Method and apparatus for planning an image acquisition in medical imaging

Abstract

Method for planning the recording of an examination area of ​​an examination object (15) in medical imaging, wherein the examination area is larger than a sensitivity area (21) of a medical imaging device (11), wherein a planning phase comprises the following procedural steps: - Definition of the investigation area by a user, - Provision of at least one predefined key performance indicator, - Planning of the recording, wherein the planning includes an automatic division of the investigation area into at least two sub-areas based on at least one predefined parameter, - in an additional planning phase, the user specifies a property of a sub-area, and - allows for the premature termination of the additional planning phase, whereby predefined properties are reset and / or the planning of an automatic structuring of the investigation area into at least two sub-areas based on at least one predefined characteristic and / or another predefined characteristic which contains at least one property that the user specified in the prematurely terminated additional planning phase is carried out again.

Description

[0001] The present invention relates to a method for planning an examination area of ​​a subject in medical imaging, wherein the examination area is larger than the sensitivity range of a medical imaging device. Furthermore, the present invention relates to a medical imaging device, a computer program, and a computer-readable data carrier designed for carrying out the method.

[0002] Medical imaging devices can generate image data of patients or other subjects. For this to work, the area of ​​the patient being examined must be positioned within the sensitivity range of the medical imaging device so that the device can acquire data from the area, process it if necessary, and display it as image data. For example, in whole-body examinations, the area being examined may be larger than the sensitivity range of the medical imaging device. To capture the entire area, it is typically divided into sub-areas that are then scanned individually.

[0003] The spatial connection between two adjacent areas should preferably be seamless in the final images used by a physician for diagnosis or examination planning. However, a detailed representation of sections of the examination area or an adaptation of the cross-section to the object being examined may be desired. This allows, for example, the exclusion of areas irrelevant to a diagnosis and / or a reduction in examination time.

[0004] Overall, when dividing the examination area into sub-areas, a user can make significantly more changes and adjustments to the patient than when acquiring a single, undivided area. Furthermore, visualizing the planning of sub-areas and their composition is complex. Well-trained users can utilize the visualized and readily available information to make patient-specific adjustments, generate high-quality image data, and / or reduce acquisition time. Less experienced users, or those required to acquire an image where individual sub-areas differ only in the area being depicted, may be distracted by the multitude of available adjustment options and visualizations. This can delay the planning process.

[0005] DE 10 2007 009 185 A1 discloses a method for planning an angiographic measurement of a body region in a magnetic resonance imaging (MRI) system, wherein the body region is larger than the maximum field of view of the MRI system. DE 10 2004 026 616 A1 discloses a method for measuring an examination area with a magnetic resonance imaging (MRI) system, wherein the examination area is larger than the maximum recording area of ​​the MRI system.

[0006] The invention is based on the objective of providing a method for planning a section-by-section acquisition of an examination area in medical imaging, which enables a level of detail corresponding to the user's needs. Furthermore, the invention aims to provide a system, a computer program product, and a computer-readable data carrier configured for carrying out the method. This objective is achieved by the features of the independent claims. Further embodiments are described in the dependent claims.

[0007] The inventive method for planning the recording of an examination area of ​​an object under investigation in medical imaging, wherein the examination area is larger than a sensitivity range of a medical imaging device, comprises a planning phase with the following process steps: - Definition of the investigation area by a user, - Provision of at least one predefined key performance indicator, - Planning of the recording, wherein the planning includes an automatic division of the investigation area into at least two sub-areas based on at least one predefined parameter.

[0008] In medical imaging, image data is created that depict the anatomy or internal structure of an object under investigation in the form of cross-sectional images or projections. An object under investigation can be, for example, a patient, a training subject, or a phantom. A medical imaging device is a system designed to perform medical imaging. Examples of medical imaging devices include X-ray and ultrasound machines, as well as computed tomography (CT) and magnetic resonance imaging (MRI) scanners.

[0009] In medical imaging, image data can be generated either of the entire object being examined or of a section, i.e., a partial volume of the object. The volume or area of ​​the object to be depicted is the examination area. This is typically selected individually for each object, depending on the medical question, and can therefore vary in size.

[0010] Every medical imaging device has a predefined sensitivity range, i.e., a measurement volume, within which image data can be generated of the section or part of the object being examined that lies within this measurement volume. The sensitivity range is typically spatially defined in relation to the medical imaging device. Therefore, when examining an object, the area being examined must be positioned within the sensitivity range of the medical imaging device so that the device can generate image data of that area.

[0011] If the size, i.e., the spatial extent of the examination area, exceeds the size of the sensitivity area, a change in the position of the examination area relative to the medical imaging device may be necessary to fully capture the entire examination area. This can be done gradually or continuously, and the specific procedure depends on the imaging modality. For example, while in ultrasound examinations the spatial relationship between the examination area and the sensitivity area can be changed by moving the transducer, in tomography devices, where the patient is positioned on a table or couch, a movement of the table or couch, coordinated with the image acquisition and possibly gradual, may be required.

[0012] If the examination area, which exceeds the sensitivity range of the medical imaging device used, is acquired stepwise, then portions of the examination area are successively brought into the sensitivity range of the medical imaging device. For a complete image of the examination area, it is necessary to divide it into several sections or sub-areas. The final image, which can be displayed to a physician on a monitor, for example, ideally represents the entire examination area in a single image, even if the examination area is larger than the sensitivity range. Consequently, the examination area should exhibit uniform contrast, and the edge or boundary of a sensitivity range should not be discernible.

