DE102013110704B4 - Marking device for ultrasound examinations, use of a body as a marking element and device and method for ultrasound examinations - Google Patents

Abstract

A marking device for ultrasound examinations, comprising at least one marking element (22) for marking an object to be examined, which has at least a first reflection surface (24) and a second reflection surface (26) for ultrasound radiation spaced apart therefrom, the first reflection surface (24) and the second reflection surface (26 ) have parallel surface normals (30, 32).

Description

The invention relates to a marking device for ultrasound examinations.

The invention also relates to the use of a body as a marking element for ultrasound examinations.

The invention also relates to a method for finding signal contributions from a marking element in ultrasound image signals.

The invention also relates to a device for carrying out the method.

The present invention is described below in particular using the example of the application of medical ultrasound, but is not restricted to this field. The invention can also be used in other areas in which ultrasound is used to examine an object to be examined, for example material testing.

The use of ultrasound in medicine, particularly intraoperative ultrasound, has the advantage over other imaging methods that it is inexpensive and easier to use. Especially in relation to X-ray-based imaging, medical ultrasound has the advantage that the patient and operating room staff are not exposed to any exposure to ionizing radiation. For example, intraoperative ultrasound is used in orthopedics to identify broken bones. The use of ultrasound is also known in the field of implantology. When using intraoperative ultrasound, it is desirable to have, if possible, automatic recognition of the structures of the object to be examined. Devices and methods are known which, for this purpose, create ultrasound images in B-mode (brightness mode) from ultrasound image signals from the ultrasound probe, which images serve as the basis for automated image recognition methods. However, the accuracy of these devices and methods is often insufficient in practice. Strong scatter and interference of the ultrasonic field at tissue and bone boundary structures lead to a poor signal-to-noise ratio. Boundary structures are also often shown broad and smeared, which makes the automatic recognition of particularly bony structures difficult. This is also due to the fact that the image quality strongly depends on the angle of the ultrasound probe to the patient's body. In practice, this often results in smeared or widened structures, depending on the angle, whose interpretation is not easy for the user. To make matters worse, two-dimensional ultrasound fields in particular are used for intraoperative ultrasound, which can lead to a considerable change in the ultrasound image and thus difficult interpretation for the user if the ultrasound probe is moved slightly.

GAMPT mbH has published instructions for use for ultrasonic reflective plates GAMPT-10202 (www.gampt.de/content/cms/downloads/pdf/manuals/sdev_10202_deu.pdf).

In order to be able to find an object to be examined more easily, a marking device can be provided which can be recognized in a simple manner during the analysis of the ultrasound images and which can be used to infer the object to be examined.

The DE 29 29 799 A1 describes a method for marking an ultrasound localization, in particular in medicine, and a device used for this purpose. An ultrasound marker for physiological diagnosis and a method of using the ultrasound marker are disclosed in US Pat U.S. 4,373,532 A described.

Accordingly, it is the object of the present invention to provide a marking device for ultrasound examinations, the use of which makes it easier to find and analyze an object to be examined.

This object is achieved by a marking device for ultrasound examinations, which comprises at least one marking element for marking an object to be examined, which has at least a first reflective surface and a second reflective surface for ultrasound radiation spaced therefrom, the first reflective surface and the second reflective surface having parallel surface normals.

The invention also incorporates the idea that an ultrasound examination is a method based on the reflection of ultrasound radiation on an examined structure. Accordingly, the invention provides that a marking device is provided with at least one marking element which can be used to mark the object to be examined. Ultrasonic radiation can be reflected on at least one first and one second reflective surface spaced apart therefrom, the reflection surfaces having parallel and preferably coincident surface normals. In the direction of propagation of the ultrasonic radiation, the first and the second reflection surface are at a distance from one another. With a time delay, incident ultrasound radiation can first arrive at the first and then at the second Reflection surface partially reflected and detected again by the ultrasonic probe. This makes it possible to determine signal components in the ultrasound image signals which can be traced back to the reflection of the ultrasound radiation on the reflection surfaces. The same orientation of the surface normals can ensure that ultrasonic radiation propagating parallel to the surface normals can be detected again by the ultrasonic probe with a portion reflected on the first and a second reflection surface, the time difference between the signal portions in the ultrasonic signal being determined by the distance between the Reflecting surfaces from each other results. It has been shown in practice that the at least one marking element can be reliably detected, in particular if its sound impedance for the ultrasonic radiation used differs significantly from the sound impedance of the environment in which the marking element is positioned, in particular that of the object to be examined.

It is advantageous if the at least one marking element has more than two reflection surfaces, the surface normals of which are aligned parallel to one another. As a result, there is advantageously the possibility that a multiple reflection of the ultrasonic radiation takes place on the at least one marking element. For example, this is done initially on an outside of the marking element on a first reflective surface. The second reflective surface, which is spaced apart therefrom, can then be arranged on an inner side of the marking element. This reflected ultrasound radiation can be reflected again, for example, on an inside third reflection surface which is spaced apart therefrom and which corresponds to the first reflection surface with the opposite direction of incidence of the ultrasound radiation. This makes it possible for ultrasound radiation to move back and forth, often reflected in the at least one marking element. Since there is a non-reflected, transmitted portion in each case, a multiple reflection in the ultrasonic image signal can be recognized as a “tail” of an ultrasonic signal propagating in the direction of time. Due to the multiple reflection of ultrasonic radiation, a large number of signal components based on reflection and following one another in the time direction can be found. These signal components are higher, the greater the jump in the sound impedance from the at least one marking element to its surroundings.

It is advantageous if the reflective surfaces are arranged on an outside or on an inside of the at least one marking element. For example, as mentioned, the first reflection surface is arranged on an outside and the second reflection surface is arranged on an inside. Opposite the first reflective surface, a further, third reflective surface can be formed on the inside of the marking element, which corresponds to the first reflective surface when the direction of incidence of the ultrasonic radiation is opposite.

It can be provided that at least one reflection surface is planar.

It can further be provided that at least one reflection surface is curved. In the case of a plurality of curved reflection surfaces, their surface normals can coincide.

It can be provided that a reflection surface is planar and a reflection surface is curved, whereby for example a plane defined by the planar reflection surface can be detected.

The reflection surfaces can, for example, be aligned parallel to one another.

In an advantageous embodiment, the at least one marking element is expediently a sphere or has a spherical shape. Regardless of the direction of irradiation, multiple reflections of ultrasonic radiation can take place on spherical surfaces, the signal components of which can be detected with the ultrasonic probe. A spherical shape can be provided, for example, in that the at least one marking element, as mentioned below, is a spherical hollow body.

In another advantageous embodiment, it is favorable if the at least one marking element has a polyhedron shape or is a polyhedron, in particular that it has a cube shape or is a cube.

The use of a ball or a cube as a marking element has proven to be particularly advantageous in practice. Ultrasonic radiation can be reflected on an outside and an inside. Ultrasonic radiation reflected on the inside can be reflected again on the inside, the first reflection surface on the outside, correspondingly with the opposite direction of incidence of the ultrasonic radiation. As a result, multiple reflections can take place with simultaneous coupling-out of ultrasonic radiation in the direction of the ultrasonic probe, which can be reliably detected in the ultrasonic image signals.

