Method for automatically adjusting image acquisition parameters, medical object and medical X-ray system

Abstract

The invention relates to a method for automatically adjusting image acquisition parameters of a medical X-ray system when taking X-ray images of a patient with an object arranged on or in the patient's body, comprising the following steps: a) providing an X-ray image of the object, wherein the object has radiopaque markings on its surface with coded information, in particular material data, relating to the object; b) determining the radiopaque markings of the X-ray image of the object, in particular by means of image recognition; c) evaluating the radiopaque markings with regard to the information contained therein, in particular material data, relating to the object; d) assigning image acquisition parameters to the information, in particular material data; and e) automatically adjusting the assigned image acquisition parameters on the X-ray system.

Description

[0001] The invention relates to a method for automatically adjusting image acquisition parameters when taking X-ray images of a patient with an object arranged on or in the patient's body according to claim 1, a medical object according to claim 10, and a medical X-ray system for carrying out such a method according to claim 11.

[0002] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0003] In well-known minimally invasive, X-ray-guided procedures, guide wires and catheters are inserted into the blood vessels through small incisions in the vascular system (e.g., in the groin). These allow for the delivery of therapies, such as the placement of vascular grafts. C-arm angiography systems, for example, can be used for imaging. Advances in technology, surgical techniques, and instrument development enable increasingly complex procedures. These procedures are also becoming longer, resulting in the application of more radiation. This leads to increased radiation exposure for both patients and staff.

[0004] For example, through the development of specific settings and optimizations of parameters such as filtering, etc., and even the adjustment of X-ray parameters to specific materials to be imaged, X-ray imaging is constantly evolving towards "low-dose" technology, i.e., the lowest possible radiation dose while maintaining the highest possible image quality. However, increasingly complex procedures and (manual) system operation can easily lead to the selection of suboptimal fluoroscopy parameters. It is common practice to select X-ray imaging parameters manually or automatically via a menu in the imaging program, depending on the examination method (e.g., fluoroscopy or 3D imaging).

[0005] It is known to mark instruments or objects to facilitate their identification on X-ray images. State-of-the-art examples include standardized position markers on fenestrated aortic stents. It is also known to implement binary information coding, e.g., of patient data, on implantable medical devices such as stents (see, for example, M. Pfister, “Binary Information Coding on Stents or Devices, e.g., for Aortic Stenting”, 2014, https: / / portal.dnb.de / opac.htm?method=simpleSearch&cqlMode=true&query=idn%3D1064138721).

[0006] The object of the present invention is to provide a method which, during interventional procedures using medical objects inserted into a patient's body, enables the best possible visualization of the object and the lowest possible radiation exposure under X-ray imaging; furthermore, it is an object of the invention to provide a medical system suitable for carrying out the method.

[0007] The problem is solved according to the invention by a method for automatically adjusting image acquisition parameters when taking X-ray images of a patient with an object arranged on or in the patient's body according to claim 1, a medical object according to claim 10, and a medical X-ray system according to claim 11. Advantageous embodiments of the invention are the subject of the respective dependent claims.

[0008] The inventive method for automatically adjusting image acquisition parameters of a medical X-ray system when taking X-ray images of a patient with at least one object arranged on or in the patient's body comprises the following steps: a) providing an X-ray image of the object, wherein the object has radiopaque markings on its surface with coded information, in particular material data, relating to the object; b) determining the radiopaque markings of the X-ray image of the object, in particular by means of image recognition; c) evaluating the radiopaque markings with regard to the information, in particular material data, relating to the object contained therein; d) assigning image acquisition parameters to the information, in particular material data; and e) automatically adjusting the assigned image acquisition parameters on the X-ray system.

[0009] In particular, the coded information contains material data, such as data on the materials and compounds it contains, or their precise composition. It may also contain other intervention-relevant information. For example, it may include information relating to an advantageous image or representation of the implant, such as a particularly favorable angulation or projection direction.

[0010] This allows for simple and quick optimization of image quality and minimization of the radiation dose during X-ray imaging in interventional procedures, without any additional steps for the operator. The system automatically sets the optimal X-ray parameters for the medical object being inserted and its material composition, ensuring optimal localization and visibility of the object in the X-ray image. Time-consuming manual adjustments are unnecessary, and the radiation dose can be kept low, which benefits the health of both the patient and the operator.

[0011] According to one embodiment of the invention, at least one further X-ray image is subsequently acquired using the image acquisition parameters set in this way. This can be achieved, for example, if the method is performed during or at the beginning of a fluoroscopy sequence (i.e., a sequence of 2D fluoroscopy images). However, it is also applicable to 3D X-ray imaging.

