JP5330006B2 - Magnetic resonance imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To support an examiner for easily analyzing the cardiac muscle movement using an image captured by a tagging method. <P>SOLUTION: An image input section 26a inputs tagged cine images of the heart, and an abnormal range setting section 26c sets an abnormal range indicating the movement area of the tag when the cardiac muscle movement is abnormal. An image analysis section 26d analyzes the cardiac muscle movement by determining whether or not each image input by the image input section 26a has an index non-exceeding the abnormal range set by the abnormal range setting section 26c. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a magnetic resonance imaging apparatus that images a subject using a magnetic resonance phenomenon, and more particularly to a technique for analyzing myocardial motion using an image captured by a tagging method.

  Conventionally, there is a tagging method as a method for analyzing the myocardial motion of the heart using a magnetic resonance imaging apparatus. This tagging method is a method of applying a selective excitation pulse that modulates magnetization according to a spatial position to linearly mark the imaging region including the heart, and then image the imaging region in time series. This is a method for observing the dynamics of the myocardium by grasping the change of the label in each generated image (see, for example, Patent Document 1 or 2).

Japanese Patent Laid-Open No. 7-178068 Japanese translation of PCT publication No. 2004-512883

  However, when analyzing myocardial motion using an image captured by the tagging method, the examiner visually compares the position of the tag in each image captured in time series to determine the motion of the myocardium. It was judged whether there was an abnormality. Therefore, conventionally, it has been very difficult to analyze the myocardial motion of the heart using the tagging method.

  The present invention has been made in view of the above, and provides a magnetic resonance imaging apparatus that assists an examiner so that myocardial motion can be easily analyzed using an image captured by a tagging method. For the purpose.

  In order to solve the above-described problems and achieve the object, the present invention according to claim 1 is a tagging for imaging a subject in time series after marking in an imaging region according to a spatial position. An image input means for inputting a plurality of images of the heart obtained by the method, an abnormal range setting means for setting an abnormal range indicating a moving range of the marker when the myocardial motion is abnormal, and an input by the image input means Image analysis means for analyzing myocardial motion of the heart by determining whether or not there is an index that does not exceed the abnormal range set by the abnormal range setting means for each of the images And

  According to the first aspect of the present invention, it is possible to assist the examiner so that the myocardial motion can be easily analyzed using the image captured by the tagging method.

FIG. 1 is a diagram illustrating an overall configuration of the MRI apparatus according to the first embodiment. FIG. 2 is a functional block diagram illustrating the configuration of the computer system according to the first embodiment. FIG. 3 is a diagram illustrating an example of range reception by the range specification reception unit according to the first embodiment. FIG. 4 is a diagram (1) illustrating another example of range reception by the range specification reception unit according to the first embodiment. FIG. 5 is a diagram (2) illustrating another example of range reception by the range specification reception unit according to the first embodiment. FIG. 6 is a diagram illustrating an example of the output of the analysis result by the image analysis unit according to the first embodiment. FIG. 7 is a flowchart for explaining a processing procedure of processing executed by the computer system according to the first embodiment. FIG. 8 is a diagram illustrating an example of accepting a range when a superimposed tagging cine image is used as a range designating image. FIG. 9 is a functional block diagram of a detailed configuration of the computer system according to the second embodiment. FIG. 10 is a diagram illustrating an example of an abnormal range setting by the abnormal range setting unit according to the second embodiment. FIG. 11 is a flowchart for explaining a processing procedure of processing executed by the computer system according to the second embodiment. FIG. 12 is a functional block diagram of a detailed configuration of the computer system according to the third embodiment. FIG. 13 is a diagram for explaining the statistical processing by the marker statistical processing unit according to the third embodiment. FIG. 14 is a flowchart for explaining a processing procedure of processing executed by the computer system according to the third embodiment.

