently has a robot-side coupling element. In addition, both holding devices have one to this coupling element corresponding mating coupling element for repeatable coupling / decoupling with the positioning device.

In one variant, only one positioning device is provided. The holding devices are set up for mutual coupling to the positioning device. Thus, it is necessary to provide only one positioning device with which successive measurements can be carried out with two different measuring systems.

The control unit is executable such that a coupling or decoupling of a holding device is carried out automatically to a positioning device. Thus, only a short set-up time for the replacement of the two fixtures is necessary.

In another variant, each holding device has its own positioning device, with which it is connected. In this way, no set-up times for coupling or decoupling of one of the two holding devices to a positioning device. The other measuring system, however, is immediately usable.

Preferably, the unused measuring system is positioned in a parking position in both variants, so that the decoupled holding device or the second positioning device does not restrict the working range of the measuring system used.

If two positioning devices are used, a particularly rapid change between the two measuring systems can be carried out by means of the control unit. In this case, the one positioning device is moved with its measuring system from a measuring position to its parking position and vice versa, the other positioning device with its measuring system from its parking position in a measuring position. A simple solution for the electrical and data connection and supply of other media, such as coolant, is to use for each measuring system its own, separate, firmly connected to this measuring system supply, such as a hose.

Advantageously, the coupling elements serve both for mechanical attachment of the holding devices to the positioning device, as well as for electrical and data connection. For this purpose, the coupling elements on separation or interfaces for releasably connecting in particular e- lektrischen supply lines and control and data lines. Measured values and states of the measuring system are read out via the data lines and the measuring system is controlled via the control lines. A mechanical connection can be produced for example by a pin on the holding device, which engages in a corresponding recess of the positioning device. Electrical lines, data lines and control lines can easily be connected to one another via plug-socket connections distributed on the robot-side and the measuring-side coupling element.

In a development, the control unit is set up to calculate an optimal measuring position of the respective other measuring system on the basis of the image information measured with one of the two measuring systems. Thus, image information can be obtained with both measuring systems from an identical angle. This applies both to individual image information as well as to image sequences of sectional images. So are

Incorrect evaluations in the assessment of image information due to projection errors excluded. Thus, differences in the viewing angle due to a slightly different geometry of the holding devices can be compensated. Since the determination of the optimum measurement position in the control unit is automatic, no storage is necessary for the adjustment of the required image information. It will thus stored only image information that is needed for a diagnosis.

An evaluation unit is expediently provided, which is set up to compute image information measured with the x-ray medical measuring system and image information measured with the further measuring system and to display it as fused image information on a display element. For this purpose, individual image information or image sequences are recorded with two measuring systems in the same measuring positions one behind the other and superposed mathematically. It is therefore possible, in particular, to provide nuclear medicine information by conversion with the sub-millimeter spatial resolution of a radiographic medical measuring system. Thus, a subsequent medical intervention such as the removal of a tumor is much more precise feasible.

Thus, due to the positioning accuracy of the positioning device and due to the known geometry of the two measuring systems with their holding devices, a system-related coregistration of the image information of the two measuring systems is given intrinsically.

Suitably, the evaluation unit is set up, based on the image information of the X-ray measurement system

To perform attenuation correction of the image information of the nuclear medicine measurement system. In this way, an improvement of the image information measured with the second measuring system is achieved.

In one development, the positioning device is at the same time also designed for coupling to a patient bed or a patient positioning device in order, for example, to carry out a rearrangement of a person to be examined for the application of radiopharmaceuticals. The person can thus be spent in a separate room. In this way, an application of radiopharmaceuticals is also feasible during an investigation quickly. Since the administered radio In addition, nuclides are usually very short-lived, it is thus ensured that the administration has taken place immediately before an examination. It can thus be ensured that the person has a high number of not yet decayed radionuclides. Therefore, particularly many decays are registered, which increases the contrast and thus the meaningfulness of the image information obtained.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

1 shows a medical diagnostic system with a positioning device in a schematic side view and Figure 2 shows another medical diagnostic system with two positioning also in a schematic side view.

