DE102014211271A1 - Method and device for calculating a position of a recording system to be set - Google Patents

Abstract

The invention relates to a method and a device for calculating a position of a recording system to be set, which can receive one or more images of an object of interest from one or more projection directions, the images being generated by rotation of the imaging system around the object and / or by displacement of the imaging system taken to / from the object. The method comprises the following steps: a) using at least one first image acquisition (AP; L) of the object of interest (9) from a first projection direction, b) recognizing a target region (W) of the object of interest in the at least one interventional intervention a first image acquisition; c) determining a second projection direction (LP; APP) favorable for the interventional intervention for at least one second image acquisition from the defined target region of the object of interest; d) displaying at least one changeable optical marking (M) in or near the target region on a display device (8) for displaying the first image recording and e) calculating the position to be set of the recording system for recording the at least one second image recording as a function of the coordinates resulting from the marking and the determined second projection direction.

Description

The invention relates to a method and a device for calculating a position of a recording system to be set, which can receive one or more images of an object of interest from one or more projection directions, the images being generated by rotation of the imaging system around the object and / or by displacement of the imaging system taken to / from the object.

Background of the invention

During an intervention, real-time images are obtained by means of fluoroscopic fluoroscopy for the navigation of the instruments, for example in the intervertebral disc space. Compared to three-dimensional (3-D) angio (graphy) images, these fluoroscopic or two-dimensional (2-D) images do not show spatial (3-D) details, but are more readily available and minimize radiation exposure for the patient and physician.

In spine surgery, a projection parallel to the intervertebral disc space of the vertebrae to be operated is necessary. Such a setting facilitates the accurate placement of instruments and implants, such as those shown in Figs. Pedicle screws. A precise adjustment of the projection directions is the basis for an optimal surgical result. This requires knowledge of the projection directions "anterior-posterior" and "lateral" and a corresponding positioning of the tracking system, e.g. on a C-arm of a C-arm X-ray machine.

Finding such a projection is often very time consuming and X-ray intensive.

Mostly measurements in pictures e.g. before and after straightening up the intervertebral disc space is not exactly possible because the images were not taken exactly from the same direction.

So far, this is solved by a trial-error method with many recordings. Suboptimal results often result in the setting of these projections and subsequently also inaccurate placement of implants.

In order to achieve an approximate comparability of images, one tries as exactly as possible, without an aid, to hit the original direction. This procedure is either very time-consuming or requires unnecessarily many test recordings.

Out US 6,195,409 B1 For example, a method for determining the orientation and location of standard tomographic slices for automatic patient scanning is known. In column 7, lines 1 to 4 of this document, it is already pointed out that it is difficult to manually find a scan prescription along the spinal cord, especially when the spine is bent.

 Object of the invention

The object of the invention is to design a method and a device of the type mentioned above in such a way that the abovementioned problem is overcome.

Presentation of the invention

This object is solved by the features of the independent claims. Advantageous developments of the invention are specified in the dependent claims.

• a) Verwendung zumindest einer ersten Bildaufnahme von dem interessierenden Objekt aus einer ersten Projektionsrichtung,
• b) Erkennen eines für einen interventionellen Eingriff definierten Zielbereichs des interessierenden Objektes in der zumindest einen ersten Bildaufnahme,
• c) Ermitteln einer für den interventionellen Eingriff günstigen zweiten Projektionsrichtung für wenigstens eine zweite Bildaufnahme von dem definierten Zielbereich des interessierenden Objekts,
• d) Anzeigen wenigstens einer änderbaren, optischen Markierung im oder nahe des Zielbereichs an einer Anzeigevorrichtung zur Anzeige der ersten Bildaufnahme und
• e) Berechnung der einzustellenden Position des Aufnahmesystems zur Aufnahme der wenigstens einen zweiten Bildaufnahme in Abhängigkeit von den sich aus der Markierung ergebenden Koordinaten und der ermittelten zweiten Projektionsrichtung.

The invention claims a method for calculating a position of a recording system to be set, which can take one or more images of an object of interest from one or more projection directions, wherein the images are rotated by rotating the imaging system around the object and / or by shifting the imaging system to / from Object to be taken away, comprising the following steps:

• a) using at least a first image acquisition of the object of interest from a first projection direction,
• b) detecting a target area of the object of interest defined for interventional intervention in the at least one first image acquisition,
• c) determining a second projection direction favorable for the interventional intervention for at least one second image acquisition of the defined target region of the object of interest,
• d) displaying at least one changeable optical mark in or near the target area on a display device for displaying the first image capture and
• e) calculation of the position to be set of the recording system for recording the at least one second image recording as a function of the coordinates resulting from the marking and the determined second projection direction.

With the invention, implants can be more accurately placed in an intervention, avoiding unnecessary X-rays.

