JP2016158863A - Medical image imaging device and imaging cross section adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mitigate an operator's load on operation of adjusting an imaging cross section in a medical image imaging device capable of imaging any cross section in a three-dimensional space.SOLUTION: An imaging cross section adjustment method includes: a step of generating a conversion matrix for three-dimensionally performing conversion from an imaging cross section's initial value to the imaging cross section's present value, when an operator's three-dimensional position adjustment of the imaging cross section has been accepted; and a step of converting the imaging cross section's initial value by using the conversion matrix. The operator's single adjustment of the imaging cross section automatically causes adjustment of another imaging cross section in an inspection corresponding to the adjustment.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a medical imaging apparatus, and more particularly to a method for adjusting the position of an imaging cross section.

  There is a medical image capturing apparatus capable of capturing an arbitrary cross section of a three-dimensional space. Among them, a magnetic resonance imaging (hereinafter referred to as “MRI”) apparatus is an apparatus that measures and images an NMR signal generated by a nuclear spin of atoms constituting an object.

  In general, a slice selective gradient magnetic field is applied to a subject placed in a static magnetic field, and simultaneously, a high-frequency magnetic field having a specific frequency is applied to excite nuclear magnetization in the imaging section. Next, position information is given to the nuclear magnetization excited by application of the phase encoding gradient magnetic field and the readout gradient magnetic field, and a nuclear magnetic resonance signal (NMR signal) at which nuclear magnetization is generated is measured.

  The measurement of the nuclear magnetic resonance signal is repeated until a measurement space called k-space is filled with signal data. The signal data filled in the k space is imaged by inverse Fourier transform. The magnetic field gradient direction of each gradient magnetic field can be set in an arbitrary direction in a three-dimensional space by controlling three gradient magnetic field coils corresponding to orthogonal three-axis directions. In the MRI apparatus, imaging of an arbitrary cross section is realized by spatial control of the gradient magnetic field.

  In a medical image imaging apparatus capable of imaging an arbitrary cross section such as an MRI apparatus, a positioning image used for determining an imaging cross section is acquired before imaging a region to be a subject of a subject. The operator adjusts the position, inclination, range, thickness, etc. (hereinafter simply referred to as a cross section) of the imaging cross section while referring to the acquired positioning image.

  As the initial value of the imaging section, a value that assumes a general subject that does not depend on a specific subject that has been stored in advance, a value that is obtained by imaging the subject in the past (Patent Document 1), and the like are given. Furthermore, there is a technique (Patent Documents 2 and 3) (hereinafter referred to as “automatic positioning”) that automatically adjusts an imaging section based on the anatomical features of the acquired positioning image.

JP 2012-232111 JP 2005-125099 International Publication No.2013 / 027540

  However, if the initial value of the imaging cross section is assumed to be a general subject, a deviation occurs due to differences in the posture, physique, and fixed state of the subject to be imaged. The imaging section must be adjusted. When the initial value of the imaging cross section is that of the same subject in the past, when the fixed state to the apparatus is slightly different from the past examination, all the imaging cross sections of the examination must be adjusted.

  In addition, the anatomy of a general subject that is a reference due to a complicated structure, a part with almost no structure, a part with a defect, or the quality of the acquired positioning image is insufficient. When it is difficult to grasp the correlation with the scientific feature, it is difficult to apply the automatic positioning, and all the imaging cross sections of the inspection must be adjusted.

  Accordingly, an object of the present invention is to reduce the burden of an operation for an operator to adjust an imaging section in a medical image imaging apparatus capable of imaging an arbitrary section in a three-dimensional space.

  In order to achieve the above object, the medical image capturing apparatus and the imaging cross-section adjustment method of the present invention change from the initial value of the imaging cross-section to the current value of the imaging cross-section when receiving the three-dimensional position adjustment of the imaging cross-section by the operator. A conversion matrix to be converted three-dimensionally is generated, and in subsequent imaging, an initial value of the imaging section is converted using the conversion matrix to obtain a difference image section to be actually imaged.

