Detection of off-label use of magnetic resonance imaging coils

Abstract

Disclosed herein is a medical system comprising: a memory storing machine executable instructions; a computing system, wherein execution of the machine executable instructions causes the computing system to perform a misalignment check comprising: receiving pose identification system data, wherein the pose identification system data comprises a set of subject coordinates and a set of coil coordinates described using a current coordinate system, wherein the set of subject coordinates describes anatomical features of a subject, wherein the set of coil coordinates describes coil positions of magnetic resonance imaging coils, wherein coil data associated with the magnetic resonance imaging coils comprises a predefined range of coil positioning coordinates with reference to the anatomical features; determining an allowed range of coil coordinates by mapping the predefined range of coil positioning coordinates to the current coordinate system using the set of subject coordinates and the anatomical features; and providing a warning signal in the event of a misalignment between the set of coil coordinates and the allowed range of coil coordinates.

Description

Technical Field

[0001] This invention relates to medical magnetic resonance imaging, and more specifically to the detection of the position of a magnetic resonance imaging coil relative to the body of the object being imaged. Background Technology

[0002] Magnetic resonance imaging (MRI) systems utilize dedicated radio frequency (RF) receiving (Rx) coils and transmit / receive (Tx / Rx) coils, which are typically optimized for different anatomical structures and clinical needs. Specific RF coils can be designed and labeled for a particular set of intended applications and anatomical structures (e.g., knee, heart, abdomen, etc.). The MRI control system can automatically identify the connected RF coils, retrieve the prescribed requirements for their intended use, report these requirements on the user interface (UI), and include them in the applicable instruction manual.

[0003] Medical MRI systems may also be equipped with a pose recognition system or subsystem for determining the pose of the object to be imaged using RF coils. The pose recognition system may include a camera mounted in the examination area and an image processing unit adapted to detect the pose of the object in the camera's output image. Methods for pose detection include template-based recognition and trained machine learning models (e.g., trained neural networks).

[0004] U.S. Patent Application US2014 / 0055127 A1 discloses a method and apparatus for identifying the position of a local coil of a magnetic resonance imaging (MRI) scanner relative to a patient's bed position. The apparatus includes at least one readout unit configured to determine the position of at least one tag at the local coil relative to the at least one readout unit. The apparatus also includes a position determination device configured to determine the position of the patient's bed relative to the MRI scanner. The position determination device is configured to determine the position of the local coil relative to the patient's bed based on the determined position of the at least one tag and the determined position of the patient's bed. Summary of the Invention

[0005] The present invention provides medical systems, methods, and computer programs in the independent claims. Embodiments are given in the dependent claims.

[0006] Modern medical MRI systems can identify RF coils connected to the system used to acquire magnetic resonance images (MR images) of a subject. However, an MRI system may not be able to detect body parts of a subject placed within a connected coil. It is possible to use RF coils that are not labeled (i.e., for imaging body parts not included in the specified or certified requirements of the coil). This can adversely affect image quality and / or subject safety.

[0007] To determine whether an RF coil is placed at a designated anatomical region of an object, embodiments of the present invention can operate in an environment including a medical MRI system and a posture recognition system. The posture recognition system can provide posture recognition system data describing the object's posture and the position of the RF coil of the MRI system. The posture recognition system may include one or more image sensors or cameras. Preferably, the sensing unit of the posture recognition system is capable of resolving human anatomy in three dimensions. This can be achieved through various methods, such as stereo camera or multi-camera imaging, triangulation techniques, structured light 3D scanning, time-of-flight imaging, interferometry, and / or coded aperture image acquisition. In contrast to magnetic resonance imaging data (MR image data or MRI data) generated using the MRI coils described herein, data generated by any one or more image sensors of the posture recognition system will be referred to as camera image data.

[0008] The pose recognition system may also include hardware and / or software adapted to perform image analysis tasks that allow the identification of human poses in camera image data. Such equipment may include one or more graphics processors, CPUs, memory, and suitable analysis engines that may be implemented in hardware, software, or both (e.g., but not limited to classifiers (e.g., trained machine learning models (e.g., multilayer perceptron feedforward neural networks)), unsupervised learning methods (e.g., self-organizing maps), or fuzzy C-means and K-means clustering algorithms); image segmentation methods (e.g., fuzzy subset data fusion using deblurring or contour-based shape descriptors with projected histograms, background subtraction, least squares estimation, Kalman filtering, star skeleton extraction, etc.)).

[0009] Therefore, a computer (e.g., a computing system or a separate dedicated computing system) can be used to implement the pose recognition system, the computer being equipped with an interface for receiving camera image data from a suitable (preferably 3D) image sensor or camera. In the example, the pose recognition system utilizes a camera to acquire camera image data of both the object and the RF coil, and processes the camera image data to determine a set of object coordinates describing the object's pose and a set of coil coordinates describing the position of the RF coil in the image.

[0010] A set of coil data can also be obtained from the environment. This coil data can be assigned to a specific RF coil currently connected to the MRI system. The coil data can define a range of coil positioning coordinates within a standard coordinate system that describes the relationship between the coil coordinates and predefined anatomical features of the theoretical model object. Predetermined anatomical features can be identified using the anatomical features of the object recognized by a pose recognition system. In the example, the pose recognition system data includes the type and location of certain joints of the object.

[0011] Identifying anatomical features in both the object's current coordinate system and the model object's standard coordinate system allows embodiments of the invention to map the standard coordinate system to the current coordinate system. In this way, a mismatch check can be performed, i.e., determining whether the observed position of the connected RF coil matches its corresponding coil positioning coordinates.

[0012] In one aspect, the present invention provides a medical system comprising:

[0013] Memory, which stores machine-executable instructions;

[0014] A computing system, wherein execution of machine-executable instructions causes the computing system to perform a mismatch check, including:

[0015] Receive attitude recognition system data, wherein the attitude recognition system data includes a set of object coordinates and a set of coil coordinates described using the current coordinate system, wherein the set of object coordinates describes the anatomical features of the object, wherein the set of coil coordinates describes the coil position of the magnetic resonance imaging coil, wherein the coil data is associated with the magnetic resonance imaging coil, and the coil data includes a predefined range of coil positioning coordinates with reference to the anatomical features;

[0016] The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and

[0017] A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

[0018] The memory may include built-in components of the computing system, system-readable exchangeable media, and / or in-circuit memory accessible by the computing system via a communication network. The computing system may include a processor and other computing hardware specified herein. The computing system may include a control unit, which may be part of or communicatively coupled to the control unit, the control unit being adapted to control a magnetic resonance imaging coil (MRI coil) and any other components of the MRI system. The computing system may include one or more computer systems, each including an independent processor, and, where applicable, each computer system being communicatively coupled to other computer systems within the computing system. This may include distributed computing approaches, such as computing networks, processor grids, and / or cloud computing resources.

[0019] In this example, the software performing the mismatch check (the implementation software) can operate independently of the software controlling and preparing the imaging process (the MRI control software). In other examples, the mismatch check can be integrated into the MRI control software; or it can be added to the MRI control software as an extension, plugin, etc.; or it can be embedded into the MRI control software through software updates, upgrades, patches, etc.

