MARKER ELEMENT FOR MARKING TISSUE

Abstract

The invention relates to a marker element for marking body tissue. The marker element has an at least approximately rotation-symmetric geometry about a longitudinal axis, is formed by interlinked, elastic and preformed wire members and can assume a radially compressed and a radially expanded state. The wire members are interlinked at their respective ends, preferably in pairs.

Claims

1. A marking body for marking body tissue, said marking body having a longitudinal axis and being substantially rotationally symmetrical in relation to the longitudinal axis, wherein the marking body is formed by interconnected, elastic, preformed metal webs and is configured to transition between a radially compressed state and a radially expanded state, wherein, when the marking body is in the expanded state, the marking body is flared in a central longitudinal section and tapers from the central longitudinal section along the longitudinal axis toward each respective end face of the marking body, a maximum external diameter of the central longitudinal section being about two times to about twenty times greater than an external diameter of the end faces of the marking body, and wherein, when the marking body is in the compressed state, the metal webs forming the marking body extend substantially in a longitudinal direction of the marking body and at least one pair of the metal webs is interconnected in an interlocking and/or cohesive fashion at respective longitudinal ends of the metal webs.

2. The marking body as claimed in claim 1, wherein the marking body is formed by 5 to 100 webs, the webs extending along the longitudinal axis between the end faces of the marking body and crossing over one another multiple times to form a lattice-like support structure with a plurality of crossing points .

3. The marking body as claimed in claim 1, wherein the webs are wires, rods, or tubes.

4. The marking body as claimed in claim 2, wherein the webs of the marking body are cohesively interconnected at the crossing points.

5. The marking body as claimed in claim 2, wherein the webs of the marking body are twisted together at the crossing points.

6. The marking body as claimed in claim 1, wherein the webs of the marking body are all connected in pairs at respective longitudinal ends of the webs.

7. The marking body as claimed in claim 1, wherein, when the marking body is in the expanded state, an external diameter of the marking body decreases continuously from the central longitudinal section along the longitudinal axis toward each end face of the marking body such that the marking body has a minimum diameter at the end faces.

8. The marking body as claimed in claim 1, wherein the webs of the marking body are formed from a titanium alloy.

9. The marking body as claimed in claim 2, wherein the lattice-like support structure is formed by a braided wire mesh.

10. The marking body as claimed in claim 1, wherein the webs have a diameter of less than about 0.15 mm.

11. The marking body as claimed in claim 1, wherein at least one of the webs is at least partly coated with a material that differs from a material of the webs.

12. The marking body as claimed in claim 1, wherein the marking body comprises a membrane, which fills at least one region between two webs.

13. The marking body as claimed in claim 1, wherein the marking body is at least partially coated with a membrane on an outside of the marking body or on an inside of the marking body.

14. An implantation system having a marking body as claimed in claim 1 and an implantation apparatus with a cannula, the marking body being situated within the cannula and being configured to move out of the cannula by actuating the implantation apparatus.

15. The implantation system as claimed in claim 14, wherein the implantation system is configured for application within a vacuum biopsy unit with a cannula which has a lateral opening for driving out a marking body.

16. A method for producing a marking body for marking body tissue, the method including: forming a tubular braided wire mesh, which has two longitudinal ends and is formed by 5 to 100 braided individual wires, and compressing the braided wire mesh in a longitudinal direction to flare the braided wire mesh radially in a central longitudinal section of the braided wire mesh.

17. The method as claimed in claim 16, wherein forming the tubular braided wire mesh includes: braiding individual wires to form a tube such that the individual wires alternately cross over and under one another at crossing points, the crossing points being substantially arranged on crossing point planes which extend transversely to a longitudinal axis of the tube, and separating a section of the tube by laser cutting the individual wires at the crossing points in a separation plane, the separation plane corresponding to one of the crossing point planes.

18. The method as claimed in claim 17, further including: after separating the section of the tube, welding longitudinal ends of the individual wires together in pairs.

19. The method as claimed in claim 17, wherein the individual wires are twisted around one another at the crossing point planes, such that a pair of two individual wires is wrapped around one another through at least 180°.

20. The method as claimed in claim 19, wherein a pair of two individual wires is wrapped around one another through 360°, 540° or 720°.