When implementing the marking device according to the invention in practice, it proves to be advantageous if the at least one marking element has a size in one spatial direction, in particular a diameter, of approximately 2 mm to approximately 4 mm. For example, a sphere with a diameter of 2 mm is used for image depths of up to 40 mm, a sphere of approximately 3 mm in diameter for image depths of up to 80 mm, and a sphere with a diameter of approximately 4 mm for image depths of up to 120 mm.

As already mentioned, the at least one marking element can be a hollow body. For example, the hollow body is a recess in the object to be examined, in particular a spherical or cube-shaped cavity in a bone when using medical ultrasound.

The hollow body can be filled with a filling material, for example a gas such as, in particular, air. A liquid filling material is also conceivable. A contrast agent, for example, whose sound impedance differs significantly from the sound impedance of the object under examination, can be used as the filler material.

In another advantageous embodiment, the at least one marking element is a solid body.

It proves to be favorable if the at least one marking element consists of a metal, in particular steel, platinum, tantalum, titanium, gold, silver, cobalt, chromium or an alloy of two or more of these materials.

Metals, in particular the metals mentioned above, and their alloys have acoustic impedances for ultrasound radiation of a size that makes them very suitable for use in marking elements in medical ultrasound examinations. For example, the acoustic impedance of steel is approximately 45 * 10 ⁶ kg / (m ² s) and is thus approximately 25 to 30 times as large as the average acoustic impedance of body tissue, which is approximately 1.6 * 10 ⁶ kg / (m ² s ) is (based on a frequency of medical ultrasound of approximately 10 MHz). As a result, steel in particular is very well suited as a material for a marking element that can be used in medical ultrasound examinations, especially for reasons of simple production and low costs.

In another advantageous embodiment of the marking device, it can be provided that the at least one marking element consists of bone or a bone substitute material.

It is favorable if the at least one marking element consists of a resorbable material such as polylactide or calcium phosphate, so that it can remain in the body during a medical ultrasound examination and can be resorbed by it.

In practice it proves to be advantageous if the ultrasonic impedance of the at least one marking element for medical ultrasonic radiation is greater than approximately 20 * 10 ⁶ kg / (m ² s), preferably greater than 25 * 10 ⁶ kg / (m ² s), for example at an ultrasonic frequency of approximately 10 MHz. With such an ultrasonic impedance, this is shown in practice, a signal component based on multiple reflections on the reflection surfaces can be reliably separated from signal components of the body tissue surrounding the marking element.

The speed of sound in the at least one marking element for medical ultrasound radiation, for example at an ultrasound frequency of approximately 10 MHz, is advantageously greater than approximately 1,500 m / s, preferably greater than approximately 3,000 m / s. The use of a material with a speed of sound that is greater than the average of body tissue (approximately 1,500 m / s) for ultrasonic radiation proves advantageous. As a result of a comparatively high speed of sound in the marking element, a relatively large number of reflections can occur per unit of time, in particular on the aforementioned second and the aforementioned third reflection surface. As a result, many signal contributions from multiple reflections can be found and analyzed in the ultrasound image signals. This makes it easier to find the marking element because, due to the increase in the speed of sound compared to the speed of sound in the vicinity of the marking element, in particular the object under investigation, the ultrasound image downstream of the marking element in the direction of propagation of the ultrasound appears to be compressed in the time direction.

Overall, it is favorable if the at least one marking element has a sound impedance and sound velocity for medical ultrasound radiation which are each greater than the sound impedance or the sound velocity for ultrasound radiation in body tissue.

It is advantageous if the at least one marking element is assigned a fastening device for securing it to the object to be examined. The marking element can comprise the fastening device. The fastening device is, for example, a screw, a rivet, a mandrel, a pin or a thread. The fastening device can be provided with a body-integrative coating, for example an osteointegrative coating.

The fastening device can be an implant on which the at least one marking element is fixed or can be fixed.

The fastening device is preferably made from a material whose sound impedance differs significantly from the material from which the marking element is made. This ensures that the fastening device makes as few disruptive contributions as possible to the ultrasound image signals, which makes it easier to find the marking element.

The marking device can have two or more marking elements. The marking elements can be arranged spatially fixed to one another or can be movable relative to one another. For example, the marking elements can be positioned independently of one another.

The marking elements can be identical or different.

As mentioned at the beginning, the invention also relates to a use. A use according to the invention is a use of a body which has at least one first reflective surface and a second reflective surface spaced therefrom with parallel surface normals as a marking element for marking an object to be examined which is examined with ultrasonic radiation.

The body can in particular have the features that were explained using the marking device according to the invention described above and advantageous embodiments thereof using the example of the marking element thereof.

As mentioned further at the beginning, the invention also relates to a method. A method according to the invention for finding signal contributions of a marking element on a marking device of the aforementioned type in ultrasound image signals is characterized in that ultrasound image signals are transmitted to a data processing device from an ultrasound probe, the ultrasound image signals being examined by the data processing device for the presence of signal components that result from multiple reflection of the Ultrasonic radiation on the marking element as a result of a jump in the sound impedance between the object to be examined and the at least one marking element.

The advantages of the method according to the invention have already been mentioned in connection with the explanation of the marking device according to the invention, so that in this regard reference can be made to the explanations given above.

In the method, a marking element of the type mentioned above is used in particular, on which incident ultrasonic radiation is reflected on at least two and preferably more than two reflection surfaces and can be detected again by the ultrasonic probe. In particular, three reflection surfaces can be provided, on the outside and twice on the inside on the marking element, whereby a multiple reflection can take place with simultaneous coupling out of ultrasonic radiation in the direction of the ultrasonic probe on and in the marking element.

The method is advantageously carried out in real time, as a result of which the method is designed to be particularly user-friendly.

It proves to be advantageous if the data processing device examines high-frequency (RF / HF) ultrasound image signals provided by the ultrasound probe. This makes it possible to determine the position of the at least one marking element on the basis of the high-frequency ultrasound image signals without the need to create ultrasound images in B-mode (brightness mode).

It is favorable if the ultrasound image signals are present in a matrix of signal components which contain spatial information in a first direction and time information in a second direction, and if the signal components are summed up in the time direction and the position of the marking element in the spatial direction is viewed as the position of the Maximum of the summation. The contributions of individual ultrasonic transducers of the ultrasonic probe can be arranged in a matrix in such a way that the spatial information is contained in a first spatial direction and the time information in a second spatial direction (for example a row or a column of the matrix). A space-dependent time integral of the received ultrasonic radiation can be provided by adding up the signal components in the time direction (time integration). In practice, assuming that the maximum of the summation corresponds to the position of the marking element, the marking element can be found in a simple manner, ideally in real time, in the spatial direction.

