JP2019092593A - Magnetic resonance imaging apparatus - Google Patents

Abstract

To reduce respiratory artifact.SOLUTION: A magnetic resonance imaging apparatus in an embodiment includes an acquisition part, an evaluation part and an execution part. The acquisition part acquires a biological signal of an analyte. The evaluation part analyzes the biological signal in real time, and evaluates a relation between a breathing instruction set beforehand and a respiratory condition of the analyte. The execution part executes a processing related to breath-hold imaging corresponding to an evaluation result by the evaluation part.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to a magnetic resonance imaging apparatus.

  The nuclear spin of the subject placed in the static magnetic field is magnetically excited with RF (Radio Frequency) pulse of Larmor frequency, and the image is re-created from the MR (Magnetic Resonance) signal generated along with this excitation. There is a magnetic resonance imaging (MRI) device to configure.

  In imaging of the upper abdomen such as the liver, respiratory body movement may cause an artifact (hereinafter also referred to as "respiration artifact"). In order to reduce respiratory artefacts, there is an imaging method called breath-hold imaging in which the subject is requested to hold a breath and imaging is performed during the breath-hold.

JP, 2008-259604, A Japanese Patent Application Laid-Open No. 9-187521

  The problem to be solved by the present invention is to provide a magnetic resonance imaging apparatus capable of reducing respiratory artefacts.

  A magnetic resonance imaging apparatus according to an embodiment includes an acquisition unit, an evaluation unit, and an execution unit. The acquisition unit acquires a biological signal of the subject. The evaluation unit analyzes the biological signal in real time, and evaluates the relationship between a preset breathing instruction and the respiratory state of the subject. The execution unit executes processing related to breath-hold imaging in accordance with the evaluation result by the evaluation unit.

FIG. 1 is a functional block diagram showing the configuration of the MRI apparatus according to the first embodiment. FIG. 2 is a diagram for explaining the process of the evaluation function according to the first embodiment. FIG. 3A is a view for explaining processing of an execution function according to the first embodiment. FIG. 3B is a view for explaining the process of the execution function according to the first embodiment. FIG. 3C is a diagram for explaining the process of the execution function according to the first embodiment. FIG. 3D is a view for explaining processing of the execution function according to the first embodiment. FIG. 4 is a flowchart showing the processing procedure of the MRI apparatus according to the first embodiment. FIG. 5 is a flowchart showing a processing procedure of voice guidance reproduction processing according to the first embodiment. FIG. 6 is a functional block diagram showing a configuration of an MRI apparatus according to Modification 2 of the first embodiment. FIG. 7 is a diagram for explaining the process of the execution function according to the third modification of the first embodiment. FIG. 8 is a flowchart showing the processing procedure of the MRI apparatus according to the second embodiment. FIG. 9 is a diagram for explaining the process of the execution function according to the third embodiment. FIG. 10 is a diagram for explaining the process of the execution function according to the third embodiment. FIG. 11 is a diagram for explaining the process of the execution function according to the third embodiment. FIG. 12 is a diagram for explaining the process of the execution function according to the third embodiment. FIG. 13 is a diagram for explaining the process of the execution function according to the third embodiment.

  Hereinafter, magnetic resonance imaging apparatuses (hereinafter, “MRI apparatuses”) according to the embodiments will be described with reference to the drawings. The embodiment is not limited to the following embodiment. Moreover, each embodiment and each modification can be combined suitably.

First Embodiment
FIG. 1 is a functional block diagram showing the configuration of the MRI apparatus 100 according to the first embodiment. As shown in FIG. 1, the MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil 2, a gradient magnetic field power supply 3, a transmission coil (RF (Radio Frequency) transmission coil) 4, a transmission circuit 5, and A coil (RF receiving coil) 6, a receiving circuit 7, a bed 8, an input circuit 9, a display 10, a memory circuit 11, and processing circuits 12 to 15 are provided. The MRI apparatus 100 further includes a respiration sensor 9a and a speaker 10a. The MRI apparatus 100 does not include the subject S (for example, a human body) shown in FIG. Further, the configuration shown in FIG. 1 is merely an example.

  The static magnetic field magnet 1 is formed in a hollow, substantially cylindrical shape (including those in which the cross section orthogonal to the central axis of the cylinder is an elliptical shape), and generates a uniform static magnetic field in the imaging space formed on the inner peripheral side Let For example, the static magnetic field magnet 1 is realized by a permanent magnet, a superconducting magnet or the like.

  The gradient magnetic field coil 2 is formed in a hollow substantially cylindrical shape (including one in which the cross section perpendicular to the central axis of the cylinder is an elliptical shape), and is disposed on the inner peripheral side of the static magnetic field magnet 1. The gradient coil 2 has three coils that generate gradient magnetic fields along x, y and z axes orthogonal to each other. Here, the x-axis, the y-axis, and the z-axis constitute an apparatus coordinate system unique to the MRI apparatus 100. For example, the direction of the x-axis is set to the vertical direction, and the direction of the y-axis is set to the horizontal direction. Further, the direction of the z-axis is set to be the same as the direction of the magnetic flux of the static magnetic field generated by the static magnetic field magnet 1.

  The gradient magnetic field power supply 3 generates a gradient magnetic field corresponding to the x axis, the y axis, and the z axis in the imaging space by individually supplying current to each of the three coils included in the gradient magnetic field coil 2. Each axis corresponds to, for example, the readout direction, the phase encoding direction, and the slice direction. Here, axes corresponding to the lead-out direction, the phase encoding direction, and the slice direction constitute a logical coordinate system for defining a slice area or volume area to be imaged. Hereinafter, the gradient magnetic field along the readout direction is referred to as a readout gradient magnetic field, the gradient magnetic field along the phase encoding direction is referred to as a phase encode gradient magnetic field, and the gradient magnetic field along the slice direction is referred to as a slice gradient magnetic field. .

  Each gradient magnetic field is superimposed on the static magnetic field generated by the static magnetic field magnet 1 and is used to give spatial position information to the magnetic resonance (MR) signal. Specifically, the read-out gradient magnetic field gives positional information in the read-out direction to the MR signal by changing the frequency of the MR signal according to the position in the read-out direction. In addition, the phase encoding gradient magnetic field gives positional information in the phase encoding direction to the MR signal by changing the phase of the MR signal along the phase encoding direction. The slice gradient magnetic field is used to determine the direction, thickness, and number of slice areas when the imaging area is a slice area, and according to the position in the slice direction when the imaging area is a volume area. By changing the phase of the MR signal, position information along the slice direction is given to the MR signal.

  The transmission coil 4 is an RF coil that applies an RF magnetic field to an imaging space in which the subject S is disposed based on an RF (Radio Frequency) pulse signal output from the transmission circuit 5. Specifically, the transmission coil 4 is formed in a hollow, substantially cylindrical shape (including one in which the cross section orthogonal to the central axis of the cylinder is an elliptical shape), and is disposed inside the gradient magnetic field coil 2 . Then, the transmission coil 4 applies an RF magnetic field to an imaging space formed in the space on the inner peripheral side of the transmission coil 4 based on the RF pulse signal output from the transmission circuit 5.

  The transmitter circuit 5 outputs an RF pulse signal corresponding to the Larmor frequency to the transmitter coil 4.

  The receiving coil 6 is an RF coil that receives an MR signal emitted from the subject S. For example, the receiving coil 6 is mounted on the subject S disposed on the inner circumferential side of the transmitting coil 4, and receives an MR signal emitted from the subject S under the influence of the RF magnetic field applied by the transmitting coil 4. Then, the receiving coil 6 outputs the received MR signal to the receiving circuit 7. For example, as the reception coil 6, a dedicated coil is used for each part to be imaged. Here, the dedicated coil means, for example, a head reception coil, a neck reception coil, a shoulder reception coil, a chest reception coil, an abdomen reception coil, a leg reception coil, a spine , And the like.

