DE102012200207B3 - Method for determining guide line for biopsy needle for executing stereotactic biopsy acquisition at lesion in breast of patient to remove lesion tissue, involves determining guide line position in coordination system associated to breast - Google Patents

Abstract

The method involves fixingly compressing a breast (10) in a tomosynthesis device (2). A three-dimensional (3D) image, which contains a lesion (14), of the breast is produced by the tomosynthesis device. A 3D-outline, which minimally circumscribes the lesion, is determined based on the 3D-image. A stretch (22), which is limited by the 3D-outline, with a maximum length (S) is determined. A guide line (24) is selected as an extension of the stretch. A position (L) of the guide line is determined in a coordination system (26) associated to the breast.

Description

The invention relates to a method for determining a guide line for a biopsy needle.

In a typically female patient, a suspected diagnosis of the presence of a lesion in her breast may result from medical evaluation. The lesion is diagnosed at a specific location inside the breast. If such a suspicious finding is present, a biopsy procedure is usually arranged or performed on the breast. When taking biopsy a biopsy needle is to be inserted into the breast in such a way that a tissue sample from the correspondingly determined site of the breast at which the lesion is suspected is removed as accurately as possible and completely.

Known is a so-called stereotactic biopsy. First, the breast is compressed in an imaging device and then one or more x-ray image pairs of the breast are taken - together with the lesion. By evaluating the stereo image pairs then the location of the lesion is known, so that the biopsy needle can be performed as accurately as possible to the lesion. Here, the needle is inserted along a guide straight in the chest. The position of the management line is estimated by the doctor by hand or by eye. In other words, the lesion is located and the location for needle delivery is controlled. The well-known stereobiopsia is mainly used in lesions that are manifested by suspicious microcalcifications. The reason for this is that X-ray imaging is the modality with which microcalcifications can best be imaged, that is, seen.

The known biopsy procedure has the disadvantage that often only an insufficient amount of tissue is removed, which is actually associated with the lesion. In many cases, the sample taken also contains tissue that lies outside the lesion.

From the US 2011/0270270 A1 For example, a method for determining a guide line for performing a biopsy procedure on a lesion is known. Here, the shortest possible distance to a lesion is determined with the help of image material. However, this may mean that the tissue associated with the lesion is also mixed with comparatively much healthy tissue during the biopsy.

From the pamphlets US 2010/0316270 A1 . US 2010/0104154 A1 . WO 2011/136925 A1 and WO 2010/096419 A2 Although methods for segmentation of lesions are known, but with which the performance of the biopsy in view of the above-mentioned disadvantage can not be significantly improved.

Object of the present invention is to propose an improved support for a Biopsieahme.

The object is achieved by a method according to claim 1, according to which a guide line for a biopsy needle is determined. The biopsy is then performed after completion of the method of the invention by inserting the biopsy needle along the guide line into the breast to perform a biopsy procedure on the lesion in the breast. The method assumes that there is already a suspicious finding for the breast and the breast is fixed in a biopsy-compatible imaging tomosynthesis device. According to the invention, a lesion-containing, ie imaging 3D image of the breast is produced with the aid of the tomosynthesis apparatus.

On the basis of the 3D image, a 3D outline outline minimally delimiting the lesion is determined. In other words, that 3D contour shape is sought that just completely encloses the lesion and thereby has an at least approximately minimal volume. Thus, the volume of the lesion z. B. touching or else with the interposition of a small distance range, d. H. Enclose edge. In particular, a 3D outline shape is selected which is flat or convex at every point of its surface.

The outline has z. B. the form of a lesion circumscribing ellipsoid. The distance then clearly results as the longest axis of the ellipsoid. The outline shape may also be a (circular) cylinder, a barrel, etc.

Within the 3D contour shape, the distance is then determined which is limited by the 3D contour shape and has a maximum length. In other words, of all the routes which are inscribable in the 3D contour shape, that is limited by this, the one selected which has the largest route length. The distance defines a straight line that penetrates the lesion at maximum length.

The leading straight is then chosen as an extension of the route. The position of the guide line is then determined in a coordinate system assigned to the breast.