[0012] According to a further embodiment of the invention, the information is encoded as a one- or multi-dimensional barcode, binary code, or other machine-readable code. A barcode is an optoelectronically readable code that, in its simplest form, consists, for example, of parallel black lines and spaces of varying widths (one-dimensional). However, these can also be colored, two-dimensional, or have a different pattern. Barcodes are known to be easy to apply optically and also easy and quick to read.

[0013] According to a further embodiment of the invention, the assignment is carried out by comparison with a stored list or with data from a database. Such lists of X-ray parameters optimized for the respective material can be stored locally, i.e., in the memory of the X-ray system, or in an external, even publicly accessible, database. The lists can be created beforehand from empirical values, experience, or simulations, or existing lists can be accessed and optimized. Advantageously, the lists can include further selection parameters, such as the type of X-ray system, the acquisition method (e.g., whether 2D or 3D X-ray imaging is used), or information about the patient (e.g., patient thickness, age, weight, etc.). These can also be automatically updated based on additional information, such as...The data can be stored or obtained via sensors, selected, or a user input can be requested.

[0014] According to a further embodiment of the invention, at least one of the following image acquisition parameters is selected as being adapted to the material of the object: X-ray current, X-ray voltage, X-ray dose, exposure time, filter setting, collimator setting, X-ray pulse length. Several or all of these X-ray parameters can also be used.

[0015] According to a further embodiment of the invention, at least one additional acquired X-ray image is used to repeat steps b to e. This is particularly quick and easy to apply when dealing with a series of fluoroscopy images (fluoroscopy images) to avoid errors during data retrieval and, for example, to always optimize for the correct object to be imaged when multiple objects are present. The process can also be carried out several times in succession in this way. In particular, the process can be repeated iteratively until a termination criterion is reached. Such a termination criterion could, for example, be a user input or the end of a fluoroscopy sequence or the procedure.

[0016] The invention further comprises an object for insertion into a patient's body, comprising at least one radiopaque marking, wherein the marking contains coded information, in particular material data, relating to the object. Such an object can be, for example, a catheter or guidewire, or an implantable object such as a stent or a MitraClip, or a surgical instrument such as an ablation tool. The marking is radiopaque, i.e., it can be detected on an X-ray image, for example, via image recognition or other optical reading methods. It can be, for example, a barcode, 2D matrix barcode, other binary code, or other machine-readable code. The marking can be arranged so that it is visible from all sides or can be arranged multiple times on different sides. The information relates in particular to material data such as the materials, compounds, and exact compositions contained within.It may also contain other intervention-relevant information. For example, it may contain information relating to a favorable image or representation of the implant, such as a particularly advantageous angulation or projection direction.

[0017] The invention further comprises a medical system for carrying out the method using an object described above, comprising an X-ray system for taking X-ray images of the object, a system control for setting X-ray parameters for the X-ray system, an image system with an algorithm for performing image recognition, an evaluation unit for evaluating the radiographically visible markings with regard to information on, in particular, material data of the object, an assignment unit for assigning image acquisition parameters to the material data, and a stored list or data connection to a database with the image acquisition parameters for the X-ray system assigned to the material data.

[0018] The invention and further advantageous embodiments according to the features of the dependent claims are explained in more detail below with reference to schematically illustrated exemplary embodiments in the drawing, without thereby limiting the invention to these exemplary embodiments. The drawing shows: Fig. 1. A view of the steps of the procedure for automatically adjusting image acquisition parameters of a medical X-ray system; Fig. 2 a description of the steps of Fig. 1 in examples; Fig. 3 to Fig. 6 views of objects for insertion into a patient's body with coded markings; and Fig. 7 a view of a medical system for carrying out the method according to the invention.

[0019] In the Fig. Figure 1 shows the steps of the procedure for automatically adjusting image acquisition parameters of a medical X-ray system when taking X-ray images of a patient with an object placed on or inside the patient's body.

[0020] During interventional procedures on a patient, in which a medical object is inserted into or onto the patient's body (e.g., into a vascular system, bone, or tissue), the procedure is often monitored and observed using X-ray imaging, such as fluoroscopy, with an X-ray machine. This method is particularly suitable for such applications because it minimizes the X-ray dose while simultaneously ensuring optimized object visibility and acceptable image quality.