  Embodiments of a magnetic resonance imaging apparatus (hereinafter referred to as “MRI (Magnetic Resonance Imaging) apparatus”) according to the present invention will be described below in detail with reference to the drawings. In the following embodiment, the description will be focused on the case where a grid-like tag is used, but the present invention is not limited to this embodiment.

  First, terms used in the following examples will be described.

  First, the “tagging method” is a method of applying a low excitation signal according to the spatial position by applying a selective excitation pulse for spatially modulating the magnetization in the imaging region to the subject. In addition, the imaging method generates images in time series. Marks applied to an image by this tagging method are called “tags”, and include a lattice-like one, a linear one, and a radial one.

  The “tagging image” refers to an image that is tagged by the tagging method, and the “tagging cine image” refers to a tagging image captured in time series.

  Hereinafter, examples of magnetic resonance imaging according to the present invention will be described in order.

  First, the overall configuration of the MRI apparatus according to the first embodiment will be described. FIG. 1 is a diagram illustrating the overall configuration of the MRI apparatus 100 according to the first embodiment. As shown in FIG. 1, an MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil 2, a gradient magnetic field power source 3, a bed 4, a bed control unit 5, a transmission RF (Radio Frequency) coil 6, a transmission unit 7, and a reception. RF coil 8, receiving unit 9, sequence control unit 10, and computer system 20 are provided.

  The static magnetic field magnet 1 is formed in a hollow cylindrical shape, and generates a uniform static magnetic field in the internal space. For example, a permanent magnet or a superconducting magnet is used as the static magnetic field magnet 1.

  The gradient coil 2 is formed in a hollow cylindrical shape and is disposed inside the static magnetic field magnet 1. The gradient magnetic field coil 2 is formed by combining three coils corresponding to the X, Y, and Z axes orthogonal to each other. These three coils generate a gradient magnetic field whose magnetic field intensity varies along each of the X, Y, and Z axes by individually receiving a current supply from the gradient magnetic field power supply 3.

  The gradient magnetic fields of the X, Y, and Z axes generated by the gradient coil 2 correspond to, for example, the readout gradient magnetic field Gr, the phase encoding gradient magnetic field Ge, and the slice selection gradient magnetic field Gs. The readout gradient magnetic field Gr is used for changing the frequency of the magnetic resonance signal in accordance with the spatial position. The phase encoding gradient magnetic field Ge is used to change the phase of the magnetic resonance signal in accordance with the spatial position. The slice selection gradient magnetic field Gs is used to arbitrarily determine an imaging section.

  The gradient magnetic field power supply 3 supplies a current to the gradient magnetic field coil 2. The couch 4 includes a couchtop 4a on which the subject P is placed. Under the control of the couch controller 5, the couchtop 4a is placed in the cavity of the gradient magnetic field coil 2 with the subject P placed thereon (imaging). Insert into the mouth). Usually, the bed 4 is installed such that the longitudinal direction is parallel to the central axis of the static magnetic field magnet 1. Under the control of the control unit 26, the bed control unit 5 drives the bed 4 to move the top 4a in the longitudinal direction and the vertical direction.

  The transmission RF coil 6 is disposed inside the gradient magnetic field coil 2 and receives a high frequency pulse from the transmission unit 7 to generate a high frequency magnetic field.

  The transmission unit 7 includes an oscillation unit, a phase selection unit, a frequency conversion unit, an amplitude modulation unit, a high frequency power amplification unit, and the like. As a result of the operation of each of these units, a high frequency pulse corresponding to the Larmor frequency is transmitted using an RF coil 6 to send. The oscillation unit generates a high-frequency signal having a resonance frequency unique to the target nucleus in the static magnetic field. The phase selection unit selects the phase of the high-frequency signal. The frequency conversion unit converts the frequency of the high-frequency signal output from the phase selection unit. The amplitude modulation unit modulates the amplitude of the high-frequency signal output from the frequency modulation unit according to, for example, a sinc function. The high frequency power amplification unit amplifies the high frequency signal output from the amplitude modulation unit.