[0013] The method according to the invention describes the planning phase in which the examination area, which is larger than the sensitivity range of the medical imaging device, is divided. First, an examination area is defined by a user. A user is typically an operator of the medical imaging device. The user preferably selects the area of ​​the object to be visualized for defining the examination area, and can make this selection without knowing the size of the sensitivity range.

[0014] Furthermore, at least one predefined parameter is provided. Planning is carried out using a planning unit. A predefined parameter can be a numerical or non-numerical value that can influence the division of the examination area into sub-areas. An example of a numerical value of a predefined parameter is a maximum duration for acquiring the examination area. Non-numerical values ​​can be relative descriptions of the required image quality at transitions between two sub-areas. The at least one predefined parameter can be fixed before the start of the method according to the invention or specified by the user. The predefined parameter can be provided by typically being stored in and retrieved from the memory of a programmable logic unit (PLC) of the medical imaging device.

[0015] Based on at least one predefined parameter, the planning process includes the automatic division of the examination area into at least two sub-areas. This planning can be performed without any interaction from the user of the medical imaging device, i.e., without requiring any action from the person operating the medical imaging device during the examination of the subject. The examination area is divided into at least two sub-areas, taking into account the predefined parameter or at least one of the predefined parameters. The method according to the invention can also take all predefined parameters into account.

[0016] Based on at least one predefined parameter, at least one further parameter can be determined or derived that is required for the automatic division of the investigation area into sub-areas. For example, if the size of the investigation area and the minimum overlap area are given as predefined parameters, the size of the sub-areas can be determined from this. Based on the size of the sub-areas, the investigation area can then be automatically divided into sub-areas.

[0017] The union of the sub-regions comprises the domain under investigation, where the at least two sub-regions can be disjoint or overlap. Typically, the boundaries of the sub-regions are chosen such that adjacent sub-regions overlap in a way that makes the transition between them in the composite map as smooth as possible. Interpolation or elastic registration can be used in the overlap region to achieve this.

[0018] Once the automatic structuring of the examination area is complete, raw medical data can be acquired from each of the at least two sub-areas. Raw medical data contains all the information about the sub-area or examination area to be visualized that the medical imaging device needs to generate the image data for that sub-area or examination area. The raw medical data is acquired for each sub-area. This typically means that a first sub-area is positioned so that it is completely encompassed or covered by the sensitivity range of the medical imaging device, and then the raw medical data for that first sub-area is acquired.Subsequently, a second sub-area of ​​the examination area is typically brought into the sensitivity range of the medical imaging device, either by repositioning the object being examined or the device itself. Consequently, the raw medical data of this second sub-area can now be acquired. If further sub-areas are present, the procedure is analogous. In contrast to the stepwise acquisition described above, the acquisition of the raw medical data for each sub-area can also be performed continuously. In this case, the individual sub-areas are not placed consecutively within the sensitivity range; instead, the entire examination area is preferably moved relative to the sensitivity range so that each sub-area is completely encompassed by the sensitivity range at least once during the movement of the examination area.

[0019] From the acquired raw medical data of the individual sub-areas, image data can be generated, after any necessary processing, depicting the sub-areas individually. Preferably, after the acquisition of the raw medical data for all sub-areas is complete, image data is generated that depicts the entire examination area. This image data, which can be either two-dimensional or three-dimensional, can be displayed to a user on a display unit, such as a monitor.

[0020] The advantage of the method according to the invention lies in the fact that the planning of the division of a large examination area into sub-areas, while adhering to at least one predefined parameter, is carried out in such a way that the acquisition of corresponding raw medical data can be performed. The user does not need to make any changes or adjustments, as the sub-areas are automatically planned by the planning unit depending on the at least one given parameter. The at least one predefined parameter is therefore crucial for the accuracy and detail of the adaptation of the sub-areas to the examination area and the medical question. The more parameters are predefined, the more precisely the at least two sub-areas can be adapted to the individual examination area and to any additional requirements.Consequently, no special prior knowledge of the user is required regarding the planning of large investigation areas, and a user-independent, standardized quality of the image data can be guaranteed.

[0021] An advantageous embodiment of the method according to the invention provides that the at least one predefined parameter describes a relationship between the area under investigation and the at least two sub-areas.

[0022] A predefined parameter can therefore specify, for example, the number of sub-areas into which the area under investigation should be divided, or a target size for each sub-area when the area under investigation is automatically divided. Alternatively, the predefined parameter can also specify an overlap area between two sub-areas, i.e., a measure of how much spatially adjacent sub-areas overlap, or the width of the boundary area encompassed by both sub-areas. Generally, the predefined parameter can also specify limit values, i.e., minima or maxima, for the examples mentioned.

[0023] It is particularly advantageous if a predefined parameter specifies the spatial size of the sensitivity range as the maximum size of a sub-area. This ensures that the raw medical data for each sub-area can be acquired in a single step when determining the sub-areas of the study area. The spatial size can be defined as a three-dimensional volume; alternatively, the maximum spatial extent along a spatial direction is conceivable.