It is also advantageous if the ultrasound image signals are present in a matrix of signal components that contain spatial information in a first spatial direction and time information in a second direction, and when the signal components are examined for signal amplitudes that are regularly arranged in the time direction, at least in sections. For example, the signals are examined in the time direction for the presence of a “signal comb” of signal amplitudes, the signal comb being viewed as resulting from multiple reflections of ultrasonic radiation on the reflection surfaces. The position of the Marking element in the time direction can then be viewed as the start of the signal comb in time.

During the examination, signal components which are below a predeterminable threshold value amplitude are advantageously regarded as having the threshold value amplitude. As has been shown in practice, the position of the marking element can thereby be detected in a simpler manner. Signal amplitudes below the threshold amplitude are considered to have the threshold amplitude. These signal components can be ignored during the examination by the data processing device. Only the signal components protruding beyond the threshold value amplitude can be examined to find the above-mentioned signal comb.

The method is particularly suitable for medical ultrasound, which is used, for example, to examine bones. For example, the procedure is used when examining the upper and lower extremities or when examining the spine. In addition to implantology, the procedure can also be used for biopsies.

It proves to be advantageous if ultrasound radiation is used in two or more beam directions aligned obliquely to one another in pairs, if the examination of the ultrasound image signals for each of the beam directions is carried out separately on a respective ultrasound image data set and if the marking element is only considered to be found when it is at least two ultrasound image data sets are considered to be present. This enables a plausibility check to be carried out. Only when the data processing device finds the marking element in two or more ultrasound image data sets, for example one of the types described above, is it considered to be arranged on the object to be examined.

As already mentioned at the beginning, the invention also relates to a device. A device according to the invention for performing one of the aforementioned methods comprises a marking device of the aforementioned type, an ultrasound probe and a data processing device, the ultrasound probe providing the data processing device with ultrasound image signals and the data processing device being designed and programmed in such a way that it examines the ultrasound image signals for the presence of signal components, which result from multiple reflections of the ultrasonic radiation on the at least one marking element of the marking device as a result of a jump in the acoustic impedance between the object under examination and the at least one marking element.

The advantages that can be achieved with the device and the mode of operation thereof have already been explained above in connection with the explanation of the marking device and the method, so that reference can be made to the preceding discussion in this regard.

Advantageous embodiments of the device result from advantageous embodiments of the marking device or advantageous embodiments of the method.

1. 1. Chirurgisches Instrumentarium, umfassend mindestens ein Implantat und eine diesem zugeordnete chirurgische Markiervorrichtung für Ultraschalluntersuchungen, die mindestens ein mittels Ultraschallstrahlung detektierbares chirurgisches Markierelement aufweist, wobei das mindestens eine Markierelement in vorgebbarer oder vorgegebener räumlicher Beziehung zum Implantat angeordnet oder anordenbar ist.
2. 2. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Wirbelkörperersatzimplantat ist.
3. 3. Instrumentarium nach Satz 1 oder 2, dadurch gekennzeichnet, dass das Implantat ein Implantat zur gegenseitigen Abstützung benachbarter Wirbelkörper ist.
4. 4. Instrumentarium nach einem Satz 3, dadurch gekennzeichnet, dass das Implantat ein Implantat zur gegenseitigen Abstützung der Dornfortsätze benachbarter Wirbelkörper ist.
5. 5. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Bandscheibenersatzimplantat ist.
6. 6. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Implantat zum Verschließen des Anulus fibrosus der Bandscheibe ist.
7. 7. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das Implantat chirurgisches Nahtmaterial ist oder umfasst.
8. 8. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass die Markiervorrichtung eine Mehrzahl von Markierelement umfasst.
9. 9. Instrumentarium nach Satz 8, dadurch gekennzeichnet, dass die Markierelemente identisch sind oder unterschiedlich sind.
10. 10. Instrumentarium nach Satz 8 oder 9, dadurch gekennzeichnet, dass die Markierelemente relativ zueinander frei positionierbar sind.
11. 11. Instrumentarium nach Satz 8 oder 9, dadurch gekennzeichnet, dass die Markierelemente in unveränderbarer Relativorientierung zueinander angeordnet sind.
12. 12. Instrumentarium nach einem der Sätze 8 bis 11, dadurch gekennzeichnet, dass die Markiervorrichtung drei in einer Ebene angeordnete Markierelemente aufweist.
13. 13. Instrumentarium nach einem der Sätze 8 bis 12, dadurch gekennzeichnet, dass drei oder mehr Markierelemente so angeordnet oder anordenbar sind, dass sie von einem gemeinsamen Punkt identische Abstände aufweisen.
14. 14. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement zumindest eine erste Reflexionsfläche und eine davon beabstandete zweite Reflexionsfläche für Ultraschallstrahlung aufweist, wobei die erste Reflexionsfläche und die zweite Reflexionsfläche parallele Flächennormalen aufweisen.
15. 15. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement eine Kugelform aufweist oder eine Kugel ist.
16. 16. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das Instrumentarium eine Befestigungseinrichtung umfasst zur Festlegung des mindestens einen Markierelementes am Körper, am Implantat oder an einem Werkzeug für das Implantat.
17. 17. Instrumentarium nach Satz 16, dadurch gekennzeichnet, dass die Befestigungseinrichtung eine Schraube, einen Niet oder einen Dorn aufweist.
18. 18. Instrumentarium nach Satz 16 oder 17, dadurch gekennzeichnet, dass die Befestigungseinrichtung eine osteointegrative Beschichtung aufweist.
19. 19. Instrumentarium nach einem der Sätze 16 bis 18, dadurch gekennzeichnet, dass das Implantat die Befestigungseinrichtung ausbildet.
20. 20. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement am Implantat festgelegt ist.
21. 21. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement in das Implantat eingebettet ist.
22. 22. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das Instrumentarium ein Werkzeug umfasst zum Einwirken auf das Implantat, welches Werkzeug in vorgegebener oder vorgebbarer räumlicher Relativorientierung am Implantat festlegbar ist.
23. 23. Instrumentarium nach Satz 22, dadurch gekennzeichnet, dass das mindestens eine Markierelement am Werkzeug festgelegt ist.