Description

[0065] Further advantages, features and details of the invention arise from the following description of the preferred embodiments and the illustrating figures, in which:

[0066] FIG. 1: shows a schematically represented marking body in a perspective view;

[0067] FIGS. 2a and 2b: show the marking body shown in FIG. 1 in an end view (FIG. 2a) and in a side view (FIG. 2b);

[0068] FIGS. 3a to 3h: show different cross-sectional shapes for webs of a marking body according to FIGS. 1 and 2;

[0069] FIGS. 4a to 4f: show different variants of how individual webs of the marking body from FIGS. 1 and 2 can be interconnected at crossing points;

[0070] FIGS. 5a to 5f: show different variants of how free ends of two webs of a marking body according to FIGS. 1 and 2 can be connected;

[0071] FIG. 6: shows a braided wire mesh as a section of the braided tube which can be used as an initial product for shaping a marking body as depicted in FIGS. 1 and 2;

[0072] FIG. 7: shows a section of a tube braided from wires, from which three braided wire meshes according to FIG. 3 can be produced by separation;

[0073] FIG. 8: shows the braided wire tube from FIG. 4, in the case of which the wires are separated at two sites by means of a laser;

[0074] FIGS. 9a to 9c: show a longitudinal section of various forms which a marking body according to FIGS. 1 and 2 can adopt;

[0075] FIG. 10: shows a perspective view of an implantation apparatus for a marking body according to FIGS. 1 and 2;

[0076] FIG. 11: shows a side view of the implantation apparatus depicted in FIG. 10;

[0077] FIG. 12A to 12C: show schematic representations of the details of the implantation apparatus depicted in FIGS. 10 and 11;

[0078] FIGS. 13a and 13b: show plan views of the implantation apparatus depicted in FIGS. 10 and 11;

[0079] FIG. 14: shows an illustration of an ultrasound recording of a marking body according to FIGS. 1 and 2, and ultrasound images resulting therefrom;

[0080] FIG. 15: illustrates how ultrasound is reflected from the webs of the marking body according to FIGS. 1 and 2;

[0081] FIG. 16: shows an ultrasound image having an artifact of the marking body, as viewed from the side;

[0082] FIG. 17: shows an ultrasound image having an artifact of the marking body in the longitudinal direction;

[0083] FIGS. 18a and 18b: show a twist of the longitudinal ends of two wires (FIG. 18a) and a twist of the free longitudinal ends of three wires (FIGS. 18b);

[0084] FIG. 19: shows a braided wire mesh similar to that illustrated in FIG. 6, with additional membranes spanned between individual wires; and

[0085] FIGS. 20a to 20d: illustrate how a marking body can look like in cross section, without a membrane (FIG. 20b), with an interior membrane (FIG. 20b) and with an exterior membrane (FIG. 20d).

[0086] FIG. 1 shows a perspective view of a schematically illustrated marking body 100 in the expanded state.

[0087] FIG. 2a shows an end view of the marking body 100 in the expanded state and FIG. 2b shows a side view of the marking body 100 in the expanded state.

[0088] The marking body 100 comprises a support structure formed by a braided wire mesh 101. The wires 108 extend from one longitudinal end of the marking body 100 to its other longitudinal end. On the path from one longitudinal end to the other longitudinal end, the wires 108 cross other wires 108 and are braided in particular, that is to say each wire 108 is alternately guided first below and then above another wire 108 of the braided wire mesh 101. As a result, a lattice-like support structure with a multiplicity of crossing points 110 arises. In relation to the depicted representation in FIGS. 1 and 2, it should be observed that these crossing points 110, at which two wires 108 in each case cross over one another and are in lateral contact, are not reproduced with accurate detail. The braided structure of the marking body 100 is better depicted in FIGS. 6 to 8, which show the initial product. The crossing points 110 at which two wires 108 are in contact in each case may for example be designed like in the braided wire mesh 101, formed by crossing wires, in FIG. 6.

[0089] The free ends 112 of the wires 108 located at the respective longitudinal ends 114, 116 of the marking body 100 are each twisted around and welded to one or more free ends of the further wires 108. Preferably, two wires 108 are always interconnected with the respective longitudinal ends 114, 116 by twisting and welding at a crossing point at the respective longitudinal end of the marking body 100.

