DE102013110704A1 - Marking device for ultrasound examinations, use of a body as a marking element as well as apparatus and method for ultrasound examinations - Google Patents

Abstract

The invention relates to a marking device for ultrasound examinations. In order to provide such a marking device, the use of which facilitates finding and analyzing an object to be examined, it is proposed according to the invention that the marking device comprises at least one marking element for marking an object to be examined, which has at least a first reflection surface and a second reflection surface for ultrasonic radiation spaced therefrom the first reflection surface and the second reflection surface have parallel surface normals. Moreover, the invention relates to a use of a body as a marking element, a method for finding signal contributions of a marking element in ultrasonic image signals and an apparatus for performing the method.

Description

The invention relates to a marking device for ultrasound examinations.

Moreover, the invention relates to a use of a body as a marking element for ultrasound examinations.

Furthermore, the invention relates to a method for finding signal contributions of a marking element in ultrasound image signals.

Furthermore, the invention relates to a device for carrying out the method.

The present invention will be described below with particular reference to the example of the application of medical ultrasound, but is not limited to this field. The invention can also be used in other fields in which ultrasound is used to examine an object under examination, for example material testing.

The use of ultrasound in medicine, especially 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 surgical staff are not exposed to ionizing radiation. For example, intraoperative ultrasound in the field of orthopedics is used to detect fractures. Also in the field of implantology, the use of ultrasound is known. When using intraoperative ultrasound, it is desirable to automatically detect structures of the examination subject, if possible. Devices and methods are known for this purpose, which generate ultrasound images in B-mode (brightness mode) from ultrasound image signals of the ultrasound probe, which serve as a basis for automated image recognition methods. However, the accuracy of these devices and methods is often inadequate in practice. Strong scattering and interference of the ultrasound field on tissue and bone border structures lead to a poor signal-to-noise ratio. Boundary structures are also often rendered wide and smeared, making it difficult to detect bony structures automatically. This is also due to the fact that the image quality depends strongly on the angle of the ultrasound probe to the patient's body. Depending on the angle, this often results in smeared or widened structures in practice, whose interpretation is not easy for the user. To make matters worse, in particular two-dimensional ultrasound fields are used for intraoperative ultrasound, which can result in a slight movement of the ultrasound probe to a significant change in the ultrasound image and thus difficult interpretation by the user.

In order to be able to find an examination object in an easier way, a marking device can be provided which can be easily recognized during the analysis of the ultrasound images and by means of which it is possible to deduce the subject of the examination.

Accordingly, it is an object of the present invention to provide a marking device for ultrasound examinations, the use of which facilitates the finding and analyzing of an examination object.

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

The idea flows into the invention that an ultrasound examination is a method based on reflection of ultrasound radiation on a structure under investigation. Accordingly, the invention provides that a marking device is provided with at least one marking element which can be used to mark the object under examination. Ultrasonic radiation can be reflected on at least a first and a second reflection surface spaced therefrom, the reflection surfaces having parallel and preferably coincident surface normals. In the propagation direction of the ultrasonic radiation, the first and the second reflection surface are at a distance from one another. Incident ultrasound radiation can be partially reflected with a time delay first at the first and then at the second reflection surface and detected again by the ultrasound probe. This makes it possible to determine signal components in the ultrasound image signals, which are due to the reflection of the ultrasound radiation at the reflection surfaces. It can be ensured by the same orientation of the surface normals that ultrasound radiation propagating parallel to the surface normal can be detected again by the ultrasound probe with a component reflecting at the first and at the second reflection surface, the time difference of the signal components in the ultrasound signal being determined by the distance of the ultrasound signal Reflection surfaces from each other results. It turns out 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 acoustic impedance of the environment by the marking element is positioned, in particular that of the examination subject.

It is advantageous if the at least one marking element has more than two reflection surfaces whose surface normals are aligned parallel to one another. As a result, the possibility is advantageously given that a multiple reflection of the ultrasound radiation takes place on the at least one marking element. For example, this first takes place on an outer side of the marking element on a first reflection surface. Subsequently, the spaced-apart second reflection surface can be arranged on an inner side of the marking element. At this reflected ultrasound radiation, for example, at a spaced-apart inside third reflective surface, which corresponds to the first reflection surface with opposite direction of incidence of the ultrasound radiation, are reflected again. As a result, there is the possibility that ultrasound radiation moves back and forth, many times reflected in at least one marking element. Since there is a non-reflected transmitted portion, a multiple reflection in the ultrasonic image signal can be recognized as a "tail" of an ultrasonic signal propagating in the time direction. As a result of the multiple reflection of ultrasound radiation, a multiplicity of time-sequential, reflection-based signal components can be found. These signal components are the higher, the greater the jump in the acoustic impedance from the at least one marking element to its surroundings.

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

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. With a plurality of curved reflecting surfaces, their surface normals can coincide.

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

The reflection surfaces can be aligned, for example, parallel to each other.