  The receiving circuit 7 generates MR signal data based on the MR signal output from the receiving coil 6, and outputs the generated MR signal data to the processing circuit 13.

  Here, an example in which the transmitting coil 4 applies an RF magnetic field and the receiving coil 6 receives an MR signal will be described, but the form of each RF coil is not limited to this. For example, the transmitting coil 4 may further have a receiving function of receiving an MR signal, and the receiving coil 6 may further have a transmitting function of applying an RF magnetic field. When the transmission coil 4 has a reception function, the reception circuit 7 also generates MR signal data from the MR signal received by the transmission coil 4. In addition, when the receiving coil 6 has a transmitting function, the transmitting circuit 5 also outputs an RF pulse signal to the receiving coil 6.

  The bed 8 includes a top 8 a on which the subject S is placed, and when imaging of the subject S is performed, the imaging space formed on the inner peripheral side of the static magnetic field magnet 1 and the gradient magnetic field coil 2 Insert the plate 8a. For example, the bed 8 is installed so that the longitudinal direction is parallel to the central axis of the static magnetic field magnet 1.

  The input circuit 9 receives input operations of various instructions and various information from the operator. For example, the input circuit 9 is realized by a trackball, a switch button, a mouse, a keyboard, a touch panel or the like. The input circuit 9 is connected to the processing circuit 15, converts an input operation received from the operator into an electric signal, and outputs the electric signal to the processing circuit 15.

  The respiration sensor 9a is attached to the abdomen of the subject S, and detects periodic movement of the subject S due to respiration. For example, the respiration sensor 9a detects the movement of the abdomen due to respiration, converts the detected movement into an electrical signal, and outputs it as a respiration signal (respiratory waveform). The respiration signal output from the respiration sensor 9 a is sent to the processing circuit 15 and used to evaluate the respiration state of the subject S. The technique for detecting the respiration signal of the subject S is not limited to the respiration sensor 9a, and any conventional technique may be applied.

  The display 10 displays various information and various images. For example, the display 10 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, a touch panel, or the like. The display 10 is connected to the processing circuit 15, and converts data of various information and various images sent from the processing circuit 15 into electric signals for display and outputs the electric signals. In addition, the display 10 according to the present embodiment presents the protocol candidate and the imaging condition candidate to the user by displaying the protocol candidate and the imaging condition candidate. The display 10 is disposed, for example, in the operation room. The display 10 is an example of a display unit.

  The speaker 10 a outputs a sound of a breathing instruction to the subject S. For example, the speaker 10a receives an electrical signal of prerecorded audio data (corresponding to audio data 11a described later) such as "breathing" or "discharging", converts the accepted electrical signal into vibration, and converts the voice into sound. Output.

  The storage circuit 11 stores various data. For example, the storage circuit 11 stores MR signal data and image data for each subject S. For example, the storage circuit 11 is realized by a semiconductor memory device such as a random access memory (RAM), a flash memory, a hard disk, an optical disk, or the like. In addition, the storage circuit 11 according to the present embodiment stores the audio data 11a.

  The voice data 11a is data for performing voice guidance for breath-hold imaging. For example, the voice data 11 a is data in which a voice “suck, spit and stop” is recorded. Specifically, voices of three breathing instructions "breathing", "spitting", and "please stop" are data sequentially recorded at a constant time interval. That is, when the voice data 11a is reproduced, voice guidance "suck, spit, stop" flows. The audio data 11a is not limited to the above example, and any audio can be recorded. In addition, a series of voices "suck, spit and stop" may not be recorded as one data. For example, three sounds of "suck", "spit" and "stop" may be separately recorded.

  The processing circuit 12 has a bed control function 12a. The processing circuit 12 is connected to the bed 8. For example, the processing circuit 12 is realized by a processor. The bed control function 12 a controls the operation of the bed 8 by outputting a control electric signal to the bed 8. For example, the bed control function 12a receives an instruction to move the table 8a in the longitudinal direction, the vertical direction, or the lateral direction from the operator via the input circuit 9, and moves the table 8a according to the received instruction. The drive mechanism of the top 8 a of the bed 8 is operated.

  The processing circuit 13 has a sequence execution function 13a. For example, the processing circuit 13 is realized by a processor. The sequence execution function 13a executes various protocols. Specifically, the sequence execution function 13a executes various protocols by driving the gradient magnetic field power supply 3, the transmission circuit 5, and the reception circuit 7 based on the sequence execution data output from the processing circuit 15.

  Here, the sequence execution data is information defining a protocol indicating a procedure for collecting MR signal data. Specifically, the sequence execution data includes the timing at which the gradient magnetic field power supply 3 supplies current to the gradient magnetic field coil 2 and the strength of the supplied current, the strength of the RF pulse current supplied to the transmission coil 4 by the transmission circuit 5, It is information defining the supply timing, the detection timing at which the reception circuit 7 detects an MR signal, and the like.

  The sequence execution function 13 a receives MR signal data from the receiving circuit 7 as a result of executing various pulse sequences, and stores the received MR signal data in the storage circuit 11. The set of MR signal data received by the sequence execution function 13a is two-dimensionally or three-dimensionally arranged according to positional information provided by the readout gradient magnetic field, the phase encoding gradient magnetic field, and the slice gradient magnetic field described above. As a result, the data is stored in the storage circuit 11 as data constituting the k space.

  When the processing circuit 13 receives the ID output from the receiving circuit 7, the processing circuit 13 stores the received ID in the storage circuit 11. At this time, the processing circuit 13 stores the ID in the storage circuit 11 for each inspection. An inspection is a unit for executing a protocol group. The protocols included in the protocol group are units for performing imaging.

  The processing circuit 14 has an image generation function 14 a. For example, the processing circuit 14 is realized by a processor. The image generation function 14 a generates an image based on the MR signal data stored in the storage circuit 11. Specifically, the image generation function 14a reads the MR signal data stored in the memory circuit 11 by the sequence execution function 13a, and performs a post-processing, ie, a reconstruction process such as Fourier transform, on the read MR signal data. Generate Further, the image generation function 14 a stores the image data of the generated image in the storage circuit 11.

  The processing circuit 15 has a control function 15a, an acquisition function 15b, an evaluation function 15c, and an execution function 15d. For example, the processing circuit 15 is realized by a processor.

  The control function 15 a controls the entire components of the MRI apparatus 100 to control the entire MRI apparatus 100. For example, the control function 15a receives input of various parameters related to the pulse sequence from the operator via the input circuit 9, and generates sequence execution data based on the received parameters. Then, the control function 15a executes various pulse sequences by transmitting the generated sequence execution data to the processing circuit 13. Further, for example, the control function 15 a reads out the image data of the image requested by the operator from the storage circuit 11, and outputs the read out image data to the display 10.

  The acquisition function 15b, the evaluation function 15c, and the execution function 15d will be described later. The control function 15a is an example of a control unit. The acquisition function 15b is an example of an acquisition unit. The evaluation function 15 c is an example of an evaluation unit. The execution function 15d is an example of an execution unit.

  The word “processor” used in the above description is, for example, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (for example, It means circuits such as Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA). Note that instead of storing the program in the memory circuit 11, the program may be directly incorporated in the circuit of the processor. In this case, the processor implements the function by reading and executing a program embedded in the circuit.

  The overall configuration of the MRI apparatus 100 according to the first embodiment has been described above.

  Here, in the breath-hold imaging, for example, the MRI apparatus 100 reproduces an audio guidance of "suck, spit, stop". The subject S performs the three actions of "sucking", "spitting", and "stopping" in order according to the voice guidance.