  The reception RF coil 8 is disposed inside the gradient magnetic field coil 2 and receives a magnetic resonance signal radiated from the subject P under the influence of the high-frequency magnetic field generated by the transmission RF coil 6.

  The receiving unit 9 includes a selector, a pre-stage amplifier, a phase detector, and an analog / digital converter. As a result of the operation of each unit, the receiving unit 9 converts the magnetic resonance signal output from the receiving RF coil 8 into a magnetic resonance signal. Based on this, magnetic resonance data is generated. The selector selectively inputs the magnetic resonance signal output from the reception RF coil 8. The pre-stage amplifier amplifies the magnetic resonance signal output from the selector. The phase detector detects the phase of the magnetic resonance signal output from the preceding amplifier. The analog-digital converter converts the signal output from the phase detector into a digital signal.

  The sequence control unit 10 scans the subject P by driving the gradient magnetic field power source 3, the transmission unit 7, and the reception unit 9 based on the sequence execution data transmitted from the computer system 20. Then, when raw data is transmitted from the receiving unit 9 as a result of scanning, the sequence control unit 10 transfers the k-space data to the computer system 20.

  Here, the “sequence execution data” is data for executing imaging based on a predetermined sequence. That is, the sequence execution data includes the strength of the power supplied from the gradient magnetic field power supply 3 to the gradient magnetic field coil 2 and the timing of supplying the power, the strength of the RF signal transmitted from the transmitter 7 to the RF coil 6 for transmission, and the RF signal. This is data defining transmission timing, timing at which the receiving unit 9 detects a magnetic resonance signal, and the like.

  The computer system 20 performs overall control of the MRI apparatus 100, data collection, image reconstruction, and the like. The computer system 20 particularly includes an interface unit 21, an image reconstruction unit 22, a storage unit 23, an input unit 24, a display unit 25, and a control unit 26.

  The interface unit 21 controls input / output of various signals exchanged with the sequence control unit 10. For example, the interface unit 21 transmits sequence execution data to the sequence control unit 10 and receives raw data from the sequence control unit 10.

  Here, the raw data received by the interface unit 21 includes the slice selection gradient magnetic field Gs generated by the gradient coil 2, the phase encoding gradient magnetic field Ge, and the readout gradient magnetic field Gr in the SE (Slice Encode) direction, PE. The information is stored in the storage unit 23 as k-space data in which spatial frequency information in the (Phase Encode) direction and the RO (Read Out) direction is associated.

  The image reconstruction unit 22 generates spectrum data or image data of a desired nuclear spin in the subject P by performing reconstruction processing such as Fourier transform on the k-space data stored in the storage unit 23.

  The storage unit 23 stores raw data (k-space data) received by the interface unit 21, image data generated by the image reconstruction unit 22, and the like for each subject P.

  The input unit 24 receives various instructions and information input from the operator. As the input unit 24, a pointing device such as a mouse or a trackball, a selection device such as a mode change switch, or an input device such as a keyboard is appropriately used.

  The display unit 25 displays various types of information such as spectrum data or image data under the control of the control unit 26. As the display unit 25, a display device such as a liquid crystal display is appropriately used.

  The control unit 26 controls the entire MRI apparatus 100. Specifically, the control unit 26 has a CPU (Central Processing Unit), a memory, and the like (not shown), and controls the operation of each unit described above by executing various programs based on instructions from the operator. To do.

  Under such a configuration, in the first embodiment, in the computer system 20, the control unit 26 inputs a tagging cine image of the heart. Further, the control unit 26 sets an abnormal range indicating a moving range of the tag when the myocardial motion is abnormal. Then, the control unit 26 analyzes the myocardial motion of the heart by determining whether or not there is a tag that does not exceed the abnormal range for each input tagging cine image.

  Hereinafter, the computer system 20 will be described in detail with a focus on the control unit 26. First, the configuration of the computer system 20 according to the first embodiment will be described. FIG. 2 is a functional block diagram illustrating the configuration of the computer system 20 according to the first embodiment.