In an advantageous embodiment, the at least one marking element is conveniently a ball or has a spherical shape. Regardless of the direction of irradiation, a multiple reflection of ultrasound radiation can take place on spherical surfaces, the signal components of which can be detected with the ultrasound probe. A spherical shape can for example be provided by the fact 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 proves to be particularly advantageous in practice. Ultrasonic radiation can be reflected on an outside and inside. Ultrasonic radiation reflected on the inside can again be reflected on the inside, the first reflection surface on the outside corresponding to the opposite direction of incidence of the ultrasound radiation. As a result, a multiple reflection with simultaneous decoupling of ultrasound radiation in the direction of the ultrasound probe can take place, which can be reliably detected in the ultrasound image signals.

In an implementation of 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 a spatial direction, in particular a diameter of about 2 mm to about 4 mm. For example, a 2 mm diameter sphere is used for image depths of up to 40 mm, a sphere of about 3 mm diameter for image depths of up to 80 mm, and a sphere with a diameter of about 4 mm for image depths up to 120 mm.

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

The hollow body may be filled with a filling material, for example a gas, in particular air. Also conceivable is a liquid filler. As a filling material, for example, a contrast agent can be used, the sound impedance differs significantly from the acoustic impedance of the object under investigation.

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, especially the aforementioned metals, and their alloys have ultrasonic signal to ultrasonic levels of a size which makes them very well suited for use in medical ultrasound marking elements. For example, the acoustic impedance of steel is about 45 × 10 ⁶ kg / (m ² s), about 25 times to 30 times the average acoustic impedance of body tissue, which is about 1.6 × 10 ⁶ kg / (m ² s ) (based on a frequency of medical ultrasound of approximately 10 MHz). As a result, especially steel, especially for reasons of ease of manufacture and low cost, is very well suited as a material for a marking element, which can be used in medical ultrasound examinations.

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 advantageous if the at least one marking element consists of a resorbable material such as polylactide or calcium phosphate, whereby it can remain in the body during a medical ultrasound examination and can be absorbed by the latter.

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

Advantageously, 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 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 greater than the average of body tissue (about 1,500 m / s) for ultrasonic radiation proves to be advantageous. Due to a comparatively high speed of sound in the marking element, relatively many reflections can take place per unit of time, in particular on the above-mentioned second and the aforementioned third reflection surface. In the ultrasound image signals many signal contributions of multiple reflections can be found and analyzed. This makes it easier to find the marking element, because due to the increase in the speed of sound relative to the speed of sound of the environment of the marking element, in particular the object under investigation, the ultrasound image in the direction of propagation of the ultrasound downstream of the marking element appears to be compressed in the direction of time.

Overall, it is advantageous 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 speed of sound for ultrasound radiation in the body tissue.

It is advantageous if the at least one marking element is associated with a fastening device for fixing on the examination subject. The marking element may 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-integrated coating, for example an osteointegrative coating.

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

Preferably, the fastening device is made of a material whose sound impedance is significantly different from that of the material from which the marking element is made. This ensures that as few disturbing contributions of the fastening device to the ultrasound image signals are contributed, whereby the finding of the marking element is facilitated.

The marking device may have two or more marking elements. The marking elements may be spatially fixed to each other or be movable relative to each other. For example, the marking elements are independently positionable.

The marking elements can be identical or different.

As mentioned above, 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 reflection surface and a second reflection surface with parallel surface normals spaced apart therefrom, as marking element for marking an examination object which is examined with ultrasound radiation.

The body may in particular have the features which have been explained with reference to the above-described marking device according to the invention and advantageous embodiments thereof by the example of their marking element.

As mentioned further, 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 kind in ultrasound image signals is characterized in that ultrasound image signals are transmitted to a data processing device by an ultrasound probe, wherein the ultrasound image signals are examined by the data processing device for the presence of signal components which are subject to multiple reflection Ultrasonic radiation at the marking result as a result of a jump in the acoustic 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 may be made to the above explanations.

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

Conveniently, the method is carried out in real time, whereby the method is designed 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 already on the basis of the high-frequency ultrasound image signals without ultrasound images having to be created in B-mode (brightness mode) for this purpose.

It is advantageous if the ultrasound image signals are present in a matrix of signal components which contains spatial information in a first direction and time information in a second direction and if the signal components are summed in the time direction and the position of the marker in the spatial direction is considered as the position of the Maximums of the summation. The contributions of individual ultrasound transducers of the ultrasound probe can be arranged in a matrix such that the spatial information is contained in a first spatial direction and the time information of a second spatial direction (for example, a row or a column of the matrix). By summing up the signal components in time direction (temporal integration), a space-dependent time integral of the received ultrasound radiation can be provided. In practice, thereby 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.

Furthermore, it proves to be advantageous if the ultrasound image signals are present in a matrix of signal components, which contains spatial information in a first spatial direction and time information in a second direction, and if the signal components are examined in regular time, at least in sections, regularly arranged signal amplitudes. For example, the signals are examined in the time direction for the presence of a "signal comb" of signal amplitudes, the signal comb being considered to result from multiple reflection of ultrasound radiation at the reflection surfaces. The position of the marking element in the time direction can then be regarded as a time beginning of the signal comb.