[0024] If a predefined parameter specifies the minimum overlap area of ​​adjacent sub-areas, it can be ensured that no sharp edge between sub-areas is visible in the final, composite image. Conversely, specifying a fixed or maximum overlap area between sub-areas as a parameter ensures that only a limited portion of raw medical data is acquired twice when capturing two adjacent sub-areas. It is often advantageous to minimize the acquisition of raw medical data, as the amount of raw medical data to be acquired can correlate with the applied energy dose in computed tomography and with the acquisition time in magnetic resonance imaging.

[0025] Furthermore, a variant of the procedure is proposed whereby the at least one predefined parameter is defined by a user in accordance with the object of investigation before the at least one predefined parameter is provided.

[0026] This variant of the procedure therefore stipulates that a user of the medical imaging device—that is, the operator or user of the system who uses or controls it during the examination of the subject—specifies an initial parameter before this parameter is provided and used to plan the imaging procedure. For example, during a whole-body examination of a patient, the user could specify the patient's maximum two-dimensional axial spatial dimensions as the initial parameter. This information can be provided to the planning unit, for example, via an input unit of the medical imaging device.

[0027] The advantage of the embodiment according to the invention lies in the fact that the user can specify at least one parameter that is taken into account when planning the recording. Thus, the properties of the sub-areas can be adapted to the object under investigation. Nevertheless, the user does not have to carry out the planning himself or intervene in the planning process. Consequently, no special prior knowledge of planning large areas of investigation is required of the user.

[0028] A further embodiment of the invention provides that the examination area is presented to the user in the planning phase analogously to a normal examination area that is smaller than the sensitivity range of the medical imaging device, and the user has the option of adjusting the displayed examination area.

[0029] A normal examination area is a portion of the object being examined that can typically be visualized using the medical imaging device employed, without requiring any change to the object's position or the sensitivity range of the medical imaging device. Consequently, the spatial extent of a normal examination area is smaller than, or at most equal to, the spatial extent of the sensitivity range of the medical imaging device in all spatial directions. The sensitivity range can therefore encompass a normal examination area. Depending on the type of medical imaging device, the maximum absolute size of the normal examination area can be determined from this relationship.

[0030] When specifying the examination area, the user can proceed as if selecting a normal examination area. Preferably, the user receives no indication that the selected examination area is larger than the sensitivity range in at least one direction. The examination area can be displayed to the user as if no subdivision into sub-areas is necessary.

[0031] When defining the examination area, in contrast to planning a normal examination area, restrictions or boundary conditions may apply that could potentially offer the user less freedom of choice. It is conceivable that the design of a medical imaging device limits the spatial extent of an examination area in at least one direction, as is the case, for example, with magnetic resonance imaging (MRI) devices for directions perpendicular to the main magnetic field.

[0032] Even after the planning unit has automatically divided the investigation area into at least two sub-areas, the information regarding this division can be omitted for the user. The complexity of the multi-stage process of recording the investigation area through subdivision can thus remain hidden from the user.

[0033] The invention provides that In an additional planning phase, a user specifies a property of a sub-area, especially before the recording of raw medical data of the sub-area takes place, taking the property into account.

[0034] This additional planning phase according to the invention can be carried out following the planning of the study based on at least one predefined parameter. The additional planning phase is optional and can be actively initiated by the user. During the planning of the study, the automatic division of the study area into several sub-areas is performed, taking the predefined parameters into account. Typically, the predefined parameters influence the relationship between the entire study area and the sub-areas and are therefore also used for the division of the study area. Predefined parameters do not usually refer to a single sub-area; that is, they do not specify information or properties for a particular section of the study area, but advantageously define the composition or configuration of the sub-areas.The advantage of planning the recording based on the predefined parameter is that the user does not have to make any adjustments and thus errors can be avoided.

[0035] If a particularly detailed recording or one individually tailored to a patient or the reason for the examination is required, adjustments and / or modifications to the individual sections are typically necessary beyond the described planning of the recording. This can be achieved or enabled according to the inventive variant of the method described here.

[0036] The user can therefore specify a property for a single sub-area, which is then considered or adhered to during the acquisition of the raw medical data for that sub-area. By specifying this property, the user can influence the acquisition of the sub-area in the same way as they can influence the acquisition of an entire examination area that, due to its size, does not need to be subdivided. Accordingly, the available properties depend on the imaging modality and the medical imaging device. Examples of properties that the user can specify include the resolution of the image data for a sub-area, which the user can change (i.e., increase or decrease), or schemes for acquiring raw medical data, as well as breathing commands.Similarly, the user can specify, for example, that a recording of a sub-area is carried out several times, possibly with different properties that the user specifies for the sub-area.

[0037] The method according to the invention is not limited to the user specifying only one property of a sub-area. Rather, the user can specify properties for two or more sub-areas of the investigation area, which are then maintained during the recording process. The properties for different sub-areas can be the same or different.

[0038] Furthermore, it is possible that an additional processing step is required to consider the user-defined property during the acquisition of the raw medical data. When acquiring a sub-area, the property should be considered in addition to the predefined parameters that define the sub-area structure. The specification of a property for an initial sub-area may affect other properties or parameters of that initial sub-area, or even of other, for example, adjacent sub-areas. This relationship is advantageously checked before the acquisition of the first sub-area begins and compared or consolidated with the properties of the other sub-areas.