[0090] At its longitudinal ends, the marking body 100 has two longitudinal sections 102, 104, from where the marking body 100 flares to a central longitudinal section 106. Consequently, the external diameter of the marking body 100 has a maximum in the central longitudinal section 106.

[0091] In the illustrated example, the braided wire mesh 101 comprises 24 wires which consist of nitinol and have a diameter of approximately 0.1 mm. In alternative embodiments of the marking body not shown here, the braided wire mesh comprises between 8 and 200 wires, for example 48 or 96 wires. In the embodiments not shown here, the marking bodies comprise braided wire meshes which are formed by wires with diameters ranging between 0.05 mm and 0.15 mm. Wires that consist of other metals, for example other titanium alloys other than nitinol can also be used. “Wires” made of plastic, for example PEEK or PLA, may also be provided in alternative embodiments of the marking body.

[0092] The individual webs may have different diameters and also different cross-sectional shapes. FIGS. 3a to 3h show different cross-sectional shapes. By way of example, the webs can be formed as a round solid wire and have a cross section as depicted in FIG. 3a. Preferably, the webs consist of a hollow wire—that is to say a type of tube—which may have a cross section as depicted in FIG. 3b. Such a hollow wire is advantageous in that it reflects sound particularly well on account of the acoustic impedance differences between the material of the wire wall and the hollow interior. FIGS. 3c and 3d illustrate that the cross-sectional form can also be a square, in particular quadrilateral. FIGS. 3e and 3f show a triangular cross-sectional form for webs, in the form of solid material (FIG. 3i) or as hollow webs (FIG. 30. FIGS. 3g and 3h illustrate that the webs in principle can each have an arbitrary, prismatic cross-sectional shape, and hence also a hexagonal shape as shown in FIGS. 3g and 3h.

[0093] Since the marking body 100 is preferably formed from a braided wire mesh, the wires typically contact each other once the crossing points. Then, a crossing point can have an appearance as depicted in exemplary fashion in FIG. 4a. A secure connection between the two crossing wires can be produced by welding at such a crossing point. FIG. 4b illustrates this on the basis of a weld spot 118 on the crossing point. Should the webs not be braided but simply contact one another laterally in an arc, as depicted in FIG. 4c, a stable marking body can also be produced by virtue of the fact that the contacting webs are connected by welding, as depicted in FIG. 4d. A weld spot 118 is also shown here. Finally, the webs can also be twisted at the crossing points. FIG. 4e shows a twist, within the scope of which the webs are wrapped around one another by 360° and are subsequently interconnected by means of a weld spot 118; see also FIG. 4f. Instead of a 360° twist, a 180° twist is also sufficient. The arising image then is similar to FIG. 4c, with the exception that the webs are then hooked in one another.

[0094] FIGS. 5a to 5f illustrate that the webs can be connected by welding (FIG. 5b), by twisting (FIGS. 5c and 5e), or by twisting and welding (FIGS. 5d and 50 not only at the crossing points but also at the free longitudinal ends 112. Weld beads 120 that typically have a larger diameter than an individual web 103 or a wire that forms a web 103 then arise as a result of welding the webs 103 at their free longitudinal ends 112.

[0095] The marking body 100 has a length LM of 6 mm; in alternative embodiments not shown here, this length may also range between 4 mm and 8 mm, however.

[0096] The maximum external diameter DMA of the marking body in the central longitudinal section 106 is 4 mm and can be between 3.5 mm and 10 mm in alternative embodiments not shown here.

[0097] To bring the marking body 100 into an elastically compressed state from the expanded state, a radial force of at least one newton must be exerted on the marking body 100.

[0098] In alternative embodiments not shown here, the self-expanding marking body 100 may have more wires and accordingly more crossing points, and so said marking body is comparatively stiffer. Accordingly, a comparatively greater radial force then is required to bring the marking body into an elastically compressed state. Likewise, the number of wires can be lower in alternative embodiments not shown here, in order to realize a marking body which already transitions into its elastically compressed state when a radial force of less than one newton is exerted.

[0099] FIGS. 3, 4 and 5 illustrate various phases of a production method for producing a marking body which has a support structure formed by a braided wire mesh. By way of example, a marking body as described in relation to FIGS. 1 and 2 can be produced in accordance with the method described below.