  According to the present invention, in a medical image imaging apparatus capable of imaging an arbitrary cross section of a three-dimensional space, if the operator adjusts the imaging cross section once, other imaging cross sections in the examination are automatically adjusted. Thus, it is possible to reduce the burden of an operation for the operator to adjust the imaging section.

It is a schematic diagram of the MRI apparatus of an Example. It is a schematic diagram of the calculation part of an Example. It is the protocol of the test | inspection of an Example. It is a screen displayed on the display apparatus of an Example. It is an example of adjustment of the section which picturizes the example. It is an example of correction of the section which picturizes the example. It is the flow of the apparatus of an Example. It is an operator's flow of an Example.

  Examples of the present invention will be described in detail below. In the present embodiment, a case where an MRI apparatus is used as an example of a medical image photographing apparatus capable of capturing an arbitrary cross section of a three-dimensional space will be described. In all the drawings for explaining the embodiments of the present invention, the same reference numerals are given to those having the same function, and the repeated explanation thereof is omitted.

  An MRI apparatus is an apparatus that obtains an image using an NMR phenomenon. FIG. 1 shows a schematic diagram thereof.

  In FIG. 1, a static magnetic field coil (101) for applying a static magnetic field to a subject (100), a gradient magnetic field coil (102) and a gradient magnetic field power source (103) for applying a gradient magnetic field to the subject, and atoms constituting the subject An irradiation coil (104) that irradiates a high-frequency pulse (hereinafter referred to as RF pulse) that causes an NMR phenomenon due to the nucleus of the nucleus, a transmission system (105) that repeatedly applies an RF pulse to the irradiation coil in a predetermined pulse sequence, and an NMR signal are detected Receiving coil (106) and receiving system (107), a computer (108) for performing image reconstruction calculation using NMR signals detected by the receiving system, a display device (109) for displaying images, and operating these A console (110) for storing data and a storage device (111) for storing data.

  The gradient magnetic field is applied to the subject in order to give position information to the NMR signal, and gradient magnetic fields in three orthogonal directions are respectively applied by a predetermined pulse sequence. An arbitrary cross section of the subject (100) is obtained by these devices.

Next, examples of the present invention will be described.
As shown in FIG. 2, the MRI apparatus of the present embodiment includes a cross-sectional initial value storage unit (201) that stores an initial value of a cross-section and a cross-sectional storage unit (202) that stores a current cross-section in a computer (108). A conversion matrix generation unit (203) for generating a conversion matrix for three-dimensional conversion from the initial value of the cross section to the current cross section, and a conversion matrix storage unit (204) for storing the conversion matrix. The table includes a section adjustment operation unit (205) that allows an operator to three-dimensionally adjust a section to be imaged.

  FIG. 3 shows the inspection protocol of this example. The inspection protocol (301) includes imaging conditions of an imaging A (302) for imaging a positioning image, an imaging B (303) for imaging an axial section, and an imaging C (304) for imaging a sagittal section. . All these imaging conditions include a cross section (305) for imaging assuming a general subject. In addition, all cross sections include values of position (306), slope (307), range (308), and thickness (309) (FIG. 3 shows only imaging A (302)). Yes.

  A screen displayed on the display device of the present embodiment is shown in FIG. The screen (401) displays positioning image display areas (402a) (402b) (402c) for displaying positioning images, an imaging condition selection area (403) for switching imaging conditions, and a correction button (404).

  FIG. 8 shows an operation flow of the operator of this embodiment, and FIG. 7 shows a processing flow of the apparatus. The operator starts the test according to the protocol (801). At this time, the apparatus initializes the conversion matrix of the conversion matrix storage unit to a unit matrix (701). The operator selects imaging A from the imaging condition selection area (802), and captures a positioning image under the conditions of imaging A (803).

