DE102007044549A1 - Test object i.e. patient, X-ray image recording method for electrophysiological ablation of patient, involves recording interested region and limiting region of object with x-ray dosages, respectively, and forming X-ray image from regions - Google Patents

Abstract

The method involves recording an interested region (3') of a test object with an X-ray dosage, and recording a limiting region (2') limited to the interested region, with another X-ray dosage, where the former dosage is larger than the latter X-ray dosage. An X-ray image (1) is formed from the interested region and the limiting region, and two image segments are separately recorded and combined together in such a manner that the interested region is irradiated with the former X-ray dosage, and the limiting region is irradiated with the latter X-ray dosage. An independent claim is also included for an X-ray system for performing a method for recording X-ray image of a test object comprising an X-ray source.

Description

The The invention relates to a method for recording an X-ray image according to the claim 1 and an X-ray system to carry out a Such method according to the claim 11th

at a big one Number of medical interventions, such as in the case of Use of catheters in the body For a patient, it is necessary to monitor for permanent X-rays to directly observe and control the procedure to be able to. Some of these medical interventions such as the Electrophysiological ablation extends over several hours. In such make is the radiation exposure that is due to the patient and the medical staff is an important problem.

It It is an object of the present invention to provide a method for receiving an x-ray picture to create the radiation exposure of a patient or of medical personnel, especially in interventional procedures at least partially reduced without limiting the monitorability. Besides that is It is an object of the invention, an X-ray system to carry out to provide such a method.

The The object is achieved by a method for receiving an X-ray image according to the claim 1 and through an x-ray system according to the claim 11; advantageous embodiments of the invention are each the subject the associated Dependent claims.

at the method according to the invention that will affect the patient or medical staff acting x-ray dose at least partially reduced by the area of interest Region of interest (ROI) of a study object at a first, for one good picture quality optimal X-ray dose is recorded while the area adjacent to the region of interest with a second, significantly lower X-ray dose is recorded. In the adjacent area so the X-ray dose reduced to keep the radiation exposure low, at the same time but it is for the doctor possible An overview of a sufficient great Area to keep the area of interest to the interested Monitor area associated with the surrounding anatomy to be able to.

To an embodiment of the invention surrounds the adjacent area the area of interest completely. In this context may be from the attending physician a complete embedding of the person of interest Area overlooked in its surroundings become. According to a further embodiment of the invention, several radiographs taken in sequence. This is especially true for prolonged interventions important.

To A first alternative of the invention will be the one of interest Area and the adjacent area simultaneously recorded by an X-ray penetrating the examination subject in its adjacent one Area radiating part is weakened so that the second, lower x-ray dose through the weakening the first X-ray dose comes about. Here, therefore, the entire, out of the interest Area and the adjacent area existing area of the examination object irradiated together, the part of the X-ray beam, which is the adjacent Area is irradiated, but is, in particular by means of at least one Filters, attenuated, so that a correspondingly reduced X-ray dose results. such Filters can in the form of aperture elements in an aperture device or a Collimator be arranged. This first alternative of the invention can be done very quickly and easily.

To In a second alternative, a first field is separated and a second partial image is taken up and assembled at closing, that in total the region of interest with a first X-ray dose and the adjacent area is irradiated with a second X-ray dose, wherein for receiving the first field of interest and the adjacent area simultaneously with each at most the second X-ray dose be irradiated. If several x-ray images are taken in series, For example, you can use a calibration image as the first partial image for several radiographs be used and corresponding respectively with several second sub-images to one x-ray image be assembled. As a result, in particular the on the adjacent Radiated total dose, ie over many X-ray images added up X-ray dose, be lowered significantly.

The realization of the second alternative can be carried out in two different ways:
First, advantageously, the first partial image is recorded with the second X-ray dose and forms the second partial image exclusively from the region of interest. In particular, the second partial image is recorded in such a way that the X-ray beam in the adjacent region is completely blanked out.

Second, advantageously, the first partial image is recorded with an X-ray dose less than the second X-ray dose and forms the second Partial image of the interest and the adjacent area, wherein the X-ray is attenuated in the adjacent area. As a result, a particular precise composition of the two partial images can be achieved.

The inventive method for taking an X-ray image or a series of x-ray images especially during interventional medical intervention.

The Invention and further advantageous embodiments according to features the subclaims become below with reference to schematically illustrated embodiments explained in the drawing, without that's a limitation the invention to these embodiments he follows; show it:

1 a plan view of an X-ray image created by the method according to the invention;

2 a view of an X-ray system according to the invention for carrying out the method according to the invention;

3 a view of the recording system of the X-ray system according to 2 with a transmitted X-ray beam;

4 a schematic sequence of a method according to the invention in a second alternative.