  However, there is a case where the reproduction speed of the voice guidance reproduced from the MRI apparatus 100 is fast for the subject S, and the subject S can not follow the instruction of the voice guidance. In such a case, the subject S can not hold his / her breath for a sufficient time. In addition, there are cases where the operator can not hold his / her breath or breath as intended by the condition (body), skill, knowledge or the like of the subject S. In addition, even if the operator can perform the intended breath holding function and starts the breath holding imaging, he / she can not hold his breath until the imaging completion, and the subject S resumes breathing during the imaging. There is also.

  As described above, in the breath holding imaging, when the breath holding function is not performed in accordance with the intention of the operator, a breathing artifact may occur, and the imaging may be retried.

  Therefore, the MRI apparatus 100 according to the present embodiment executes the following processing functions in order to reduce respiratory artefacts.

  The acquisition function 15b acquires a biological signal of the subject S. For example, the acquisition function 15b acquires the respiration signal output from the respiration sensor 9a as a biological signal. The technique for detecting the respiration signal of the subject S is not limited to the respiration sensor 9a, and any conventional technique may be applied.

  The evaluation function 15 c analyzes the biological signal in real time, and evaluates the relationship between the breathing instruction set in advance and the respiratory state of the subject S. For example, the evaluation function 15 c estimates the respiration state of the subject S by analyzing the respiration signal acquired by the acquisition function 15 b in real time. Then, the evaluation function 15c evaluates the relationship between the estimated breathing state and the breathing instruction.

  Specifically, the evaluation function 15 c evaluates, as a relationship with the breathing instruction, whether the current breathing state of the subject S corresponds to the breathing state required for the breathing instruction set in advance. Further, for example, the evaluation function 15 c evaluates whether the subject S has appropriately executed a preset breathing instruction as a relationship with the breathing instruction.

  FIG. 2 is a diagram for explaining the process of the evaluation function 15 c according to the first embodiment. FIG. 2 illustrates the waveform of the respiration signal of the subject S detected in the breath holding imaging. The horizontal axis in FIG. 2 corresponds to time, and the vertical axis corresponds to inspiratory phase / expiratory phase.

  As shown in FIG. 2, the evaluation function 15c sequentially identifies each breathing condition required for each feature included in the breath holding function. Here, the breathing instruction to be evaluated by the evaluation function 15 c is set in advance. For example, in the breath holding imaging, it is decided to sequentially perform three actions of "sucking," "spitting," and "stopping" as breath holding features. Among these, in order to perform the act of "sucking", it is appropriate that "the end of exhalation". In addition, it is appropriate to be at the end of inspiratory phase in order to perform the function of "discharge". In addition, it is appropriate that "the end of exhalation" is performed in order to act as "stop" for breath holding imaging. In other words, the evaluation function 15c is a sequence of three actions of "sucking", "breathing", and "stopping" among the breath holding features, and the breathing state "end exhalation" and "end of inspiration" required for each action. , And “end exhalation” in order.

  Here, the “end of exhalation” has a waveform feature in which the negative slope is zero or the negative slope is small. In addition, “the end of intake” has a feature that the positive slope becomes 0 or the positive slope becomes smaller.

  Therefore, when the breath holding imaging is started, the evaluation function 15 c sequentially evaluates whether or not the current respiration state of the subject S corresponds to each identified respiration state, using the features of the respiration state. For example, the evaluation function 15 c evaluates whether “end exhalation” is or not based on the waveform of the respiration signal under natural respiration before the start of the breath holding function. In the example shown in FIG. 2, the evaluation function 15 c evaluates to “end exhalation” in the period T1. Subsequently, the evaluation function 15c evaluates whether or not the "end of inspiration" is based on the waveform of the respiration signal at the time of holding the breath. In the example shown in FIG. 2, the evaluation function 15 c evaluates to “end of intake” in the period T2. Then, the evaluation function 15 c evaluates whether “end exhalation” is or not based on the waveform of the respiration signal at the time of breath holding function. In the example shown in FIG. 2, the evaluation function 15 c evaluates to “end exhalation” in the period T3.

  In addition, the evaluation function 15 c evaluates whether or not the subject S can properly hold his / her breath. The “breath-hold” is characterized in that the respiration signal is flat (the amount of change in amplitude is equal to or less than the threshold). In this case, the evaluation function 15c evaluates whether or not "hold breath" is appropriate based on the waveform of the respiration signal at the time of holding breath. In the example shown in FIG. 2, the evaluation function 15 c evaluates to “hold breath” in the period T4.

  As described above, the evaluation function 15 c evaluates the relationship between the respiratory state of the subject S and the preset respiratory state on the basis of the waveform of the respiratory signal of the subject S. Then, the evaluation function 15c outputs the evaluation result to the execution function 15d.

  Note that the content illustrated in FIG. 2 is merely an example and is not limited to the content illustrated. For example, the breathing state evaluated by the evaluation function 15 c is not limited to “end exhalation” and “end of inspiration”. For example, the evaluation function 15 c may evaluate “respiratory resumption”. "Respiratory resumption" is characterized in that the amplitude increases from the "breath holding" state. The respiratory condition may be evaluated further in consideration of "respiratory volume", "response speed", "respiratory speed" and the like. The "respiratory volume" corresponds to the amplitude of the respiratory signal and is detected by being above or below an arbitrary threshold. The “response speed” corresponds to the time from when the voice instruction is reproduced to when the respiration signal of the subject S changes. Also, "breathing rate" corresponds to the cycle of the breathing signal, and is used to adjust the timing of reproducing three voice instructions "breathing", "spitting", and "stop". Also, for example, the evaluation function 15c may evaluate using the waveform shape of the respiration signal. In this case, the waveform shape (Sine waveform etc.) intended by the operator may be registered, and the evaluation function 15c may evaluate in accordance with the similarity between the registered waveform shape and the waveform shape of the current respiration signal. it can.

  Further, in FIG. 2, the upper side of the vertical axis corresponds to the inspiratory phase, and the lower side of the vertical axis corresponds to the expiratory phase. However, the embodiment is not limited to this. For example, the vertical axis in FIG. 2 may be reversed depending on the sensor or measurement logic for measuring respiration. In this case, since the waveform cycle corresponding to the breathing cycle is reversed, the features of “end exhalation” and “end of inspiration” described above are true reverse cycles. That is, in this case, "end exhalation" has a feature that the positive slope becomes 0 or becomes smaller, and "end inspiration" becomes such that the negative slope becomes 0 or negative slope. Has the characteristic of a waveform that becomes smaller.

  The execution function 15d executes processing related to breath-hold imaging in accordance with the evaluation result by the evaluation function 15c. For example, the execution function 15d adjusts the execution conditions associated with breath-hold imaging. Also, for example, the execution function 15 d displays information associated with adjustment of the execution condition or information associated with the evaluation result.

  As a specific example, the execution function 15d controls voice guidance reproduction processing associated with breath-hold imaging. That is, in the reproduction of the voice data 11a in which the voice of "suck, spit and stop" is recorded, the execution function 15d takes three breaths of "suck," "spit," and "stop." Control so that the voice of the instruction is reproduced at an appropriate timing. The breathing instruction represents a voice for instructing the subject S to hold a breath.