[0020] Not as a limitation, pose recognition system data can be obtained from camera image data recorded using one or more cameras, where using multiple cameras can have the advantage of allowing 3D pose recognition. However, single-camera technology (3D camera) that provides 3D camera image data can also be used. Determining pose recognition system data based on 3D camera image data can have the advantage of allowing the determination of one or more 3D points in the set of object coordinates and the set of coil coordinates with improved accuracy.

[0021] For example, known methods for pose recognition from images can be used to obtain the set of object coordinates. Determining the object's pose by estimating the coordinates of its joints can be advantageous. In this case, anatomical features may include joints. However, any other choice of anatomical features may also facilitate pose recognition. The set of object coordinates can be obtained using appropriate techniques (e.g., pattern matching or running a trained machine learning model).

[0022] One way to implement a pose recognition system is to have a trained neural network that labels the positions of the joints of an object in camera image data. For example, the neural network can be trained using labeled training images, which are labeled with the positions of a selected set of object joints. When camera image data is input into the trained neural network, the network can label the positions of the selected object joints. The same trained neural network can be trained to provide the positions of the set of coil coordinates.

[0023] The pose of an object can be defined by the position of its joints. Then, the allowable range of coil coordinates can be defined by mapping a predefined range of coil positioning coordinates of the reference object's joints to the current coordinate system using the set of object coordinates and anatomical features.

[0024] The set of coil coordinates can also be obtained from camera image data. For this purpose, the RF coil can have one or more characteristic predefined patterns, markings, or codes that can be detected by one or more cameras. In the example, the RF coil housing has a label, for example, a sticker printed with one or more predefined patterns. The position and orientation of the coil can then be obtained, for example, by matching one or more predefined patterns with camera image data to detect the size, orientation, and deformation of the patterns, and, if multiple predefined features exist, their spatial arrangement.

[0025] The outputs of one or more cameras or other sensing devices used as input to an attitude recognition system that generates attitude recognition system data can be interpreted according to a known spatial scale, which may have the characteristics of one or more corresponding cameras or sensing devices. For example, when recording images of a grid in a predefined spatial configuration, the mapping describing the appearance of the equidistant grid in the camera image data generated by a given camera of the system can be known. Such a correspondence can be used to define a current coordinate system that can be overlaid on the camera image data of the object and the RF coil to obtain a quantitative description of the corresponding positions of the anatomical features of the RF coil and the object.

[0026] Assume that the prescribed requirements for the intended use of the RF coil are available (i.e., the permitted or anticipated use of the RF coil to record magnetic resonance imaging data (MR image data or MRI data) of one or more anatomical features or regions), as part of a set of coil data assigned to a given RF coil attached to an MRI system. Such prescribed requirements can be expressed as a range of coil positioning coordinates in a theoretical coordinate system known as the standard coordinate system. The standard coordinate system describes the position of the model body relative to the theoretical object. The origin of the standard coordinate system can be aligned with the anatomical features of the model body. The orientation of the standard coordinate system can also be defined based on the anatomical features of the model body.

[0027] This can be beneficial if at least one anatomical feature of the model body corresponds to one of the anatomical features described by the set of object coordinates (the recorded anatomical features). This simplifies the mapping between the standard coordinate system and the current coordinate system used to determine the allowable range of the coil coordinates. A large number of correspondences between the recorded anatomical features and the anatomical features of the theoretical object can improve the accuracy of determining the allowable range of the coil coordinates.

[0028] Determining multiple permissible ranges for coil coordinates to identify mismatches in different (linearly independent) coordinate systems can be beneficial. In the example, the current coordinate system includes three linearly independent coordinates, allowing for the localization of anatomical features and magnetic resonance imaging (MRI) coils in three dimensions, and there can exist a permissible range for coil coordinates defined for each of the three dimensions. The three corresponding permissible ranges for coil coordinates can then define a volume or box within which MRI coil localization is acceptable.

[0029] Mismatches between the set of coil coordinates and the permissible range of coil coordinates can be detected in various ways. Criteria for classifying matches and mismatches may involve one or more coil coordinates in the set of coil coordinates being outside the boundaries of the permissible range of coil coordinates. An exemplary criterion may specify a mismatch if one of the coil coordinates is outside its corresponding permissible range. Another exemplary criterion may combine multiple linearly independent coordinates to define a cylindrical volume for, for example, the permissible coil position of an MRI coil. Further exemplary criteria may add an uncertainty range to each permissible range of coil coordinates to account for potential imprecision in determining the permissible range of coil coordinates. Another exemplary criterion may consider deviations in one dimension from other dimensions as acceptable by defining a permissible range for the coil coordinates representing acceptable dimensions. Similarly, an exemplary criterion may specify a mismatch only if more than one coordinate is outside its corresponding permissible range of coil coordinates. Another exemplary criterion may consider a deviation from the MRI coil's orientation as a mismatch, where the corresponding predefined range of coil positioning coordinates describes the angular range required for the MRI coil's orientation.

[0030] Providing a warning signal can produce one or more different beneficial effects. For example, a warning signal can cause the computing system and / or MRI system to store, for example, log file entries describing the detection of a mismatch between the set of coil coordinates and the allowable range of coil coordinates. Alternatives to the additional output caused by the warning signal can include output on the graphical user interface, which may include, but is not limited to, one or more of the following: a description of one or more mismatched coordinates, a timestamp, a magnitude of the deviation between the set of coil coordinates and the allowable range of coil coordinates, a description of the correct placement of the MRI coil, a description of the steps performed to move the MRI coil to a specified position and / or orientation, etc. Such information can also be included in the log file entries. The warning signal can cause an audible warning. The warning signal can alternatively or additionally affect the control flow of the MRI system, such as, but not limited to, blocking or stopping the imaging scan, setting different magnetic field strengths to be provided by the MRI coil during the imaging scan, requiring the user to confirm that the mismatch is ignored for the next MRI scan, or any other action that may be appropriate to consider the detected mismatch.

[0031] Embodiments of the present invention can be advantageous because they can help detect improper placement of MRI coils at an early stage (preferably before the start of an MRI scan). Therefore, embodiments can prevent the adverse effects of improper placement, such as reduced image quality of MR image data and / or excessively high specific absorption (SAR). Thus, embodiments can contribute to the physical safety of the object being imaged. For example, if an abdominal MRI coil is used to image an infant, an MRI coil approved for abdominal MRI scans in adults may result in unacceptably high SAR. In another example, an MRI coil approved for knee imaging is placed around the torso. The MRI system can then calculate the SAR, assuming the knee is in the scanner rather than the torso. Because the actual SAR depends on tissue properties (i.e., conductivity, dielectric constant, etc.), the delivered whole-body SAR and local SAR may exceed the displayed SAR, even exceeding standard safety limits. However, in a local transmit / receive (TR) coil, the SAR will be primarily delivered to the area around the knee, and power absorption in the body is negligible. In this respect, operators may prefer to use a smaller local TR coil to scan the patient. However, because SAR depends on the tissue physical properties of the coil at the site of RF power deposition, the local SAR displayed by the system may be incorrect and may exceed the displayed value or even the safety limit.