In the 1 is an x-ray picture 1 shown, which was created by the method according to the invention. The X-ray picture 1 has centrally a mapped area of interest 3 on which of an imaged adjacent area 2 ' is surrounded. The pictured area of interest 3 ' was recorded at a higher X-ray dose than the imaged adjacent region 2 so that the image quality of the displayed area of interest 3 ' is higher than the image quality of the imaged adjacent area 2 ,

In the 2 is an inventive X-ray system 4 shown. The X-ray system 4 has a C-arm 12 with an X-ray source 5 and an X-ray detector 6 as well as a system control 7 and an image system 8th on. On a patient couch 11 is a research object 10 arranged in the form of a patient. Through the X-ray system 4 can X-ray images of the examination subject 10 to be created. The X-ray source 5 sends from a focal point 16 from an x-ray 13 out, which through the collimator 9 or its diaphragm elements 14 ; 15 can be shaped. This is magnified in the 3 shown. There are different aperture elements 14 ; 15 available: radiopaque aperture elements 15 blind the X-ray 13 or part of the X-ray beam 13 complete and semi-transparent panel elements 14 call an attenuation of the X-ray 13 or part of the X-ray beam 13 and thereby reduce its X-ray dose. It can also work in a collimator 9 partially transparent panel elements 14 be provided with different transparency.

The first alternative of the method according to the invention can be achieved, for example, by means of such a collimator 9 will be realized. This is an X-ray image 1 taken, the part of the x-ray beam 13 who is the area of interest 3 of the examination object 10 irradiated, no attenuation is experienced, so that the applied X-ray dose the area of interest 3 with high quality images. In the part of the X-ray 13 that is the adjacent area 2 irradiated, are one or more partially transparent aperture elements 14 introduced into the beam path so that the applied X-ray dose is significantly attenuated. This will make this adjacent area 2 shown with lower quality. The resulting X-ray image 1 is designed as in 1 shown.

The first and second X-ray dose or the weakening are chosen as that one possible low x-ray dose while interacting with the patient and the medical staff the picture quality sufficiently high for the purpose remains. additionally can be the adjacent area with a different window function (window level) and with a larger filter kernel (kernel) are processed to reduce the intensity and noise on the pictured adjacent area to the one of interest on the depicted one Area similar close.

The second alternative of the invention is in the 4 shown. First, in a first step 17 a first field is recorded, then in a second step 18 a second sub-picture is taken and subsequently, in a third step 19 composed the two sub-images. The composing of the partial images can be realized, for example, by using the image system 8th of the X-ray system 4 the picture data of the two partial pictures adds together pixel by pixel.

In a first variant of the second alternative of the invention, the second, lower X-ray dose is used in the recording of the first partial image, with this second X-ray dose of the entire, from the interest and the adjacent area composing area is recorded. Subsequently, the second field is recorded, in which case only the area of interest 3 exposed to X-radiation is, so the adjacent area 2 complete with apertures or filters, for example the radiopaque aperture elements 15 , disappears.

The X-ray dose affecting the area of interest 3 is applied, is chosen in this first variant such that the total X-ray dose, in total during the first field and the second field on the area of interest 3 effects, ensures good image quality. The second lower X-ray dose is chosen so that the radiation exposure for the patient and the medical staff is as low as possible.

If a series of X-ray images is made, the procedure is as follows. First, a sequence of fluoroscopic images is created over a period of time during which a periodic patient movement occurs. Such a patient movement is, for example, a respiratory cycle or a heartbeat cycle. Each of these images from the sequence represents a first partial image for the corresponding time of the periodic patient movement. Subsequently, the X-ray beam 13 so deluded that only the area of interest 3 is irradiated, and there are included for at least one further periodic patient movement second partial images.

each first subpicture will be with one at the appropriate time periodic patient movement recorded second sub-image composed. To ensure, that at the same time of the periodic patient movement associated first and second fields can be composed, known Image registration techniques can be used or it can the help of ECG and respiratory signals are resorted to.

The Sequence of first frames may also be considered a sequence of calibration frames for many Cycles of second fields are used. This becomes the Creation of several X-ray images a first field composed with different second fields. The calibration images can then renewed at regular intervals be non-periodic Patient movements. In this second variant, the X-ray dose, which during the entire engagement, so for a larger sequence of x-rays is radiated to the adjacent area, especially low held when z. B. only the sequence of first fields in relatively large intervals is recreated.