[0039] Depending on the property specified by the user, information about the object under investigation and the sub-areas defined by the planning is necessary or helpful. This information can be displayed to the user on a monitor, for example. The specified property for a sub-area and any further properties that may result from it, or for other sub-areas, can be visualized for the user, i.e., displayed on the monitor. Specifying a property through visual control is also conceivable. For example, to change the size of a sub-area, not only can a numerical value be specified, but a boundary line can also be moved or shifted by interacting with the monitor. In this way, the user can directly and visually verify the specified property and its influence on other properties.

[0040] The advantage of the additional planning phase lies in the fact that, before recording large areas of investigation, it allows for detailed and individually tailored adjustments or planning specific to the object under investigation. The basic and feasible division of the investigation area into sections, which is carried out during the planning phase, can thus be adapted by the user to the object of investigation in such a way as to achieve requirements such as the most detailed possible representation or the shortest possible examination time. This is particularly recommended for a well-trained user who is proficient in handling a multitude of properties and parameters and who, by specifying properties, does not unintentionally alter the results achieved in the recording process based on predefined parameters.A less well-trained user does not need to initiate the additional planning phase, therefore cannot carry out detailed planning, but can rely on a standardized quality of the image data.

[0041] An advantageous embodiment of the method according to the invention provides that the specified property describes a spatial extent of the sub-area.

[0042] Initially, the spatial extent of all sub-areas is determined by the planning based on at least one predefined parameter. For example, in a whole-body examination, a sub-volume can cover the entire axial cross-section of an object under examination and, in the longitudinal direction, correspond to the maximum extent of the sensitivity range of the medical imaging device in that direction. The method according to the invention allows the user to change the spatial extent in at least one spatial direction, i.e., the size of the sub-volume. Building on the previous example, in a whole-body examination of the blood vessels located in the examination area, i.e., throughout the entire body, a sub-volume can be reduced so that the sub-volume is limited to the area containing blood vessels. In this way, highly curved vessels with as little peripheral anatomy as possible can be imaged.When raw medical data is acquired from a smaller area, this can either result in a reduction in the amount of data or in an improvement in image quality with the same amount of data. Advantages of reduced data volume have been cited, for example, in computed tomography (CT) and magnetic resonance imaging (MRI) scans.

[0043] The advantage of this version of the procedure is that the sub-areas can be individually adapted to the clinical question, thereby achieving improved image quality.

[0044] Furthermore, a variant of the procedure is proposed whereby a first sub-area differs from a neighboring sub-area in the property that was specified by the user for the first sub-area.

[0045] The user can specify a property for a single sub-area, while the specification does not apply to adjacent sub-areas. For example, different spatial dimensions, i.e., sizes, can be specified as properties for different sub-areas. This allows the user to individually adapt the sub-areas to the medical question and the object under investigation.

[0046] In a further embodiment of the invention, a restriction is provided for specifying a property of a sub-area.

[0047] The user can specify at least one property for a sub-area, which is then considered or adhered to when recording that sub-area. Typically, the user can specify such properties to adapt the recordings to the subject of the examination and / or the medical question when dealing with examination areas that do not require subdivision. However, the scope of these properties may be limited, for example, by restricting the value range of a numerical property or by not allowing a property to be specified for a sub-area. Alternatively, boundary conditions may apply to the properties, which must be met or fulfilled when specifying the properties.

[0048] In two-dimensional magnetic resonance imaging (MRI), an example of a limitation is the orientation of the slices to be displayed within a sub-area. For instance, if a whole-body coronal view of a patient is required, the examination area typically needs to be divided into sub-areas. To ensure continuity and uniformity of the coronal view across the entire examination area, all sub-areas should be acquired in the same orientation. Only then can adjacent sub-areas be aligned in a way that allows for a meaningful medical diagnosis. It is therefore advantageous that boundary conditions for imaging properties do not apply equally to all images, but rather depend on them.For example, in angiography, a spatially continuous representation of vessels across different sub-areas may require a variable sagittal orientation for different sub-areas.

[0049] The advantage of restricting a property is therefore that the impact of specifying a property for one sub-area on other sub-areas is taken into account and limited, thus ensuring a quality of medical image data that enables medical evaluation.

[0050] An advantageous embodiment of the method according to the invention provides that spatially representable information relating to the sub-areas is visualized for the user on a display unit of the medical imaging device. For example, the boundaries of sub-areas resulting from the planning of the image acquisition constitute spatially representable information relating to these sub-areas. These boundaries can be displayed to a user on a monitor. Preferably, such a representation of the boundaries is overlaid with an image that shows the outline of the object under examination and, optionally, also depicts the anatomy or internal structure of the object under examination. The level of detail of the overlaid image is typically significantly lower than in the image data whose acquisition is planned using the overlaid image. The boundaries of the sub-areas can be displayed superimposed on the overlaid image.

[0051] The easiest way to understand the spatial information regarding the sub-areas is to mark the boundaries of the sub-areas, separating adjacent sub-areas only by a line. This allows the user to clearly see the division of the entire examination area into sub-areas on the monitor.

[0052] The described visualization is sufficient, but optional, if the additional planning phase, in which the user can specify at least one further property, is not executed. The described representation of the sub-area boundaries is clear and requires no special user training. A representation of the sub-areas can also be omitted for this user, so that they do not need to be aware of the automatic sub-area division.