[0032] In an embodiment, the execution of the machine-executable instructions also causes the computing system to:

[0033] Receive a coil identifier describing the magnetic resonance imaging coil; and

[0034] Receive the coil data obtained in response to querying the magnetic resonance imaging coil database using the coil identifier.

[0035] This increases the likelihood of correctly identifying the MRI coil. Coil identifiers can be obtained in several ways. For example, the MRI coil may include a memory chip that is read whenever the MRI coil is connected to the MRI system. Another possibility is to include identification information (e.g., barcodes, QR codes, alphanumeric codes, etc.) that can be captured and interpreted by a posture recognition system on the MRI coil's label.

[0036] In another embodiment, the medical system further includes a magnetic resonance imaging system adapted to acquire medical image data of the object using the magnetic resonance imaging coils in response to receiving a predefined start signal from the computing system. The execution of the machine-executable instructions also causes the computing system to provide the warning signal in the event of a mismatch between the set of coil coordinates and the allowable range of the coil coordinates before sending the start signal to the magnetic resonance imaging system.

[0037] Providing a warning signal before starting a scan allows the operator of the magnetic resonance imaging (MRI) system to correct the position and / or orientation of the MRI coils. This can help improve the image quality of the MR image data and / or increase the probability of keeping the SAR experienced by the object during the scan within the prescribed boundaries.

[0038] In another embodiment, the execution of the machine-executable instructions also causes the computing system to provide the start signal only if the set of coil coordinates matches within the allowable range of the coil coordinates.

[0039] As described herein, this prevents MRI scans from being performed with MRI coils outside the tag. Such out-of-tag use can increase the risk of SAR (Special Radiation Assay) exceeding safety limits for the subject being imaged. Therefore, suppressing the start signal upon detection of out-of-tag use can improve the subject's physical safety. Furthermore, it can prevent MRI scans that provide MR image data with low image quality. Signs of low image quality can include low contrast, low sharpness, and / or excessively low or high brightness in the scanned image. Low-quality scans may necessitate repeat scans to obtain MR image data with improved image quality, which can also increase the risk of the subject suffering from high total SAR.

[0040] In another embodiment, the machine-executable instructions further cause the computing system to obtain a predicted specific absorptivity, the calculated predicted specific absorptivity being the absorptivity that the object would experience in an attitude described by the set of object coordinates when the magnetic resonance imaging system runs a planned magnetic resonance imaging scan using the magnetic resonance imaging coil at the coil location, the coil data also including a specific absorptivity safety value specific to the magnetic resonance imaging coil, and the execution of the machine-executable instructions further causes the computing system to provide the start signal only if the predicted specific absorptivity does not exceed the specific absorptivity safety value.

[0041] Specific absorptivity (SAR) is a measure of the rate at which the human body absorbs energy per unit mass when exposed to radio frequency (RF) electromagnetic fields, which can occur during imaging scans of a subject using a detected MRI coil. The predicted SAR can be determined by a computing system or any other computing system used by or communicatively connected to the computing system and / or any control unit of the MRI system with the MRI coil attached. The predicted SAR can be determined, for example, using a tissue model of the subject's anatomical region, determined by a posture recognition system as being covered by the MRI coil at the detected coil location. Safe values ​​for SAR can be predetermined by medical safety regulations or medical indications applicable to or specific to the subject being imaged. Preventing MRI scans where the predicted SAR exceeds the safe SAR value can improve the subject's safety by preventing excessive doses of energy (e.g., heat) per unit mass from entering the subject's tissues.

[0042] In another embodiment, the medical system further includes a user interface, and providing the warning signal includes sending the warning signal to the user interface, the warning signal including the predicted specific absorption rate and the specific absorption rate safety value, the execution of the machine-executable instructions further causing the computing system to perform the following operation in response to the warning signal being sent to the user interface if the predicted specific absorption rate does not exceed the specific absorption rate safety value: submitting the start signal only in response to receiving a rejection confirmation signal from the user interface.

[0043] Transmitting the predicted SAR and SAR safety values ​​to the user interface allows the operator of the medical system and / or the corresponding MRI system to view the predicted SAR and SAR safety values. This enables the operator to compare the predicted SAR with the SAR safety values, thereby assessing whether the potential increase in SAR during the planned MRI scan is acceptable for the current subject. During the planned MRI scan, the operator can optionally request the subject's consent to possible SAR safety value exceedances and only transmit a rebuttal confirmation signal if the subject consents to an exception. The user interface may include output devices (e.g., a display, speakers, etc.) and input devices (e.g., a keyboard, mouse, etc.).

[0044] In another embodiment, the predefined range of the coil positioning coordinates refers to the anatomical features of the model object, and the coil data also includes a specified specific absorption rate, which is determined as the absorption rate that the model object would experience when the magnetic resonance imaging system uses the magnetic resonance imaging coil within the predefined range of the coil positioning coordinates to perform a predefined magnetic resonance imaging reference scan of the model object. The machine-executable instructions further enable the computing system to:

[0045] The predicted specific absorptivity is obtained, calculated as the absorptivity that the object would experience in the attitude described by the set of object coordinates when the magnetic resonance imaging system operates a planned magnetic resonance imaging scan using the magnetic resonance imaging coil at the coil position; and

[0046] The start signal is provided only if the predicted specific absorption rate does not exceed the specified specific absorption rate.

[0047] The predicted specific absorption rate (predicted SAR) can be determined by a computing system or by any computing system and / or any control unit of an MRI system with an attached MRI coil, or by any other computing system communicatively connected to it. The predicted SAR can be determined, for example, using a tissue model of the subject's anatomical region, determined by a posture recognition system as being covered by the MRI coil at the detected coil location. A specified specific absorption rate (specified SAR) can be a predetermined known value, such as an empirical SAR value, an average SAR value, a typical SAR value, and / or an experimentally determined reference SAR value, which can be predicted regularly and reasonably if the MRI coil is used in full compliance with its specified requirements and / or certification requirements. Preventing MRI scans where the predicted SAR exceeds the specified SAR can improve subject safety by preventing excessive doses of energy (e.g., thermal energy) per unit mass from entering the subject's tissues.

[0048] In another embodiment, the medical system further includes a user interface, and providing the warning signal includes sending the warning signal to the user interface, the warning signal including one or more of the following:

[0049] Information characterizing the difference between the set of coil coordinates and the allowable range of the coil coordinates;

[0050] Information characterizing the difference between anatomical reference features and anatomical target features of the object, the coil data including an expected use identifier that indicates the magnetic resonance imaging system to use the anatomical reference features that the magnetic resonance imaging coil is allowed to image within a predefined range of the coil positioning coordinates, and the execution of the machine-executable instructions further causes the computing system to use the pose recognition system data to identify whether the anatomical target features of the object are imaged when the magnetic resonance imaging coil is positioned as described by the set of coil coordinates and the object is positioned as described by the set of object coordinates; and

[0051] Information describing the repositioning of the magnetic resonance imaging coil is required to resolve the mismatch.

