JP5295536B2 - Magnetic resonance imaging apparatus and preview image display apparatus - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus and a preview image display apparatus.

  2. Description of the Related Art A magnetic resonance imaging (MRI) apparatus is known as an apparatus for imaging a subject by using a nuclear magnetic resonance (NMR) phenomenon. This magnetic resonance imaging apparatus is widely used in fields such as medical use and industrial use.

  When imaging a subject using a magnetic resonance imaging apparatus, the main scan (scan) for collecting magnetic resonance signals from the subject in the imaging space in which a static magnetic field is formed corresponds to the main scan condition. carry out.

  Specifically, by accommodating the subject in an imaging space in which a static magnetic field is formed, the direction of spin in protons in the subject is aligned with the direction of the static magnetic field, and a magnetization vector is obtained. Go to the obtained state. Thereafter, an RF pulse having a resonance frequency is irradiated from an RF coil (Radio Frequency Coil) to generate a nuclear magnetic resonance phenomenon and change the magnetization vector of the proton. Then, the magnetic resonance signal generated from the proton returning to the original magnetization vector is received by the RF coil.

  Then, a magnetic resonance image is generated as a main scan image based on the magnetic resonance signals collected in the execution of the main scan.

  In this magnetic resonance imaging apparatus, operation data such as scan parameters is input to the operation apparatus by an operator, and the main scan conditions are set so as to correspond to the input operation data. The operation device is, for example, a graphical user interface (GUI), and displays a plurality of input items on which operation data is input by an operator on a display screen. Then, the operator inputs operation data so as to respond to a plurality of input items displayed on the display screen by using an input device such as a keyboard. Specifically, scan parameters such as TR, TE, and flip angle are input (see, for example, Patent Document 1).

JP 2007-111112 A (FIG. 3 etc.)

  Thus, in the operating device, a plurality of input items are displayed on the display screen, and the operator sequentially inputs operation data to the plurality of input items. For this reason, when the operator is not accustomed to the input operation, it takes time to accurately input the operation data so as to generate a desired magnetic resonance image. Therefore, the subject is efficiently imaged. It was sometimes difficult.

  In particular, in order to set a magnetic resonance image having a desired image contrast, such as a T1-weighted image, a T2-weighted image, or a proton density-weighted image, specialized scans are required for setting the main scan conditions, and the scan conditions are set quickly. In many cases, the above-mentioned problems have become apparent.

  Therefore, the present invention provides a magnetic resonance imaging apparatus and a preview image display apparatus that can improve imaging efficiency for imaging a subject.

  The magnetic resonance imaging apparatus of the present invention performs a main scan for collecting a magnetic resonance signal from a subject in a static magnetic field space so as to correspond to the main scan condition, and the magnetic resonance signal collected in the execution of the main scan is used. A magnetic resonance imaging apparatus for generating a magnetic resonance image as a main scan image based on the main scan image generated when the main scan is performed so as to correspond to the main scan condition. A preview image generating unit that generates a simulation image as a preview image; and a display unit that displays the preview image generated by the preview image generating unit on a display screen before performing the main scan.

  In addition, the preview image display device according to the present invention collects the main scan for collecting magnetic resonance signals from the subject in the static magnetic field space so as to correspond to the main scan condition. A preview image generation unit that generates a simulation image simulated for the main scan image generated based on the magnetic resonance signal as a preview image, and the preview image generated by the preview image generation unit And a display unit for displaying on the display screen before implementation.

  Preferably, a main scan condition setting unit for setting the main scan condition is provided, and the main scan condition setting unit is inputted by an operator with a position of a slice region in the subject for generating the main scan image Based on the command, the main scan condition is set, and the preview image generation unit generates the preview image for the slice region set by the main scan condition setting unit.

  Preferably, an image contrast setting unit that sets an image contrast of a magnetic resonance image generated as the main scan image based on a command input by an operator, and the main scan condition setting unit includes the image contrast setting unit. The main scan condition is set so that the main scan image is generated at the image contrast set by the image forming unit, and the preview image generating unit corresponds to the image contrast set by the image contrast setting unit. In addition, the preview image is generated based on the main scan condition set by the main scan condition setting unit.

  Preferably, a disease setting unit that sets a disease included in the slice region set by the main scan condition setting unit based on a command input by an operator, and the preview image generation unit includes the disease setting A simulation image that is simulated for the main scan image generated when the disease set by the unit is included in the slice region is generated as the preview image.