  As shown in FIG. 2, the storage unit 23 particularly includes an image data storage unit 23a. The image data storage unit 23 a stores the image data generated by the image reconstruction unit 22. For example, the image reconstruction unit 22 stores a tagging image of the heart. In addition, the image reconstruction unit 22 uses a cross-sectional image of the heart used for designating a cross-section for generating a tagging image in an examination using the tagging method, and a tagging positioning image used for designating a tag position. Also remember.

  Each tagging cine image stored by the image data storage unit 23a includes information on tags such as the tag type and tag interval set at the time of imaging and information on the abnormal range set at the time of analysis as supplementary information. include.

  As shown in FIG. 2, the control unit 26 includes an image input unit 26a, a range designation receiving unit 26b, an abnormal range setting unit 26c, and an image analysis unit 26d.

  The image input unit 26a inputs a tagging cine image of the heart obtained by the tagging method. Specifically, the image input unit 26a accepts the designation of the inspection performed using the tagging method from the operator via the input unit 24, and reads the tagging cine image of the specified inspection from the image data storage unit 23a. Enter.

  The range designation receiving unit 26b displays an image indicating the tag position applied by the tagging method on the display unit 25 as a range designation image, and then designates a range of an arbitrary size for the image. An operation to be performed is received from the operator.

  Specifically, the range designation accepting unit 26b first accepts the designation of the inspection performed using the tagging method from the operator, and uses the tagging positioning used to determine the position of the tag in the designated inspection. The image is read from the image data storage unit 23a. The range designation receiving unit 26b displays the read tagging positioning image on the display unit 25 as a range designation image. Thereafter, the range designation accepting unit 26b accepts an operation for setting a range of an arbitrary size with reference to a tag applied to the range designating image displayed on the display unit 25 via the input unit 24.

  FIG. 3 is a diagram illustrating an example of range reception by the range specification reception unit 26b according to the first embodiment. For example, as illustrated in FIG. 3, the range designation receiving unit 26 b uses a rectangular range R extending in the horizontal direction or a rectangular shape extending in the vertical direction with reference to the tag T applied to the range designation image S. An operation for setting the range R is accepted.

  In addition, the method for the range designation receiving unit 26b to accept the range designation is not limited to the method described above. 4 and 5 are diagrams illustrating another example of range reception by the range designation receiving unit 26b according to the first embodiment. For example, as shown in FIG. 4, the range designation receiving unit 26 b enlarges and displays a part of the tag T applied to the range designation image S, and sets the range R for the enlarged tag T. You may make it receive operation to perform. Further, for example, when the tag is in a radial shape, an operation for setting a rectangular range R extending in an oblique direction along the radiation tag T is accepted as shown in FIG.

  The abnormal range setting unit 26c sets an abnormal range indicating the moving range of the tag when the myocardial motion is abnormal. Specifically, the abnormal range setting unit 26c sets the range specified by the operation received by the range specification receiving unit 26b as the abnormal range. The abnormal range set here is used for analyzing the myocardial motion of the heart by the image analysis unit 26d described below.

  The image analysis unit 26d analyzes the myocardial motion of the heart by determining whether there is a tag that does not exceed the abnormal range set by the abnormal range setting unit 26c for the tagging cine image input by the image input unit 26a. To do.

  Specifically, the image analysis unit 26d calculates a tag movement amount compared with the tagging positioning image for each tagging cine image input by the image input unit 26a, and the calculated movement amount does not exceed the abnormal range. It is determined whether or not there is. If there is a tag whose movement amount does not exceed the abnormal range, the image including the tag and the location of the tag are output to the display unit 25 as analysis results.