The present invention also relates to a surgical instrument set, for example having the features mentioned below. One of the above-mentioned marking devices can be used as part of the surgical instruments. One of the aforementioned methods and / or the aforementioned device can be used with the surgical instruments. The instruments can be part of the device, or vice versa:

1. 1. Surgical instruments, comprising at least one implant and a surgical marking device assigned to it for ultrasound examinations, which has at least one surgical marking element that can be detected by means of ultrasound radiation, the at least one marking element being or can be arranged in a predetermined or predetermined spatial relationship to the implant.
2. 2. Instrument set according to sentence 1, characterized in that the implant is a vertebral body replacement implant.
3. 3. Instrument set according to sentence 1 or 2, characterized in that the implant is an implant for mutual support of adjacent vertebral bodies.
4. 4. Instrument set according to a sentence 3, characterized in that the implant is an implant for mutual support of the spinous processes of adjacent vertebral bodies.
5. 5. Instrument set according to sentence 1, characterized in that the implant is an intervertebral disc replacement implant.
6. 6. Instrument set according to sentence 1, characterized in that the implant is an implant for closing the annulus fibrosus of the intervertebral disc.
7. 7. Instrument set according to one of the preceding sentences, characterized in that the implant is or comprises surgical suture material.
8. 8. Instrument set according to one of the preceding sentences, characterized in that the marking device comprises a plurality of marking elements.
9. 9. Instrument set according to sentence 8, characterized in that the marking elements are identical or different.
10. 10. Instrument set according to sentence 8 or 9, characterized in that the marking elements can be freely positioned relative to one another.
11. 11. Instrument set according to sentence 8 or 9, characterized in that the marking elements are arranged in an unchangeable relative orientation to one another.
12. 12. Instrument set according to one of sentences 8 to 11, characterized in that the marking device has three marking elements arranged in one plane.
13. 13. Instrument set according to one of sentences 8 to 12, characterized in that three or more marking elements are arranged or can be arranged so that they are at identical distances from a common point.
14. 14. Instrument set according to one of the preceding sentences, characterized in that the at least one marking element has at least one first reflective surface and a second reflective surface spaced therefrom for ultrasonic radiation, the first reflective surface and the second reflective surface having parallel surface normals.
15. 15. Instrument set according to one of the preceding sentences, characterized in that the at least one marking element has a spherical shape or is a sphere.
16. 16. Instrument set according to one of the preceding sentences, characterized in that the instrument set comprises a fastening device for fixing the at least one marking element on the body, on the implant or on a tool for the implant.
17. 17. Instrument set according to sentence 16, characterized in that the fastening device has a screw, a rivet or a mandrel.
18. 18. Instrument set according to sentence 16 or 17, characterized in that the fastening device has an osteointegrative coating.
19. 19. Instrument set according to one of sentences 16 to 18, characterized in that the implant forms the fastening device.
20. 20. Instrument set according to one of the preceding sentences, characterized in that the at least one marking element is fixed on the implant.
21. 21. Instrument set according to one of the preceding sentences, characterized in that the at least one marking element is embedded in the implant.
22. 22. Instrument set according to one of the preceding sentences, characterized in that the instrument set comprises a tool for acting on the implant, which tool can be fixed on the implant in a predetermined or predeterminable spatial relative orientation.
23. 23. Instrument set according to sentence 22, characterized in that the at least one marking element is fixed on the tool.

• 1: eine erfindungsgemäße Vorrichtung und einen mittels Ultraschallstrahlung untersuchten Patienten;
• 2: eine schematische Darstellung eines Markierelementes einer erfindungsgemäßen Markiervorrichtung;
• 3: eine weitere schematische Darstellung eines Markierelementes;
• 4: eine weitere schematische Darstellung eines Markierelementes;
• 5: eine Visualisierung von Ultraschallbildsignalen mit einer räumlichen Information in den Zeilen und einer zeitlichen Information in den Spalten, wobei Signalbeiträge von einem Markierelement einer erfindungsgemäßen Markiervorrichtung gezeigt sind;
• 6: eine vergrößerte Darstellung von Detail A in 5;
• 7: eine Darstellung, bei der die Signalamplituden der Ultraschallbildsignale in 5 in Zeitrichtung aufsummiert sind;
• 8: ausschnittsweise die Signalamplituden in Raumrichtung der Ultraschallbildsignale in 5;
• 9: eine schematische Darstellung eines Markierelementes, das drei Ultraschallstrahlenbündeln ausgesetzt ist;
• 10: ein Markierelement mit einer Befestigungseinrichtung;
• 11: ein weiteres Markierelement mit einer Befestigungseinrichtung;
• 12: ein weiteres Markierelement mit einer Befestigungseinrichtung;
• 13: ein weiteres Markierelement mit einer Befestigungseinrichtung;
• 14: ein Markierelement, festgelegt an einer Endfläche eines Wirbelkörpers (teilweise durchbrochen) in Seitenansicht;
• 15: den Wirbelkörper und das Markierelement aus 14 von caudal;
• 16: zwei Wirbelkörper mit daran festgelegten Markierelementen;
• 17: die Wirbelkörper und die Markierelemente aus 16 von caudal;
• 18: drei Wirbelkörper und daran festgelegte Markierelemente von dorsal;
• 19: die Wirbelkörper und die Markierelemente aus 18 von caudal;
• 20: ein Markierelement, an einem Halteteil festgelegt;
• 21: ein Markierelement, an einem andersartigen Halteteil festgelegt;
• 22: Implantat in Gestalt chirurgischen Nahtmaterials mit daran festgelegten Markierelementen;
• 23: ein Implantat in Gestalt chirurgischen Nahtmaterials mit einem daran festgelegten Markierelement;
• 24: ein Implantat in Gestalt eines Bandscheibenverschlusses mit daran festgelegtem Markierelement;
• 25: ein weiterer Bandscheibenverschluss mit daran festgelegtem Markierelement;
• 26: ein weiterer Bandscheibenverschluss mit zwei daran festgelegten Markierelementen;
• 27: ein weiterer Bandscheibenverschluss mit vier daran festgelegten Markierelementen;
• 28: weiterer Bandscheibenverschluss mit einem daran festgelegten Markierelement;
• 29: ein Bandscheibenersatzimplantat mit einem darin eingebetteten Markierelement;
• 30: ein Implantat zur Abstützung der Dornfortsätze benachbarter Wirbelkörper und drei daran festgelegte Markierelemente;
• 31: ein Implantat zur gegenseitigen Abstützung benachbarter Wirbelkörper und drei daran festgelegte Markierelemente und
• 32: ein Implantat zur Abstützung benachbarter Wirbelkörper und ein Einsetzwerkzeug, wobei am Einsetzwerkzeug zwei Markierelemente festgelegt sind, sowie eine Ultraschallsonde.

The following description of preferred embodiments of the invention is used in conjunction with the drawing to explain the invention in greater detail. Show it:

• 1 : a device according to the invention and a patient examined by means of ultrasound radiation;
• 2 : a schematic representation of a marking element of a marking device according to the invention;
• 3 : a further schematic representation of a marking element;
• 4th : a further schematic representation of a marking element;
• 5 : a visualization of ultrasound image signals with spatial information in the rows and temporal information in the columns, signal contributions from a marking element of a marking device according to the invention being shown;
• 6th : an enlarged view of detail A in 5 ;
• 7th : a representation in which the signal amplitudes of the ultrasonic image signals in 5 are summed up in time direction;
• 8th : the signal amplitudes in the spatial direction of the ultrasonic image signals in 5 ;
• 9 : a schematic representation of a marking element that is exposed to three ultrasonic beams;
• 10 : a marking element with a fastening device;
• 11 : a further marking element with a fastening device;
• 12 : a further marking element with a fastening device;
• 13 : a further marking element with a fastening device;
• 14th : a marker attached to an end surface of a vertebral body (partially broken) in side view;
• 15th : the vertebral body and the marker 14th from caudal;
• 16 : two vertebral bodies with marking elements attached thereto;
• 17th : the vertebral bodies and the marking elements 16 from caudal;
• 18th : three vertebral bodies and marking elements attached to them from the dorsal side;
• 19th : the vertebral bodies and the marking elements 18th from caudal;
• 20th : a marker attached to a support member;
• 21st : a marker attached to a different type of holder;
• 22nd : Implant in the form of surgical suture material with marking elements fixed thereon;
• 23 : an implant in the form of surgical suture material with a marking element attached thereto;
• 24 : an implant in the form of an intervertebral disc closure with a marking element attached thereto;
• 25th : Another intervertebral disc closure with a marking element attached to it;
• 26th : Another intervertebral disc closure with two marking elements attached to it;
• 27 : Another intervertebral disc closure with four marking elements attached to it;
• 28 : Another intervertebral disc closure with a marking element attached to it;
• 29 : a disc replacement implant having a marker embedded therein;
• 30th : an implant to support the spinous processes of adjacent vertebral bodies and three marking elements attached to it;
• 31 : an implant for mutual support of adjacent vertebral bodies and three marking elements attached to it and
• 32 : an implant for supporting adjacent vertebral bodies and an insertion tool, with two marking elements being fixed on the insertion tool, and an ultrasound probe.

In the drawing, features that are the same or have the same effect are given the same reference symbols in order to achieve greater clarity.

1 shows a device according to the invention in a perspective view 10 for ultrasound examinations using a data processing device 12 , an ultrasound probe 14th and one a marker 22nd comprehensive marking device according to the invention 16 having. Ultrasound image signals from the ultrasound probe 14th can be generated by the data processing device 12 are fed. The data processing device 12 can use the ultrasound image signals as an ultrasound image on a display device 18th represent. Furthermore, the data processing device 12 examine the ultrasound image signals for signal components, in particular from the marking element 22nd the marking device 16 come. It is possible to examine the high-frequency HF / RF ultrasound image signals directly.

The device 10 comes present when examining a patient 20th used, especially its extremities such as arms and legs. The following also refers to examinations of the patient's spine 20th and biopsies received.

With the device 10 a preferred embodiment of a method according to the invention can be carried out, as was / is explained above and below.

The marking device 16 comprises one or more marking elements 22nd for marking an object of investigation. Exemplary marking elements 22nd are in the 2 to 4th shown. All marking elements 22nd What is common is that they have a first, external reflection surface 24 and a second, inner-side reflective surface spaced therefrom 26th exhibit. Furthermore, each marking element 22nd one of the second reflective surface 26th spaced third, inside reflection surface 28 on. This corresponds to the first, outside reflection surface 24 , but if the direction of propagation of the ultrasonic radiation is reversed, it is, so to speak, backwards to the reflection surface 24 arranged.

Every reflection surface 24 to 28 is a surface normal 30th , 32 , 34 assigned, where the surface normals 30th to 34 are parallel to one another and, as in the present case, preferably even coincide.

The marking elements 22nd In the present case, they are solid bodies and are preferably made of a material that has a sound impedance for medical ultrasonic radiation that differs significantly from the sound impedance of body tissue. The marking elements are particularly preferably made of a metal, for example steel, with platinum, tantalum, titanium, gold, silver, cobalt, chromium or an alloy thereof also being conceivable. For other types of applications, the marking elements can be made from bone (allogeneic, autogenous or xenogenous) or bone substitute material, from PEEK, PMMA, or a ceramic material. The marking elements 22nd can be absorbable, e.g. B. made of polylactide or calcium phosphate.

Unlike the marking elements 22nd It can be provided that the marking elements of the marking device do not consist of a solid material, but are hollow bodies. A filler material, such as an ultrasound contrast agent, can be accommodated in the hollow bodies. Marking elements that are in the form of cutouts, for example on a bone, are also conceivable.

The marking element 22nd of 2 has a spherical shape, the marking element 22nd of 3 a cube shape and the marker 22nd of 4th the shape of a hemisphere.

Ultrasonic radiation from the ultrasonic probe 14th along a direction of propagation 36 on the marking element 22nd hits, is first at the reflection surface 24 reflected. The proportion of reflected ultrasonic radiation is greater, the greater the jump in the sound impedance between the marking element 22nd and the environment in which it is recorded. A part of the ultrasonic radiation is accordingly reflected and can be detected by the ultrasonic probe, whereas a further part of the ultrasonic radiation is in the marking element 22nd penetrates.

The penetrating ultrasonic radiation is then on the second reflection surface 26th reflected. A portion of it can come from the marking element 22nd exit and be detected again by the ultrasound probe. The remaining portion is reflected again, namely on the third reflection surface 28 . Further multiple reflections of ultrasonic radiation then take place within the marking element 22nd on the reflective surfaces 26th , 28 whose surface normals are opposite to each other.

There is only a portion of each on the reflection surface 26th Striking radiation is transmitted and can the marking element 22nd leave, and only a portion of each on the reflection surface 28 The marking element can use ultrasonic radiation that hits it 22nd leave. As a result, the ultrasonic radiation runs in the marking element 22nd back and forth.

Ultrasonic radiation emitted by the ultrasonic probe 14th facing side from the marking element 22nd emerges, can move against the direction of propagation 36 towards the ultrasound probe 14th spread and is detected by this. As a result, a structure can arise in the ultrasound image signals which is created by the multiple reflections of the ultrasound radiation on the reflection surfaces 24 , 26th and 28 results. Due to the unchangeable geometry of the marking element 22nd the repeatedly reflected ultrasound radiation becomes noticeable in the form of a "tail" in the ultrasound image signals ( 5 ).

5 shows ultrasound image signals from the ultrasound probe 14th in a matrix 37 that one spatial direction 38 and a time direction 40 having. The spatial direction 38 results from ultrasonic transducers of the ultrasonic probe which are arranged next to one another in lines and which each emit ultrasonic radiation. The ultrasonic transducers are in 5 at the top of the matrix 37 arranged to view. The time direction 40 results in a manner known per se from the time between the emission and the arrival of the ultrasonic radiation.

The matrix 37 shows signal components 42 through the marker 22nd surrender. The position of the marking element is leading in the direction of time 22nd (in 5 characterized by reference signs 22 ' ) clearly visible. At this point, the amplitude of the ultrasonic signal increases due to the large proportion of reflected ultrasonic radiation on the first reflection surface 24 strong. The high signal amplitude results from the large difference in the sound impedances of the marking element 22nd made of steel on the one hand and the surrounding body tissue on the other. The increase in the signal amplitude is located downstream in the time direction in the matrix 37 the tail 44 as a result of the repeated reflection of ultrasonic radiation on the marking element 22nd clearly visible.

The use of a material for the marking element in which the speed of sound for ultrasonic radiation is significantly higher than in the tissue surrounding it has proven to be advantageous. Within the marking element 22nd ultrasonic radiation spreads faster, so that signal components 42 of the marking element 22nd are compressed in relation to the signal components of the environment in the time direction. This gives the possibility of a large proportion of the total from the marking element 22nd decoupled ultrasonic radiation with the ultrasonic probe 14th capture. The signal components 42 thereby allow a simple and reliable detection of the marking element 22 ' in the ultrasound image signals both in the time direction and in the spatial direction.