  FIGS. 3A to 3D are diagrams for explaining the process of the execution function 15d according to the first embodiment. FIGS. 3A, 3B, 3C, and 3D sequentially illustrate temporal changes in the respiration signal of the subject S detected in real time in breath-hold imaging. Specifically, FIG. 3A exemplifies a change in the respiration signal acquired at time t1. FIG. 3B exemplifies a change in the respiration signal acquired at time t2. FIG. 3C exemplifies the change in the respiration signal acquired at time t3. FIG. 3D exemplifies the change of the respiration signal acquired at time t4. The horizontal axes of FIGS. 3A to 3D correspond to time, and the vertical axes correspond to the inspiratory phase / expiratory phase. The time t1 is a temporary point included in the period T1 of FIG. The time t2 is a temporary point included in the period T2 of FIG. Time t3 is a temporary point included in period T3 of FIG. Time t4 is a temporary point included in period T4 of FIG.

  As shown in FIGS. 3A to 3D, when the breath-hold imaging is started, the execution function 15 d sequentially receives the evaluation results by the evaluation function 15 c. Then, the execution function 15d controls the reproduction of the audio data 11a according to the received evaluation result.

  For example, at time t1, the execution function 15d receives an evaluation result indicating that the current respiratory state is "end exhalation" (FIG. 3A). At the timing when the evaluation result is received, the execution function 15d causes the speaker 10a to output a voice of "sucking". Subsequently, at time t2, the execution function 15d receives an evaluation result indicating that the current breathing state is "the end of the inspiration" (FIG. 3B). At the timing when the evaluation result is received, the execution function 15d causes the speaker 10a to output a voice of "discharge". Then, at time t3, the execution function 15d receives an evaluation result indicating that the current breathing state is "the end of exhalation" (FIG. 3C). At the timing when the evaluation result is received, the execution function 15d causes the speaker 10a to output a voice "Please stop." After that, at time t4, the execution function 15d receives an evaluation result indicating that “hold of breath” is appropriate (FIG. 3D). When the evaluation result is received, the execution function 15d outputs a breath holding imaging start request to the sequence execution function 13a. Thus, the sequence execution function 13a starts the breath holding imaging.

  As described above, the execution function 15d executes the processing related to the breath-hold imaging according to the evaluation result by the evaluation function 15c. Specifically, the execution function 15d adjusts the output timing of the sound related to the breath-hold imaging as the execution condition. The execution function 15d also adjusts the start timing of the breath-hold imaging as an execution condition.

  The contents illustrated in FIGS. 3A to 3D are merely examples, and the present invention is not limited to the contents illustrated. For example, the execution function 15d may output a sound of "please ease" after a predetermined time (for example, the time required for breath holding imaging) has elapsed since the sound of "please stop" is output. . In addition, the execution function 15d may notify the operator and the subject S of a message to the effect that "breath holding" is properly performed, when "breath holding" is properly performed. .

  Also, for example, if the execution function 15 d detects “resume resumption” before a predetermined time has elapsed since the voice “Please stop” is output, a message indicating that respiration has been resumed. May be displayed on the display 10. Also, for example, the execution function 15d may notify the operator of an evaluation result (for example, response speed or the like) by the evaluation function 15c. This notification can be output in any output form such as voice, message display, and alarm sound.

  FIG. 4 is a flowchart showing the processing procedure of the MRI apparatus 100 according to the first embodiment. FIG. 5 is a flowchart showing a processing procedure of voice guidance reproduction processing according to the first embodiment. The processing procedure shown in FIG. 5 corresponds to the processing procedure of the process of step S105 shown in FIG.

  In step S101, the control function 15a sets an imaging condition. For example, the control function 15a receives an input of imaging conditions by an operator on a graphical user interface (GUI), and sets an imaging condition of a protocol defined in sequence execution data according to the received input.

  In step S102, the bed control function 12a moves the top 8a on which the subject S is placed. Specifically, the bed control function 12a inserts the top 8a into the imaging space such that the imaging region set by the imaging condition is positioned at the center of the magnetic field.

  In step S103, the sequence execution function 13a executes a preparation scan. For example, in the preparatory scan, for example, a scan for collecting profile data indicating the sensitivity of the arrangement direction of each coil element (or channel), and a sensitivity map indicating the sensitivity distribution of each coil element (or channel) Scan, and a scan for collecting spectrum data to determine the center frequency of the RF pulse.

  In step S104, the acquisition function 15b starts acquisition of a respiration signal. For example, the acquisition function 15b starts acquisition of the respiration signal output from the respiration sensor 9a. Although acquisition of a respiration signal is basically performed until acquisition of MR signal data is completed, the acquisition may be interrupted (ended) when the respiration signal becomes unnecessary.

  In step S105, the evaluation function 15c and the execution function 15d execute voice guidance reproduction processing. Here, the processing procedure of the voice guidance reproduction processing will be described with reference to FIG.

  In step S201, the evaluation function 15c specifies a breathing state suitable for the first of the breath holding features. For example, the evaluation function 15 c specifies “end exhalation” as a breathing state suitable for the behavior of “sucking”.

  In step S202, the evaluation function 15c evaluates whether or not the current respiration state of the subject S is the identified respiration state. For example, the evaluation function 15 c evaluates whether or not the current respiratory condition acquired by the acquisition function 15 b is “end exhalation” suitable for the behavior of “sucking”. Specifically, the evaluation function 15 c evaluates whether “the end of exhalation” is or not based on whether or not the current breathing waveform has the “end of exhalation” feature. If the evaluation function 15 c evaluates that the current respiratory state is “end exhalation”, the evaluation function 15 c outputs an evaluation result to the execution function 15 d.

  In step S203, the execution function 15d outputs a voice corresponding to the work according to the evaluation result. For example, when the execution function 15d receives an evaluation result indicating that the current respiratory state is "end exhalation" by the evaluation function 15c, the speaker 10a may sound "suck" as a sound corresponding to the act of "sucking". Output from

  In step S204, the processing circuit 15 determines whether or not there is a next feature of the breath holding features. For example, when the first feature "sucking" is completed, the processing circuit 15 determines that "spit" exists as the next feature (Yes at step S204), and proceeds to processing at step S205. Further, for example, when the second function "discharge" is completed, the processing circuit 15 determines that "stop" is present as the next function (Yes at step S204), and the process proceeds to step S205.

  In step S205, the evaluation function 15c specifies a breathing state suitable for the next function. For example, the evaluation function 15 c specifies “end of inspiration” as a breathing state suitable for “breathing” if the next feature is “breathing”. Also, for example, if the next function is "stop", the evaluation function 15c specifies "end exhalation" as a breathing state suitable for "stop". Then, the processing circuit 15 proceeds to the process of step S202. As a result, the processing circuit 15 repeatedly executes the processing of step S202 to step S205 until it is determined that the next behavior does not exist (No at step S204).

  If it is determined that the next behavior does not exist (No at Step S204), at Step S206, the evaluation function 15c evaluates whether "hold of breath" is appropriate. For example, the evaluation function 15c evaluates whether or not the "breath-hold" is appropriate based on whether or not the current breathing waveform has the "breath-hold" feature. If “hold breath” is appropriate (Yes at step S206), the evaluation function 15c outputs an evaluation result indicating that “hold breath” is appropriate to the execution function 15d, and the process proceeds to step S207. On the other hand, when the "breath holding" is not appropriate (No at Step S206), the processing circuit 15 proceeds to Step S201. That is, the processing circuit 15 executes the voice guidance of the breath holding function from the beginning again.

  In step S207, when the execution function 15d receives an evaluation result indicating that "hold of breath" is appropriate, the execution function 15d outputs a request for starting of hold of breath holding. For example, the execution function 15d outputs a breath holding imaging start request to the sequence execution function 13a.

  It returns to the explanation of FIG. In step S106, the sequence execution function 13a starts breath-hold imaging. For example, the sequence execution function 13a starts the preset breath-hold imaging at the timing of receiving the breath-hold imaging start request output from the execution function 15d.