  The above-described processing will be described in more detail. First, the image analysis unit 26d searches the tagging cine image input by the image input unit 26a for a pixel representing a tag from the pixels included in the image. Subsequently, for each searched pixel, the image analysis unit 26d specifies a pixel representing the same portion of the same tag in the tagging positioning image, and calculates a moving distance from the position of the specified pixel. Then, the image analysis unit 26d determines, for each pixel, whether or not the calculated movement amount exceeds the abnormal range. If there is an excess, an image including the pixel and a tag including the pixel are included. The location is output to the display unit 25.

  FIG. 6 is a diagram illustrating an example of an output of an analysis result by the image analysis unit 26d according to the first embodiment. As shown in FIG. 6, for example, the image analysis unit 26d has a tag whose movement amount does not exceed the abnormal range after the tagging cine images input by the image input unit 26a are arranged in time series and displayed in a list format. The image and its tag are emphasized and output. The example of FIG. 6 shows a case where an image of time phase n + 3 is emphasized and output.

  In this way, the location of the tag output as an analysis result by the image analysis unit 26d has a narrower movement range than other locations. Therefore, the myocardium at the position of the tag output as the analysis result can be analyzed as having abnormal movement.

  Next, a processing procedure of processing executed by the computer system 20 according to the first embodiment will be described. FIG. 7 is a flowchart for explaining a processing procedure of processing executed by the computer system 20 according to the first embodiment. In the computer system 20 according to the first embodiment, as shown in FIG. 7, first, the control unit 26 captures a tagging cine image of the heart based on an instruction from the operator (step S101).

  When the operator gives an instruction to start analysis (step S102, Yes), the image input unit 26a reads out and inputs the tagging cine image as the analysis result target from the image data storage unit 23a (step S103). The range designation receiving unit 26b displays a range designation image (step S104), and accepts an operation for designating a range for the displayed range designation image (step S105).

  Subsequently, the abnormal range setting unit 26c sets an abnormal range based on the range designated by the operator (step S106). Then, the image analysis unit 26d analyzes each tagging cine image input by the image input unit 26a (step S107), and outputs the analysis result to the display unit 25 (step S108).

  As described above, in the first embodiment, the image input unit 26a inputs the tagging cine image of the heart, and the abnormal range setting unit 26c displays the abnormal range indicating the tag moving range when the myocardial motion is abnormal. Set. Then, the image analysis unit 26d determines, for each image input by the image input unit 26a, whether or not there is an index that does not exceed the abnormal range set by the abnormal range setting unit 26c. Is analyzed. Thereby, it is possible to provide the examiner with an analysis result useful for determining whether or not the myocardium is abnormal. Therefore, according to the first embodiment, it is possible to assist the examiner so that the myocardial motion can be easily analyzed using the image captured by the tagging method.

  In the first embodiment, the range designation receiving unit 26b causes the display unit 25 to display an image indicating the tag position on the display unit 25 as an image for range designation. An operation for specifying the range is accepted from the operator. Then, the abnormal range setting unit 26c sets the range specified by the operation received by the range specification receiving unit 26b as the abnormal range. Therefore, according to the first embodiment, the examiner can easily set an abnormal range as a reference for detecting an abnormality of myocardial motion based on the range designation image.

  In the first embodiment, the case where the tagging positioning image is used as the range specifying image has been described. However, the present invention is not limited to this. For example, tagging cine images captured in time series in the inspection may be superimposed, and the superimposed image may be used as the range designation image.

  In that case, the range designation receiving unit 26b first superimposes each tagging cine image input by the image input unit 26a, and causes the display unit 25 to display the superimposed tagging cine image as a range designation image. Thereafter, the range designation accepting unit 26b accepts an operation for setting a range of an arbitrary size with reference to a tag applied to the range designating image displayed on the display unit 25 via the input unit 24.

  FIG. 8 is a diagram illustrating an example of accepting a range when a superimposed tagging cine image is used as a range designating image. For example, as shown in FIG. 8, the range designation receiving unit 26b accepts an operation for setting a rectangular range R based on an arbitrary tag applied to a range designation image on which a tagging cine image is superimposed.