[0052] The user interface can be used to display one or more characterizing and / or descriptive information (hereinafter referred to as "mismatch information") transmitted by warning signals to the operator of the medical system and / or MRI system. This can facilitate the operator's decision on an appropriate response to the detected mismatch. Without limitation, the information characterizing the difference between the set of coil coordinates and the permissible range of coil coordinates may include one or more indications of the distance (e.g., length in millimeters) between the corresponding mismatched coordinate pairs in the set of coil coordinates and the permissible range of coil coordinates.

[0053] Intended use identifiers may include human-readable or coded indications of one or more anatomical reference features intended for imaging with a given MRI coil. For example, an MRI coil designed for imaging a knee / chest may have been assigned an intended use identifier, specifying "knee" and "chest" as applicable anatomical reference features, respectively. Intended use identifiers may be obtained, for example, as part of coil data, and / or may be obtained from an MRI coil database specified herein. Assuming that an MRI coil will be used to acquire medical MR image data when the MRI coil is positioned as described by the set of coil coordinates and the object is positioned as described by the set of object coordinates, then the posture recognition system, medical system, and / or MRI system can identify and include anatomical target features in the posture recognition system data as anatomical features of the object most likely to be imaged in the spatial configuration of the detected object and the MRI coil. If no anatomical reference feature corresponds to a detected anatomical target feature, then the anatomical reference feature and / or anatomical target feature can be displayed to the operator using a user interface.

[0054] Similarly, information describing the repositioning of the MRI coil (which is required to resolve mismatches) may include specified requirements regarding the length of one or more MRI coils that should be moved to achieve proper placement of the MRI coil within the permissible range of coil coordinates, specified requirements for anatomical reference features corresponding to the permissible range of coil coordinates, and / or safety measures and / or further operational instructions to be observed when repositioning the MRI coil within the permissible range of coil coordinates.

[0055] In another embodiment, the execution of the machine-executable instructions also causes the computing system to:

[0056] Information describing the anatomical reference features is sent to the user interface; and

[0057] The mismatch check is repeated in response to receiving a relocation confirmation from the user interface.

[0058] This ensures that the required repositioning of the MRI coil has been performed correctly.

[0059] In another embodiment, the set of object coordinates includes joint position coordinates for the object. Since the object's joints convey information about the spatial configuration of the object's body, this facilitates accurate determination of the object's pose.

[0060] In another embodiment, the medical system further includes a posture recognition system adapted to provide posture recognition data to the computing system. The posture recognition system may have dedicated computing resources available, which can operate independently of the computing system and / or any control unit of the MRI system used. This allows for the implementation of computationally demanding posture recognition technologies compared to the case of one or more control units of the computing system and / or the MRI system.

[0061] In another embodiment, the medical system also includes a magnetic resonance imaging coil database. This can reduce communication latency compared to an MRI coil database shared via a communication or computing network.

[0062] In another aspect, the present invention provides a method for medical imaging, the method comprising:

[0063] Receive attitude recognition system data, wherein the attitude recognition system data includes a set of object coordinates and a set of coil coordinates described using the current coordinate system, wherein the set of object coordinates describes the anatomical features of the object, and wherein the set of coil coordinates describes the coil position of the magnetic resonance imaging coil;

[0064] Receive a coil identifier describing the magnetic resonance imaging coil;

[0065] Receive coil data obtained in response to querying a magnetic resonance imaging coil database using the coil identifier, wherein the coil data includes a predefined range of coil positioning coordinates with reference to the anatomical features;

[0066] The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and

[0067] A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

[0068] In another aspect, the present invention provides a computer program including machine-executable instructions for execution by a computing system controlling a medical system, wherein execution of the machine-executable instructions causes the computing system to:

[0069] Receive attitude recognition system data, wherein the attitude recognition system data includes a set of object coordinates and a set of coil coordinates described using the current coordinate system, wherein the set of object coordinates describes the anatomical features of the object, and wherein the set of coil coordinates describes the coil position of the magnetic resonance imaging coil;

[0070] Receive a coil identifier describing the magnetic resonance imaging coil;

[0071] Receive coil data obtained in response to querying a magnetic resonance imaging coil database using the coil identifier, wherein the coil data includes a predefined range of coil positioning coordinates with reference to the anatomical features;

[0072] The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and

[0073] A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

[0074] It should be understood that one or more embodiments of the foregoing embodiments of the present invention may be combined, as long as the combined embodiments are not mutually exclusive.

[0075] Those skilled in the art will recognize that aspects of the present invention can be implemented as apparatus, method, or computer program product. Therefore, aspects of the present invention can take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all collectively referred to herein as "circuit," "module," or "system." Furthermore, aspects of the present invention can take the form of a computer program product implemented on one or more computer-readable media having computer-executable code implemented thereon.

[0076] Any combination of one or more computer-readable media can be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" encompasses any tangible storage medium capable of storing instructions executable by a processor or computing system of a computing device. A computer-readable storage medium may be referred to as a computer-readable non-transient storage medium. A computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be capable of storing data accessible by a computing system of a computing device. Examples of computer-readable storage media include, but are not limited to: floppy disks, magnetic hard disk drives, solid-state drives, flash memory, USB thumb drives, random access memory (RAM), read-only memory (ROM), optical discs, magneto-optical discs, and register files of computing systems. Examples of optical discs include compact discs (CDs) and digital multi-purpose discs (DVDs), such as CD-ROMs, CD-RWs, CD-Rs, DVD-ROMs, DVD-RWs, or DVD-R discs. The term "computer-readable storage medium" also refers to various types of recording media accessible by computer devices via a network or communication link. For example, data can be retrieved on a modem, on the Internet, or on a local area network. Any suitable medium may be used to transmit computer-executable code implemented on a computer-readable medium, including but not limited to: wireless, wired, fiber optic cable, RF, etc., or any suitable combination thereof.

[0077] Computer-readable signal media may include, for example, propagated data signals in baseband or as a portion of a carrier wave, in which computer-executable code is implemented. Such propagated signals may take any of a variety of forms, including but not limited to: electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and is capable of delivering, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0078] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that can be directly accessed by a computing system. "Computer storage device" or "storage device" is another example of a computer-readable storage medium. A computer storage device is any non-volatile computer-readable storage medium. In some embodiments, a computer storage device may also be computer memory, or vice versa.

[0079] As used herein, the term "computing system" encompasses electronic components capable of running programs or machine-executable instructions or computer-executable code. References to computing systems, including examples of "computing systems," should be interpreted as potentially including more than one computing system or processing core. A computing system can, for example, be a multi-core processor. A computing system can also refer to a collection of computing systems, either within a single computer system or distributed across multiple computer systems. The term "computing system" should also be interpreted as potentially referring to a collection or network of multiple computing devices, each of which includes a processor or computing system. Machine-executable code or instructions can be run by multiple computing systems or processors that may be within the same computing device or even distributed across multiple computing devices.