[0053] More extensive spatially represented information relating to the sub-areas can also be displayed. This is particularly useful during the additional planning phase, where the user specifies at least one further property that is taken into account when acquiring the raw medical data. In a simple embodiment, the overlap between two adjacent sub-areas can be displayed, which the user can modify during the additional planning phase. Similarly, during the additional planning phase, the user can specify navigators for individual spatial points in one or more sub-areas, or saturation zones within one or more sub-areas. These individual spatial points or saturation zones can be displayed to the user. Preferably, the information is displayed with the corresponding background image.The boundaries of the sub-areas can also be visualized. Likewise, adjacent sub-areas can be graphically linked, so that the specification of a property can extend to multiple sub-areas, and not just one sub-area, but all graphically linked sub-areas are included taking this property into account.

[0054] The visualization of such information is not tied to the additional planning phase; it can also be displayed without the user initiating this phase. However, this requires the availability of information suitable for visualization. If no saturator or navigator is used during data acquisition, it cannot be displayed. The amount and selection of information to be visualized can preferably be configured in advance. This configuration should ideally be tailored to the specific needs of the user, defining the information to be visualized based on the process step.

[0055] The advantage of this embodiment lies in the fact that helpful spatial information can be visualized for the user. The level of detail of the information can be tailored to the user or depends on the properties specified in an additional planning phase. The method according to the invention enables application- and user-specific visualization, thus avoiding errors in the planning of a recording.

[0056] In a further embodiment of the invention, the user specifies a first and a second property for at least one sub-area in the additional planning phase.

[0057] Based on the structured sub-areas and at least one predefined parameter, the user can assign not only a first property but also a second property to a sub-area, which are considered or adhered to when the sub-area is included. In particular, before including all sub-areas, the user can assign properties to individual sub-areas or to multiple sub-areas at once, which are then considered when the respective sub-areas are included. Consequently, the second property can relate to a different sub-area than the first property.

[0058] The advantage of this procedure is that a user, especially a trained user, can tailor numerous individual adjustments of the sub-areas and examination methods to the object of examination and to the individual medical question.

[0059] According to the invention, premature termination of the additional planning phase is enabled, whereby predefined properties are reset and / or the planning of an automatic subdivision of the investigation area into at least two sub-areas is restarted based on the at least one predefined parameter and / or a further predefined parameter which contains at least one property that the user specified in the prematurely terminated additional planning phase. The user can therefore prematurely terminate or abort the inventive method for planning the acquisition of a large investigation area after specifying at least one property of a sub-area. This means that the acquisition of the investigation area is not carried out and all predefined properties for at least one sub-area are no longer available.The predefined properties cannot be visualized or used for data collection after premature termination. Furthermore, the planning process, which automatically divided the study area into sub-areas, can also be reversed. Consequently, no sub-areas exist anymore, and their corresponding boundaries can no longer be displayed.

[0060] The advantage of this method lies in the fact that, when planning a complex or detailed image capture that requires specifying multiple properties, the user can undo the specified properties or completely suspend the planning and start anew. This is particularly advantageous when the boundary conditions or limitations for other properties were not considered when specifying properties, and the desired properties can no longer be adapted for a capture, or only with considerable effort. This allows the user to replan, possibly based on the existing sub-areas. This can save time in the overall planning process.

[0061] According to an alternative version of the invention, after the premature termination of the additional planning phase, the planning of an automatic division of the investigation area into at least two sub-areas based on the at least one predefined parameter is carried out again.

[0062] Alternatively, if the additional planning phase is terminated prematurely, all predefined properties are reset or, in particular, no longer visualized, even if they relate to the division of the investigation area into sub-areas. The sub-area structure is dissolved, so that after the premature termination of the additional planning phase, the investigation area exists and / or is displayed as a single unit. At least one predefined parameter is given. This predefined parameter can correspond to the predefined parameter that existed before the execution of the additional planning phase. Alternatively, and possibly in addition to this predefined parameter, another predefined parameter can contain or reflect at least one property that the user specified in the prematurely terminated additional planning phase.Based on at least one predefined parameter, the planning—that is, the automatic division of the investigation area into sub-areas—can be carried out in such a way that the subsequent survey takes into account a property specified in the prematurely terminated additional planning phase, without requiring a further additional planning phase. The feasibility of this approach may depend on the specified property and any associated boundary conditions. For example, it is conceivable that the property describing the spatial extent of the sub-area is incorporated into the planning as a predefined parameter, whereas a saturation range specified in the prematurely terminated additional planning phase is not used as a predefined parameter for the planning.

[0063] The advantage of this embodiment of the invention lies in the fact that the planning of the automatic structuring of the investigation area restarts after the premature termination of the additional planning phase, and the user does not have to perform any further planning steps. The resulting sub-areas are not yet influenced by the specified properties, and the user can specify properties again if necessary. This is particularly advantageous if a user is overwhelmed by the specification of complex properties. Furthermore, the sub-areas displayed in the initial state can reflect the specified properties of the prematurely terminated additional planning phase.

[0064] Furthermore, the invention relates to a medical imaging device comprising a computing unit which includes a planning unit, wherein the planning unit is designed for planning an image of an examination area of ​​an object under investigation.