[0021] A prerequisite for this procedure is the application of coded information regarding the object's material composition to the object itself. These coded markings must be radiopaque. One- or two-dimensional barcodes or other binary codes that are easily readable are particularly advantageous. Other machine-readable codes can also be used. These can be easily applied to medical objects, such as guide wires, catheters, vascular prostheses, stents, stent grafts or shunts, mitral clips, heart valves, prostheses, nails, or screws. The application can be carried out at the factory or by the hospital or user to prepare usable medical objects for an X-ray-guided procedure. The coding contains, in particular, information about the materials and compounds from which the object is made and / or their precise composition.The markings can be applied, printed, glued, notched, punched, welded, etc.

[0022] In a first step 10, at least one X-ray image of the object is provided, whereby the object has radiopaque markings on its surface with coded information about the object's material data. The X-ray image can be provided, for example, from a storage device, or it can be acquired and used live by the X-ray machine performing the monitoring. The stored X-ray image may have been acquired and saved previously, for example, as a pre-operative process, by the same X-ray machine or a different X-ray machine. The X-ray image can be a two-dimensional projection X-ray image (e.g., fluoroscopy or radiography) or a 3D volume X-ray image. Examples of X-ray images 15 are in the Fig. Figures 3 to 6 show stents 16 being inserted into a patient's vascular system 19. Fig. 4 and Fig. 6 are each one-dimensional barcodes 17 on the stents 16, in the Fig. In addition, a binary code 18 is arranged in 4, in which Fig. 3 and Fig. Only 18 binary codes are present. The binary codes shown are merely examples. They consist of spheres of two different sizes, one representing a "0" and the other a "1", and are arranged in a circular or spiral pattern. This results in a wave pattern that is visible in a projection from all directions and can be read unambiguously with regard to its sequence.

[0023] In a second step 11, the X-ray image is processed, for example, via an imaging system 22 using software to identify the radiographically visible markings of the object. For this purpose, an image recognition algorithm stored on the imaging system is used. The image processing is performed automatically based on the acquired X-ray image of the object. Additional image processing can also be carried out, such as segmentation of the object.

[0024] In a third step 12, the radiographically visible markings identified in the X-ray image are then evaluated with regard to the material data information they contain about the object. For example, the barcode or binary code is decoded using an evaluation unit 25, and the corresponding material information is identified. The evaluation unit 25 can also use an algorithm for this purpose. An example is shown in the Fig. Figure 2 shows that the barcode 16 indicates that the object consists of 100% nitrinol. Step 11 (the second step) and step 12 (the third step) can also be performed together by an image recognition algorithm. Image recognition algorithms are known for this purpose.

[0025] In a fourth step, optimized image acquisition parameters for the X-ray device performing the monitoring are automatically assigned to the identified material data. This can be done, for example, via a system-internal or external list or internal or external database containing optimized image acquisition parameters for a wide variety of possible material data. The lists or data may have been previously created experimentally or empirically, generated from simulations, or compiled using machine learning. System-internal or publicly accessible data or lists can be used. Fig. Figure 2 shows an excerpt 27 from such a list as an example: the material "Nitrinol" is assigned specific image acquisition parameters. These image acquisition parameters can include, for example, X-ray current, X-ray voltage, X-ray dose, exposure time, filter settings (strength, position, shape of the filters, etc.), collimator settings, and X-ray pulse length.

[0026] The list / database may contain additional selection options, such as the type of imaging (fluoroscopy, radiography, 3D imaging, photon counting, or integrated X-ray detector, etc.) and / or patient characteristics (thickness, weight, etc., e.g., via a patient model). Further information can be used for selection purposes, which may be requested by a user or retrieved from another source (system control, sensor data, etc.). The list / database can be of any complexity or consist of only a few entries.

[0027] Once the assigned image acquisition parameters have been queried, they are automatically set in a fifth step (14). For this purpose, the previously set image acquisition parameters are changed if they do not match. Subsequently, another X-ray image can be acquired with the newly set image acquisition parameters. The image acquisition parameters are optimized for the object being imaged, ensuring that it is optimally depicted in the subsequent X-ray image. This creates a closed control loop.

[0028] An iterative procedure is also conceivable, in which the subsequent X-ray image is analyzed for coded markings of the same or another object, material data is decoded, and X-ray parameters are assigned and adjusted. This can be particularly advantageous if the coded markings on the previous X-ray image are difficult to discern or if multiple objects are present. The procedure can be repeated iteratively until a termination criterion is reached. Such a termination criterion could be, for example, user input or the end of a fluoroscopy sequence or procedure.

[0029] Furthermore, the detectability of the medical object in the initial X-ray image can be compared with that in the subsequent X-ray image (with the assigned X-ray imaging parameters), and then an appropriate measure can be taken (e.g., resetting one or more X-ray imaging parameters).

[0030] The encoding of material data can be "public knowledge", i.e., publicly accessible, or it can be individually accessible only to users of a specific medical X-ray system.