  In step S107, the image generation function 14a generates an image. For example, the image generation function 14a generates an image based on the MR signal data acquired by breath-hold imaging.

  In step S108, the control function 15a displays an image. For example, the control function 15a causes the display 10 to display the image generated by the image generation function 14a.

  The contents shown in FIGS. 4 and 5 are merely examples, and the present invention is not limited to the contents shown in the drawings. For example, the processing procedures illustrated in FIG. 4 and FIG. 5 are not limited to the above order. For example, the timing to start acquisition of a respiration signal (step S104) can be performed at any timing before the voice guidance reproduction process is started.

  Further, for example, in the above-described example, although the case where the breath holding imaging is performed once is illustrated, the present invention is not limited to this. For example, in the case where the breath holding imaging is performed a plurality of times, the embodiment can be applied to each voice guidance reproduction process that is performed before the respective breath holding imaging.

  In addition, it is preferable to set an upper limit on the number of times the voice guidance is executed again from the beginning. This is because the examination time is extended and the load on the subject S is increased as the number of times of execution of the voice guidance is increased. For example, when the number of times of execution of the voice guidance has reached the upper limit (for example, three times), it is preferable to adjust the execution condition related to the breath holding imaging. For example, the execution function 15 d cancels the breath-hold imaging or executes a previously designated function or protocol. In this case, the execution function 15d can automatically execute the registered adjustment content by registering the adjustment content of the execution condition in advance. The number of times of the upper limit can be arbitrarily changed by the operator.

  As described above, in the MRI apparatus 100 according to the first embodiment, the acquisition function 15 b acquires the respiration signal of the subject S. Then, the evaluation function 15c analyzes the respiration signal in real time, and evaluates the relationship with the preset breathing instruction. Then, the execution function 15d executes a process related to breath-hold imaging in accordance with the evaluation result by the evaluation function 15c. According to this, the MRI apparatus 100 according to the first embodiment can reduce respiratory artefacts.

  For example, the MRI apparatus 100 can adjust the audio guidance regarding the breath-hold imaging at an appropriate timing according to the breathing state of the subject S by the above-described processing. As a result, it becomes possible for the subject S to easily and reliably perform the breath holding function intended by the operator. For this reason, the MRI apparatus 100 can reduce a respiratory artifact caused by the subject S not being able to perform the breath holding function intended by the operator. Along with this, the MRI apparatus 100 can reduce the probability that the breath holding imaging will be re-imaging, and can improve the throughput.

(Modification 1 of the first embodiment)
In the first embodiment, the case of performing real-time analysis of the respiration signal acquired from the subject S has been described, but the invention is not limited thereto. For example, real-time analysis of other biological signals may be combined. It is.

  For example, when an electrocardiogram signal of the subject S can be acquired, the evaluation function 15c performs real-time analysis of the electrocardiogram signal. As one example, the evaluation function 15 c analyzes the electrocardiogram signal, and evaluates whether or not the respiratory condition of the subject S is rest depending on whether or not the heart rate (or pulse wave) is equal to or more than a threshold. Do. For example, it is known that if you hold your breath for a long time by breath-hold imaging, your heart rate will rise as you get harder. Therefore, in the case where the breath holding imaging is performed multiple times, it is necessary to perform the second (or third or subsequent) breath holding imaging after confirming whether the breathing state of the subject S is at rest or not. It is suitable. Therefore, when the heart rate of the subject S is less than the threshold, the evaluation function 15 c evaluates that the respiratory state of the subject S is rest. Then, the evaluation function 15c outputs the evaluation result to the execution function 15d. The execution function 15d performs, for example, the second (or third or later) breath holding imaging (or permits execution of the breath holding imaging) when the state of the subject S is stable, or the like. Execute processing according to

  In addition, measurement of the heart rate from an electrocardiogram signal can be performed by detection of an Impulse waveform, for example. In addition, as other biosignals, biosignals that can be acquired by any conventional technique can be applied as an analysis target as well as the electrocardiogram signal. For example, when the breath of the subject S is rising, the dystrophy of the pulse wave is recognized. Therefore, the evaluation function 15 c uses the feature that “the dystrophy of the pulse wave is not recognized”, the state of the subject S is You may evaluate that it is stable.

  In the process according to the first modification of the first embodiment described above, the respiration signal may not necessarily be used. That is, the acquisition function 15a acquires an electrocardiogram signal as a biological signal of the subject S. Then, the evaluation function 15b analyzes the electrocardiogram signal in real time, and evaluates the relationship between the breathing instruction set in advance and the breathing state of the subject. For example, the evaluation function 15b evaluates whether or not the breathing state of the subject is rest by the process according to the first modification of the first embodiment described above. Then, the execution function 15d executes a process related to breath-hold imaging in accordance with the evaluation result by the evaluation function 15b.

  In addition, in the processing according to the first modification of the first embodiment described above, breathing instructions (for example, three voice instructions and timings of "breathing", "spitting", and "stop") are set in advance. It does not have to be That is, even if the breathing instruction is not set in advance, the evaluation function 15b can analyze the electrocardiogram signal in real time to evaluate whether the breathing state of the subject S is at rest or not.

(Modification 2 of the first embodiment)
Also, for example, the parameters and threshold values described in the above embodiments can be arbitrarily changed by the operator. In addition, as a change of a parameter or a threshold, addition or deletion of a parameter or a threshold shall be included.

  FIG. 6 is a functional block diagram showing the configuration of the MRI apparatus 100 according to the second modification of the first embodiment. An MRI apparatus 100 according to the second modification of the first embodiment has a configuration similar to that of the MRI apparatus 100 illustrated in FIG. 1, and is different in that the processing circuit 15 further includes a parameter management function 15 e. Therefore, the points having the same functions as those of the configuration described in FIG.

  The parameter management function 15 e changes at least one of the parameter and the threshold value used for evaluation in the evaluation function 15 c in accordance with the input of the operator. For example, the operator performs an input to change the parameter for evaluating “end exhalation” from “slope” to “amplitude” of the respiration signal. When this change is received, the parameter management function 15 e changes the parameter for evaluating “end exhalation” from “slope” to “amplitude” of the respiration signal. In this case, for example, the evaluation function 15 c evaluates to “end expiratory” when the amplitude of the respiration signal becomes equal to or less than the threshold.

  Also, for example, the operator performs an input to change the threshold used for the various parameters described above to an arbitrary value. When this change is received, the parameter management function 15 e changes the threshold used for various parameters to the value input by the operator.

  Also, for example, the parameter management function 15 e performs the change of the parameter or the threshold in the unit of the subject S, the age unit, the gender unit, the site unit, the protocol unit, the coverage unit, the time unit, any other unit Can. Note that coverage is a unit in which all slices to be imaged are divided into an arbitrary number of pieces that can be collected at one time.

  Thus, the parameter management function 15 e changes at least one of the parameter and the threshold used for evaluation in the evaluation function 15 c in accordance with the input of the operator. In addition, the parameter management function 15e can appropriately change the type of the work to be evaluated, its parameters, and the threshold according to the input of the operator.

(Modification 3 of the first embodiment)
Moreover, it is not limited to the voice guidance mentioned above. For example, the execution function 15d may output a voice of “Start breath holding imaging” before imaging.

  FIG. 7 is a diagram for explaining the process of the execution function 15d according to the third modification of the first embodiment. FIG. 7 illustrates the waveform of the respiration signal of the subject S detected in the breath-hold imaging. The horizontal axis in FIG. 7 corresponds to time, and the vertical axis corresponds to inspiratory phase / expiratory phase.

  As shown in FIG. 7, at time t0, the execution function 15d outputs an audio of “Start breath-hold imaging”. Note that this voice may be output, for example, when a normal breathing signal under natural breathing is detected by the evaluation function 15c, or is automatically output a certain time before the breath holding imaging is started. It is also good.