Advantageously, in the investigation, signal components which lie below a predefinable threshold amplitude are regarded as having the threshold amplitude. As can be seen in practice, this allows the position of the marking element to 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 over the Threshold amplitude protruding signal components can be examined to find the above-mentioned signal comb.

The method is particularly suitable for medical ultrasound, which are used, for example, for the examination of bones. For example, the method is used in the examination of upper and lower extremities or in a study of the spine. In addition to implantology, the procedure can also be used in biopsies.

It proves to be advantageous if ultrasonic radiation is used in two or more obliquely aligned beam directions in pairs, if the examination of the ultrasound image signals for each of the beam directions is performed separately on a respective ultrasound image data set and if the marker is only found to be found when it is in at least two ultrasonic image data sets is considered to be present. This can be done a plausibility check. 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 located on the examination subject.

As already mentioned, the invention also relates to a device. A device according to the invention for carrying out 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 ultrasound image signals to the data processing device and the data processing device being designed and programmed to examine the ultrasound image signals for the presence of signal components, which result from multiple reflection of the ultrasonic radiation at the at least one marking element of the marking device as a result of a jump in the acoustic impedance between the object to be examined and the at least one marking element.

The achievable with the device advantages and their operation have already been explained above in connection with the explanation of the marking device and the method, so that reference can be made in this regard to the above embodiment.

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

• 1. Chirurgisches Instrumentarium, umfassend mindestens ein Implantat und eine diesem zugeordnete chirurgische Markiervorrichtung für Ultraschalluntersuchungen, die mindestens ein mittels Ultraschallstrahlung detektier bares chirurgisches Markierelement aufweist, wobei das mindestens eine Markierelement in vorgebbarer oder vorgegebener räumlicher Beziehung zum Implantat angeordnet oder anordenbar ist.
• 2. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Wirbelkörperersatzimplantat ist.
• 3. Instrumentarium nach Satz 1 oder 2, dadurch gekennzeichnet, dass das Implantat ein Implantat zur gegenseitigen Abstützung benachbarter Wirbelkörper ist.
• 4. Instrumentarium nach einem Satz 3, dadurch gekennzeichnet, dass das Implantat ein Implantat zur gegenseitigen Abstützung der Dornfortsätze benachbarter Wirbelkörper ist.
• 5. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Bandscheibenersatzimplantat ist.
• 6. Instrumentarium nach Satz 1, dadurch gekennzeichnet, dass das Implantat ein Implantat zum Verschließen des Anulus fibrosus der Bandscheibe ist.
• 7. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das Implantat chirurgisches Nahtmaterial ist oder umfasst.
• 8. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass die Markiervorrichtung eine Mehrzahl von Markierelement umfasst.
• 9. Instrumentarium nach Satz 8, dadurch gekennzeichnet, dass die Markierelemente identisch sind oder unterschiedlich sind.
• 10. Instrumentarium nach Satz 8 oder 9, dadurch gekennzeichnet, dass die Markierelemente relativ zueinander frei positionierbar sind.
• 11. Instrumentarium nach Satz 8 oder 9, dadurch gekennzeichnet, dass die Markierelemente in unveränderbarer Relativorientierung zueinander angeordnet sind.
• 12. Instrumentarium nach einem der Sätze 8 bis 11, dadurch gekennzeichnet, dass die Markiervorrichtung drei in einer Ebene angeordnete Markierelemente aufweist.
• 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. 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. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement eine Kugelform aufweist oder eine Kugel ist.
• 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. Instrumentarium nach Satz 16, dadurch gekennzeichnet, dass die Befestigungseinrichtung eine Schraube, einen Niet oder einen Dorn aufweist.
• 18. Instrumentarium nach Satz 16 oder 17, dadurch gekennzeichnet, dass die Befestigungseinrichtung eine osteointegrative Beschichtung aufweist.
• 19. Instrumentarium nach einem der Sätze 16 bis 18, dadurch gekennzeichnet, dass das Implantat die Befestigungseinrichtung ausbildet.
• 20. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement am Implantat festgelegt ist.
• 21. Instrumentarium nach einem der voranstehenden Sätze, dadurch gekennzeichnet, dass das mindestens eine Markierelement in das Implantat eingebettet ist.
• 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. Instrumentarium nach Satz 22, dadurch gekennzeichnet, dass das mindestens eine Markierelement am Werkzeug festgelegt ist.