According to FIG. 1, a medical diagnostic system 2 has a positioning device 4. This positioning device 4 is designed as a positioning robot, in particular as a conventional multi-axis industrial robot, and has a plurality of robot arms 6, which are connected to each other via pivot joints 8. It is positioned by means of a control unit 10. The robot arms 6 and the hinges 8 allow a very free positioning of the positioning device 4th

The positioning device 4 has a robot-side coupling element 12 at its free end. A measuring-side coupling element 16 arranged on a first holding device 14 is coupled to this robot-side coupling element 12. The holding device 14 is designed as a C-arm and carries at its two ends opposite one another an X-ray measuring system comprising an X-ray source 18 and an X-ray detector 20. A second holding device 22 with a single-photon emission tomograph comprising a scintillation detector 24 also has a measuring-side Coupling element 16, which is identical in construction to the measuring-side coupling element 16 of the first holding device 14. This second holding device 22 is in its parking position.

The robot-side coupling element 12 and the measuring-side coupling element 16 are mechanically connected to each other after coupling. In addition, interfaces for electrical supply lines are provided which electrically supply the X-ray measuring system arranged on the first holding device 14. By means of interfaces for data lines also provided in the two coupling elements 12, 16, measured values of the X-ray measuring system can be transmitted and states of the X-ray measuring system can be read out. Furthermore, interfaces for data lines are integrated into the two coupling elements 12, 16, by means of which measured values and states of the measuring system in the measurement mode can be read out. Finally, interfaces for control lines are provided, by means of which the measuring system located in the measuring mode can be controlled. The electrical lines, the data lines and the control lines are connected to one another via the plug-socket connections distributed on the robot-side coupling element 12 and the measuring-side coupling element 16.

On a patient positioning device 26, which includes a patient bed 28, and an adjustment unit 30, is a person to be examined 32. By means of the control unit 10, the adjustment unit 30 is controlled, which adjusts the patient bed 28 in the horizontal direction 34. In addition, a rotation or tilting of the patient bed 28 is possible. This preferably has a radiation-transparent lying surface.

For positioning the X-ray measuring system arranged on the positioning device 4, the control unit 10 is provided. The control unit 10 controls the positioning device 4. Thus, an almost arbitrary position of X-ray source 18 and X-ray detector 20 for performing measurements and for measuring image information.

After completion of the measurements with the X-ray measuring system, the first holding device 14 is moved away from the person to be examined by means of its pivoting arm and moved with the X-ray measuring system arranged on it to a defined location. The robot-side coupling element 12 and the measuring-side coupling element 16 of the first holding device 14 are decoupled from each other. The first holding device 14 with the X-ray measuring system is now in its parking position. It is held, for example, on a wall bracket, not shown in the figure.

Subsequently, the measuring-side coupling element 16 of the second holding device 22 is coupled to the robot-side coupling element 12 of the positioning device 4. The positioning device 4 is moved with the second holding device 22 and the SPECT measuring system arranged thereon to a measuring position and is available there for carrying out further measurements and measuring further image information.

The image information is processed by means of an evaluation unit, not shown in the figures, and displayed on a display element, which is also not shown in the figures. Since the positioning device 4 enables a very exact positioning of both measuring systems, measurements can be carried out and image information measured by means of both measuring systems from a same point of view.

The image information can be stored in a memory integrated in the evaluation unit. Thereby, it is possible to compute image information of the X-ray measuring system and image information of the SPECT, which were taken from the same point of view. The resulting fused image information includes X-ray medical and nuclear medicine information. Since the X-ray gene measuring system has a much better spatial resolution than the nuclear medicine measuring system, the nuclear medicine image information is thus provided with a better spatial resolution. In this way, for example, for a doctor finding out the image information, a tumor can be located much more accurately than just by means of a SPECT. The use of a SPECT and of this spatially separate X-ray measuring system, in which a computational overlay of the image information is not feasible or only with great difficulty and a large error, provides a poor result, since the same measurement position can not be reproduced on different measuring systems.

For the measurement of the image information, various examination programs are stored in the control unit in a program memory not shown in the figures. Thus, the implementation of individual two-dimensional angiographic images with the X-ray measuring system is possible as well as the successive rotation of the holding device 14 designed as a C-arm for subsequent three-dimensional reconstruction of the measurement data in the manner of a computer tomograph. In addition, it is possible to carry out measurements with the SPECT from identical positions in order to be able to superimpose the image information obtained with both measuring systems. However, both measuring systems can also be used completely independently of each other.