(Modification 4 of the first embodiment)
Also, for example, the execution function 15d may adjust the content of the voice guidance of each time when the voice guidance is redone.

  For example, the execution function 15d adjusts the volume of the sound to be output. Specifically, the execution function 15d increases the volume of the sound to be output when the "breath holding" is not appropriate.

  Also, for example, the execution function 15d adjusts the frequency of the sound to be output. Specifically, the execution function 15d changes the sex of the voice "suck, spit, stop". Also, for example, the execution function 15 d switches the audio data to be output to another audio data prepared in advance. Specifically, the execution function 15d switches to a voice having the same content of "suck, spit, stop," but different in the speaker's speaking style (polite language, dialect, etc.). As a result, the effect of improving the intelligibility of the voice guidance or awakening the sleeping subject S is expected.

  Also, for example, the execution function 15d adjusts the content of the sound to be output according to the evaluation result by the evaluation function 15c. For example, when the execution function 15d evaluates that breathing is shallow for a preset breathing instruction (for example, when the amplitude of the breathing signal is small), the voice "Please breathe deeper next" Are output from the speaker 10a. As described above, the execution function 15 d can notify the subject S of a method for improving respiration, in accordance with the evaluation result for the breathing instruction set in advance.

  Also, for example, in the evaluation result by the evaluation function 15c, when it is suspected that the subject S is asleep and it is necessary to redo it, the execution function 15d generates a large imaging sound to wake up the subject S. A ringing protocol (eg, EPI etc.) may be inserted automatically.

  Further, for example, in the evaluation result by the evaluation function 15c, even if it is repeated a certain number of times or more, the action intended by the operator may not be intended. As one example, it may not be the action intended by the operator even if it is retried more than a fixed number of times because the breathing instruction can not be followed. In this case, the execution function 15d may change the protocol of the intended breath-hold imaging to a protocol that does not require a breath-hold. For example, RMC imaging or synchronous imaging can be applied as a protocol that does not require breath holding. The adjustment of the protocol group will be described in detail in a later embodiment.

Second Embodiment
In the first embodiment, the case of analyzing the breathing signal at the time of voice guidance of breath holding imaging in real time and adjusting the execution condition of voice guidance and breath holding imaging has been described, but the embodiment is limited to this is not. For example, when practicing voice guidance, it is also possible to analyze a breathing signal at the time of training and adjust the execution condition according to the result.

  The MRI apparatus 100 according to the second embodiment has a configuration similar to that of the MRI apparatus 100 illustrated in FIG. 1, and is different in that the processing circuit 15 executes a process related to the practice of voice guidance. In the second embodiment, therefore, differences from the first embodiment will be mainly described, and descriptions of points having the same functions as the configurations described in the first embodiment will be omitted.

  FIG. 8 is a flowchart showing the processing procedure of the MRI apparatus according to the second embodiment. In addition, since the process of step S101-step S104 shown in FIG. 8 is the same as the process of step S101-step S104 shown in FIG. 4, description is abbreviate | omitted. Moreover, since the process of step S106-step S108 shown in FIG. 8 is the same as the process of step S106-step S108 shown in FIG. 4, description is abbreviate | omitted.

  In step S305, the execution function 15d reproduces the voice guidance for practice. For example, the execution function 15d reproduces voice data 11a for voice guidance used for breath-hold imaging as voice guidance for practice. In this practice voice guidance, for example, three breathing instructions of "breathing", "spitting", and "stop" are voice-outputted at fixed time intervals. At this time, the acquisition function 15b acquires a respiration signal in the practice of the respiration instruction in the breath-hold imaging.

  In step S306, the execution function 15d adjusts the voice guidance. For example, the evaluation function 15 c analyzes the respiration signal in practice to evaluate the relationship between the preset breathing instruction and the respiration state of the subject S in practice. For example, the evaluation function 15 c evaluates the response time of the subject S to a breathing instruction. Here, when it is evaluated that the response time of the subject S is delayed as compared with the response time required for the voice guidance for practice, the execution function 15d performs the respiration output in the next step S307. Adjust the output timing of the instruction to advance by the time that was delayed. When the response time of the subject S is not delayed, the execution function 15d does not adjust the output timing of the breathing instruction.

  In step S307, the execution function 15d reproduces the voice guidance. For example, the execution function 15d outputs a breathing instruction in voice at the output timing adjusted in step S306. When the output timing of the breathing instruction is not adjusted in step S306, the execution function 15d outputs the breathing instruction at the same timing as the practice voice guidance.

  The content illustrated in FIG. 8 is merely an example, and the content is not limited to the content illustrated. For example, the processing procedure illustrated in FIG. 8 is not limited to the above order. For example, the timing to start acquisition of the respiration signal (step S304) can be performed at any timing before the training voice guidance is reproduced.

  Further, in the example of FIG. 8, the execution function 15d has described the case of adjusting the output timing of the breathing instruction as the execution condition, but the embodiment is not limited to this. For example, the execution function 15d may adjust an imaging condition of a breath-hold imaging protocol or protocol to be performed. The execution function 15d may be changed to a protocol that does not require breath holding. For example, RMC imaging or synchronous imaging can be applied as a protocol that does not require breath holding. The change of the protocol will be described in detail in the later embodiments.

  Thus, in the MRI apparatus 100 according to the second embodiment, the acquisition function 15 b acquires a respiration signal in the practice of the respiration instruction in the breath-hold imaging. The evaluation function 15c evaluates the relationship between the preset breathing instruction and the result of the exercise by analyzing the respiration signal in the practice. Then, the execution function 15d adjusts the execution condition related to the breath-hold imaging based on the relationship between the breathing instruction and the result of the exercise. According to this, the MRI apparatus 100 according to the second embodiment can evaluate before the main imaging (breath holding imaging) whether the subject S can execute the breath holding intended by the operator. it can.

  In the second embodiment, the output timing of the breathing instruction and the protocol group are adjusted as execution conditions related to the breath holding imaging, but the embodiment is not limited to this. For example, the execution function 15d may only present the evaluation result by the evaluation function 15c to the operator. Thereby, the operator can take some measures before the main imaging (breath holding imaging). For example, the operator can manually adjust the execution conditions associated with breath-hold imaging.

  Also, in the second embodiment, a series of processes from the evaluation result of the breathing state of the subject S in practice to the voice guidance of the main imaging and the execution of the main imaging have been described. May not necessarily be performed. For example, the execution function 15d may not necessarily perform the main imaging. Specifically, when it is evaluated that the subject S can not perform breathing according to the breathing instruction as a result of practice, the execution function 15d may repeatedly perform practice. Also, the execution function 15d may only present the evaluation result of the practice by the evaluation function 15c to the operator.

Third Embodiment
In the embodiment described above, the case of adjusting the output timing of the sound related to the breath-hold imaging has been described as the execution condition, but the embodiment is not limited to this. For example, as an execution condition, the MRI apparatus 100 can also perform adjustment on a protocol group of breath-hold imaging.

  An MRI apparatus 100 according to the third embodiment has a configuration similar to that of the MRI apparatus 100 illustrated in FIG. 1, and is different in that the processing circuit 15 performs adjustment regarding a breath hold imaging protocol group. Thus, in the third embodiment, differences from the first embodiment will be mainly described, and descriptions of points having the same functions as the configurations described in the first embodiment will be omitted.

  The execution function 15d according to the third embodiment performs adjustment on a protocol group of breath-hold imaging as an execution condition. The following five patterns (first to fifth patterns) can be mentioned as adjustments regarding the protocol group. Hereinafter, five patterns of adjustment regarding the protocol group will be described in order using FIGS. 9 to 13.