  In this manner, the range designation receiving unit 26b superimposes each tagging cine image input by the image input unit 26a and displays the superimposed image as a range designation image, whereby the inspector is actually captured. With reference to the tag change in the tagging cine image, it is possible to easily set an abnormal range as a reference for detecting an abnormality of myocardial motion.

  In the first embodiment, the case where the abnormal range is set based on the range specified by the operator has been described. However, the present invention is not limited to this. For example, the abnormal range may be set based on the tag position applied by the tagging method implemented in the past and information on the abnormal range specified in the past.

  Therefore, in the following, as a second embodiment, a case where an abnormal range is set based on a tag applied by a tagging method performed in the past and information on the abnormal range specified in the past will be described. The configuration of the MRI apparatus according to the second embodiment is basically the same as that shown in FIG. 1, and only the functions of the computer system are different. Therefore, here, the function of the computer system according to the second embodiment will be mainly described.

  First, the configuration of the computer system 30 according to the second embodiment will be described. FIG. 9 is a functional block diagram of a detailed configuration of the computer system 30 according to the second embodiment. Here, for convenience of explanation, functional units that play the same functions as the respective units shown in FIG. 2 are given the same reference numerals, and detailed descriptions thereof are omitted.

  As shown in FIG. 9, the control unit 36 particularly includes an image input unit 26a, a sign information input unit 36e, an abnormal range setting unit 36c, and an image analysis unit 26d.

  The sign information input unit 36e inputs information on a tag applied by a tagging method performed in the past and an abnormal range specified in the past. Specifically, designation of a tagging image captured in a past examination is received from an operator via the input unit 24, and information about tags and abnormal ranges included as incidental information in the designated tagging image is displayed as an image. Data is read from the data storage unit 23a and input.

  The abnormal range setting unit 36c sets an abnormal range based on the information input by the sign information input unit 36e. Specifically, when the information regarding the tag and the abnormal range is input by the sign information input unit 36e, the abnormal range setting unit 36c, based on the information and the information regarding the tag set in the current imaging, Set. It is assumed that information regarding the tag set in the current imaging is stored in an internal memory (not shown) or the like when the imaging condition is set by the operator.

  FIG. 10 is a diagram illustrating an example of an abnormal range setting by the abnormal range setting unit 36c according to the second embodiment. In FIG. 10, the left diagram shows the tag and the abnormal range applied by the tagging method implemented in the past, and the right diagram shows the tag set in the current imaging.

  As illustrated in FIG. 10, for example, the abnormal range setting unit 36 c calculates the ratio between the tag interval I1 of the tag applied in the past and the tag interval I2 of the tag set in the current imaging. Then, the abnormal range setting unit 36c enlarges (or reduces) the abnormal range R1 set in the past at the calculated ratio, and analyzes the tagging cine image obtained by the current imaging with the enlarged (or reduced) range. Is set as an abnormal range R2 used in the above.

  For example, it is assumed that the tag interval I1 of the tag applied in the past is 5 mm, and the tag interval I2 of the tag set in the current imaging is 10 mm. In that case, the abnormal range setting unit 36c enlarges the abnormal range set in the past twice (10 [mm] / 5 [mm]), and uses the expanded range as the abnormal range used in this analysis. Set.

  Next, a processing procedure of processing executed by the computer system 30 according to the second embodiment will be described. FIG. 11 is a flowchart for explaining a processing procedure of processing executed by the computer system 30 according to the second embodiment. In the computer system 30 according to the second embodiment, as illustrated in FIG. 11, first, the control unit 36 captures a tagging cine image of the heart based on an instruction from the operator (step S201).

  When the operator gives an instruction to start the analysis (step S202, Yes), the image input unit 26a reads out and inputs the tagging cine image as the analysis result target from the image data storage unit 23a (step S203). Further, the sign information input unit 36e inputs information related to the tag and the abnormal range of the tagging image captured in the past (step S204).