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

• 1. Surgical instrumentation, comprising at least one implant and associated therewith a surgical marking device for ultrasound examinations, which has at least one detectable by means of ultrasonic radiation Bares surgical marker, wherein the at least one marking element is arranged or can be arranged in a predeterminable or predetermined spatial relationship to the implant.
• 2. Instrumentarium according to sentence 1, characterized in that the implant is a vertebral body replacement implant.
• 3. Instrumentation according to sentence 1 or 2, characterized in that the implant is an implant for mutual support of adjacent vertebral bodies.
• 4. Instrumentation 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. Instrumentation according to sentence 1, characterized in that the implant is an intervertebral disc replacement implant.
• 6. Instrumentation according to sentence 1, characterized in that the implant is an implant for closing the annulus fibrosus of the intervertebral disc.
• 7. Instrumentation according to one of the preceding sentences, characterized in that the implant is surgical suture material or comprises.
• 8. Instrumentation according to one of the preceding sentences, characterized in that the marking device comprises a plurality of marking element.
• 9. Instrumentation according to sentence 8, characterized in that the marking elements are identical or different.
• 10. Instrumentation according to sentence 8 or 9, characterized in that the marking elements are freely positionable relative to each other.
• 11. Instrumentation according to sentence 8 or 9, characterized in that the marking elements are arranged in immutable relative orientation to each other.
• 12. Instrumentarium according to one of the sentences 8 to 11, characterized in that the marking device has three arranged in a plane marking elements.
• 13. Instrumentation according to one of the sentences 8 to 12, characterized in that three or more marking elements are arranged or can be arranged so that they have identical distances from a common point.
• 14. Instrumentation according to one of the preceding sentences, characterized in that the at least one marking element has at least a first reflection surface and a second reflection surface for ultrasonic radiation spaced therefrom, wherein the first reflection surface and the second reflection surface have parallel surface normals.
• 15. Instrumentation according to one of the preceding sentences, characterized in that the at least one marking element has a spherical shape or is a ball.
• 16. Instrumentation according to one of the preceding sentences, characterized in that the instrumentation 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. Instrumentation according to sentence 16, characterized in that the fastening device comprises a screw, a rivet or a mandrel.
• 18. Instrumentation according to sentence 16 or 17, characterized in that the fastening device has an osteointegrative coating.
• 19. instrumentation according to one of the sentences 16 to 18, characterized in that the implant forms the fastening device.
• 20. instrumentation according to one of the preceding sentences, characterized in that the at least one marking element is fixed to the implant.
• 21. Instrumentation according to one of the preceding sentences, characterized in that the at least one marking element is embedded in the implant.
• 22. Instrumentation according to one of the preceding sentences, characterized in that the instrumentation comprises a tool for acting on the implant, which tool can be fixed in predetermined or predeterminable spatial relative orientation on the implant.
• 23. Instrumentation according to sentence 22, characterized in that the at least one marking element is fixed to the tool.

The following description of preferred embodiments of the invention is used in conjunction with the drawings for a more detailed explanation of the invention. 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;

4 : a further schematic representation of a marking element;

5 a visualization of ultrasound image signals having spatial information in the rows and temporal information in the columns, wherein signal contributions are shown by a marking element of a marking device according to the invention;

6 : an enlarged view of detail A in 5 ;

7 : A representation in which the signal amplitudes of the ultrasonic image signals in 5 summed up in time direction;

8th : Sectional the signal amplitudes in the spatial direction of the ultrasound image signals in 5 ;

9 a schematic representation of a marking element, which 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;

14 a marking element defined on an end face of a vertebral body (partially pierced) in side view;

15 : the vertebral body and the marking element 14 from caudal;

16 two vertebral bodies with marking elements attached thereto;

17 : the vertebral bodies and the marking elements 16 from caudal;

18 three vertebral bodies and marking elements of dorsal fixed thereto;

19 : the vertebral bodies and the marking elements 18 from caudal;

20 a marking element fixed to a holding part;

21 a marking element fixed to a different holding part;

22 : Implant in the form of surgical suture with marking elements attached thereto;

23 an implant in the form of surgical suture with a marker attached thereto;

24 an implant in the form of a disc closure with a marking element attached thereto;

25 another intervertebral disc closure with marking element attached thereto;

26 another intervertebral disc closure with two marking elements attached thereto;

27 another intervertebral disc closure with four marking elements attached thereto;

28 : further intervertebral disc closure with a marking element attached thereto;

29 a disc replacement implant having a marker embedded therein;

30 an implant for supporting the spinous processes of adjacent vertebral bodies and three marking elements fixed thereto;

31 an implant for mutual support of adjacent vertebral bodies and three marking elements fixed thereto and

32 an implant for supporting adjacent vertebral bodies and an insertion tool, wherein two marking elements are fixed on the insertion tool, and an ultrasound probe.

In the drawing, the same or equivalent features for greater clarity with the same reference numerals.

1 shows a perspective view of a device according to the invention 10 for ultrasound examinations, which is a data processing device 12 , an ultrasound probe 14 and a marking element 22 comprehensive marking device according to the invention 16 having. Ultrasound image signals coming from the ultrasound probe 14 can be generated, the data processing device 12 be supplied. The data processing device 12 can the ultrasound image signals as an ultrasound image on a display device 18 represent. Furthermore, the data processing device 12 examine the ultrasonic image signals for signal components, in particular the marking element 22 the marking device 16 come. It is possible to directly examine the high-frequency RF / RF ultrasound image signals.

The device 10 is present in the examination of a patient 20 used, in particular its extremities such as arms and legs. The following also includes examinations of the patient's spine 20 and biopsies received.

With the device 10 a preferred embodiment of a method according to the invention is feasible, as has been explained above and below.