[0065] The invention enables the planning of an examination area of ​​a medical imaging object, where the examination area is larger than the sensitivity range of a medical imaging device. The acquisition of the raw medical data for the sub-areas can then be performed. The user does not need to make any changes or adjustments, as the sub-areas are planned by the planning unit based on at least one predefined parameter. If a predefined parameter specifies the minimum overlap area of ​​adjacent sub-areas, it can be ensured that no sharp edge between sub-areas is visible in the final, composite image. Consequently, no special prior knowledge of planning large examination areas is required of the user.An additional planning phase can be carried out, so that before recording large areas of investigation, there is the possibility of making detailed adjustments or plans tailored to the specific object of investigation.

[0066] The advantages of the medical imaging device according to the invention essentially correspond to the advantages of the inventive method for planning an image of an examination area of ​​an object under investigation, which are described in detail beforehand. Features, advantages, or alternative embodiments mentioned here can also be transferred to the other claimed items and vice versa.

[0067] Furthermore, the invention relates to a computer program product comprising a program that can be directly loaded into the memory of a programmable processing unit of a medical imaging device. The program provides means for executing a method for planning the acquisition of an examination area of ​​a subject in medical imaging, where the examination area is larger than the sensitivity range of a medical imaging device, when the program is executed in the processing unit of the medical imaging device. The computer program may require additional program resources, such as libraries and auxiliary functions, to implement the corresponding embodiments of the method.The computer program can comprise software with source code that still needs to be compiled and bound or that only needs to be interpreted, or executable software code that only needs to be loaded into a corresponding computing unit and / or control unit for execution.

[0068] Furthermore, the invention relates to a computer-readable data carrier on which a program is stored that is provided for the execution of a method for planning an image of an examination area of ​​an object under investigation in medical imaging, wherein the examination area is larger than a sensitivity range of a medical imaging device.

[0069] Further advantages, features and details of the invention will become apparent from the exemplary embodiments described below and from the drawings. The drawings show: Fig. 1 a medical imaging device according to the invention in a schematic representation, Fig. 2 a flowchart of a first embodiment of a method according to the invention, and Fig. 3 a flowchart of a second embodiment of a method according to the invention.

[0070] Fig. Figure 1 schematically illustrates a magnetic resonance imaging (MRI) device as an example of a medical imaging device 11 according to the invention. The medical imaging device 11 comprises a detector unit formed by a magnetic unit 13, with a main magnet 17 for generating a strong and, in particular, constant main magnetic field 18. Furthermore, the medical imaging device 11 has a cylindrical patient reception area 14 for receiving a specimen 15, wherein the patient reception area 14 is enclosed in a cylindrical shape in a circumferential direction by the magnetic unit 13. The specimen 15 can be moved into the patient reception area 14 by means of a patient positioning device 16 of the medical imaging device 11. For this purpose, the patient positioning device 16 has a table that is movably arranged within the medical imaging device 11.Within the patient acquisition area 14 is the sensitivity area 21 of the medical imaging device 11. Image data can be generated from the section or part of the object of examination 15 located within the sensitivity area 21. In magnetic resonance imaging, the sensitivity area is typically a cuboid or a cylinder parallel to the magnet unit 13. The center of the sensitivity area 21 is typically located at the isocenter of the magnet unit 13, and the spatial extent of the sensitivity area 21 parallel to the main magnetic field 18 is usually about 40 cm. The magnet unit 13 is shielded from the outside by a housing 31 of the magnetic resonance device.

[0071] The magnet unit 13 further comprises a gradient coil unit 19 for generating magnetic field gradients, which are used for spatial encoding during imaging. The gradient coil unit 19 is controlled by a gradient control unit 28. The magnet unit 13 also includes a high-frequency antenna unit 20, which in the illustrated case is configured as a body coil permanently integrated into the medical imaging device 11, and a high-frequency antenna control unit 29 for exciting a polarization that arises in the main magnetic field 18 generated by the main magnet 17. The high-frequency antenna unit 20 is controlled by the high-frequency antenna control unit 29 and transmits high-frequency magnetic resonance (MRI) drive sequences into an examination space, which is essentially formed by the patient acquisition area 14.The high-frequency antenna unit 20 is further designed to receive magnetic resonance signals, in particular from the object under investigation 15.

[0072] The medical imaging device 11 includes a processing unit 24 for controlling the main magnet 17, the gradient control unit 28, and the high-frequency antenna control unit 29. The processing unit 24 centrally controls the medical imaging device 11, for example, by performing a predetermined imaging gradient echo sequence. Control information, such as imaging parameters, as well as reconstructed magnetic resonance image data, can be displayed to a user on a display unit 25, for example, on at least one monitor, of the medical imaging device 11. The medical imaging device 11 also includes an input unit 26, by means of which information and / or parameters can be entered by a user during a measurement procedure. The processing unit 24 can comprise the gradient control unit 28 and / or the high-frequency antenna control unit 29 and / or the display unit 25 and / or the input unit 26.

[0073] The medical imaging device 11 further comprises an image data acquisition unit 32. In this case, the image data acquisition unit 32 is formed by the magnetic unit 13 together with the high-frequency antenna control unit 29 and the gradient control unit 28. The computing unit 24 further comprises a planning unit 33. The medical imaging device 11, together with the input unit 26, the display unit 25, the computing unit 24, and the planning unit 33, is thus designed to carry out a method according to the invention.