[0080] Machine-executable instructions or computer-executable code may include instructions or programs that instruct a processor or other computing system to perform an aspect of the invention. Computer-executable code for performing operations toward the aspects of the invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​(e.g., Java, Smalltalk, C++, etc.) and conventional programming languages ​​(e.g., the "C" programming language or similar programming languages), and compiled into machine-executable instructions. In some instances, the computer-executable code may be in the form of a high-level language or in a pre-compiled form, and may be used in conjunction with an interpreter that generates the machine-executable instructions at runtime. In other instances, the machine-executable instructions or computer-executable code may be in the form of programming a programmable gate array.

[0081] Computer executable code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet through an Internet service provider).

[0082] Aspects of the invention have been described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block or portion of the flowchart, illustration, and / or block diagram can be implemented by computer program instructions in the form of computer-executable code, where appropriate. It should also be understood that blocks in different flowcharts, illustrations, and / or block diagrams can be combined without mutual exclusion. These computer program instructions can be provided to a computing system of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which run via the computing system of the computer or other programmable data processing apparatus, create units for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0083] These machine-executable instructions or computer program instructions may also be stored in a computer-readable medium that can instruct a computer, other programmable data processing apparatus or other device to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture, the article of manufacture including instructions that implement functions / actions specified in flowcharts and / or one or more block diagrams.

[0084] Machine-executable instructions or computer program instructions may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device, thereby creating a computer-implemented process, such that the instructions running on the computer or other programmable apparatus provide for performing the functions / actions specified in the flowchart and / or one or more block diagram boxes.

[0085] As used herein, a "user interface" is an interface that allows a user or operator to interact with a computer or computer system. A "user interface" can also be referred to as a "human-machine interface device." A user interface can provide information or data to and / or receive information or data from an operator. A user interface enables input from an operator to be received by the computer and can provide output from the computer to the user. In other words, a user interface allows an operator to control or manipulate a computer, and the interface allows the computer to indicate the effects of the operator's control or manipulation. Displaying data or information on a monitor or graphical user interface is an example of providing information to an operator. Receiving data via a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, game controller, webcam, head-mounted device, foot pedal, wired gloves, remote control, and accelerometer are all examples of user interface components that enable the reception of information or data from an operator.

[0086] As used herein, "hardware interface" encompasses the interfaces that enable a computer system to interact with and / or control external computing devices and / or devices. A hardware interface allows a computing system to send control signals or commands to external computing devices and / or devices. A hardware interface also enables a computing system to exchange data with external computing devices and / or devices. Examples of hardware interfaces include, but are not limited to: Universal Serial Bus (USB), IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connectivity, wireless LAN connectivity, TCP / IP connectivity, Ethernet connectivity, control voltage interfaces, MIDI interfaces, analog input interfaces, and digital input interfaces.

[0087] As used herein, the term "display" or "display device" encompasses an output device or user interface suitable for displaying images or data. A display can output visual, auditory, and / or tactile data. Examples of displays include, but are not limited to: computer monitors, television screens, touchscreens, haptic electronic displays, Braille screens, cathode ray tubes (CRTs), memory tubes, bistable displays, electronic paper, vector displays, flat panel displays, vacuum fluorescent displays (VFs), light-emitting diode (LED) displays, electroluminescent displays (ELDs), plasma display panels (PDPs), liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, projectors, and head-mounted displays.

[0088] Magnetic resonance (MR) data is defined herein as measurements of radio frequency signals emitted by atomic spins, recorded using the antenna of a magnetic resonance imaging (MRI) device during a magnetic resonance imaging (MRI) scan. MRI data is an example of medical MR image data. MRI images, or MR images, are defined herein as two-dimensional or three-dimensional visualizations reconstructed from anatomical data contained within MRI data. Such visualizations can be performed using a computer. Attached Figure Description

[0089] Preferred embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0090] Figure 1 An example of a medical system is illustrated; and

[0091] Figure 2 The illustration shows the use of Figure 1 A flowchart of the methods used in medical systems.

[0092] List of reference numerals

[0093] 100 Medical System

[0094] 102 objects

[0095] 104 magnetic resonance imaging coil

[0096] 110 camera

[0097] 120 Magnetic Resonance Imaging Coil Database

[0098] 130 computing system

[0099] 132 processor

[0100] 134 Hardware or Network Interface

[0101] 136 User Interface

[0102] 140 memory

[0103] 142 Magnetic Resonance Imaging Command

[0104] 144 Attitude Recognition System Group

[0105] 146 Camera Image Data Acquisition Command

[0106] 148 camera image data

[0107] 150 posture recognition instructions

[0108] 152 object coordinates

[0109] 154 Coil Detection Command

[0110] 156 coil coordinates

[0111] 158 coil identifier

[0112] 160 mismatch check group

[0113] 162 coil data query command

[0114] Range of 164 coil positioning coordinates

[0115] 166 coordinate system mapping command

[0116] Allowable range of 168 coil coordinates

[0117] 170 Mismatch Check Command

[0118] 172 Warning Signs Detailed Implementation

[0119] In these figures, elements with the same number are either equivalent elements or perform the same function. If the functions are equivalent, elements that have already been discussed need not be discussed again in the following figures.

[0120] Figure 1An example of a medical system 100 is illustrated. Figure 1 The medical system 100 shown is to be understood as purely illustrative. Specifically, in Figure 1 Components shown as coupled or integrated can also be implemented as separate or independent components, and components shown as separate or independent can also be implemented as coupled or integrated components; components shown as hardware can also be implemented as software, and components shown as software can also be implemented as hardware; the components shown can also be implemented in a modified manner, replaced by different components, or omitted in alternative embodiments; similarly, additional components can be added to the configuration shown.

[0121] Medical system 100 may include a computing system 130 equipped with a processor 132, a hardware or network interface 134, a user interface 136, and a memory 140. Input / output devices that may be connected to the user interface 136, such as display devices, speakers, keyboards, and / or mice, are not shown.

[0122] Magnetic resonance imaging coil (MRI coil) 104 is shown connected to hardware or network interface 134. A 3D camera system including two cameras 110 is also shown connected to hardware or network interface 134. Magnetic resonance imaging coil database (coil database) 120 is also shown connected to hardware or network interface 134. Coil database 120, and optionally any other device connected to computing system 130, can be connected to hardware or network interface 134 via local connection (e.g., cable or fiber optic cable) or via a communication network (e.g., cable-driven or wireless network or uplink to the Internet).