[0100] Initially, a tubular braided wire mesh is provided, the latter for example being able to comprise between 8 and 200 individual wires which are braided with one another and, as a consequence, cross at crossing points. These are 24 individual wires in the depicted example.

[0101] As may be gathered from FIG. 2b, the marking body 100 preferably has a length LM ranging between 5 mm and 8 mm. The external diameter DMA in the fully expanded state is between 4 mm and 6 mm. The diameter of the individual wires 108 is preferably slightly less than 0.1 mm. The weld beads 120 at the free ends 112 of the wires have a diameter of greater than 0.1 mm, the latter preferably being at least 0.12 mm Hence, the marking body 100 is suitable for use with an implantation apparatus 1004 in which the difference between an internal cannula diameter DKI and a driving-out element external diameter DA is no more than 0.1 mm—even when the manufacturing tolerances are taken into account. Incidentally, the internal cannula diameter DKI is not necessarily greater than the external diameter d of the compressed marking body 100.

[0102] As can already be gathered from FIG. 3, the webs of the support structure can either be solid (wires) or hollow (tubes). The profiles may have a circular or ellipsoidal cross section. They may also be triangular, quadrilateral or in the form of an n-gon. The profiles can also change along a web. By way of example, a web could have a rectangular profile in the center and a circular profile at the longitudinal ends.

[0103] FIG. 4, which is explained in more detail above, shows examples of possible interlocking connections as a result of crossing, contacting or twisting at the crossing points. FIG. 4 likewise illustrates that the connection of the crossing points can additionally be cohesive, for example as a result of adhesive bonding, welding or soldering.

[0104] FIG. 5, likewise explained in more detail above, shows examples of possible forms of interlocking and cohesive connections at the free longitudinal ends 112 of the wires 108. The ends can be interconnected in pairs or in groups; see also FIG. 18.

[0105] What can likewise be gathered from FIG. 6 is that the free longitudinal ends 218 of the wires 202 are not only welded to one another but also twisted around one another. In combination, this ensures that the interconnected longitudinal ends of the wires do not separate from one another.

[0106] Unlike what is depicted in idealized fashion in the FIGS. 3 to 5, the longitudinal ends of the individual wires 202 are not all exactly in one (separation) plane 212 (see FIGS. 4 and 5), but are alternately slightly offset in relation to such an idealized plane, preferably in the longitudinal direction. This has the advantageous effect that the marking body 200 can be better compressed at its longitudinal ends 218 because the weld beads 220 are not all located next to one another but are at least slightly offset from one another in the longitudinal direction of the marking body 200.

[0107] The marking body 100 is preferably formed from a braided wire mesh 200, as depicted in FIG. 6 in exemplary fashion. FIG. 6 shows a braided wire mesh 200 as a section of a braided wire tube 202 (see FIG. 7), which is braided from 24 individual wires in the depicted example. The braided wire mesh 200 that will form the marking body 100 is formed from 24 individual wires 108 which cross under or over one another nine times between their longitudinal ends 112 and which are twisted around one another and welded to one another at their longitudinal ends 112 in pairs such that the braided wire mesh 200 has respective weld beads 120 at the longitudinal ends 112 of the wires 108. As can be gathered from FIG. 6, the longitudinal ends 112 of the interconnected wires 108 are not only welded to one another but also twisted around one another.

[0108] To produce a braided wire mesh 200 as depicted in FIG. 3, a wire tube 202 as depicted in FIG. 4 is produced first. To produce the tube 202, 24 individual wires 108, for example, are braided with one another such that they alternately cross over and under one another at the crossing points 210. Crossing point planes 214 that extend transversely to a longitudinal direction of the tube 202 arise in this way. Once the individual wires 108 have each crossed one another in pairs nine times, two individual wires are twisted around one another in each case such that twists 216 arise. The wire tube 202 thus forms crossing point planes 214 that alternate with separating planes 212 at which a respective braided wire mesh 200 should be separated from the wire tube 202. In the example illustrated, nine crossing point planes 214 are followed in each case by a respective separation plane 212. In the separation planes, the wires 108 are in each case fully wrapped about one another twice in pairs such that a wrap-around angle of 720° arises. In other exemplary embodiments not shown, the wrap-around angle can also be only 360° or else 540°.