Due to the repeated reflection of ultrasonic radiation in the marking element 22nd form the signal components in time direction 40 especially a signal comb 46 , which in the enlarged view of the 6th better to recognize and in 8th , on the will be discussed below, is also shown.

The marking element 22nd can by displaying the ultrasound image signals as an ultrasound image on the display device 18th easily recognized by the surgeon. In particular, it is also possible that the data processing device 12 the position of the marking element 22nd determined in the ultrasound image signals by checking for the presence of signal components of the marking element 22nd to be examined. In this regard, the 7th and 8th referenced.

The ultrasound image signals can from the data processing device 12 in time direction 40 are summed up. This results in a time integral 48 of the ultrasound image signals in spatial direction 38 ( 7th ). The data processing device 12 can be in time integral 48 the maximum 50 determine the summation and assume that it is in spatial direction 38 the marking element 22nd at the maximum 50 is located. In other words, the position of the maximum 50 in spatial direction 38 as the position of the marking element 22nd be considered. This assumption is based on the idea that due to the high acoustic impedance for ultrasonic radiation of the marking element 22nd In the time direction, more ultrasound radiation and thus ultrasound energy is reflected by it than by the body tissue surrounding it.

On the signal ridge 46 due to the multiple reflection in a marking element 22nd has already been received. 8th shows part of the tail 44 in the matrix 37 . The signal comb can be clearly seen 46 , which has a sequence of regularly repeating signal amplitudes of approximately the same level. The signal comb 46 is partially interrupted, as the received ultrasound image signals can also be subject to interference such as scattering or interference, which causes the signal comb 46 does not get a perfect comb shape. However, the regular sequence of signal amplitudes can be approximately the same size from the data processing device 12 , preferably in real time.

To make it easier to find the signal comb, it can be provided that signal amplitudes that are below a predeterminable threshold value amplitude 52 than the threshold amplitude 52 are viewed as having. The amplitude of the ultrasound image signals is therefore at the threshold value amplitude 52 cut off below. The signal components that are equal to the threshold amplitude 52 can be made by the algorithm of the data processing device 12 when finding the signal comb 46 can be skipped, allowing faster analysis of the ultrasound image signals.

The data processing device 12 takes the position of the marking element 22nd than in time direction 40 leading on the signal crest 46 at (reference sign 22 ' in 8th ).

In practice, it has been shown that the finding of objects to be examined, for example special structures in the patient 20th , using the marking device 16 is significantly facilitated and reliable by the data processing device 12 can be supported by analyzing the ultrasound image signals in real time.

9 shows schematically the marking element 22nd which is exposed to three ultrasound beams. The ultrasound bundles spread in directions of propagation 54 , 56 and 58 which pairs are misaligned to each other. For example, an ultrasound probe 14th with compound ultrasound mode used to generate the three beams.

With the arrangement according to 9 it is advantageous if the marking element 22nd Has spherical shape. The multiple reflection of incoming ultrasonic bundles is independent of direction in this case. Therefore, only reflected ultrasound radiation from the same ultrasound bundle is returned to the ultrasound probe 14th receive. This makes it possible to generate an ultrasound image data set for each ultrasound beam. Only when the data processing device 12 , for example in one of the ways described above, the marking element 22nd Detected in the ultrasound image data sets of at least two beam bundles, this is viewed as detected overall.

In order to fix it on the object to be examined, for example a bone, the marking device 16 a fastening device 60 exhibit ( 10 to 13 ). The fastening device 60 is preferred with the marking element 22nd connected and made of a different material. The material of the fastener 60 preferably has a sound impedance for ultrasonic radiation which differs significantly from that of the material from which the marking element 22nd is made. Preferably, the material of the fastening device 60 have an acoustic impedance which is equal to or similar to that of the environment in which the marking element 22nd is positioned. An interference from reflections on the fastening device 60 on the signal components 42 as a result of the marking element 22nd can thereby be reduced.

With the marking element 22nd according to 10 is the fastening device 60 a bone screw 62 .

With the marking element 22nd according to 11 is the fastening device 60 a surgical dowel 64 , especially for anchoring to the bone.

With the marking element 22nd according to 12 comprises the fastening device 60 two spaced apart pins 66 . The fastening device 60 is therefore cramp-like.

With the marking element 22nd according to 13 comprises the fastening device 60 a pen 68 covered by a coating. The coating is, for example, an osteointegrative coating, in particular with titanium powder, in order to enable better anchoring on the bone.

The device 10 , the marking device 16 and the method explained above are particularly suitable for use in an ultrasound-assisted biopsy, for example on the patient's spine 20th . It is particularly advantageous, for example, to use it in an ADCT operation (Autologous Disc-derived Chondrocyte Transplantation), a method for the biological reconstruction of damaged intervertebral discs, which will be discussed briefly. In such a method, the patient's own intervertebral disc cells are removed from a damaged intervertebral disc, for example after a herniated disc (prolapse). The cells are in vitro outside of the patient 20th expands and after a latency period of a few months, for example three months, is re-injected into the damaged disc in an aqueous solution. Up until now, the cells have been removed and injected with limited control by means of x-ray-based imaging.

It is also known to improve the conventional ADCT process by injecting biomaterial into the intervertebral disc in addition to or as an alternative to the body's own cells. The biomaterial can, for example, polymerize in the intervertebral disc after injection.

With the previous ADCT, which is performed under X-ray control, the operation is subject to considerable restrictions. In particular, it is not possible to represent a transverse sectional plane through the spine, but rather the representation of the spine takes place only in an anterior-posterior or lateral representation. Furthermore, there is the problem that with X-ray control only the positioning of the injection cannulas can be checked before the injection or removal on the intervertebral disc, the actual injection or removal of the cells or biomaterial, however, has to be carried out "blindly" without an X-ray view, in order to detect damage from ionizing X-rays avoid. In this context, the exposure of the patient or the operating room staff to ionizing X-rays is also negative.

The present invention makes it possible to remove cells or to inject cells or biomaterial into the intervertebral disc under ultrasound vision. For this purpose, there is preferably the possibility of the spine 70 of the patient 20th on vertebral bodies 72 , 74 and / or the intervertebral disc 76 to mark. For this purpose the marking device 16 with at least one and preferably several marking elements 22nd used.

The use of ultrasonic radiation from the ultrasonic probe 14th proves to be particularly advantageous because there is no radiation exposure for the patient 20th Cells can be removed and injected. The choice of the cutting plane can be made by orienting the ultrasound probe 14th and thus the ultrasonic field can be freely selected. Oriented on the marking element or elements 22nd it is easy for the surgeon to attach the cannulas for extraction or emission safely and reliably to the intervertebral disc 76 to place (not shown).

In the following, with reference in particular to the 14th to 32 different options for placing marking elements 22nd on the spine 72 received. The marking elements 22nd can for example on the vertebral bodies 72 , 74 , their cranial or caudal end plates, their laminae, the facet joints of adjacent vertebral bodies 72 , 74 or spinous processes of the vertebral bodies 72 , 74 be positioned.