[0123] Object 102 is shown in the vicinity of medical system 100. MRI coil 104 is shown covering the anatomical features of object 102. Figure 1 In the example, the anatomical feature covered by MRI coil 104 is the elbow of subject 102. Camera 110 is shown with an orientation that allows for the acquisition of camera image data 148 of subject 102 and MRI coil 104. MRI coil 104 may include a radio frequency coil (RF coil), such as a receiving coil (Rx coil) or a transmit / receive coil (Tx / Rx coil), which can receive a body portion of subject 102 that may include or be adjacent to one or more anatomical features. MRI coil 104 may be part of an MRI system that may include other coils such as a scanner coil adapted to receive subject 102 with RF coil 104 attached to the corresponding body portion and adapted to generate a magnetic gradient field that allows for the acquisition of MR image data of subject 102 at a desired spatial resolution.

[0124] The object 102, MRI coil 104, camera 110, and possibly other components of the MRI system and / or medical system 100 may be located in an examination chamber. The camera 110 may be mounted or adapted to be positioned in such an examination chamber where it is capable of simultaneously capturing the object 102 with the MRI coil 104 attached. The MRI system may also include a scanner stage adapted to support the object 102 and move it into and out of the aperture of the scanner coil.

[0125] Camera 110 may be located at a point in the examination room (e.g., mounted on a wall or ceiling of the examination room, or supported by a bracket on the floor of the examination room), or may be attached to a component of an MRI system (e.g., a scanner coil) or medical system 100. Camera 110 may have a field of view that allows capture of object 102 and MRI coil 104, which are supported by a portion of the scanner stage located outside the aperture of the scanner coil. For example, it may be advantageous to arrange cameras 110 such that their field of view can capture MRI coil 104 and one or more anatomical features of object 102 adjacent to MRI coil 104 outside the aperture of the scanner coil, such that object coordinates 152 of at least said adjacent anatomical features can be determined based on camera image data 148. Similarly, the field of view may be defined such that sufficient space is available to capture at least a portion of MRI coil 104, thereby allowing all required coil coordinates to be determined based on camera image data 148.

[0126] Memory 140 can store multiple sets of data and instructions. For example, memory 140 can store a set of instructions 142 that, if executed by processor 132, would cause medical system 100 to perform the steps of a procedure for preparing and acquiring magnetic resonance image data of subject 102 using MRI coil 104 (MRI instruction 142). Memory 140 can also store a set of data and instructions 144 (PRS set 144) related to the function of the posture recognition system and a set of data and instructions 160 (mismatch check set 160) related to the mismatch check routine.

[0127] MRI instruction 142 may include calls to one or more sets of pose recognition system instructions (PRS instructions) 146, 150, 154 and calls to one or more sets of mismatch check instructions (MC instructions) 162, 166, 170. The MRI instruction may also perform read and / or write access to PRS data 148, 152, 156 in PRS group 144 and MC data 164, 168, 172 in MC group 160. Similarly, MC instructions 162, 166, 170 may call, read, or write elements in PRS group 144, and PRS instructions 146, 150, 154 may call, read, or write elements in MC group 160. Memory 140 may also store coil identifier 158, which may be received in response to MRI coil 104 being connected to computing system 130. PRS instructions 146, 150, 154 and MC instructions 162, 166, 170 can invoke instructions of MRI instruction 142 and can have at least read access to coil identifier 158. MRI instructions 142, PRS instructions 146, 150, 154 and MC instructions 162, 166, 170 can access hardware or network interface 134 and user interface 136.

[0128] MRI coil 104, its connection to hardware or network interface 134, MRI command 142, and coil identifier 158 can be considered components of an MRI system. Camera 110, its connection to hardware or network interface 134, and PRS commands 146, 150, and 154 can be considered components of an attitude recognition system. Coil database, its connection to hardware or network interface 134, and MC commands 162, 166, and 170 can be considered components of a mismatch inspection system (MC system). Access to hardware or network interface 134 and user interface 136 by MRI commands 142, PRS commands 146, 150, and 154, and MC commands 162, 166, and 170 can be restricted to the corresponding interface ports used by the MRI system, PRS system, and MC system. In this case, if data needs to be sent or received via an interface port outside a given system, the commands assigned to the given system may have to call appropriate commands from another system. Some examples are given below.

[0129] An exemplary use case for the medical system 100 may include using the processor 132 to execute MRI instructions 142. At appropriate points in the MRI process implemented by the MRI instructions 142 (e.g., when the MRI coil 104 has been positioned to cover the anatomical features of the object 102, but an MRI scan using the MRI coil 104 has not yet begun), the MRI instructions 142 may include calls to one or more of the PRS instructions 146, 150, 154 to obtain PRS data 148, 152, 156.

[0130] In the example, MRI instruction 142 includes a call to camera image data acquisition instruction 146. Execution of camera image data acquisition instruction 146 enables processor 132 to use camera 110 to acquire camera image data 148 of object 102 and MRI coil 104.

[0131] MRI instruction 142 or camera image data acquisition instruction 146 may include a call to pose recognition instruction 150. Execution of pose recognition instruction 150 may cause processor 132 to implement a pose recognition technique (e.g., one or more of those described herein) that receives at least a portion of camera image data 148 and, in response, provides a set of object coordinates 152. The set of object coordinates 152 may describe anatomical features of the object 102 as captured in the camera image data 148. Each anatomical feature described by the set of object coordinates 152 may be assigned to one or more object coordinates in the identified object coordinates 152.

[0132] MRI instruction 142 or pose recognition instruction 150 may include a call to coil detection instruction 154. Execution of coil detection instruction 154 may cause processor 132 to implement a coil detection routine (e.g., one or more of those routines described herein) that receives at least a portion of camera image data 148 and, in response, provides a set of coil coordinates 156. The set of coil coordinates 156 may describe the position and / or orientation of the MRI coil 104 as captured in the camera image data 148. For example, each of the position and orientation of the MRI coil 104 may be described by coil coordinates 156 of a corresponding two-dimensional or three-dimensional vector.

[0133] The set of object coordinates and the set of coil coordinates can be given in the current coordinate system, which can reflect the geometric properties (e.g., optical curvature or bending effect) of the imaging process of camera 110 onto camera image data 148.

[0134] Still in the exemplary use case, at appropriate points in the MRI process implemented by MRI instruction 142 (e.g., when PRS instructions 146, 150, 154 have been successfully completed but an MRI scan using MRI coil 104 has not yet started), MRI instruction 142 may include a call to one or more of MX instructions 162, 166, 170 to obtain MC data 164, 168, 172.

[0135] In the example, MRI instruction 142 includes a call to coil data query instruction 162. Execution of coil data query instruction 162 causes processor 132 to send coil identifier 158 to coil database 120 to query a range 164 of coil positioning coordinates for MRI coil 104. The range 164 of coil positioning coordinates can be given in a standard coordinate system, describing the relationship between the required coil coordinates of MRI coil 104 and predefined anatomical features of a theoretical model object. Coil data query instruction 162 may include checking whether the range 164 of coil positioning coordinates specific to MRI coil 104, as described by coil identifier 158, is already stored in memory 140, and conditions for querying database 120 can only be implemented if a suitable range 164 of coil positioning coordinates cannot be found. The range 164 of coil positioning coordinates may include multiple ranges, for example, one range for each dimension represented by linear independent coordinates.