Upon completion of the procedure, the biopsy needle may be inserted along the guide line with respect to the breast. From the spatial position of the guide line, the entry point of the biopsy needle into the breast and the angle is determined, below which the biopsy needle for tissue removal to lead is. As a result, the biopsy needle passes through the lesion along the route and thus at maximum length. The method step, with which a distance of maximum length is determined within the 3D contour, ensures that later the guide line passes through the lesion in exactly this direction, so that as long as possible a section of the guide line actually penetrates the lesion. Thus, a maximally long biopsy sample can be completely removed from the lesion. The biopsy, ie a corresponding tissue cylinder, is thus removed in maximum longitudinal extent of the lesion. In contrast, in the known method, it is to be expected on the basis of the 2D information that the lesion is not always penetrated in the direction of its maximum extent, so that only a smaller longitudinal section of the guide straight line actually penetrates the lesion and tissue can be removed there.

The invention is based on the fundamental insight that the known stereoscopic imaging uses only a 2D imaging: Therefore, the lesion is always seen only as a 2D projection of their actual 3D shape. The actual 3D formation of the lesion is therefore not clearly recognizable and can not be used to guide the needle. The invention uses the 3D information obtained by tomosynthesis about the actual spatial shape of the lesion in order to arrive at an optimal needle guide along the guide straight line and thus to penetrate the lesion at maximum length. Thus, according to the invention, a breast biopsy is supported by 3D tomosynthesis imaging.

Thus, a 3D tomosynthesis scan of the fixed and compressed breast is performed, in which a suspicious finding already exists. For this purpose, in particular a compression plate suitable for biopsy is used. The biopsy can therefore be taken with unchanged clamped chest. Thus, the achievable location accuracy of the lesion is used optimally.

According to the invention, the position of the guide straight line is determined in a coordinate system in which the breast is also registered. This is z. B. the coordinate system of Tomosynthesegerätes. The location assignment then takes place via the acquired tomosynthesis image information and the known position of the image coordinate system in the tomosynthesis device. The leading straight can then be found relative to the tomosynthesis device.

The entire procedure is performed on compressed and fixed breasts. This is only solved after completion of the procedure from the Tomosynthesegerät. In particular, the breast is only released after the actual biopsy has been carried out, which, however, no longer counts as part of the method according to the invention.

While the breast is still fixed in the Tomosynthesegerät, may possibly take a control recording, for example, when the biopsy needle along the guide straight line is aligned. The control recording is usually carried out before the actual puncture of the biopsy needle to again check the correct orientation before the puncture. Here is the recording of a stereo image pair or a new Tomosynthesescan possible. A control recording can also take place if the biopsy needle is inserted along the guide line so far that the sample would have to be taken at the lesion. Thus, the actually correct position of the biopsy needle can also be checked during the biopsy procedure.

In a preferred embodiment of the method, a central point of the 3D outline shape is determined and its position in the coordinate system is determined. For example, the center point is a center of gravity or center of the 3D outline shape. The location of the lesion in the coordinate system is thus initially determined. Subsequently, by selecting the orientation and position of the route, only the appropriate direction of penetration for the guide straight line through the lesion has to be determined. Here, it is particularly conceivable to always choose the route so that it passes through the central point, but together with the above condition of a maximum length. Tomosynthesis usually takes place in layers parallel to the detector surface. A spatial coordinate of the central point results here, for example, from the layer numbering of the tomosynthesis data with known distances between the layers.

The central point, for example, by a viewer of Tomosynthesedaten manually or by a computing unit -. B. by image analysis of the 3D image, so the Tomosynthesedaten - automatically determined.

In a further preferred embodiment, such microcalcifications are associated with the lesion in the 3D image. The 3D outline shape is then determined as such a 3D outline shape which minimally delimits all microcalcifications associated with the lesion. In other words, the smallest possible 3D outline shape is chosen, which still preserves all microcalcifications. The microcalcifications associated with a lesion are also referred to as clusters. In other words, a determination of the outline shape is determined by an analysis of the cluster. For example, said analysis may consist of determining the shape of the lesion, the symmetry, and the dimension in three spatial directions.

In an alternative embodiment, in the 3D image, the lesion is segmented as a 3D area by a segmentation method. Corresponding image-based segmentation methods are known in great variety. The 3D contour shape is then determined as a 3D shape minimally bounding outline shape. z. For example, a tumor underlying the lesion is segmented and this circumscribed the 3D outline shape.

With the mentioned variants, therefore, an analysis of the morphology of the lesion takes place. That is, the shape of the tumor underlying the lesion is analyzed, for example, by segmentation in 3D or analysis of the spatial location of a cluster of microcalcifications. In particular, a cluster can be characterized by a circumscribing ellipse whose directions and lengths of the principal axes can then be determined.