The marking device 16 includes one or more marking elements 22 for marking an object of investigation. Exemplary marking elements 22 are in the 2 to 4 shown. All marking elements 22 is common that they have a first, outside reflection surface 24 and a second, inneinseitige reflection surface spaced therefrom 26 exhibit. Furthermore, each marking element 22 one from the second reflection surface 26 spaced third, inside reflecting surface 28 on. This corresponds to the first, outside reflection surface 24 , but in the opposite direction of propagation of the ultrasonic radiation, it is in a sense backward to the reflection surface 24 arranged.

Every reflection surface 24 to 28 is a surface normal 30 . 32 . 34 assigned, wherein the surface normals 30 to 34 are parallel to each other and, as in the present case, preferably even coincide.

The marking elements 22 in the present case are solid bodies and preferably made of a material which has a sound impedance for medical ultrasound radiation, which differs significantly from the acoustic impedance of body tissue. Particularly preferably, the marking elements are made of a metal, for example of steel, wherein also platinum, tantalum, titanium, gold, silver, cobalt, chromium or an alloy thereof is conceivable. For other applications, the marking elements can be made from bone (allogeneic, autogenous or xenogeneic) or bone substitute material, from PEEK, PMMA, or a ceramic material. The marking elements 22 may be absorbable, eg. B. from polylactide or calcium phosphate.

Unlike the marking elements 22 it can be provided that marking elements of the marking device do not consist of a solid material but are hollow bodies. In the hollow bodies, a filling material, such as an ultrasound contrast agent, may be included. Also conceivable are marking elements which are in the form of recesses, for example on a bone.

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

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

The penetrating ultrasonic radiation is then at the second reflection surface 26 reflected. A portion of it may be from the marking element 22 emerge and be detected again by the ultrasound probe. The remainder is reflected again, at the third reflection surface 28 , Subsequently, further multiple reflections of ultrasound radiation take place within the marking element 22 at the reflection surfaces 26 . 28 whose surface normals are opposite to each other.

There is only one share of each on the reflection surface 26 impinging radiation is transmitted and may be the marking element 22 leave, and in each case only a portion of on the reflecting surface 28 Apt ultrasonic radiation can be the marking element 22 leave. As a result, the ultrasound radiation runs in the marking element 22 back and forth.

Ultrasonic radiation, which is at the ultrasound probe 14 facing side of the marking 22 can exit, contrary to the direction of propagation 36 towards the ultrasound probe 14 spread and is detected by this. In the ultrasound image signals, this may result in a structure that is due to the multiple reflections of the ultrasound radiation at the reflection surfaces 24 . 26 and 28 results. Due to the invariable geometry of the marking element 22 makes the repeatedly reflected ultrasonic radiation in the form of a "tail" noticeable in the ultrasound image signals ( 5 ).

5 shows ultrasound image signals of the ultrasound probe 14 in a matrix 37 that have a spatial direction 38 and a time direction 40 having. The spatial direction 38 results from ultrasound transducer arranged side by side next to one another in line form, which each emit ultrasonic radiation. The ultrasonic transducers are in 5 at the top edge of the matrix 37 arranged to look at. The time direction 40 results in a conventional manner by the time duration between the emission and the arrival of the ultrasonic radiation.

The matrix 37 shows signal components 42 passing through the marking element 22 result. Leading in the time direction is the position of the marking element 22 (in 5 characterized by reference numerals 22 ' ) clearly visible. At this point, the amplitude of the ultrasonic signal increases due to the large proportion of reflected ultrasound radiation at the first reflection surface 24 strong. The high signal amplitude results from the large difference between the acoustic impedances of the marking element 22 made of steel on the one hand and the surrounding body tissue on the other. In the time direction the increase of the signal amplitude is downstream in the matrix 37 the tail 44 due to the repeated reflection of ultrasonic radiation at the marking element 22 clearly recognizable.

It proves to be advantageous to use a material for the marking element, in which the speed of sound for ultrasonic radiation is significantly higher than in the surrounding tissue. Within the marking element 22 Ultrasonic radiation spreads faster, so that signal components 42 of the marking element 22 compressed in relation to the signal components of the environment in time direction. This gives the possibility of getting a large share of the total from the marking element 22 decoupled ultrasonic radiation with the ultrasonic probe 14 capture. The signal components 42 allow thereby 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 22 form the signal components in time direction 40 in particular a signal comb 46 in the enlarged view of the 6 better to recognize and in 8th , which will be discussed below, is also shown.

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

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

On the signal comb 46 due to multiple reflection in a marker 22 has already been received. 8th shows part of the tail 44 in the matrix 37 , Clearly visible is the signal crest 46 which has a sequence of regularly repeating signal amplitudes of approximately equal magnitude. The signal comb 46 is partially interrupted, since the received ultrasonic image signals can also be subject to interference such as scattering or interference, whereby the signal comb 46 does not get a perfect comb shape. However, the regular sequence of signal amplitudes of approximately equal magnitude may be provided by the computing device 12 , preferably in real time.