In the representations according to 14th and 15th is a marking element 22nd about the fastening device 60 , for example the dowel 64 into an end plate 78 introduced from caudal or cranial. For introducing the marking element 22nd For example, a distraction tool can be used with one working end of the marking element 22nd with the fastening device 60 receives and into the end plate 78 depresses. Another working end of the tool can be on the opposite end plate 78 of the vertebral body 74 prop up.

When presented according to 16 is on the vertebral bodies 72 , 74 one marking element each 22nd fixed, preferably near the intervertebral disc 76 , especially adjacent to the intervertebral disc 76 . The intervertebral disc can act as the middle between the marking elements 22nd be recognized. For positioning the two marking elements, a template can be provided, for example a spacer drilling sleeve, through the use of which receptacles for the marking elements 22nd with fastening devices at a defined distance from each other in the vertebral bodies 72 , 74 can be introduced.

When using two or more marking elements 22nd it is possible to define a direction (straight line through the marking elements) or a plane through three marking elements 22nd is stretched.

When presented according to 17th come two marker elements 22nd used on a spinous process 80 and a lamina 82 of the vertebral body 72 are fixed, instead of being fixed on the lamina, fixing on a facet joint can also take place. The use of three marking elements is more preferred 22nd , see the 18th and 19th , for example on the spinous process 80 , on a facet joint 84 superior and a facet joint 84 inferior.

The ones from the marking elements 22nd A defined plane allows a coordinate system to be defined, which can be used for orientation. In particular, the marking elements form 22nd a surgical referencing device in the form of a so-called "rigid body". The rigid body makes it particularly easy to perform an extraction or injection on the intervertebral disc 76 perform. With the ultrasound probe 14th can be the level of the marking elements 22nd are recorded. For example, the position of the ultrasound plane relative to the cannula can be adjusted by means of a mechanical coupling. For example, the cannula is aligned perpendicular to the plane of the ultrasound. The positioning of the cannula in the caudal-cranial direction can be adjusted by virtue of the distance between the marking elements 22nd from each other the position of the intervertebral disc 76 can be determined.

Two or more marking elements 22nd can also be connected via a common fastening device, for example one of the fastening devices 60 the 10 to 13 . Accordingly, the fastening device can be a carrier, to a certain extent a “rigid body” for two or more marking elements 22nd be that can be fixed to a body structure via this carrier.

One or more marking elements 22nd can also be a holding part 86 be assigned to attach to body tissue or, as mentioned below, to an implant. The holding part 86 according to 20th has a clamp-like shape with two legs spaced apart from one another 88 , 90 . The marking element 22nd can between the thighs 88 , 90 be clamped or pressed.

With the holding part 86 according to 21st is a blind hole-shaped receptacle 92 formed in which the marking element 22nd can be used. The marking element 22nd can, for example, be jammed or pressed or by gluing in the receptacle 92 be held.

It is also conceivable that a marking element 22nd is fixed in a holding part by casting (not shown).

As with the fastening device 60 it is advantageous if the acoustic impedance for ultrasonic radiation of a holding part 86 is different from that of the material from which the marking element 22nd is made. Ideally, the sound impedance is the material of the holding part 86 equal to or approximately equal to the acoustic impedance of body tissue.

As already mentioned, the present invention also relates to a surgical instrument set with at least one implant and a marking device assigned to it. The implant and the at least one marking element of the marking device are arranged or can be arranged in a predefined or predefinable spatial relationship to one another. This makes it possible to use the marking device as a target device for determining the position and preferably the orientation of the implant. The surgeon is given the opportunity to find the implant in a simple manner with the aid of the at least one marker element. In particular, the device 10 which can be part of the set of instruments or which can be part of the set of instruments, and which use one of the methods described above.

In the following, with reference to the 22nd to 32 discussed different instruments and the implants they encompass. Marking elements of marking devices of the instruments are each given the reference symbol 22nd occupied. These are in particular spherical and made, for example, of a metal.

With a set of instruments 94 according to 22nd are two identical implants 96 provided, each designed as a surgical suture material 98 . The thread-like suture 98 each has a marking element attached to it 22nd on. The implant 96 thereby each forms a fastening device for the marking element 22nd .

The implants 96 serve in particular to close a defect 100 in an annulus fibrosus 102 the intervertebral disc 76 . The marking element 22nd can be outside or inside the intervertebral disc 76 to be placed. The sutures 98 For example, they can be sewn or knotted around the defect 100 close.

With a set of instruments 104 according to 23 is an implant 106 in the form of sutures 108 and a marking element fixed thereon 22nd intended. Two sections 110 , 112 The sutures can be sutured or knotted together to cover the defect 110 close.

The 24 to 27 show different variants of a set of instruments 114 each with a locking implant 116 to close a defect in the annulus fibrosus 102 include. The closing implant 116 has two investment areas 118 , 120 to the outside or inside of the annulus fibrosus 102 on. The investment areas 118 , 120 are through a connection area 122 who has the defect 100 can intervene.

The closing implant 116 is preferably elastic, for example with a textile structure.

With the variant according to 24 is a marking element on the inside of the intervertebral disc at the contact area 120 fixed in the variant 25th a marker 22nd at the investment area 118 outside the intervertebral disc 76 . The variant according to 26th includes two marking elements 22nd inside and outside of the system areas 118 , 120 .

The variant according to 27 has four marking elements on the outside of the contact area 120 are arranged. Three or more marking elements 22nd can be concentric with respect to an axis 124 be arranged, which can represent a target axis for the cannula.

Marking elements 22nd can also be used in the locking implant 116 be embedded.

An in 28 illustrated instruments 126 includes an implant 128 , which is a closure implant to close the annulus fibrosus 102 is. The implant 128 has a reticulate shape. At least one marker element 22nd is on the implant 128 attached. The implant 128 can be used to close a defect 100 for example on the outside of the annulus fibrosus 102 be sewn on.

29 shows a set of instruments 130 with an implant 132 , which is a disc replacement implant. It can be between the vertebral bodies 72 , 74 are introduced and preferably has a sponge-like structure and shape. In addition, the aforementioned polymerizing biomaterial and cells can be introduced by injection. The implant 132 serves in particular as a replacement for the nucleus pulposus of an intervertebral disc.

At least one marker element 22nd can in the implant 132 be embedded or attached to it. This in particular gives the possibility of postoperatively viewing the implant under ultrasound 132 to be found again, in particular to inject further biomaterial and nucleus cells there.

30th shows an implant 138 for mutual support of spinous processes 80 , 136 adjacent vertebral body 72 , 74 as it is for example in the WO 2010/000488 A1 is described. The implant 138 is part of a set of instruments 140 and comprises a first support member 142 and a second support member 144 for the spinous processes 80 or. 136 as well as a clamping element 146 for tensioning the support elements 142 , 144 relative to each other. On the support elements 142 , 144 and on the clamping element 146 is a marker each 22nd set.