[0109] FIG. 7 shows the tube 202 formed by the wires 108, the tube 206 having been separated at two separation sites 208 by means of a laser beam. The separation sites 208 are situated in precisely one separation plane 212, that is to say where the twists 216 are situated. The weld beads 120 arise from the laser cutting such that the then free, pairwise interconnected longitudinal ends 112 of the wires 108 are interconnected both by twisting and by a laser welding. As a result of the twisting 216, the connected longitudinal ends 112 of in each case two wires 108 arise as depicted in FIGS. 5d and 5f following the laser cutting.

[0110] Following the separation of the braided wire mesh 200 from the wire tube 202, the former can be shaped into the marking body 100 by virtue of being compressed in the longitudinal direction. As a result, the braided wire mesh 200 bulges outward in a central longitudinal section while the longitudinal ends are constricted if the compression is for example implemented by means of two tools, each formed by a hollow hemisphere, moving toward one another. Depending on the tool shape, the marking body 100 can adopt shapes as depicted in longitudinal sections in FIGS. 9a to 9c.

[0111] FIGS. 10, 11, 12 and 13 show an implantation apparatus 1004 for implanting a marking body 100. The implantation apparatus 1004 comprises a handle 1010 and an implantation part 1008. The cannula 1006, in which the marking body 100 is initially situated, is part of the implantation part 1008.

[0112] A cannula tip 1012 at the distal end of the cannula 1006 has been whetted in such a way that it facilitates a percutaneous implantation of the marking body 100 by piercing the cannula 1006 into body tissue. The cannula 1006 preferably consists of stainless steel.

[0113] To eject the marking body 100 from the cannula 1006, provision is made of a displaceable driving-out element 1018, which can be actuated from the handle 1010 by means of the sliding element 1016.

[0114] FIG. 12A shows an implantation system 1000 having a marking body 100 of an implantation apparatus 1004. In this case, the marking body 100 in the pre-loaded state, that is to say with a compressed support structure, is situated within the cannula 1006 of the implantation apparatus 1004. This state of the implantation system 1000 represents a typical delivery state, in which the implantation system 1000 is made available in a ready-to-use state for the user, for example a surgeon.

[0115] The implantation part 1008 of the implantation apparatus 1004 substantially consists of a cannula 1006 which has a cannula tip 1012 at its distal end, that is to say the end distant from the handle 1010. As a rule, the marking body 100 in the preloaded state is situated in this region within the cannula 1006, just inside the outlet at the cannula tip 1012. In particular, the cannula 1006 can be formed from a suitable metal.

[0116] The cannula 1006 has a length LKA which for example can adopt a value ranging between 25 mm and 200 mm, preferably between 50 mm and 150 mm. The length LKA of the cannula 1006 has an influence on the range of the implantation apparatus 1004 in respect of the reachability of tissue sites in the body of a patient to be labeled. The longer cannulas are used when adjustment aids are used, for example stereotaxis.

[0117] The implantation apparatus 1004 comprises a handle 1010 and an implantation part 1008. The handle 1010 comprises a handle housing 1014 and a sliding element 1016, which for example could be produced from a suitable plastic.

[0118] The sliding element 1016 is connected to the handle housing 1014 but is movable relative to the handle housing 1014 in the axial direction of the cannula 1006. Consequently, the sliding element 1016 can be moved along a straight, guided sliding path between a pre-loaded position 1020 and a driving-out position 1022.

[0119] This movement is transferred from the sliding element 1016 via a driving-out element 1018, which is connected to the sliding element 1016 and which can be formed for example by way of a wire or a sufficiently stable plastics fiber, to the distal region at a distance from the handle 1010. Consequently, when the sliding element 1016 is moved to the driving-out position 1022, the pre-loaded marking body 100 can be driven out of the cannula 1006 to the tissue site to be labeled at the distal end of the cannula 1006 by way of a sliding movement of the driving-out element 1018.

[0120] This is achieved by virtue of the driving-out element 1018 that is aligned coaxially with respect to the cannula 1006 being moved in the direction of the cannula tip 1012 and hence pushing the pre-loaded marking body 100 out of the cannula 1006 past the cannula tip 1012.