A preferred embodiment of the method assumes that in the later execution of the biopsy a biopsy device is used, which is given the guide straight. The device then guides the biopsy needle exactly along the guide line. The biopsy device contains, for example, metallic parts which are potentially radiologically disruptive. The biopsy device according to this embodiment is then brought into an X-ray-covered imaging region of the tomosynthesis apparatus only after an X-ray of the breast which is used to produce the 3D image. The biopsy device is then also registered in the coordinate system in which the position of the guide line is determined. In other words, z. B. a movable biopsy unit used, which from a defined registered position out of the field of view, but can also be retracted into this. When entering the defined end position, the device is then automatically registered again on the coordinate system.

However, in an alternative embodiment, an X-ray transparent biopsy device may also be used. This can then also remain during the X-ray imaging to generate the 3D image in place and so for example permanently registered in the relevant coordinate system.

In a further preferred embodiment of the invention, the tomosynthesis system has a compression plate which compresses the breast and fixes it and which is also suitable for biopsy. An intersection of the guide line with the compression plate is then chosen as the entry point for the biopsy needle; an angle of the guide straight line to the compression plate is selected as the entry angle for the biopsy needle. The Biopsieahme can then be done by the compression plate. The chest is easily accessible when compressed. The placement of the biopsy needle along the guide line is particularly well possible on the compression plate.

For a further description of the invention reference is made to the embodiments of the drawings. Each shows in a schematic schematic diagram:

1 a tomosynthesis device with compressed and fixed breast of a patient,

2 the lesion 1 in detail.

1 shows a tomosynthesis device 2 with one, a detector 4 in the form of an X-ray detector-containing object table 6 and a compression plate 8th , A breast 10 a not shown patient 12 is between object table 6 and compression plate 8th compressed and fixed in place. In the chest 10 there is an already diagnosed lesion 14 , at which with the help of a biopsy needle 16 a biopsy procedure should be performed.

With the help of the Tomosynthesegerätes 2 becomes a 3D image 18 the breast 10 generated. This is done in the form of fluoroscopy as part of a 3D tomosynthesis scan. The 3D image 18 also contains an image of the lesion 14 , Now, a 3D outline shape 20 , in 1 shown dashed, for the image of the lesion 14 determined. This is determined to be the lesion 14 minimally bounded. In other words, the 3D outline shape with the smallest volume is sought, which is the image of the lesion 14 still completely contains. The 3D contour shape is in particular formed as smooth as possible, z. B. by having only flat and convex patches or only certain maximum radii of curvature for all patches are allowed.

Then all possible, in the 3D outline 20 einbringbaren - that is limited by the shell - routes, ie straight line sections examined. From those, the one which has the maximum length is selected. In other words, the straight line direction becomes the largest findable longitudinal extent of the 3D outline shape 20 searched.

In 1 here is the track 22 discovered. Then the leadership straight 24 as an extension of the route 22 certainly. Finally, in one of the chest 10 assigned coordinate system 26 a position L of the management line 24 certainly. The coordinate system 26 Here is first the Tomosynthesegerät 20 assigned. About the registered imaging of the breast 10 in This system is the coordinate system 26 then the breast 10 assigned.

Subsequently, now along the leadership line 24 in the coordinate system 26 be aligned. Now the biopsy needle 16 along, ie in the axial direction of the guide line 24 in the chest 10 introduced and up to the lesion 14 brought there to take the biopsy sample of a sample 28 perform.

The inventive method is at the latest before the insertion of the needle into the patient 12 completed.

2 shows in detail the lesion 14 as well as the found 3D outline shape 20 , In a preferred embodiment of the invention becomes a central point 30 , here the geometric center, the 3D outline shape 20 certainly. Also its position L is in the coordinate system 26 determined. Out of all possible in the outline form 20 inscribable routes are then considered only those that pass through the central point 30 lead and from this the distance 22 selected as such with maximum length s.

2 also shows a variant of the method in which in the 3D image 18 microcalcifications 32 localized to the lesion 14 belong together and form a cluster together. The 3D outline 20 is then chosen so that it encloses the cluster with a small distance or as narrow as possible, ie with a running in its vicinity or even the smallest volume. In an alternative variant, instead of the micro-calcifications 32 the lesion 14 as such by an image-based 3D segmentation method as a 3D area 34 segmented (in 2 shown in phantom). The 3D outline 20 is then chosen to be the 3D area 34 minimally bounded.

The orientation of the biopsy needle 16 at the management line 24 takes place for. B. manually by a physician performing the biopsy. 1 shows in an alternative embodiment, as the biopsy needle 16 in a biopsy device 36 is maintained or guided to this particularly exactly along the guide line 24 to be able to position. This is achieved by a corresponding linear constraint.