  Subsequently, the abnormal range setting unit 36c sets an abnormal range based on the information input by the sign information input unit 36e (step S205). Then, the image analysis unit 26d analyzes each tagging cine image input by the image input unit 26a (step S206), and outputs the analysis result to the display unit 25 (step S207).

  As described above, in the second embodiment, the sign information input unit 36e inputs information about a tag applied by a tagging method performed in the past and an abnormal range specified in the past. Then, the abnormal range setting unit 36c sets an abnormal range based on the information input by the sign information input unit 36e. Therefore, according to the second embodiment, it becomes possible to set the abnormal range in the new analysis based on the abnormal range used in the analysis performed in the past, and the burden on the inspector regarding the setting of the abnormal range. Can be reduced.

  In the first and second embodiments, different embodiments have been described with respect to the setting of the abnormal range, but the present invention is not limited to this. For example, statistical processing regarding the amount of tag movement may be performed using each tagging cine image to be analyzed, and the processing result may be output as information serving as a reference when setting an abnormal range.

  Therefore, in the following, as a third embodiment, a case will be described in which the result of statistical processing related to the amount of tag movement is output. The configuration of the MRI apparatus according to the third embodiment is basically the same as that shown in FIG. 1, and only the functions of the computer system are different. Therefore, here, the function of the computer system according to the third embodiment will be mainly described.

  First, the configuration of the computer system 40 according to the third embodiment will be described. FIG. 12 is a functional block diagram illustrating a detailed configuration of the computer system 40 according to the third embodiment. Here, for convenience of explanation, functional units that play the same functions as the respective units shown in FIG. 2 are given the same reference numerals, and detailed descriptions thereof are omitted.

  As shown in FIG. 12, the control unit 46 particularly includes an image input unit 26a, a range designation receiving unit 26b, an abnormal range setting unit 26c, an image analysis unit 26d, and a sign statistical processing unit 46f.

  The sign statistical processing unit 46f performs statistical processing on the amount of tag movement using each tagging cine image input by the image input unit 26a, and outputs a processing result. Specifically, the image analysis unit 26d first calculates a tag movement amount compared to the tagging positioning image for each tagging cine image input by the image input unit 26a, and performs statistical processing based on the calculated movement amount. I do.

  FIG. 13 is a diagram for explaining the statistical processing by the marker statistical processing unit 46f according to the third embodiment. FIG. 13 shows a tag T1 set in the tagging positioning image and a tag T2 in the tagging cine image of a predetermined time phase, respectively. As shown in the figure, for example, the marker statistical processing unit 46f calculates the movement amount d based on the tagging positioning image for each of the lattice intersections in the lattice tag.

  Then, after calculating the movement amount d for all tagging cine images input by the image input unit 26a, the marker statistical processing unit 46f calculates the maximum value, the minimum value, the average value, the standard deviation, etc. of all the calculated movement amounts d. The statistical value of is calculated. Thereafter, the sign statistical processing unit 46f outputs the calculated statistical value to the display unit 25 as a result of the statistical processing.

  Next, a processing procedure of processing executed by the computer system 40 according to the third embodiment will be described. FIG. 14 is a flowchart for explaining a processing procedure of processing executed by the computer system 40 according to the third embodiment. In the computer system 40 according to the third embodiment, as shown in FIG. 14, first, the control unit 46 captures a tagging cine image of the heart based on an instruction from the operator (step S301).

  When the operator gives an instruction to start analysis (step S302, Yes), the image input unit 26a reads out and inputs the tagging cine image as the analysis result target from the image data storage unit 23a (step S303).

  Subsequently, the sign statistical processing unit 46f executes statistical processing related to the amount of tag movement using each tagging cine image input by the image input unit 26a (step S304), and outputs the processing result of the statistical processing (step S305). ). The range designation receiving unit 26b displays a range designation image (step S306), and accepts an operation for designating a range for the displayed range designation image from the operator (step S307).