[0136] The range 164 of coil positioning coordinates can describe multiple anatomical features of the model object, allowing the use of MRI coil 104 to acquire MRI data. For this purpose, the range 164 of coil positioning coordinates can include a range 164 of coil positioning coordinates for each coordinate, describing the range of MRI coil 104 permitted for one of the permitted anatomical features. Specifically, a pair of coordinates describing the permitted range for two different anatomical features can have different coordinate origins, which can be specific to the respective anatomical feature. For example, the range 164 of coil positioning coordinates for MRI coil 104 permitted for both knees and both elbows can include four sets of permitted coordinate ranges (where each set of permitted coordinate ranges can be assigned to one of the permitted anatomical features), can include, for example, three coordinate ranges to express the permitted use of MRI coil 104 in three dimensions, and can have already been assigned a coordinate origin, which can be different from the origin of each coordinate range assigned to any of the other sets of permitted coordinate ranges. If needed, a range of coordinates within a given set of allowed coordinate ranges can be represented relative to different available coordinate origins. This is achieved by calculating the distance between the corresponding origins for each coordinate and adding the corresponding distance to the corresponding coordinate.

[0137] MRI instruction 142 or coil data query instruction 162 may include a call to coordinate system mapping instruction 166. Coordinate system mapping instruction 166 may be adapted to identify one or more anatomical features of object 102 using a system that may, for example, reside in memory 140 or be available, for example, via hardware or network interface 134, unique descriptors of anatomical features (with pose recognition systems having detected these anatomical features and described them in this set of object coordinates 152 for corresponding anatomical features of the model object).

[0138] The coordinate system mapping instruction 166 can be adapted to use anatomical features to determine (detect, calculate, and / or infer) common geometric information in and / or derived from the set of object coordinates in the current coordinate system. This common geometric information may exist in the range 164 of the coil coordinates and / or any other available information about the model object also in the standard coordinate system, or it may be calculated and / or inferred from the range 164 of the coil coordinates and / or any other available information about the model object also in the standard coordinate system. In the example, the coordinate system mapping instruction 166 can cause the processor 132 to calculate the position and orientation of a specific anatomical feature of object 102 and / or the positions of two or more anatomical features of object 102 and one or more difference vectors between these two or more positions.

[0139] Similarly, for theoretical model objects in a standard coordinate system, the same common geometric information regarding position and orientation can be obtained using appropriate computation (if necessary). This common geometric information should be sufficient to compute a mapping to express the range 164 of coil positioning coordinates in the current coordinate system. In the example, the mapping is represented by one or more elementary transformation matrices (e.g., spatial translation, rotation, and / or dilation, capable of transforming the position and orientation of one or more anatomical features of the model object represented by the common geometric information in the standard coordinate system into corresponding positions and orientations of one or more anatomical features of object 102 represented by the same common geometric information in the current coordinate system).

[0140] The coordinate system mapping instruction 166 can then enable the processor 132 to use such a defined mapping to map the range 164 of the coil positioning coordinates from the standard coordinate system to the current coordinate system, so as to obtain the allowable range 168 of the coil coordinates.

[0141] MRI instruction 142 or coordinate system mapping instruction 166 may include a call to mismatch check instruction 170. Mismatch check instruction 170 may apply one or more logical criteria to compare the set of coil coordinates 156 with an allowable range 168 of coil coordinates. In one example, mismatch check instruction 170 may be configured to detect a mismatch if one or more coil coordinates in coil coordinates 156 are outside the corresponding allowable range 168 of the coil coordinates. In another example, mismatch check instruction 170 may be configured to detect a mismatch if a predefined linear combination of two or more coil coordinates in coil coordinates 156 is outside the corresponding allowable range 168 of the coil coordinates. In yet another example, mismatch check instruction 170 may be configured to comply with tolerances added to one or more allowable ranges 168 of the coil coordinates to account for potential inaccuracies in the output of PRS data 148, 152, 156 and / or in the mapping determined by coordinate system mapping instruction 166.

[0142] If the mismatch check instruction 170 causes a determination that there is a mismatch between coil coordinates 156 and the allowed range 168 of coil coordinates, but the range 164 of coil positioning coordinates indicates that there is another range 164 of coil positioning coordinates in which the MRI coil 104 is allowed to image the object, then the mismatch check instruction 170 can exit the mismatch check routine by calling the coordinate system mapping instruction 166 to determine another mapping for one of the ranges 164 of coil positioning coordinates. This allows the mismatch check to be performed by checking the results obtained for the selected range 164 of coil positioning coordinates through subsequent new calls to the mismatch check instruction 170.

[0143] If the mismatch check instruction 170 determines that a mismatch exists between coil coordinates 156 and all allowed ranges 168 of coil coordinates for a given MRI coil 104, then the mismatch check instruction 170 can continue by generating and providing a warning signal 172. The warning signal 172 may include any information describing the detected mismatch (mismatch information), such as, but not limited to, the set of coil coordinates 156, one or more allowed ranges 168 of coil coordinates(s), camera image data 148, indication of the deviation between coil coordinates 156 and the allowed ranges 168 of coil coordinates, timestamps of the acquisition of camera image data 148, timestamps of the acquisition of the mismatch check result, instructions on how to correct the detected mismatch, coil identifiers, operational and safety instructions for using MRI coil 104 to correct the detected mismatch, etc. The warning signal 172 may be used to cause various effects, such as, but not limited to, displaying a portion of the mismatch information using the user interface 138, writing a portion of the mismatch information to a log file entry, pausing, aborting, transferring, or restarting the MRI workflow instruction 142, etc.

[0144] Figure 2 The illustration shows the use of a medical system (e.g., Figure 1 A flowchart of an exemplary method for a medical system 100 is provided. Step 202 includes receiving posture recognition system data. The posture recognition system data can be determined by analyzing camera images 144 of the object 118 and the MRI coil 114. The posture recognition system data may include a set of object coordinates 150 describing the anatomical features of the object 118. The posture recognition system data may also include a set of coil coordinates 154 describing the coil position of the magnetic resonance imaging coil 114. The object coordinates 150 and the coil coordinates 154 can be given in the current coordinate system associated with the camera image 144.

[0145] Step 204 includes receiving a coil identifier 156 describing the magnetic resonance imaging coil 114. Examples of receiving the coil identifier 156 may include: reading the coil identifier 156 from the internal memory of the MRI coil 114 when the MRI coil 114 is connected to the MRI system 102, and querying the coil identifier 156 from a coil database using the code of the MRI coil 114 identified in the camera image 144.

[0146] Step 204 also includes receiving coil data 158 obtained in response to querying the magnetic resonance imaging coil database using coil identifier 156. Coil data 158 may include a predefined range of coil positioning coordinates measured relative to one or more anatomical features of the model object in a standard coordinate system.

[0147] Step 206 involves determining the allowable range of coil coordinates by mapping a predefined range of coil positioning coordinates to the current coordinate system. This can be accomplished based on the identification of one or more anatomical features detected on object 118 and the object coordinates 150 corresponding to the coordinates of one or more corresponding anatomical features of the model object in the standard coordinate system.