Preferably, the second projection direction is aligned as orthogonal as possible to the first projection direction in order to provide an optimal view for instrument navigation.

To determine the second projection direction in step c) above, at least one second image acquisition of the object of interest from a second projection direction can be used.

• – Erkennen des für den interventionellen Eingriff definierten Zielbereichs des interessierenden Objektes in der wenigstens einen zweiten Bildaufnahme und
• – Anzeigen wenigstens einer änderbaren, optischen Markierung im oder nahe des Zielbereichs an einer Anzeigevorrichtung zur Anzeige der zweiten Bildaufnahme, wobei die sich aus der Markierung ergebenden Koordinaten in die Berechnung der einzustellenden Position des Aufnahmesystems einfließen.

The following additional steps can be performed:

• Detecting the target area of the object of interest for the interventional intervention in the at least one second image acquisition and
• Displaying at least one changeable optical marking in or near the target area on a display device for displaying the second image recording, the coordinates resulting from the marking being used in the calculation of the position of the recording system to be set.

The recording system can thereby automatically in the calculated position to be set, e.g. be guided by a motor and / or robot and / or manually by the user.

One of the two projection directions e.g. the first direction of projection represents an anterior-posterior view and the other of the two directions of projection, e.g. the second direction of projection represents a lateral view or vice versa.

A further aspect of the invention is a device, in particular a medical device, which is designed to carry out the above-mentioned method in terms of hardware and / or firmware and / or software.

This can be used as a medical device e.g. an X-ray (diagnostic) device, computed tomography or a C-arm device with a recording system or as an image system for said devices be formed.

The abovementioned developments of the invention with regard to the method apply correspondingly to the device.

Description of one or more embodiments

Hereinafter, advantageous embodiments of the invention will be described with reference to an embodiment with reference to a drawing.

In the drawing show:

1 an X-ray diagnostic device for carrying out the method according to the invention,

2 an exemplary sequence of the procedure according to the invention.

In 1 is an X-ray diagnostic device, for example a C-arm system 1 showing a rotatable mounted C-arm 2 has at its ends an X-ray source, for example an X-ray source 3 , and an X-ray image detector 4 are attached. The X-ray image detector 4 may be a rectangular or square semiconductor flat detector, preferably made of amorphous silicon. X-ray source and detector form a recording system. In the beam path of the X-ray source 3 there is a patient table 5 for receiving a target area of interest, for example an intervertebral disc space of an object to be examined, here the patient 9 , At the X-ray diagnostic device is an image system 6 connected to the image signals of the X-ray detector 4 receives and processes. The picture system 6 furthermore includes an evaluation calculator 7 and a display device 8th , preferably designed as a dual-monitor system.

The rotatably mounted C-arm is used to create 3-D image data sets 2 with X-ray source 3 and image detector 4 turned. The X-ray source 3 mimics one of a beam focus of the X-ray source 3 outgoing beam 10 pointing to the x-ray image detector 4 meets. The X-ray source 2 and the X-ray image detector 4 each run around the target area of interest such that the X-ray source 2 and the X-ray image detector 4 on opposite sides of the target area of interest.

There are also conceivable so-called Biplan X-ray machine with two C-arms for such use.

2 shows an exemplary flow (workflow) of the procedure according to the invention, for example, in the image system 6 can be implemented.

• 1. Aufnahme wenigstens eines Bildes L, das den Zielbereich z.B. ein Bandscheibenfach ungefähr in der lateralen Ansicht zeigt.
• 2. Aufnahme wenigstens eines Bildes AP, das den Zielbereich ungefähr in der anterior-posterior Ansicht zeigt.
• 3. Automatische Erkennung z.B. mit optischen Markierung bzw. ggf. manuelle optische Markierung zur Definition des Zielbereichs. Im definierten Zielbereich W können ein oder mehrere erkannte Wirbelkörper und/oder Bandscheibenfächer liegen. a. Im Bild AP wird mit einer änderbaren optischen Markierung M im oder nahe des Zielbereichs W die korrekte laterale Projektionsrichtung angegeben. b. Im Bild L wird mit einer änderbaren optischen Markierung M) im oder nahe des Zielbereichs W die korrekte anterior-posterior Projektionsrichtung angegeben. c. C-Bogen Positionierung bzw. Positionierung des Aufnahmesystems anhand einer berechneten Projektionsrichtung aus den Koordinaten der Markierungen und der angegebenen, einzustellenden Projektionsrichtungen LP und APP. d. GGf. Aufnahme zumindest eines zweiten Bildes nach der Positionierung gemäß c.

In order to determine or calculate a suitable direction of projection for a surgical intervention, at least one image is acquired. Preferably, two images from different recording views are recorded or recorded, for which the procedure below is described in more detail. In a preferred embodiment, the two viewing views are orthogonal to each other, for example, anterior-posterior and lateral views.