  Subsequently, the abnormal range setting unit 26c sets an abnormal range based on the range specified by the operator (step S308). Then, the image analysis unit 26d analyzes each tagging cine image input by the image input unit 26a (step S309), and outputs the analysis result to the display unit 25 (step S310).

  As described above, in the third embodiment, the marker statistical processing unit 46f performs statistical processing on the amount of tag movement using each tagging cine image input by the image input unit 26a, and outputs a processing result. Therefore, according to the third embodiment, the examiner can easily set an abnormal range as a reference for detecting an abnormality of myocardial motion while quantitatively grasping the tag change in the tagging cine image actually captured. Will be able to be set.

  In the third embodiment, the case where the result of the statistical processing is output has been described. However, the present invention is not limited to this. For example, the abnormal range may be set based on the result of statistical processing. In this case, for example, the abnormal range setting unit 26c determines the size of the abnormal range based on statistical values such as the maximum value, the minimum value, the average value, and the standard deviation calculated by the sign statistical processing unit 46f. . Thereby, since the abnormal range is set according to the change of the tag in the tagging cine image actually captured, the burden on the inspector can be further reduced.

  In addition, each component of each device illustrated in the above embodiments is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured.

  For example, all of the functions of the computer systems 20, 30 and 40 described in the first, second, and third embodiments, or any two of the functions are implemented in one computer system, and in response to a request from an operator. The function to be executed may be switched as appropriate.

  As described above, the magnetic resonance imaging apparatus according to the present invention is useful when analyzing myocardial motion using an image captured by the tagging method, and particularly when it is required to reduce the labor required for the analysis. Useful for.

100 MRI system (magnetic resonance imaging system)
DESCRIPTION OF SYMBOLS 1 Static magnetic field magnet 2 Gradient magnetic field coil 3 Gradient magnetic field power supply 4 Bed 4a Top plate 5 Bed control part 6 Transmission RF coil 7 Transmission part 8 Reception RF coil 9 Reception part 10 Sequence control part 20, 30, 40 Computer system 21 Interface Unit 22 Image reconstruction unit 23 Storage unit 23a Image data storage unit 24 Input unit 25 Display unit 26, 36, 46 Control unit 26a Image input unit 26b Range designation reception unit 26c, 36c Abnormal range setting unit 26d Image analysis unit 36e Sign information Input unit 46f Sign statistics processing unit

Claims (5)

An image input means for inputting a plurality of images of the heart obtained by a tagging method for imaging a subject in time series after marking in an imaging region according to a spatial position;
An abnormal range setting means for setting an abnormal range indicating a moving range of the sign when the myocardial motion is abnormal;
Image analysis means for analyzing myocardial motion of the heart by determining whether or not there is an index that does not exceed the abnormal range set by the abnormal range setting means for each image input by the image input means; A magnetic resonance imaging apparatus comprising: An image indicating the position of the sign applied by the tagging method is displayed on the display unit as a range designation image, and an operation for designating an arbitrary size range is performed on the range designation image. Further comprising a range designation receiving means for receiving from a person,
The magnetic resonance imaging apparatus according to claim 1, wherein the abnormal range setting unit sets a range designated by an operation accepted by the range designation accepting unit as the abnormal range.   The magnetic resonance imaging apparatus according to claim 2, wherein the range designation receiving unit superimposes each image input by the image input unit and displays the superimposed image as the range designation image. It further comprises a sign information input means for inputting information about a sign given by a tagging method carried out in the past and an abnormal range designated in the past,
The magnetic resonance imaging apparatus according to claim 1, wherein the abnormal range setting unit sets the abnormal range based on information input by the marker information input unit.   5. The method according to claim 1, further comprising a marker statistical processing unit that performs a statistical process on a moving amount of the marker using each image input by the image input unit and outputs a processing result. The magnetic resonance imaging apparatus described in 1.