For a simplified finding of the signal comb it can be provided that signal amplitudes below a predefinable threshold amplitude 52 lie as the threshold amplitude 52 be considered. The ultrasonic image signals are thus in terms of their amplitude at the threshold amplitude 52 cut off below. The signal components equal to the threshold amplitude 52 may be from the algorithm of the data processing device 12 when finding the signal crest 46 be skipped, whereby a faster analysis of the ultrasound image signals is possible.

The data processing device 12 takes the position of the marking element 22 as in time direction 40 leader in the signal comb 46 on (reference numeral 22 ' in 8th ).

In practice it turns out that the finding of objects to be examined, for example special structures in the patient 20 , using the marking device 16 is much easier and reliable from the data processing device 12 can be supported by analyzing the ultrasound image signals in real time.

9 schematically shows the marking element 22 , which is exposed to three ultrasound beams. The ultrasound beams propagate in directions of propagation 54 . 56 and 58 out, which are aligned in pairs wrong. For example, an ultrasound probe 14 used with compound ultrasound mode to create the three beams.

In the arrangement according to 9 it is advantageous if the marking element 22 Has spherical shape. The multiple reflection of incoming ultrasound beams in this case is direction independent. It is therefore only reflected ultrasound radiation of the same ultrasound beam back to the ultrasound probe 14 receive. This provides the possibility of generating an ultrasound image data set for each ultrasound beam. Only then, when the data processing device 12 For example, in one of the ways described above, the marking element 22 detected in the ultrasound image data sets of at least two radiation beams, this is considered to be detected as a whole.

For fixing to the examination subject, such as a bone, the marking device 16 a fastening device 60 exhibit ( 10 to 13 ). The fastening device 60 is preferred with the marking element 22 connected and made of a different material. The material of the fastening device 60 preferably has a sound impedance for ultrasonic radiation, which differs substantially from that of the material from which the marking element 22 is made. Preferably, the material of the fastening device 60 have a sound impedance equal to or similar to that of the environment in which the marking element 22 is positioned. A disturbing influence of reflections on the fastening device 60 on the signal components 42 as a result of the marking element 22 can be reduced.

At the marking element 22 according to 10 is the fastening device 60 a bone screw 62 ,

At the marking element 22 according to 11 is the fastening device 60 a surgical dowel 64 , in particular for anchoring to the bone.

At the marking element 22 according to 12 includes the fastening device 60 two spaced pins 66 , The fastening device 60 is thereby cramp-like.

At the marking element 22 according to 13 includes the fastening device 60 a pen 68 coated with a coating. The coating is, for example, an osteointegrative coating, in particular with titanium powder, in order to allow better anchoring to the bone.

The device 10 , the marking device 16 and the method described above are particularly suitable for use in an ultrasound-assisted biopsy, for example on the patient's spine 20 , Particularly advantageous is, for example, the application in an ADCT operation (Autologous Disc-derived Chondrocyte Transplantation), a method for the biological reconstruction of damaged discs, which will be briefly discussed. In such a method, a damaged intervertebral disc, for example, after a herniated disc (prolapse) patient's own intervertebral disc cells are removed. The cells are in vitro outside the patient 20 expanded and after a latency period of a few months, for example, three months, injected again in aqueous solution into the damaged disc. The removal and the injection of the cells is so far under limited control by X-ray-based imaging.

It is also known to improve the method of the conventional ADCT in that biomaterial is injected into the disc additionally or alternatively to the body's own cells. For example, the biomaterial may polymerize after injection into the disc.

In the previous ADCT, which is carried out under X-ray control, the operation is subject to considerable restrictions. In particular, no representation of a transverse sectional plane through the spine is possible, but the representation of the spine takes place only in anterior-posterior or lateral representation. Further, there is the problem that in X-ray control, only the positioning of the injection cannulas before injection or removal on the disc can be controlled, the actual injection or removal of the cells or the biomaterial, however, "blind" to perform without X-ray vision to damage by ionizing X-rays avoid. Of course, the burden on the patient or the surgical staff due to ionizing X-ray radiation is also negative in this context.

The present invention makes it possible to carry out the removal of cells or the injection of cells or biomaterial into the disc under ultrasound vision. For this purpose, the possibility is preferably given to the spine 70 of the patient 20 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 22 used.

The use of ultrasonic radiation of the ultrasound probe 14 proves to be particularly advantageous because 20 cells can be removed and injected without radiation exposure for the patient. The choice of the cutting plane can be made by orientation of the ultrasonic probe 14 and thus the ultrasonic field can be chosen freely. Oriented on the marking element (s) 22 It is possible for the surgeon in a simple manner, the needles for extraction or emission safely and reliably on the intervertebral disc 76 to place (not shown).

The following is by reference in particular to the 14 to 32 on different possibilities of the placement of marking elements 22 on the spine 72 received. The marking elements 22 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 the 14 and 15 is a marker 22 over the fastening device 60 , for example, the dowel 64 in an end plate 78 introduced by caudal or cranial. For introducing the marking element 22 For example, a distraction tool can be used which with one working end the marking element 22 with the fastening device 60 picks up and into the end plate 78 presses. Another working end of the tool may be at the opposite end plate 78 of the vertebral body 74 support.