[0121] FIG. 12B depicts detail B of FIG. 12A, specifically a detailed view in the region of the cannula tip 1012 of the implantation system 1000 in the pre-loaded state. In this view, the marking body 100, in particular, can be seen in the compressed state, said marking body being situated within the cannula 1006 behind the driving-out element 1018 and in front of the cannula tip 1012 from the view of the handle 1010. On account of its prestress, the marking body maintains the position in the cannula 1006 and cannot fall out on its own. On account of this property, additional features or apparatuses for fixing the marking body 100 within the cannula 1006 can be dispensed with.

[0122] FIG. 12C shows a further detailed, schematic view of the cannula 1006, this time as detail C from FIG. 12B. In this view, the distal end of the driving-out element 1018 is visible within the cannula 1006. Furthermore, the external diameter DKA and the internal diameter DKI of the cannula 1006 are labeled.

[0123] Together with the cannula length LKA, the internal diameter DKI of the cannula 1006 describes the size of the internal cavity formed by the cannula 1006 and at the same time restricts the maximum possible diameter DM of the marking body 100 in the compressed state or, optionally, the maximum possible diameter DK of a clamp (should the marking body comprise the latter), in order to ensure an ability of the marking body 100 to pass through or move in the cannula 1006 during pre-loading and driving out. An internal diameter DKI of less than 1.1 mm, particularly preferably of 1.0 mm was found to be preferable.

[0124] The external diameter DKA of the cannula 1006 describes the diameter of the external cannula wall. Under the assumption of a constant cannula wall thickness that is as small as possible, the internal diameter DKI of the cannula 1006 simultaneously increases with increasing external diameter DKA, and hence there also is an increase in the maximum possible external diameter of a marking body 100 to be implanted. However, at the same time, an increasing external diameter DKA leads to a greater degree of invasiveness or injury to skin and tissue when carrying out the implantation.

[0125] A sufficiently small external diameter DKA ensures the option of a percutaneous implantation of the marking body 100 without having to resort to a stab incision of the skin at the entry site of the cannula 1006 or anesthetization of the relevant tissue. An external diameter DKA of between 1 mm and 1.5 mm, particularly preferably of 1.2 mm was found to be preferable.

[0126] By means the implantation apparatus, a marking body of the type presented here for percutaneous marking can be implanted into soft tissue, such as breast tissue or axillary lymph nodes following a lymph node biopsy.

[0127] The fields of application include the marking of suspicious tissue, the marking of lesions before or during chemotherapy, and the marking of a biopsy removal site. The location of a removed tumor may likewise be marked for improved orientation within the scope of radiation treatment planning.

[0128] By way of example, within the scope of an intervention, the marking body 100 is used as follows:

[0129] Initially, the marking body is implanted at a desired site by virtue of the distal end 1012 of the cannula 1006 of the implantation apparatus 1004 being pierced up to the desired implantation location in body tissue and a marking body 100 being ejected from the distal end 1012 of the cannula 1006.

[0130] Subsequently, the body tissue can be examined using an imaging ultrasound method for example, an ultrasound recording of the marked tissue being made. This is depicted in FIGS. 14 and 15. The marking body can be recognized in the ultrasound recording on account of a circular artifact 310 or X-shaped artifact 312; see FIGS. 16 and 17.

[0131] In the case of sonography using medical ultrasound (1 MHz to 40 MHz, for example in the B mode [brightness modulation]; the mode in which two-dimensional brightness images are generated), the support structure of the marking body 100 causes incident ultrasound waves in the central longitudinal section of the marking body to strike a structure that is circular in cross section. What is obtained by matching the parameters of web diameter (or width and thickness), web number, web intensity and web material is that only some of the acoustic energy is reflected by the structure and the remaining part of the energy is transmitted, as depicted in exemplary fashion in FIG. 15. As a result, a full circle or a circular arrangement of individual points, depending on resolution and parameter settings of the ultrasound, arises as a representation in the ultrasound image; see FIG. 16. In the case of other structures of this form, the ultrasound energy would be largely reflected at the first surface of the marker and a shadow would arise in the image. A marking body 100 of the type described here can consequently be distinguished from other markers with a similar shape.