The marking elements 22nd allow the implant 138 to be found in the body and its location on the spinous processes 80 , 136 and to control their spreading relative to one another. It is preferably also possible for the implant 138 to be checked postoperatively and percutaneously and, in particular, to be readjusted. The marking elements 22nd can also be used to locate the intervertebral disc postoperatively 76 are used, a further injection should be made postoperatively as part of an ADCT procedure.

A set of instruments 148 according to 31 includes an implant 150 with pedicle screws 152 by a stabilizing element in the form of a rod 154 are connected to each other. The pedicle screws 152 are in a known manner with vertebral bodies 72 , 74 and 155 screwed. This allows them to be supported relative to one another. On at least one implant component, for example a pedicle screw 152 , can have at least one marking element 22nd be fixed. For example, see 31 , are on a pedicle screw 152 three markers 22nd set. These can form a “rigid body” mentioned above to define a coordinate system. Here, too, an injection into an intervertebral disc can be postoperatively 76 in the context of an ADCT procedure, the marking elements 22nd to find the intervertebral disc 76 can be used.

A set of instruments 156 with an implant 158 is, for example, of the type of fixation system as described in WO 2011/128220 A1 is described. The implant 158 can for example be a pedicle screw 160 and a stabilizing element in the form of a rod to be connected to this 162 include. It can be the implant 150 according to 31 act.

The instruments 156 further comprises a tool 164 . The tool 164 can in the present case percutaneously with the pedicle screw 160 and adjust their orientation percutaneously. This serves to create an opening in the pedicle screw 160 relative to the rod 162 aligned so that it can be inserted into the opening. For this purpose the tool can 164 an insertion opening 166 have which is aligned with the opening of the pedicle screw. At one edge of the insertion opening 166 can have at least one marking element 22nd be set, preferably several marking elements 22nd . Under sight using the ultrasound probe 14th is it possible to use the marking elements 22nd to detect as explained above and thereby the insertion opening 166 for inserting the rod 162 easy to find.

Claims (28)

A marking device for ultrasound examinations, comprising at least one marking element (22) for marking an object to be examined, which has at least a first reflective surface (24) and a second reflective surface (26) for ultrasonic radiation spaced apart therefrom, the first reflective surface (24) and the second reflective surface (26 ) have parallel surface normals (30, 32). Marking device according to Claim 1 , characterized in that the at least one marking element (22) has more than two reflection surfaces (24, 26, 28), the surface normals (30, 32, 34) being parallel to one another. Marking device according to Claim 1 or 2 , characterized in that the reflective surfaces (24, 26, 28) are arranged on an outside or on an inside of the marking element (22). Marking device according to one of the preceding claims, characterized in that at least one reflective surface (24, 26, 28) is planar. Marking device according to one of the preceding claims, characterized in that at least one reflective surface (24, 26, 28) is curved. Marking device according to one of the preceding claims, characterized in that the reflective surfaces (24, 26, 28) are aligned parallel to one another. Marking device according to one of the Claims 1 to 3 or 5 , characterized in that the at least one marking element (22) has a spherical shape or is a sphere. Marking device according to one of the preceding claims, characterized in that the at least one marking element (22) has a size in one spatial direction, in particular a diameter, of 2 mm to 4 mm. Marking device according to Claim 8 , characterized in that the size of the at least one marking element (22) in the spatial direction is the diameter of the at least one marking element (22). Marking device according to one of the preceding claims, characterized in that the at least one marking element (22) is a solid body. Marking device according to one of the Claims 1 to 9 , characterized in that the at least one marking element (22) is a hollow body. Marking device according to one of the preceding claims, characterized in that the at least one marking element (22) consists of bone or a bone substitute material. Marking device according to one of the preceding claims, characterized in that the at least one marking element (22) consists of a resorbable material. Marking device according to one of the preceding claims, characterized in that the ultrasonic impedance of the at least one marking element (22) for medical ultrasonic radiation is greater than 20 * 10 ⁶ kg / (m ² s). Marking device according to Claim 14 , characterized in that the ultrasonic impedance is greater than 25 * 10 ⁶ kg / (m ² s). Marking device according to one of the preceding claims, characterized in that the speed of sound in the at least one marking element (22) for medical ultrasound radiation is greater than 1,500 m / s. Marking device according to Claim 16 , characterized in that the speed of sound is greater than 3,000 m / s. Marking device according to one of the preceding claims, characterized in that the at least one marking element (22) is assigned a fastening device (60) for securing it to the object to be examined. Marking device according to one of the preceding claims, characterized in that the marking device (16) comprises several marking elements (22). Use of a body which has at least one first reflective surface (24) and a second reflective surface (26) spaced apart therefrom with parallel surface normals (30, 32) as a marking element (22) for marking an object to be examined which is being examined with ultrasonic radiation. Method for finding signal contributions of a marking element (22) of a marking device (16) according to one of the preceding claims in ultrasonic image signals which are transmitted to a data processing device (12) from an ultrasonic probe (14), the ultrasonic image signals from the data processing device (12) for the presence of Signal components are examined which result from multiple reflections of the ultrasonic radiation on the marking element (22) as a result of a jump in the sound impedance between the object under examination and the marking element. Procedure according to Claim 21 , characterized in that the method is carried out in real time. Procedure according to Claim 21 or 22nd , characterized in that the data processing device (12) examines high-frequency (RF / HF) ultrasonic image signals provided by the ultrasonic probe (14). Method according to one of the Claims 21 to 23 , characterized in that the ultrasound image signals are present in a matrix (37) of signal components (42) which contains spatial information in a first direction and time information in a second direction, and that the signal components (42) are added up in the time direction (40) and the position of the marking element (22) in the spatial direction is viewed as the position of the maximum (50) of the summation. Method according to one of the Claims 21 to 24 , characterized in that the ultrasound image signals are present in a matrix (37) of signal components (42), which contains spatial information in a first direction and time information in a second direction, and that the signal components (42) in the time direction (38), At least in sections, regularly arranged signal amplitudes are examined. Procedure according to Claim 25 characterized in that, during the examination, signal components (42) which are below a predeterminable threshold value amplitude (52) are viewed as having the threshold value amplitude (52). Method according to one of the Claims 21 to 26th , characterized in that ultrasound radiation is used in two or more pairs of obliquely aligned beam directions, that the examination of the ultrasound image signals for each of the beam directions is carried out separately on a respective ultrasound image signal data set and that the marking element (22) is only seen as found when it is in at least two ultrasound image signal data sets are considered to be present. Device for carrying out the method according to one of the Claims 21 to 27 , comprising a marking device (16) according to one of Claims 1 to 19th , an ultrasound probe (14) and a data processing device (12), the ultrasound probe (14) providing the data processing device (12) with ultrasound image signals and the data processing device (12) being designed and programmed in such a way that it examines the ultrasound image signals for the presence of signal components (42) which result from multiple reflections of the ultrasonic radiation on at least one marking element (22) of the marking device (16) as a result of a jump in the acoustic impedance between the object under examination and the at least one marking element (22).

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