In the presentation according to 16 is on the vertebral bodies 72 . 74 one marking element each 22 fixed, preferably near the intervertebral disc 76 , in particular adjacent to the intervertebral disc 76 , The intervertebral disc can be used as the middle between the marking elements 22 be recognized. For a positioning of the two marking elements, a template may be provided, for example a spacer sleeve, by their use receptacles for the marking 22 with fasteners at a defined distance from each other in the vertebral bodies 72 . 74 can be introduced.

When using two or more marking elements 22 It is possible to choose a direction (straight line through the marking elements) or a plane too define by three marking elements 22 is spanned.

In the presentation according to 17 come two markers 22 For use on a spinous process 80 and a lamina 82 of the vertebral body 72 are fixed, wherein instead of fixing to the lamina can also be a determination on a facet joint. More preferred is the use of three marking elements 22 , see. the 18 and 19 , for example on the spinous process 80 , on a facet joint 84 superior and a facet joint 84 inferior.

The of the marking elements 22 Defined level allows to define a coordinate system by means of which an orientation can be made. In particular, the marking elements form 22 a surgical referencing device in the form of a so-called "rigid body". In particular, the rigid body facilitates extraction or injection on the intervertebral disc 76 perform. With the ultrasound probe 14 can be the level of the marking elements 22 be recorded. For example, the position of the ultrasound plane relative to the cannula can be adjusted by a mechanical coupling. For example, the cannula is aligned perpendicular to the ultrasonic plane. The positioning of the cannula in caudal-cranial direction can be adjusted by the fact that due to the distance of marking elements 22 from each other the position of the intervertebral disc 76 can be determined.

Two or more marking elements 22 may also be connected via a common fastening device, for example one of the fastening devices 60 of the 10 to 13 , Accordingly, the attachment means may be a carrier, in a sense a "rigid body" for two or more marking elements 22 be that can be fixed on a support structure on a body structure.

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

At the holding part 86 according to 21 is a blind hole-shaped recording 92 formed, in which the marking element 22 can be used. The marking element 22 For example, it can be jammed or crushed or stuck in the receptacle 92 be held.

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

As with the fastening device 60 It is advantageous if the sound impedance for ultrasonic radiation of a holding part 86 is different from that of the material from which the marking element 22 is made. Ideally, the sound impedance of the material of the holding part 26 equal to or approximately equal to the acoustic impedance of body tissue.

As already mentioned, the present invention also relates to a surgical instrument with at least one implant and a marking device associated therewith. The implant and the at least one marking element of the marking device are arranged or can be arranged in a predefined or predeterminable 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 easily given the opportunity to locate the implant using the at least one marking element. In particular, the device may 10 which may be part of the instrumentation or which may form part of the instrumentation and which use one of the methods described above.

The following is with reference to the 22 to 32 on different instruments and their respective implants. Markers of Markiervorrichtungen the instrumentation are each denoted by the reference numeral 22 busy. These are in particular spherical and made for example of a metal.

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

The implants 96 especially serve to close a defect 100 in a annulus fibrosus 102 the intervertebral disc 76 , The marking element 22 can each be outside or inside the intervertebral disc 76 to be placed. The sutures 98 can be sewn or knotted, for example, to the defect 100 close.

With an instrument 104 according to 23 is an implant 106 in the form of suture 108 and one attached to it marking 22 intended. Two sections 110 . 112 of the suture can be sutured or knotted together to form the defect 110 close.

The 24 to 27 show different variants of an instrument 114 , each a closing implant 116 for closing a defect in the annulus fibrosus 102 include. The closing implant 116 has two investment areas 118 . 120 to the outside or inside concerns on Anulus fibrosus 102 on. The investment areas 118 . 120 are over a connection area 122 that the defect 100 can pass through, interconnected.

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

In the variant according to 24 is a marking element on the inside in the intervertebral disc at the contact area 120 set, in the variant 25 a connecting element 22 at the investment area 118 outside the disc 76 , The variant according to 26 includes two marking elements 22 inside and outside of the investment 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 22 can be concentric with respect to an axis 124 be arranged, which can represent a target axis for the cannula.

marking elements 22 can also in the closing implant 116 be embedded.

An in 28 illustrated instrumentation 126 includes an implant 128 , which is a closing implant for closing the annulus fibrosus 102 is. The implant 128 has a reticular shape. At least one marking element 22 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 an instrument 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 above-mentioned polymerizing biomaterial and cells may be introduced by injection. The implant 132 serves in particular as a replacement for the nucleus pulposus of an intervertebral disc.

At least one marking element 22 can in the implant 132 be embedded or attached to it. As a result, in particular the possibility exists, postoperatively under ultrasound view the implant 132 again, especially to inject more biomaterial and nucleus cells there.

30 shows an implant 138 for the 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 an instrument 140 and includes a first support member 142 and a second support element 144 for the spinous processes 80 respectively. 136 and 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 in each case a marking element 22 established.