[0074] The medical imaging device 11 shown may, of course, include other components that are commonly found in magnetic resonance imaging (MRI) devices. Furthermore, the general operating principle of an MRI device is well known to those skilled in the art, so a detailed description of the other components is omitted.

[0075] There are other medical imaging devices that enable the implementation of the method according to the invention. These also possess the components claimed by the method, which are described in the example of the magnetic resonance imaging device. These other medical imaging devices are known to those skilled in the art, so a detailed description is omitted.

[0076] Fig. Figure 2 shows a flowchart of a first embodiment of a method according to the invention for planning the acquisition of an examination area of ​​a subject 15 in medical imaging. The aim of the method is to generate an image of a subject 15 located in the patient acquisition area 14 of a medical imaging device 11. The specified examination area is larger than the sensitivity range 21 of the medical imaging device 11. Therefore, it is necessary to modify the spatial relationship between the subject 15 and the sensitivity range 21, i.e., with the medical imaging device 11. It must be ensured that the medical imaging device 11, with its image data acquisition unit 32, acquires raw medical data from the entire examination area so that it can be represented as image data.The procedure can be carried out in accordance with the inventive method.

[0077] In a first process step 50, the user specifies the examination area. The examination area can be specified directly by entering numerical values ​​using the input unit 26 of the medical imaging device 11 or by modifying boundary lines displayed on a display unit 25. Alternatively, the user can specify the examination area indirectly, for example, by indicating that a head examination of a patient is to be performed. The processing unit 33 of the medical imaging device 11 can process the specification, determine an examination area, and display it.

[0078] In a second process step 100, at least one predefined parameter is provided. This at least one predefined parameter is typically stored in a memory of the programmable computing unit 24, and the planning unit 33 can preferably access it and execute the provision of the at least one predefined parameter. A predefined parameter may, for example, have been stored by the manufacturer as a fixed value in a memory of the programmable computing unit 24. It is also conceivable that a predefined parameter is defined by a user in accordance with the object under investigation before it is provided. If a predefined parameter is thus required in the further course of the process according to the invention, the planning unit 33 can provide this predefined parameter for the desired use.

[0079] A predefined parameter can influence the subdivision of the examination area by specifying, for example, limit values ​​for the number of subdivisions or the size of the subdivided sections, the sub-areas, which can be placed, for example, within the sensitivity range 21 of the medical imaging device 11. In the following process step 200, the acquisition is planned by dividing the examination area into at least two sub-areas, taking into account at least one predefined parameter. This planning can be carried out by the planning unit 33. Spatially represented information concerning the sub-areas can be visualized for the user on a display unit 25 of the medical imaging device 11.

[0080] If the planning in process step 200 is completed and the user of the medical imaging device does not wish to or cannot make any further adjustments, the raw medical data from each of the at least two sub-areas are acquired in process step 400. For this purpose, the planning unit 33 can transmit or provide the result of the planning to the computing unit 24 of the medical imaging device 11. Based on the results or information, the computing unit 24 of the medical imaging device 11 can begin the acquisition of the raw medical data by the image data acquisition unit 32 of the medical imaging device 11. In process step 400, all data required for the generation and acquisition of the raw medical data, as well as for the production of image data of the examination area, are available.

[0081] Fig. Figure 3 shows a flowchart of a second embodiment of a method according to the invention for planning an image of an examination area. In contrast to the first embodiment, this method allows the user to individually adapt the image to the clinical question and the object being examined. The first embodiment describes a method in which the planning of the image does not require any user interaction, but is carried out by the planning unit 33. In contrast, in the second embodiment, a user of the medical imaging device 11 can make changes to the result specified or suggested by the planning unit 33 for the automatic division of the examination area into sub-areas. The method in the second embodiment begins with the process steps 50, 100, and 200 described in detail in the first embodiment.It is also possible to connect the acquisition of raw medical data from each of the at least two sub-areas, i.e., process step 400, to process step 200, so that the first method according to the invention ends at this point. In this case, the user does not adapt the sub-areas to the object under investigation.

[0082] However, the user has the option, after completing the planning of the automatic division of the examination area into at least two sub-areas (process step 200) and before beginning the acquisition of the raw medical data (process step 400), to specify at least one property for at least one sub-area in an additional planning phase (process step 300). Process step 300 is optional. If a first property is specified for a first sub-area, this first property is also taken into account when acquiring the raw medical data for that first sub-area. After specifying the first property, the user can also specify a second or more properties simultaneously or consecutively, which affect the first sub-area or further sub-areas.The user can specify a property for a first sub-area, whereby the first sub-area differs from a neighboring sub-area in the property specified by the user for the first sub-area.

[0083] A property can describe the spatial extent of the sub-area for which the property is specified. For example, by specifying the property, the user can influence the size or position of the sub-area. It is also conceivable that restrictions apply to the specification of a property. Thus, compared to specifying properties for areas of investigation that are not divided into sub-areas, the user may have less freedom in choosing a property. These restrictions or boundary conditions may arise from the desired uniformity of the entire area of ​​investigation.

[0084] The specification of at least one property is carried out using the input unit 26 of the medical imaging device 11. The changes resulting from the specified properties can be visualized on the display unit 25, for example a monitor.