• 1. Recording at least one image L, which shows the target area, for example, an intervertebral disc space approximately in the lateral view.
• 2. Take at least one image AP showing the target area approximately in the anterior-posterior view.
• 3. Automatic recognition, eg with optical marking or, if necessary, manual optical marking for defining the target area. In the defined target area W, one or more detected vertebral bodies and / or intervertebral disc compartments may be located. a. In the image AP, the correct lateral projection direction is indicated with a changeable optical marking M in or near the target area W. b. In the image L, the correct anterior-posterior projection direction is indicated with a changeable optical marking M) in or near the target area W. c. C-arm positioning or positioning of the recording system based on a calculated projection direction from the coordinates of the markers and the specified, to be set projection directions LP and APP. d. Possibly. Recording at least one second image after the positioning according to c.

The C-arm or shooting system positioning can be fully motorized automatically with the help of a motor or a robot and automatically carried out in the desired position. A manual positioning of the C-arm or the recording system by the user is conceivable.

This method can also be used to compare time-varying recordings. Thus, pre- and postoperative images can be directly compared. This allows a software-based automatic evaluation of clinical parameters, e.g. Lordosis / kyphosis angle or disc height achieved after interventional intervention, etc.

With this method, the recording system can be accurately positioned again. Comparative measurements may be used to evaluate clinically relevant parameters, e.g. Height of the intervertebral disc space before and after the placement of an implant to be performed.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

1

C-arm system

2

C-arm

3

X-ray source

4

X-ray image detector

5

Patient table

6

image system

7

evaluation computer

8th

display device

9

patient

10

ray beam

AP

Anterior-posterior imaging

L

Lateral imaging

W

recognized or defined target area

M

optical marking (s)

LP

Calculated lateral projection direction

APP

 Calculated anterior-posterior projection direction

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

• US 6195409 B1 [0008]

Claims (10)

Method for calculating a position of a recording system to be set, the one or more images (L, AP) of an object of interest ( 9 ) can be received from one or more projection directions, the images being recorded by rotation of the recording system around the object and / or by displacement of the recording system towards the object and / or from the object, comprising the following steps: a) using at least one first image recording ( AP; L) of the object of interest ( 9 ) from a first projection direction, b) recognition of a target area (W) of the object of interest in the at least one first image acquisition, c) determination of a second projection direction (LP, APP) favorable for the interventional procedure for at least one second image acquisition from the defined target area of the object of interest, d) displaying at least one changeable optical mark (M) in or near the target area on a display device ( 8th ) for displaying the first image recording and e) calculating the position to be set of the recording system for recording the at least one second image recording as a function of the coordinates resulting from the marking and the determined second projection direction. A method according to claim 1, characterized in that the second projection direction is aligned as orthogonal to the first projection direction. Method according to claim 1 or 2, characterized in that for determining the second projection direction in step c) at least one second image acquisition (AP; L) of the object of interest from a second projection direction is used. Method according to the preceding claim, characterized in that further steps are carried out: detecting the target area (W) of the object of interest (P) defined in the interventional intervention in the at least one second image acquisition and displaying at least one changeable optical marking (M ) in or near the target area on a display device ( 8th ) for displaying the second image recording, the coordinates resulting from the marking being included in the calculation of the position of the recording system to be set. Method according to one of the preceding claims, characterized in that the recording system is automatically guided in the calculated position to be set. Method according to one of the preceding claims, characterized in that the one of the two projection directions represents an anterior-posterior view and the other of the two projection directions represents a lateral view. Medical device having a receiving system, configured to carry out the method according to one of the preceding claims, comprising: a) means for using at least one first image acquisition (AP; L) of the object of interest ( 9 ) from a first projection direction, b) means for detecting a target area (w) of the object of interest in the at least one first image acquisition, c) means for determining a second projection direction (LP, APP) favorable for the interventional procedure at least a second image capture from the defined target area of the object of interest, d) means for displaying at least one changeable optical mark (M) in or near the target area on a display device for displaying the first image capture, and e) means for calculating the position to be set of the capture system for recording the at least one second image recording as a function of the coordinates resulting from the marking and the determined second projection direction. Apparatus according to claim 7, characterized in that for determining the second projection direction at least a second image recording of the object of interest from a second projection direction is used. Device according to one of the preceding claims, characterized in that the one of the two projection directions represents an anterior-posterior view and the other of the two directions of projection represents a lateral view. A device according to any one of the preceding apparatus claims 8 or 9, comprising: means for detecting the interventional intervention target area (W) of the object of interest in the at least one second image acquisition means and means for displaying at least one changeable optical marker (M) in the or near the target area on a display device for displaying the second image recording, wherein the coordinates resulting from the marking are included in the calculation of the position to be set of the recording system.

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