In a first embodiment, the biopsy device 36 but not X-ray transparent, that is, they would have an X-ray based Tomosynthesebildgebung in Tomosynthesegerät 2 to disturb. During a fluoroscopy of the breast 10 for generating the 3D image 18 therefore becomes the biopsy device 36 from an imaging area detected by X-rays 38 of the tomosynthesis device 2 removed or stored outside this.

Only after the fluoroscopy is the biopsy device 36 in the in 1 shown position, z. B. procedure on a guide, not shown. Only there does she penetrate the picture area 38 one.

In an alternative embodiment, the biopsy device is 36 X-ray transparent, so that they also during the X-ray imaging in the imaging area 38 can remain.

1 also shows in another optional variant a biopsy suitable compression plate 8th which also from the biopsy needle 16 can be penetrated. Is the position L of the guide line 24 in the coordinate system 26 is known, whose intersection 40 with the compression plate 8th as entry point 42 for the biospienadel 16 in the chest 10 established. A then known angle 44 between the leadership line 24 and the compression plate 8th then becomes an entrance angle 46 for the biopsy needle 16 in the chest 10 selected.

2 shows how after completion of the procedure the biopsy needle 16 along the leadership line 24 in the chest 10 penetrates and so in the example a circular cylindrical sample 28 tissue from the lesion 14 takes (in 2 shown in dashed lines). Because of the identity with the track 22 also the leading straight 24 along a maximum extent of the lesion 14 extends, the entire sample is 28 exclusively from the area of the lesion 14 and not taken from surrounding tissue.

LIST OF REFERENCE NUMBERS

2

Tomosynthesegerät

4

detector

6

stage

8th

compression plate

10

chest

12

patient

14

lesion

16

biopsy needle

18

3D image

20

3D outline form

22

route

24

straight guide

26

coordinate system

28

sample

30

Central point

32

microcalcifications

34

3D Area

36

biopsy device

38

imaging area

40

intersection

42

entry point

44

angle

46

entry angle

L

location

s

maximum length

Claims (6)

Method for determining a management line ( 24 ) for a biopsy needle ( 16 ) for performing a biopsy procedure on a lesion ( 14 ) in a breast ( 10 ), whereby the breast ( 10 ) in a biopsy-capable imaging tomosynthesis apparatus ( 2 ) is compressed by the following steps: - with the help of the tomosynthesis device ( 2 ), the lesion ( 14 ) containing 3D image ( 18 ) of the breast ( 10 ), - based on the 3D image ( 18 ), the lesion ( 14 ) minimally bounded 3D outline ( 20 ), - one through the 3D outline ( 20 ) limited route ( 22 ) with maximum length (s) is determined, - the guide line ( 24 ) is used as an extension of the route ( 22 ), - in one of the breasts ( 10 ) coordinate system ( 26 ) the position (L) of the guiding line ( 24 ) certainly. Method according to Claim 1, in which a central point ( 30 ) of the 3D contour ( 20 ) and its position (L) in the coordinate system ( 26 ) is determined. Method according to Claim 1 or 2, in which - in the 3D image ( 18 ) of the lesion ( 14 ) associated microcalcifications ( 32 ), and - the 3D outline ( 20 ) as one all of the lesion ( 14 ) associated microcalcifications ( 32 ) minimally bounded 3D outline ( 20 ) is determined. Method according to Claim 1 or 2, in which - in the 3D image ( 18 ) the lesion ( 14 ) as 3D area ( 34 ), - the 3D outline ( 20 ) as one the 3D area ( 34 ) minimally bounded 3D outline ( 20 ) is determined. Method according to one of claims 1 to 5, in which a radiologically potentially interfering biopsy device ( 36 ) only after one of the generation of the 3D image ( 18 ) radiography of the breast ( 10 ) into an imaging area ( 38 ) of the Tomosynthesegerätes ( 2 ) is brought. Method according to one of the preceding claims, wherein the tomosynthesis system ( 2 ) one the breast ( 10 ) compressing, biopsy-compatible compression plate ( 8th ), where an intersection point ( 40 ) of the leadership line ( 24 ) with the compression plate ( 8th ) as entry point ( 42 ) and an angle ( 44 ) of the leadership line ( 24 ) to the compression plate ( 8th ) as entrance angle ( 46 ) for the biospienadel ( 16 ) to get voted.

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