[0085] If the user has specified all required or desired properties in process step 300 and / or agrees with the visualized properties of the sub-areas, process step 400, i.e., the acquisition of the raw medical data from each of the at least two sub-areas, can proceed. If the user does not agree with the changes to the sub-areas caused by the specified properties and can no longer reverse the changes as desired or specify further properties so that the sub-areas are acquired as intended, the process according to the invention is prematurely terminated in process step 500. Process step 500 does not involve acquiring the raw medical data (process step 400) of the sub-areas in the form specified by process step 300.Alternatively, after premature termination (process step 500), the process can optionally be restarted by providing a predefined parameter (process step 100), based on which the investigation area is divided into at least two sub-areas (process step 200). In this case, the process can be continued according to the description in process step 300 or process step 400.

[0086] In process step 400, the image data acquisition unit 32 can acquire the raw medical data of the individual sub-areas. For this to occur, a magnetic resonance imaging (MRI) acquisition sequence must be executed by the MRI scanner. The MRI acquisition sequence is configured to ensure that the specifications for the sub-areas are adhered to during image data generation. The processing unit 24 is configured to control the MRI acquisition sequence with the specified properties and to control the gradient control unit 28 and / or the high-frequency antenna control unit 29 according to the specifications of the MRI acquisition sequence. During the execution of the MRI acquisition sequence, the raw medical data is acquired by the image data acquisition unit 32.This raw medical data can be acquired separately for each sub-area or continuously for the entire examination area while it is moved relative to the sensitivity area 21. The raw medical data can be processed separately for each sub-area; if necessary, the image data of the sub-areas can be reconstructed and then combined into an image representing the entire examination area. Alternatively, the raw medical data of the individual sub-areas can be processed as a single dataset, allowing the image data of the entire examination area to be reconstructed directly. The image data can be displayed to the user on the display unit 25.

[0087] The in Fig. 2 and Fig.The three illustrated process steps of an embodiment of a method according to the invention are executed by the computing unit 24, comprising the planning unit 33, together with the medical imaging device 11. For this purpose, the planning unit 33 includes the necessary software and / or computer programs, which are stored in a memory unit of the planning unit 33. The software and / or computer programs comprise program elements designed to execute the method according to the invention when the computer program and / or the software is executed in the planning unit 33 by means of a processor unit of the medical imaging device 11.

[0088] Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by the person skilled in the art without leaving the scope of protection of the invention.

[0089] In summary, the invention relates to a method and a device for planning the acquisition of an examination area of ​​a subject in medical imaging, wherein the examination area is larger than the sensitivity range of a medical imaging device. A level of detail appropriate to the user's needs is achieved by dividing the examination area into at least two sub-areas based on at least one predefined parameter, and by acquiring raw medical data from each of the at least two sub-areas.

Claims

[1] Method for planning the recording of an examination area of ​​an object (15) in medical imaging, wherein the examination area is larger than a sensitivity area (21) of a medical imaging device (11), wherein a planning phase comprises the following process steps: - Definition of the investigation area by a user, - Provision of at least one predefined key performance indicator, - Planning of the recording, wherein the planning includes an automatic division of the investigation area into at least two sub-areas based on at least one predefined parameter, - in an additional planning phase, the user specifies a property of a sub-area, and - allows for the premature termination of the additional planning phase, whereby predefined properties are reset and / or the planning of an automatic structuring of the investigation area into at least two sub-areas based on at least one predefined characteristic and / or another predefined characteristic which contains at least one property that the user specified in the prematurely terminated additional planning phase. [2] Method according to the preceding claim, wherein the at least one predefined parameter describes a relationship between the area under investigation and the at least two sub-areas. [3] Method according to one of the preceding claims, wherein the at least one predefined parameter is defined by a user in accordance with the object of investigation (15) prior to the provision of the at least one predefined parameter. [4] Method according to one of the preceding claims, wherein the examination area is presented to the user in the planning phase analogous to a normal examination area which is smaller than the sensitivity range of the medical imaging device, and the user has the possibility to adjust the presented examination area. [5] Method according to one of the preceding claims, wherein spatially representable information relating to the sub-areas is visualized for the user on a display unit (25) of the medical imaging device (11). [6] Method according to one of the preceding claims, wherein the specified property describes a spatial extent of the sub-area. [7] Method according to one of the preceding claims, wherein a first sub-area differs from an adjacent sub-area in the property specified by the user for the first sub-area. [8] Method according to one of the preceding claims, wherein a restriction is provided for specifying a property of a sub-area. [9] Method according to one of the preceding claims, wherein the user specifies a first and a second property for at least one sub-area in the additional planning phase. [10] Medical imaging device (11) designed for carrying out a method according to one of the preceding claims for planning a recording of an examination area of ​​an examination object (15). [11] Computer program product comprising a program that can be loaded directly into a memory of a programmable computing unit (24) of a medical imaging device (11), with programming means to execute a method for planning an image of an examination area of ​​an examination object (15) according to any one of claims 1 to 9 when the program is executed in the computing unit (24) of the medical imaging device (11). [12] Computer-readable data carrier on which a program is stored which is intended for the execution of a method for planning a recording of an investigation area of ​​an investigation object (15) according to any one of claims 1 to 9.

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