  Preferably, the storage device stores characteristic data at each position of the subject, and the preview image generation unit generates the preview image using the characteristic data stored in the storage unit. To

  According to the present invention, it is possible to provide a magnetic resonance imaging apparatus and a preview image display apparatus that can improve imaging efficiency for imaging a subject.

  Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings.

(Device configuration)
FIG. 1 is a configuration diagram showing a configuration of a magnetic resonance imaging apparatus 1 in an embodiment according to the present invention.

  As shown in FIG. 1, the magnetic resonance imaging apparatus 1 includes a scanning unit 2 and an operation console unit 3.

  In the present embodiment, in the magnetic resonance imaging apparatus 1, in the imaging space B in which the static magnetic field is formed, the scanning unit 2 transmits an RF pulse to the imaging region of the subject, and in the imaging region where the RF pulse is transmitted. The main scan for obtaining the generated magnetic resonance signal is performed so as to correspond to the main scan condition. Thereafter, in the magnetic resonance imaging apparatus 1, the operation console unit 3 generates a magnetic resonance image of the imaging region as a main scan image based on the magnetic resonance signals collected by performing the main scan.

  The scanning unit 2 will be described.

  As shown in FIG. 1, the scanning unit 2 includes a static magnetic field magnet unit 12, a gradient coil unit 13, an RF coil unit 14, an object moving unit 15, an RF drive unit 22, a gradient drive unit 23, The main scanning is performed on the imaging region of the subject SU based on the control signal output from the operation console unit 3.

  The scanning unit 2 is formed to have a cylindrical shape, for example, and accommodates the subject SU with the columnar space at the center thereof as the imaging space B. The scan unit 2 is placed on the subject moving unit 15 in the imaging space B in which the static magnetic field is formed by the static magnetic field magnet unit 12 when performing the main scan on the imaging region of the subject SU. The RF coil unit 14 transmits an RF pulse so as to excite spins in the imaging region of the subject SU, and the gradient coil unit 13 transmits a gradient pulse to the imaging region of the subject SU to which the RF pulse has been transmitted. . Then, the RF coil unit 14 receives a magnetic resonance signal generated in the imaging region of the subject SU.

  Each component of the scanning unit 2 will be described sequentially.

  The static magnetic field magnet unit 12 includes a superconducting magnet (not shown), and is configured to form a static magnetic field in the imaging space B in which the subject SU is accommodated. Here, the static magnetic field magnet unit 12 forms a static magnetic field along the body axis direction (z direction) of the subject SU placed on the subject moving unit 15. That is, the static magnetic field magnet unit 12 is a horizontal magnetic field type. In addition, the static magnetic field magnet unit 12 may be a vertical magnetic field type, and may be configured to form a static magnetic field along a direction in which a pair of permanent magnets face each other.

  The gradient coil unit 13 is configured to form a gradient magnetic field in the imaging space B where the static magnetic field is formed by the static magnetic field magnet unit 12 and to add spatial position information to the magnetic resonance signal received by the RF coil unit 14. Yes. Here, the gradient coil unit 13 includes three systems so as to correspond to the three axial directions orthogonal to each other in the x direction, the y direction, and the z direction. These transmit gradient pulses so as to form gradient magnetic fields in the frequency encoding direction, the phase encoding direction, and the slice selection direction according to the imaging conditions. Specifically, the gradient coil unit 13 applies a gradient magnetic field in the slice selection direction of the subject SU, and selects a slice of the subject SU to be excited when the RF coil unit 14 transmits an RF pulse. The gradient coil unit 13 applies a gradient magnetic field in the phase encoding direction of the subject SU, and phase encodes the magnetic resonance signal from the slice excited by the RF pulse. The gradient coil unit 13 applies a gradient magnetic field in the frequency encoding direction of the subject SU, and frequency encodes the magnetic resonance signal from the slice excited by the RF pulse.

  In the imaging space B where a static magnetic field is formed, the RF coil unit 14 transmits an RF pulse, which is an electromagnetic wave, to the imaging region of the subject SU to form a high-frequency magnetic field, and proton spins in the imaging region of the subject SU. Is configured to excite. Then, the RF coil unit 14 receives an electromagnetic wave generated from protons in the imaging region of the excited subject SU as a magnetic resonance signal. Here, as shown in FIG. 1, the RF coil unit 14 includes a transmission coil 14a and a reception coil 14b. Here, the transmission coil 14a is, for example, a bird gauge type body coil, is arranged so as to surround the imaging region of the subject SU, and transmits an RF pulse. On the other hand, the receiving coil 14b is a surface coil and receives a magnetic resonance signal.