The marking elements 22 allow it, the implant 138 in the body and its location on the spinous processes 80 . 136 and control their spread relative to each other. Preferably, it is also possible for the implant 138 postoperative and percutaneous control and especially readjustment. The marking elements 22 can also be used to postoperatively locate the intervertebral disc 76 be used postoperatively, another injection into this in the context of an ADCT intervention.

An instrument 148 according to 31 includes an implant 150 with pedicle screws 152 by a stabilizing element in the form of a rod 154 connected to each other. The pedicle screws 152 are in a conventional manner with vertebral bodies 72 . 74 and 155 screwed. As a result, they can be supported relative to each other. On at least one implant component, for example a pedicle screw 152 , at least one marking element 22 be set. For example, see 31 , are attached to a pedicle screw 152 three marking elements 22 established. These can form a previously mentioned "rigid body" for the definition of a coordinate system. Again, postoperatively, an injection into an intervertebral disc 76 as part of an ADCT intervention done by the marking elements 22 to find the intervertebral disc 76 be used.

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

The instrumentation 156 also includes a tool 164 , The tool 164 can present percutaneously with the pedicle screw 160 and adjust their orientation percutaneously. This serves to open the pedicle screw 160 relative to the staff 162 to align with it this can be inserted into the opening. For this purpose, the tool 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 be at least one marking element 22 be set, preferably a plurality of marking elements 22 , Under view by means of the ultrasound probe 14 is it possible to use the marking elements 22 as explained above, and thereby the insertion opening 166 for insertion of the rod 162 easy to find.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2010/000488 A1 [0144]
• WO 2011/128220 A1 [0147]

Claims (25)

 A marking device for ultrasound examinations, comprising at least one marking element for marking an examination subject, which has at least a first reflection surface and a second reflection surface for ultrasonic radiation spaced therefrom, wherein the first reflection surface and the second reflection surface have parallel surface normals. Marking device according to claim 1, characterized in that the at least one marking element has more than two reflection surfaces, wherein the surface normals are parallel to each other. Marking device according to claim 1 or 2, characterized in that the reflection surfaces are arranged on an outer side or on an inner side of the marking element. Marking device according to one of the preceding claims, characterized in that at least one reflection surface is planar. Marking device according to one of the preceding claims, characterized in that at least one reflection surface is curved. Marking device according to one of the preceding claims, characterized in that the reflection surfaces are aligned parallel to each other. Marking device according to one of the preceding claims, characterized in that the at least one marking element has a spherical shape or is a ball. Marking device according to one of the preceding claims, characterized in that the at least one marking element has a size in a spatial direction, in particular a diameter, of about 2 mm to about 4 mm. Marking device according to one of the preceding claims, characterized in that the at least one marking element is a solid body. Marking device according to one of claims 1 to 8, characterized in that the at least one marking element is a hollow body. Marking device according to one of the preceding claims, characterized in that the at least one marking element 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 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 for medical ultrasound radiation is greater than approximately 20 · 10 ⁶ kg / (m ² s), preferably greater than 20 · 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 for medical ultrasound radiation is greater than about 1,500 m / s, preferably greater than about 3,000 m / s. Marking device according to one of the preceding claims, characterized in that the at least one marking element is associated with a fixing device for fixing on the examination subject. Marking device according to one of the preceding claims, characterized in that the marking device comprises a plurality of marking elements.  Use of a body which has at least a first reflection surface and a second reflection surface with parallel surface normals spaced apart therefrom, as a marking element for marking a test object, which is examined with ultrasound radiation.  Method for finding signal contributions of a marking element of a marking device according to one of the preceding claims in ultrasound image signals which are transmitted to a data processing device by an ultrasound probe, wherein the ultrasound image signals are examined by the data processing system for the presence of signal components which are caused by multiple reflection of the ultrasound radiation at the marking element as a result of a jump give the acoustic impedance between the object under investigation and the marking element. A method according to claim 18, characterized in that the method is carried out in real time. The method of claim 18 or 19, characterized in that the data processing device of the ultrasonic probe provided high-frequency (RF / RF) ultrasound image signals examined. Method according to one of Claims 18 to 20, characterized in that 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 in which the signal components are summed up in the time direction and the position of the signal Markierelementes in the spatial direction is considered as the position of the maximum of the summation. Method according to one of Claims 18 to 21, characterized in that 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 in which the signal components regularly, at least in sections arranged signal amplitudes are examined. A method according to claim 22, characterized in that in the investigation signal portions which are below a predetermined threshold amplitude, are considered to have the threshold amplitude. Method according to one of claims 18 to 23, 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 direction is performed separately on a respective ultrasound image signal data set and that the marking element only found to be found when considered present in at least two ultrasound image signal sets.  Apparatus for carrying out the method according to any of claims 18 to 24, comprising a marking device according to one of claims 1 to 16, an ultrasound probe and a data processing device, wherein the ultrasound probe provides ultrasound image signals to the data processing device and the data processing device is designed and programmed such that it transmits the ultrasound image signals investigated for the presence of signal components resulting from multiple reflection of the ultrasonic radiation at the at least one marking element of the marking device as a result of a jump in the acoustic impedance between the object to be examined and the at least one marking element.

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