  FIGS. 9 to 13 are diagrams for explaining the processing of the execution function 15d according to the third embodiment. FIGS. 9 to 13 illustrate the relationship between the progress of the protocol group related to breath-hold imaging and the transition of the monitor that displays the respiration waveform. In FIGS. 9 to 13, the protocol group includes five protocols of “Locator et al.”, “Breath holding A”, “breath holding B”, “no breath holding A”, and “no breath holding B”. “Locator etc.” is a protocol for capturing a positioning image. Also, "breath holding A" and "breath holding B" are protocols for breath holding imaging. Also, "no breath holding A" and "no breath holding B" are protocols that do not require breath holding. The names of the protocol groups illustrated in FIG. 9 to FIG. 13 are merely for convenience of explanation, and in reality, any name can be set by the designer or the operator.

  First, the first pattern will be described. The first pattern is a method in which the execution function 15d inserts a break time between the protocol groups as an adjustment on the protocol groups. In the upper part of FIG. 9, imaging of “breath holding A” is performed. When the imaging of "breath holding A" is completed, a voice "please ease" is output from the speaker 10a, and "breath holding A" is completed (middle part of FIG. 9). Here, as shown in the middle part of FIG. 9, at the time when “hold breath A” is completed, the subject S is fatigued by the breath hold function, and the rest of the subject S is not secured. Therefore, the execution function 15d inserts a rest time between the protocol groups until the subject S rests. For example, the evaluation function 15 c analyzes the respiration signal in real time, and evaluates whether or not the respiration state of the subject is rest. Here, "rest" is evaluated by, for example, the shape of a typical breathing waveform at rest. Then, the execution function 15d executes a process of inserting a waiting time between the protocol groups set in advance, when it is evaluated that the breathing state of the subject is not rest. As a result, as shown in the lower part of FIG. 9, the execution function 15d puts the MRI apparatus 100 in a standby state without starting the execution of the next protocol "breath-hold B". Then, when it is evaluated that the subject's breathing state is at rest, the execution function 15 d ends the rest time (waiting time) and starts imaging of “breath-hold B”.

  Next, the second pattern will be described. The second pattern is a method in which the execution function 15d rearranges the order of the plurality of protocols included in the protocol group as adjustment on the protocol group. In addition, since the upper stage and middle stage of FIG. 10 are the same as the upper stage and middle stage of FIG. 9, description is abbreviate | omitted. As shown in the lower part of FIG. 10, the execution function 15d changes the order of the plurality of protocols included in the protocol group when it is evaluated that the breathing state of the subject S is not rest. For example, in FIG. 10, the protocol performed next to "breath holding A" is "breath holding B". Here, when it is evaluated that the respiratory state of the subject S is not rest, the execution function 15d searches for a protocol that does not require breath-hold among the unexecuted protocols. In FIG. 10, “no breath holding A” and “no breath holding B” are searched. Therefore, the execution function 15d, for example, changes the order of "breath holding B" and "breath holding no A", and performs imaging of "breath holding no A" first. In this case, it is preferable that the execution function 15d present a message of “change protocol for patient rest” to the operator. Thereby, the subject S can secure a rest during imaging of “no breath holding A”.

  Next, the third pattern will be described. The third pattern is a method in which the execution function 15d inserts a break protocol between the protocol groups as adjustment on the protocol groups. In addition, since the upper stage and middle stage of FIG. 11 are the same as the upper stage and middle stage of FIG. 9, description is abbreviate | omitted. As shown in the lower part of FIG. 11, the execution function 15d inserts a rest protocol between the protocol groups when it is evaluated that the respiratory state of the subject S is not rest. For example, in FIG. 11, the protocol to be executed next to "breath holding A" is "breath holding B". Here, if it is evaluated that the respiratory state of the subject S is not rest, the execution function 15d first executes the pre-scan included in the unexecuted protocol. Therefore, the execution function 15d inserts, for example, "pre-scan" in front of "breath-hold B". In this case, the execution function 15d preferably presents the operator with a message that "the pre-scan of the remaining imaging is performed until the patient rest is confirmed". Thereby, the subject S can secure a rest during imaging of “pre-scan”. In addition, not only "pre-scan" but arbitrary break protocols can be inserted. Here, "pre-scan" is a generic name of preliminary imaging performed prior to "main imaging (main scan)" for imaging a diagnostic image.

  Next, the fourth pattern will be described. The fourth pattern is a method in which the execution function 15d changes the breath holding imaging protocol to a breath holding unnecessary protocol as adjustment on the protocol group. In addition, since the upper stage and middle stage of FIG. 12 are the same as the upper stage and middle stage of FIG. 9, description is abbreviate | omitted. As shown in the lower part of FIG. 12, the execution function 15 d changes the breath holding imaging protocol to a breath holding unnecessary protocol when it is evaluated that the breathing state of the subject S is not rest. For example, in FIG. 12, the protocol to be executed next to "breath holding A" is "breath holding B". Here, if it is evaluated that the breathing state of the subject S is not rest, the execution function 15d changes the protocol of the breath holding imaging to a protocol not requiring breath holding. For example, the execution function 15 d changes “breathing B” to “RMC”. In this case, it is preferable that the execution function 15d presents a message to the operator that "because it is determined that it is difficult to hold a breath, the next imaging is changed to imaging that does not require breathing." Thereby, the subject S can continue imaging without holding his / her breath.

  Next, the fifth pattern is described. The fifth pattern is a method in which the execution function 15 d changes the imaging condition of the breath holding imaging protocol as adjustment regarding the protocol group. In addition, since the upper stage and middle stage of FIG. 13 are the same as the upper stage and middle stage of FIG. 9, description is abbreviate | omitted. As shown in the lower part of FIG. 13, the execution function 15 d changes the imaging condition of the breath-hold imaging protocol when it is evaluated that the respiration state of the subject S is not rest. For example, in FIG. 13, the protocol to be executed next to "breath holding A" is "breath holding B". Here, when it is evaluated that the respiratory state of the subject S is not rest, the execution function 15d changes the imaging condition of the breath-hold imaging protocol. For example, the execution function 15d changes the TR (Repetition Time) of the "breath-hold B" from "2000" to "100". In this case, it is preferable that the execution function 15d present a message of “change to an imaging condition that results in a short breath hold” to the operator. Thereby, even if the subject S is tired, imaging can be performed in such a short time that it is possible to hold a breath. In addition, it is also possible not only to change imaging conditions so that imaging time may become short, for example, to change imaging conditions so that it can image by a simple breath holding feature.

  As described above, the execution function 15d performs adjustment on the breath hold imaging protocol group as the execution condition.

  The first to fifth patterns described in the third embodiment are executed according to the evaluation result in which the evaluation function 15 c evaluates whether or not the respiratory state of the subject S is rest. It is suitable. For example, the execution function 15d executes a process related to breath-hold imaging in accordance with whether or not the respiratory state of the subject S is rest. Then, for example, when the breathing state of the subject S is not at rest, the execution function 15d inserts a rest time between the protocol group of the breath holding imaging. Also, for example, when the breathing state of the subject S is not at rest, the execution function 15d changes the order of the plurality of protocols included in the protocol group of the breath holding imaging. Also, for example, when the subject S is not at rest, the execution function 15d inserts a protocol for resting between the protocol groups of the breath holding imaging. Also, for example, if the subject S's breathing state is not at rest, the execution function 15 d changes the breath holding imaging protocol to a breath holding unnecessary protocol. Also, for example, when the breathing state of the subject S is not at rest, the execution function 15 d changes the imaging condition of the breath-hold imaging protocol.