[0132] To make ultrasound recordings by means of sonography, use is made of a probe 300 which can transmit ultrasound 302 and can receive reflected ultrasound. By way of example, if the transmitted ultrasound strikes an object with a different acoustic impedance to the surrounding body tissue, the ultrasound is scattered and partly 304 reflected back to the probe 300; see FIG. 15. The wires of a marking body can be ultrasound-reflecting objects. A marking body of the type described here is then represented in ultrasound recordings (sonography recordings) as is indicated in FIG. 14 and as is visible in FIGS. 16 and 17.

[0133] The characteristic circular shape of the image representation of the marking body in the ultrasound image allows the marking body to be automatically recognized and hence detected in an ultrasound recording, for example by means of an appropriately trained convolutional neural network (CNN).

[0134] The marking body 100 can be placed in a soft tissue without air inclusions (e.g., fatty tissue) and can be insonated with ultrasonic waves ranging between 1 MHz and 40 MHz. It then reflects only part of the ultrasonic power at the first side, which faces the ultrasound, and reflects a second part of the ultrasonic power at the second side, which is distant from the ultrasound, as a result of which the marking body has a circular representation in an ultrasound image within the scope of medical ultrasound imaging; see FIGS. 14 and 15.

[0135] Then, the marking body is detectable by means of an automatic or semiautomatic method, preferably by analyzing ultrasound data or by analyzing x-ray recordings or by analyzing MRI data.

[0136] To improve the visibility in the ultrasound image, or for other purposes, the marking body can be provided with a membrane 400. This can be realized in various ways; see FIGS. 19 and 20. By way of example, the marking body 100 can be coated with a membrane 400 from the outside or from the inside; see FIGS. 20b and 20d. The membrane 400 can be produced from silicone or polyurethane or parylene, for example. The membrane serves to fully or partly separate the interior of the marking body from the surroundings. This can improve the recognizability and detectability, or this can create a space which can be filled with other substances or gases (e.g., cytostatic agents, ICG, etc.). As shown in FIG. 19, the membrane may also only be spanned between the relevant wires in individual fields of the lattice-like support structure formed by the wires 108.

LIST OF REFERENCE SIGNS

[0137] 100 Marking body

[0138] 101 Braided wire mesh

[0139] 102, 104 Constricted longitudinal sections

[0140] 103 Webs

[0141] 105 Crossing points

[0142] 106 Central longitudinal section

[0143] 108 Wires

[0144] 110 Crossing points

[0145] 112 Free ends of the wires

[0146] 114, 116 Longitudinal ends of the marking body

[0147] 118 Weld spot

[0148] 120 Weld beads

[0149] 200 Braided wire mesh

[0150] 202 Wire tube

[0151] 208 Separation point

[0152] 212 (Separation) plane

[0153] 214 Crossing point plane

[0154] 216 Twist

[0155] 300 Ultrasound probe

[0156] 302 Transmitted ultrasound

[0157] 304 Reflected ultrasound

[0158] 310, 312 Image representation of a marking body in the ultrasound image

[0159] 400 Membrane

[0160] LM Length of the marking body

[0161] DMA Maximum external diameter of the marking body in the flared state

[0162] DKI Internal cannula diameter

[0163] DKA External cannula diameter

[0164] LKA Cannula length

[0165] 1000 Implantation system

[0166] 1004 Implantation apparatus

[0167] 1005 Clamp

[0168] 1006 Cannula

[0169] 1008 Implantation part

[0170] 1010 Handle

[0171] 1012 Cannula tip

[0172] 1014 Handle housing

[0173] 1016 Sliding element

[0174] 1018 Driving-out element

[0175] 1020 Pre-loaded position

[0176] 1022 Driving-out position

[0177] 1102 Wires

[0178] 1104 Braided wire mesh

[0179] 1106, 1108 Longitudinal ends of the marking body

[0180] 1110 Crossing points

[0181] 1112 Central longitudinal section

[0182] 1118 Free ends

[0183] 1120 Weld beads

[0184] 1122 Sleeve

[0185] 1124 Weld spot

[0186] 1200 Braided wire mesh

[0187] 1202 Wire tube

[0188] 1206 Twist

[0189] 1210 Crossing point planes

[0190] 1212 Separation plane

[0191] 1214 Separation points

[0192] 1300 Circular artifact

[0193] 1302 X-shaped artifact