  The subject moving unit 15 includes a cradle 15a and a cradle moving unit 15b, and the cradle 15a is moved between the inside and the outside of the imaging space B based on a control signal output from the control unit 30. The moving unit 15b is configured to move. Here, the cradle 15a is a table having a placement surface on which the subject SU is placed. As shown in FIG. 1, the cradle 15a is moved in the horizontal direction xz and the up / down direction y by the cradle moving unit 15b. To the imaging space B where a static magnetic field is formed. The cradle moving unit 15b moves the cradle 15a and accommodates it inside the imaging space B from the outside. The cradle moving unit 15b includes, for example, a roller drive mechanism, and drives the roller by an actuator to move the cradle 15a in the horizontal direction xz. The cradle moving unit 15b includes, for example, an arm-type drive mechanism, and moves the cradle 15a in the vertical direction y by changing the angle between the two intersecting arms.

  The RF drive unit 22 is configured to drive the RF coil unit 14 to transmit an RF pulse in the imaging space B so as to form a high-frequency magnetic field in the imaging space B. Specifically, the RF drive unit 22 uses a gate modulator (not shown) to send a signal from an RF oscillator (not shown) based on a control signal from the operation console unit 3 to a predetermined timing and a predetermined envelope. After modulation into a line signal, the signal modulated by the gate modulator is amplified by an RF power amplifier (not shown) and output to the RF coil unit 14 to transmit an RF pulse.

  The gradient driving unit 23 applies a gradient pulse to the gradient coil unit 13 based on a control signal from the operation console unit 3 and drives it to generate a gradient magnetic field in the imaging space B in which a static magnetic field is formed. It is configured. The gradient drive unit 23 includes three systems of drive circuits (not shown) corresponding to the three systems of gradient coil units 13.

  The data collection unit 24 is configured to collect magnetic resonance signals received by the RF coil unit 14 based on a control signal from the operation console unit 3. Here, in the data collection unit 24, the phase detector (not shown) detects the magnetic resonance signal received by the RF coil unit 14 using the output of the RF oscillator (not shown) of the RF drive unit 22 as a reference signal. Thereafter, using an A / D converter (not shown), the magnetic resonance signal, which is an analog signal, is converted into a digital signal and output.

  The operation console unit 3 will be described.

  As illustrated in FIG. 1, the operation console unit 3 includes a control unit 30, a data processing unit 31, an operation unit 32, a display unit 33, and a storage unit 34. The operation console unit 3 controls the scan unit 2 to perform the main scan on the imaging region of the subject SU, and the subject is based on the magnetic resonance signals collected by the scan unit 2 performing the main scan. A magnetic resonance image is generated as a main scan image for the imaging region of the SU, and the generated main scan image is displayed.

  Each component of the operation console unit 3 will be described sequentially.

  The control unit 30 includes a computer and a memory that stores a program that causes the computer to execute predetermined data processing, and controls each unit. Here, the control unit 30 executes the main scan by outputting a control signal to each of the RF driving unit 22, the gradient driving unit 23, and the data collecting unit 24 so as to correspond to the set main scanning condition. Let At the same time, a control signal is output to the data processing unit 31, the display unit 33, and the storage unit 34 to perform control.

  The data processing unit 31 includes a computer and a memory that stores a program that executes predetermined data processing using the computer, and performs data processing based on a control signal output from the control unit 30. To do.

  FIG. 2 is a block diagram showing the data processing unit 31 in the embodiment according to the present invention.

  As illustrated in FIG. 2, the data processing unit 31 includes a main scan condition setting unit 311, an image contrast setting unit 311 b, a disease setting unit 312, a preview image generation unit 313, and a main scan image generation unit 314. The computer is configured to function as each of the above-described units by a program.

  The main scan condition setting unit 311 of the data processing unit 31 is configured to set the main scan condition when performing the main scan on the subject based on a command input by the operator in the operation unit 32.

  Specifically, the main scan condition setting unit 311 sets the position of the slice region where the main scan image is generated in the subject SU as the main scan condition based on the operation data input by the operator. Here, on the positioning image displayed on the display unit 33, the coordinate data input by the operator using the pointing device of the operation unit 32 to select the slice position for the main scan of the subject SU is controlled. After receiving via the unit 30, the position of the slice region where the main scan is performed in the subject SU is set based on the coordinate data.