  The contents described above are merely examples, and the present invention is not limited to the contents described above. For example, when a plurality of protocols for breath holding imaging are included in the protocol group, the execution function 15 d sets the order of the protocols so that the protocol with the longer breath holding time is performed first. As a result, the execution function 15d can execute the protocol with a long breath holding time before the state of the subject S decreases (for example, accumulation of fatigue), and as a result, the imaging of the entire protocol group is appropriately performed. Can.

  Also, for example, in the evaluation result by the evaluation function 15c, it may be suspected that the subject S is asleep or diligent, and it may be necessary to redo. In such a case, for example, the execution function 15d may automatically insert a protocol (for example, EPI or the like) in which a large imaging sound is emitted. Thereby, the execution function 15d can wake up when the subject S is sleeping, and can perform alerting when the subject S is blurred.

  Also, for example, the execution function 15d can change the synchronization condition, such as changing from breathing synchronization to imaging by ECG synchronization.

(Other embodiments)
The present invention may be embodied in various different forms other than the above-described embodiment.

(Processing when the breath holding of the subject S is interrupted)
For example, the evaluation function 15 c can detect that the breath holding has been interrupted by evaluating whether or not breathing has resumed during the breath holding imaging. Note that "resume resumption" can be evaluated by the feature that the amplitude increases from the "breath holding" state.

  Therefore, the execution function 15d suspends or suspends the breath-hold imaging when the breath-hold is interrupted when the breath-hold of the subject S is interrupted, and the collected data when the breathing is automatically resumed It is possible to Then, the execution function 15d can execute the following processing in order to collect imaging data included in the remaining protocol groups.

  For example, the execution function 15d reproduces a breathing instruction for performing breath-hold imaging again. The execution function 15d resumes the paused imaging for breath holding.

  Also, for example, the execution function 15 d changes the imaging condition so that the remaining imaging data can be collected. The execution function 15d reproduces the breathing instruction of the breath-hold imaging again. Then, the execution function 15d resumes the breath holding imaging that has been paused.

  Also, for example, the execution function 15d changes the imaging method or sequence type that does not require breath holding. Then, the execution function 15d resumes the main imaging that has been paused.

  Also, for example, the execution function 15d inserts a new protocol. Then, the execution function 15d causes the imaging condition control unit to change the imaging conditions so that the remaining imaging data can be collected. In addition, the execution function 15 d causes the display 10 to display a message indicating that the protocol has been changed to the one that can collect the remaining imaging data.

  Further, each component of each device illustrated is functionally conceptual, and does not necessarily have to be physically configured as illustrated. That is, the specific form of the dispersion and integration of each device is not limited to that shown in the drawings, and all or a part thereof is functionally or physically dispersed in any unit depending on various loads, usage conditions, etc. It can be integrated and configured. Furthermore, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as wired logic hardware.

  In addition, all or part of the processes described as being automatically performed among the processes described in the above-described embodiment and modification may be manually performed, or may be manually performed. All or part of the described processing can also be performed automatically in a known manner. In addition to the above, the processing procedures, control procedures, specific names, and information including various data and parameters shown in the above documents and drawings can be arbitrarily changed unless otherwise specified.

  In addition, the imaging method described in the above-described embodiment and modification can also be realized by executing an imaging program prepared in advance by a computer such as a personal computer or a workstation. This imaging program can also be distributed via a network such as the Internet. The imaging program can also be recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, a DVD, and the like, and can be executed by being read from the recording medium by a computer.

  Moreover, in said embodiment and modification, real time means performing each process immediately, whenever each data used as a process target generate | occur | produce. For example, the process of displaying an image in real time is not limited to the case where the time at which the subject is imaged and the time at which the image is displayed completely coincide, and the image may be slightly delayed depending on the time required for each process such as image processing. Is a concept that includes the case where it is displayed.

  According to at least one embodiment described above, respiratory artifacts can be reduced.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

100 MRI apparatus 15 processing circuit 15a control function 15b acquisition function 15c evaluation function 15d execution function

Claims (23)

An acquisition unit for acquiring a biological signal of the subject;
An evaluation unit that analyzes the biological signal in real time and evaluates a relationship between a preset breathing instruction and a breathing state of the subject;
An execution unit that executes processing related to breath-hold imaging in accordance with an evaluation result by the evaluation unit. The acquisition unit acquires a respiration signal of the subject as the biological signal,
The evaluation unit estimates the respiration state of the subject by analyzing the respiration signal in real time, and evaluates the relationship between the estimated respiration state and the respiration instruction.
The magnetic resonance imaging apparatus according to claim 1. The execution unit adjusts an execution condition related to the breath-hold imaging.
The magnetic resonance imaging apparatus according to claim 1. The acquisition unit acquires, as the biological signal, a respiration signal in a practice of a respiration instruction in the breath-hold imaging,
The evaluation unit evaluates a relationship between a preset breathing instruction and a breathing state of the subject in the exercise by analyzing a respiration signal in the exercise;
The execution unit adjusts an execution condition related to the breath-hold imaging based on a relationship between the breathing instruction and a breathing state of the subject in the exercise.
The magnetic resonance imaging apparatus according to claim 1. The execution unit adjusts, as the execution condition, an output timing of voice related to the breath-hold imaging.
A magnetic resonance imaging apparatus according to claim 3 or 4. The execution unit adjusts start timing of the breath-hold imaging as the execution condition.
A magnetic resonance imaging apparatus according to claim 3 or 4. The execution unit performs, as the execution condition, adjustment regarding a protocol group of the breath holding imaging.
A magnetic resonance imaging apparatus according to claim 3 or 4. The evaluation unit analyzes the biological signal in real time, and evaluates whether the respiratory state of the subject is rest or not.
The magnetic resonance imaging apparatus according to any one of claims 1 to 7. The execution unit inserts a break time between the breath hold imaging protocol group when the breathing state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 8. The execution unit rearranges the order of a plurality of protocols included in the protocol group of the breath holding imaging when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 8. The execution unit inserts a protocol for resting between the protocol groups of the breath holding imaging when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 8. The execution unit changes the breath-hold imaging protocol to a breath-hold-free protocol when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 8. The execution unit changes an imaging condition of the breath-hold imaging protocol when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 8. The execution unit displays information related to the adjustment of the execution condition.
A magnetic resonance imaging apparatus according to claim 3 or 4. The execution unit displays information related to the evaluation result.
The magnetic resonance imaging apparatus according to any one of claims 1 to 14. The evaluation unit evaluates, as a relationship with the respiration instruction, whether the current respiration condition of the subject corresponds to the respiration condition required for the respiration instruction.
The magnetic resonance imaging apparatus according to any one of claims 1 to 15. The image processing apparatus further includes a changing unit that changes at least one of a parameter and a threshold used for evaluation in the evaluation unit according to an input of the operator.
The magnetic resonance imaging apparatus according to any one of claims 1 to 16. An acquisition unit for acquiring a biological signal of the subject;
An evaluation unit which analyzes the biological signal in real time and evaluates whether or not the respiratory state of the subject is rest;
An execution unit that executes processing related to breath-hold imaging in accordance with whether or not the breathing state of the subject is at rest. The execution unit inserts a break time between the breath hold imaging protocol group when the breathing state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 18. The execution unit rearranges the order of a plurality of protocols included in the protocol group of the breath holding imaging when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 18. The execution unit inserts a protocol for resting between the protocol groups of the breath holding imaging when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 18. The execution unit changes the breath-hold imaging protocol to a breath-hold-free protocol when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 18. The execution unit changes an imaging condition of the breath-hold imaging protocol when the respiratory state of the subject is not at rest.
The magnetic resonance imaging apparatus according to claim 18.

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