In contrast to FIG. 1, the diagnostic system 2 according to FIG. 2 has a second positioning device 36, which is likewise designed as a robot. Furthermore, the patient positioning device 26 is also designed as a robot. The first positioning device 4 is connected with its robot-side coupling element 12 with the measuring-side coupling element 16 of the first holding device 14. The second positioning device 36 is coupled with its robot-side coupling element 12 to the measuring-side coupling element 16 of the second holding device 22. Both positioning devices tions are controlled by a common control unit 10.

In this way, a decoupling of a holding device 14,22 from their positioning device 4,36 only in case of service is necessary or if one of the two measuring systems is to be replaced with another measuring system, for example, instead of a nuclear medical examination, a medical intervention by means of a surgical Micro- perform skops.

During the examination of a person 34, therefore, no additional set-up time is necessary for exchanging the two holding devices 14, 22 in order to be able to measure with the respective other measuring system. The unneeded positioning device 4, 36 is merely brought into a parked position in which it does not obstruct a positioning of the respective other measuring device. A multiple change between the two measuring systems is thus possible quickly. In FIG. 2, the second positioning device 36 is in its parking position.

The patient bed 28 can be moved to a place spatially separated from the location of the medical diagnostic system 2. For this purpose, for example, the entire patient positioning device 26 is moved on rails, for example. Alternatively, the patient bed 28 is gripped by one of the positioning devices 4, 36 and moved with their help. For this purpose, a matching coupling element is provided on the patient bed 28. Thus, the person lying on the patient bed 28 to be examined 32 can spend immediately before the examination in a treatment room for the application of a radiopharmaceutical and then transported back to the location of the medical diagnostic system 2, by the short time between the application of radionuclide and the At the beginning of the examination, it is possible to ensure that a sufficiently large quantity of the radiopharmaceutical is present at the beginning of a To generate valuable and thus well-readable image information by means of the SPECT.

Claims

claims 1. Medical diagnostic system (2) with two measuring systems each having a holding device (14, 22), with at least one positioning device (4, 36) connected to the holding device (14, 22) for positioning the measuring systems and having a common control unit ( 10) arranged to sequentially position both measuring systems for performing measurements, one measuring system being an X-ray measuring system with one X-ray source (18) and one X-ray detector (20), and the other measuring system being another measuring system. 2. The medical diagnostic system (2) according to claim 1, wherein the further measuring system is a positron emission tomograph (PET) comprising two scintillation detectors. 3. The medical diagnostic system (2) according to claim 1, wherein the further measuring system is a single photon emission tomograph (SPECT) comprising one or two scintillation detectors. 4. The medical diagnostic system (2) according to claim 1, wherein the further measuring system is optionally a biopsy system, an optical imaging system or an operating microscope. 5. The medical diagnostic system (2) according to any one of claims 1 to 4, wherein the at least one positioning device (4,36) has a robot-side coupling element (12), and wherein both holding devices (14,22) a to this coupling element (12) corresponding measured sided Coupling element (16) for repeatable coupling / decoupling with the positioning device (4,36). 6. A medical diagnostic system according to claim 5, wherein only one positioning device (4,36) is provided and the holding devices (14,22) for alternate coupling to the positioning device (4,36) are provided. 7. Medical diagnostic system (2) according to one of claims 1 to 4, wherein each holding devices (14,22) has its own positioning device (4,36), with which it is connected. 8. The medical diagnostic system (2) according to any one of the preceding claims, wherein in each case the unused measuring system is positioned in a parking position. 9. Medical diagnostic system (2) according to any one of claims 5 to 8, wherein via the coupling elements (12,16), the mechanical fastening of the holding devices (14,22) on the positioning tion (4,36) takes place and the coupling elements (12 , 16) further comprise interfaces for the detachable connection of supply lines and of data and control lines. 10. Medical diagnostic system (2) according to one of the preceding claims, wherein an evaluation unit is provided, which is set up with the X-ray measurement system measured image information and measured with the other Messsys- tem information with each other and displayed as fused image information on a display element. 11. Medical diagnostic system (2) according to claim 10, wherein the evaluation unit is set up to determine a weakening correction of the image information of the nucleic-medical measuring system on the basis of the image information of the X-ray-medical measuring system. 12. Medical diagnostic system (2) according to one of the preceding claims, wherein the control unit (10) is arranged to calculate an optimal measurement position of the respective other measurement system based on the measured image information with one of the two measuring systems. 13. Medical diagnostic system (2) according to one of the preceding claims, wherein the positioning device (4,36) in addition to a patentee (28) can be coupled.