[0031] In the Fig.Figure 7 shows the medical X-ray system 21 for carrying out the procedure. It includes an X-ray device, for example, with a C-arm 20 imaging system with an X-ray detector and an X-ray source for acquiring X-ray images. The X-ray system 21 is controlled by a control unit 23; for example, X-ray imaging parameters are set by the control unit 23. The X-ray system 21 also includes an image processing system 22 for processing X-ray images, in particular with an algorithm / software for image recognition. Additionally, the X-ray system 21 includes an evaluation unit 25 for evaluating the radiographically visible markings with regard to information on the object's material data. The evaluation unit 25 can also be part of the image processing system 22. Here, another algorithm / software may be present, or the image recognition algorithm / software can perform the evaluation simultaneously.Furthermore, the X-ray system has an assignment unit 26 which assigns image acquisition parameters to the material data, which are stored, for example, in a list in a storage unit 24.

[0032] The X-ray system may also include a robotic navigation system for navigating medical objects through a patient's body in connection with an interventional procedure.

[0033] The invention can be summarized as follows: To optimize X-ray dose and image quality, a method for automatically adjusting image acquisition parameters of a medical X-ray system when taking X-ray images of a patient with an object arranged on or in the patient's body is provided, comprising the following steps: a) Providing an X-ray image of the object, wherein the object has radiolucent markings on its surface with coded information, in particular material data, relating to the object; b) Using image recognition to detect the radiolucent markings of the image of the object; c) Evaluating the radiolucent markings with regard to the information, in particular material data, relating to the object contained therein; d) Assigning image acquisition parameters to the information, in particular material data.and e) Automatic adjustment of the assigned image acquisition parameters on the X-ray system. The procedure automates the selection of material-dependent fluoroscopy parameters and guarantees optimization for the medical object actually visible in the X-ray image. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] M. Pfister, “Binary information coding on stents or devices, e.g. for aortic stenting”, 2014, https: / / portal.dnb.de / opac.htm?method=simpleSearch&cqlMode=true&query=idn%3D1064138721

[0005]

Claims

[1] Method for automatically adjusting image recording parameters of a medical X-ray system (21) when recording X-ray images (15) of a patient with at least one object (16) arranged on or in the body of the patient, comprising the following steps: a) providing an X-ray image (15) of the object (16), wherein the object (16) has X-ray-visible markings (17; 18) on its surface with coded information, in particular material data, about the object (16), b) determining the X-ray visible markings (17; 18) of the X-ray image (15) of the object (16), in particular by means of image recognition, c) evaluating the X-ray visible markings (17; 18) with regard to the information contained therein, in particular material data, relating to the object (16), d) Assignment of image acquisition parameters to the information, in particular material data, and e) Automatic setting of the associated image acquisition parameters on the X-ray system (21). [2] Method according to claim 1, wherein at least one further X-ray image is subsequently recorded with the image recording parameters thus set. [3] Method according to one of the preceding claims, wherein the information is encoded as a one-dimensional or multi-dimensional barcode, binary code or other machine-readable code. [4] Method according to one of the preceding claims, wherein the assignment is carried out based on a comparison with a stored list or data from a database. [5] Method according to one of the preceding claims, wherein the image acquisition parameters include at least one of the following: X-ray current, X-ray voltage, X-ray dose, acquisition time, filter setting, collimator setting, X-ray pulse length. [6] Method according to one of the preceding claims, wherein patient information is additionally taken into account when setting the associated image acquisition parameters. [7] Method according to claim 2, wherein the at least one further acquired X-ray image is used for a repetition of steps b to e. [8] Method according to claim 7, wherein the method is repeated iteratively until a termination criterion is reached. [9] Method according to one of the preceding claims, wherein an adaptation to a type of recording is additionally taken into account when setting the associated image recording parameters. [10] Object (16) for insertion into the body of a patient, comprising at least one X-ray visible marking (17; 18), wherein the marking comprises coded information, in particular material data, relating to the object (16). [11] Medical X-ray system (21) for carrying out a method according to one of claims 1 to 9 using an object (16) according to claim 10, comprising • an X-ray device for taking X-ray images (15) of the object (16), • a system control (23) for setting X-ray parameters for the X-ray device, • an image system (22) with an algorithm for performing image recognition, • an evaluation unit (25) for evaluating the X-ray visible markings with regard to the information, in particular material data, about the object (16), • an allocation unit (26) for allocating image recording parameters to the information, in particular material data, and • a storage unit with a stored list or a data connection to a database, comprising the information, in particular material data, associated image recording parameters for the X-ray device.

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