In a second variant of the second alternative of the invention for a X-ray also a first field and a second field are created separately and composed. The first partial image contains both the person of interest as well as the adjacent area and is at a uniform low X-ray dose, which is lower than the second X-ray dose, recorded. For the first Partial image will be both areas with the same X-ray dose irradiated. Subsequently a second partial image is created for which different x-ray doses for the used area of interest and the adjacent area become. Become afterwards the first and the second part of the picture is taken together again an x-ray picture, in which the area of interest in total at a serious X-ray dose and the adjacent area in total at a second X-ray dose was recorded, wherein the first X-ray dose is greater as the second X-ray dose.

Also in this embodiment can Sequences of X-ray images to be created. In this context, the second variant the advantage that the assembly of the two partial images is more precise feasible, because both partial images are over extend both areas, and that non-linear image registration techniques can be used to not or little predictable movements of a patient too compensate. The second partial image can be recorded in this way that the X-ray dose acting on the adjacent area is very low.

The Invention leaves summarize in the following way: To reduce the Radiation exposure of a patient or the medical staff especially in interventional procedures without the monitorability is to be limited a method for recording at least one x-ray image of an examination subject by means of an X-ray system provided, wherein a region of interest of the examination object with a first x-ray dose and an area adjacent to the region of interest a second X-ray dose is recorded, wherein the first X-ray dose is greater as the second X-ray dose, and wherein the X-ray image from the depicted region of interest and the imaged adjacent one Area is formed.

Claims (11)

Method for recording at least one x-ray image ( 1 ) of an examination object ( 10 ) by means of an X-ray system ( 4 ), one area of interest ( 3 ) of the examination object ( 10 ) with a first x-ray dose and an area adjacent to the region of interest ( 2 ) is recorded with a second X-ray dose, wherein the first X-ray dose is greater than the second X-ray dose, and wherein the X-ray image ( 1 ) from the depicted area of interest ( 3 ' ) and the imaged adjacent area ( 2 ' ) is formed. Method according to claim 1, wherein the region of interest ( 3 ) and the adjacent area ( 2 ) can be recorded at the same time by 10 ) radiating X-ray ( 13 ) is attenuated in its portion radiating through the adjacent area in such a way that the second, lower X-ray dose is due to the attenuation of the first X-ray dose. Method according to Claim 1, in which a first partial image and a second partial image are recorded separately and then combined so that, overall, the region of interest ( 3 ) with a first X-ray dose and the adjacent area ( 2 ) are irradiated with a second X-ray dose, wherein for receiving the first field of interest ( 3 ) and the adjacent area ( 2 ) are irradiated simultaneously with at most the second X-ray dose. Method according to one of the preceding claims, wherein the X-ray beam ( 13 ) is attenuated by means of at least one filter. Method according to claim 3, wherein the first partial image is recorded completely with the second X-ray dose and the second partial image is recorded exclusively in the region of interest ( 3 ) maps. Method according to claim 5, wherein the second partial image is recorded in such a way that the x-ray beam ( 13 ) in the adjacent area ( 2 ) is completely hidden. The method according to claim 3, wherein the first partial image is recorded with an X-ray dose less than the second X-ray dose, and the second partial image captures the region of interest. 3 ) and the adjacent area ( 2 ), the X-ray beam ( 13 ) in the adjacent area ( 2 ) is weakened. Method according to one of the preceding claims, wherein a plurality of X-ray images ( 1 ) are recorded in sequence. Method according to one of the preceding claims, wherein the adjacent area ( 2 ) the area of interest ( 3 ) completely surrounds. Method for recording at least one x-ray image while an interventional medical procedure according to one of claims 1 to 9th X-ray system ( 4 ) for carrying out a method according to one of claims 1 to 10, comprising - an X-ray source ( 5 ) for emitting an X-ray beam ( 13 ), - an X-ray detector ( 6 ) for detecting the object to be examined ( 10 ) radiating X-ray ( 13 ), - a collimator ( 9 ) for the partial and / or complete attenuation of the X-ray beam ( 13 ) in subareas, - a system control ( 7 ) and an image system ( 8th ), wherein the X-ray system ( 4 ) is suitable, an X-ray image ( 1 ) of the examination subject ( 10 ), which is an area of interest ( 3 ) and an area adjacent to the region of interest ( 2 ), the region of interest ( 3 ) at a first x-ray dose and the adjacent area ( 2 ) was recorded at a second X-ray dose, wherein the first X-ray dose is greater than the second X-ray dose.