  Next, the operator selects the imaging B from the imaging condition selection area (804), and adjusts the imaging cross section of the imaging B (805). FIG. 5 shows examples of adjustment of positioning images (501a), (501b), and (501c) and imaging cross sections. According to the positioning image (501b) of the axial section, the median plane of the subject is clearly inclined with respect to the initial value (502) of the imaging section, so the operator rotates the initial value (502) to obtain the imaging section. Adjust to (503) (805). In accordance with this adjustment, the position of the imaging section in the coronal section positioning image (501c) is also adjusted at the same time. At this time, since the imaging section has been changed, the condition of the branch (702) becomes true (Yes), and a conversion matrix is generated that converts the initial imaging section value (502) to the current imaging section (503). Then, the generated conversion matrix is stored in the conversion matrix storage unit (706).

  Thereafter, the operator selects the imaging C from the imaging condition selection area (806), and presses the correction button (404) (807). At this time, since the correction button (404) has been pressed, the branch (703) becomes true (Yes), and the initial value of the imaging section of the imaging C is converted by the conversion matrix (707). FIG. 6 shows a conversion example. According to the positioning image (501b) of the axial section, the median plane of the subject is clearly inclined with respect to the initial value (601) of the imaging section, but is corrected to the imaging section (602) after conversion by the conversion matrix. The In accordance with this conversion, the position of the imaging section in the coronal section positioning image (501c) is also adjusted simultaneously.

  As described above, the present embodiment converts the initial value of the imaging section into an optimal imaging section corresponding to the inclination of the imaging region of the subject by adjusting the imaging section in any positioning image. Create a transformation matrix. In the subsequent imaging, the initial value of the imaging section is converted using the created conversion matrix to obtain an optimal imaging section corresponding to the inclination of the imaging region of the subject. Thereby, in the second and subsequent imaging, the operator does not need to adjust the initial value of the imaging cross section, so that the operation burden related to the adjustment of the imaging cross section of the operator can be reduced.

  In the above embodiment, the initial value of the imaging section is stored in advance. However, when the examination protocol is obtained by imaging the subject in the past, the fixed state to the apparatus is the past. Even if they are different, the cross section can be adjusted to the same position as the past by pressing the correction button in the imaging C in the above embodiment.

  Or, when adjusting the cross section by automatic positioning, for some reason, it is difficult to grasp the correlation with the anatomical features of a general subject to be a reference, even if automatic positioning could not be applied, in the above embodiment, By pressing the correction button in imaging C, it is possible to adjust from a cross section assuming a general subject.

  100 subject, 101 static magnetic field coil, 102 gradient magnetic field coil, 103 gradient magnetic field power supply, 104 irradiation coil, 105 transmission system, 106 reception coil, 107 reception system, 108 computer, 109 display device, 110 console, 111 storage device

Claims (3)

A medical imaging apparatus capable of imaging an arbitrary imaging cross section in a three-dimensional space,
A cross-section adjusting operation unit that allows an operator to adjust the imaging cross-section three-dimensionally;
A section initial value storage unit for storing an initial value of the imaging section;
A cross-sectional storage unit that stores a current value of the imaging cross-section;
A conversion matrix generating unit that generates a conversion matrix for three-dimensional conversion from the initial value of the imaging section to the current value of the imaging section;
A conversion matrix storage unit for storing the conversion matrix;
A cross-section converter that converts the initial value of the imaging cross-section using the conversion matrix;
A medical image imaging apparatus comprising:   A medical imaging apparatus, wherein the medical imaging apparatus is a magnetic resonance imaging apparatus. An imaging cross-section adjustment method in a medical image imaging apparatus capable of imaging an arbitrary imaging cross-section in a three-dimensional space,
Receiving a three-dimensional position adjustment of the imaging section by an operator;
Generating a conversion matrix for three-dimensional conversion from an initial value of the imaging section to a current value of the imaging section;
Converting an initial value of the imaging section using the conversion matrix;
An imaging cross-section adjustment method comprising:

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