[0148] Step 208 involves evaluating one or more criteria to determine whether the detected coil coordinates 154 are within the allowable range of previously determined coil coordinates. If this is true, the method can proceed to continue the MRI scan routine 210 without affecting the results of steps 202-208. If a mismatch is detected between the set of coil coordinates and the allowable range of coil coordinates, the method can proceed to providing a warning signal 212, which can trigger automatic and / or user-based actions to appropriately respond to the detected mismatch.

[0149] Although the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary, and not restrictive; the invention is not limited to the disclosed embodiments.

[0150] Those skilled in the art, through studying the accompanying drawings, disclosure, and claims, will be able to understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude multiple. A single processor or other unit may implement the functions of several items recited in the claims. Although certain measures are recited in dissimilar dependent claims, this does not imply that combinations of these measures cannot be advantageously used. Computer programs may be stored / distributed on suitable media, such as optical storage media or solid-state media supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. No reference numerals in the claims should be construed as limiting the scope.

Claims

1. A medical system comprising: Memory, which stores machine-executable instructions; A computing system, wherein execution of machine-executable instructions causes the computing system to perform a mismatch check, including: The system receives attitude recognition system data, which includes a set of object coordinates and a set of coil coordinates described using the current coordinate system. The object coordinates describe the anatomical features of the object, and the coil coordinates describe the coil positions of the magnetic resonance imaging coils. Receive a coil identifier describing the magnetic resonance imaging coil; Receive coil data obtained in response to querying a magnetic resonance imaging coil database using the coil identifier, wherein the coil data is associated with the magnetic resonance imaging coil and includes a predefined range of coil positioning coordinates referenced to the anatomical features; The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

2. The medical system of claim 1 further includes a magnetic resonance imaging system adapted to acquire medical image data of the object using the magnetic resonance imaging coils in response to receiving a predefined start signal from the computing system, wherein the execution of the machine-executable instructions further causes the computing system to provide the warning signal in the event of a mismatch between the set of coil coordinates and the permissible range of the coil coordinates before sending the start signal to the magnetic resonance imaging system.

3. The medical system of claim 2, wherein the execution of the machine-executable instructions further causes the computing system to provide the start signal only if the set of coil coordinates matches within the allowable range of the coil coordinates.

4. The medical system of claim 2, wherein the machine-executable instructions further cause the computing system to obtain a predicted specific absorptivity, the calculated predicted specific absorptivity being the absorptivity that the object would experience in an attitude described by the set of object coordinates when the magnetic resonance imaging system uses the magnetic resonance imaging coil at the coil location to run a planned magnetic resonance imaging scan, the coil data further including a specific absorptivity safety value specific to the magnetic resonance imaging coil, and the execution of the machine-executable instructions further causes the computing system to provide the start signal only if the predicted specific absorptivity does not exceed the specific absorptivity safety value.

5. The medical system of claim 4, further comprising a user interface, wherein providing the warning signal includes sending the warning signal to the user interface, the warning signal including the predicted specific absorption rate and the specific absorption rate safety value, and the operation of the machine-executable instructions further causes the computing system to perform the following operation in response to the warning signal being sent to the user interface if the predicted specific absorption rate does not exceed the specific absorption rate safety value: submitting the start signal only in response to receiving a rejection confirmation signal from the user interface.

6. The medical system of claim 2, wherein the predefined range of the coil positioning coordinates refers to the anatomical features of the model object, the coil data further includes a specified specific absorption rate, the specified specific absorption rate being determined as the absorption rate that the model object would experience when the magnetic resonance imaging system uses the magnetic resonance imaging coil within the predefined range of the coil positioning coordinates to perform a predefined magnetic resonance imaging reference scan of the model object, and the machine-executable instructions further enable the computing system to: The predicted specific absorptivity is obtained, calculated as the absorptivity that the object would experience in the attitude described by the set of object coordinates when the magnetic resonance imaging system operates a planned magnetic resonance imaging scan using the magnetic resonance imaging coil at the coil position; and The start signal is provided only if the predicted specific absorption rate does not exceed the specified specific absorption rate.

7. The medical system of claim 1, further comprising a user interface, wherein providing the warning signal includes sending the warning signal to the user interface, the warning signal comprising one or more of the following: Information characterizing the difference between the set of coil coordinates and the allowable range of the coil coordinates; Information characterizing the difference between anatomical reference features and anatomical target features of the object, the coil data including an expected use identifier that indicates the magnetic resonance imaging system to use the anatomical reference features that the magnetic resonance imaging coil is allowed to image within a predefined range of the coil positioning coordinates, and the execution of the machine-executable instructions further causes the computing system to use the pose recognition system data to identify whether the anatomical target features of the object are imaged when the magnetic resonance imaging coil is positioned as described by the set of coil coordinates and the object is positioned as described by the set of object coordinates; and Information describing the repositioning of the magnetic resonance imaging coil is required to resolve the mismatch.

8. The medical system of claim 7, wherein the execution of the machine-executable instructions further causes the computing system to: Information describing the anatomical reference features is sent to the user interface; and The mismatch check is repeated in response to receiving a relocation confirmation from the user interface.

9. The medical system according to claim 1, wherein the set of object coordinates includes joint position coordinates for the object.

10. The medical system according to claim 1 further includes a posture recognition system, the posture recognition system being adapted to provide the posture recognition system data to the computing system.

11. The medical system according to claim 1 further includes a magnetic resonance imaging coil database.

12. A method for medical imaging, the method comprising: Receive attitude recognition system data, wherein the attitude recognition system data includes a set of object coordinates and a set of coil coordinates described using the current coordinate system, wherein the set of object coordinates describes the anatomical features of the object, and wherein the set of coil coordinates describes the coil position of the magnetic resonance imaging coil; Receive a coil identifier describing the magnetic resonance imaging coil; Receive coil data obtained in response to querying a magnetic resonance imaging coil database using the coil identifier, wherein the coil data includes a predefined range of coil positioning coordinates with reference to the anatomical features; The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

13. A computer program product comprising machine-executable instructions for execution by a computing system controlling a medical system, wherein, The execution of the machine-executable instructions enables the computing system to: Receive attitude recognition system data, wherein the attitude recognition system data includes a set of object coordinates and a set of coil coordinates described using the current coordinate system, wherein the set of object coordinates describes the anatomical features of the object, and wherein the set of coil coordinates describes the coil position of the magnetic resonance imaging coil; Receive a coil identifier describing the magnetic resonance imaging coil; Receive coil data obtained in response to querying a magnetic resonance imaging coil database using the coil identifier, wherein the coil data includes a predefined range of coil positioning coordinates with reference to the anatomical features; The allowable range of coil coordinates is determined by mapping a predefined range of coil positioning coordinates to the current coordinate system using the set of object coordinates and the anatomical features; and A warning signal is provided if there is a mismatch between the set of coil coordinates and the allowable range of the coil coordinates.

Images