  In addition, the main scan condition setting unit 311 sets the scan parameters for performing the main scan for the subject SU as the main scan conditions based on the operation data input by the operator. For example, scan parameters such as TR and TE are set. Although details will be described later, in the present embodiment, the main scan condition setting unit 311 determines the image contrast of the magnetic resonance image generated as the main scan image by the image contrast setting unit 311b based on the operation data input by the operator. After that, the scan parameters such as TR and TE are automatically selected and the main scan condition is set so that the main scan image is generated with the image contrast set by the image contrast setting unit 311b. . Here, the main scan condition setting unit 311 extracts the scan parameter corresponding to the image contrast set by the image contrast setting unit 311b from the database stored in the storage unit 34 in association with the image contrast and the scan parameter. Set as the main scan condition.

  The image contrast setting unit 311b of the data processing unit 31 is configured to set the image contrast of the magnetic resonance image generated as the main scan image based on the operation data input by the operator. Here, the operator selects one image contrast from a menu image including a plurality of character strings of image contrast types on the display screen of the display unit 33 by using the operation unit 32, whereby data of the image contrast types is selected. Is entered. The image contrast setting unit 311b receives the input data via the control unit 30, and then sets the image contrast of the magnetic resonance image generated as the main scan image based on the input data.

  The disease setting unit 312 of the data processing unit 31 is configured to set the disease included in the slice region set by the main scan condition setting unit 311 based on operation data input by the operator. Here, the disease data is input when the operator selects one disease from the menu image including character strings of a plurality of disease types on the display screen of the display unit 33 using the operation unit 32. The disease setting unit 312 receives the input data via the control unit 30, and then sets a disease based on the input data.

  The preview image generation unit 313 of the data processing unit 31 performs a main scan on a simulation image simulated for the main scan image generated by performing the main scan when the main scan is performed under the main scan condition. It is configured to generate as a preview image before implementation. In the present embodiment, the preview image generation unit 313 generates a preview image for the slice area set by the main scan condition setting unit 311. Also, the preview image generation unit 313 generates a preview image so as to correspond to the image contrast set by the image contrast setting unit 311b. In addition, the preview image generation unit 313 generates, as a preview image, a simulation image that is simulated for the main scan image that is generated when the disease set by the disease setting unit 312 is included in the slice region. Here, the preview image generation unit 313 generates this preview image using the characteristic data stored in the storage unit 34.

  The main scan image generation unit 314 of the data processing unit 31 outputs the magnetic resonance signals collected by the scan unit 2 executing the main scan so as to correspond to the main scan condition set by the main scan condition setting unit 311. The raw scan image is generated for the subject SU as raw data. Specifically, the main scan image generation unit 314 acquires the magnetic resonance signal collected by the data collection unit 24 by performing the main scan as a digital signal, and performs image reconstruction on the magnetic resonance signal converted into the digital signal. A configuration process is performed to generate a main scan image for the slice region of the subject SU. For example, the main scan image is reconstructed by performing inverse Fourier transform on the magnetic resonance signals collected so as to correspond to the k-space. Then, the main scan image generation unit 314 outputs image data of the generated main scan image to the display unit 33.

  The operation unit 32 is configured by operation devices such as a keyboard and a pointing device. The operation unit 32 is input with operation data by an operator and outputs the operation data to the control unit 30.

  In the present embodiment, the operation unit 32 receives operation data input by the operator for the position of the slice region where the main scan image is generated in the subject SU, and outputs the operation data to the main scan condition setting unit 311. In addition, the operation unit 32 receives operation data from the operator and outputs the scan parameters to the main scan condition setting unit 311 for the scan parameters when performing the main scan for the subject SU. Further, the operation unit 32 receives operation data input by the operator and outputs the image contrast of the magnetic resonance image generated as the main scan image to the image contrast setting unit 311b. In addition, the operation unit 32 receives operation data input by the operator and outputs it to the disease setting unit 312 for the types of diseases included in the slice region where the main scan is performed on the subject.

  The display unit 33 is configured by a display device such as an LCD, and displays an image on the display screen based on a control signal output from the control unit 30.

  In the present embodiment, the display unit 33 displays the positioning image generated for determining the slice position for performing the main scan of the subject SU on the display screen. For example, the positioning image generated based on the magnetic resonance signal collected by the positioning scan performed before the main scan is displayed on the display screen. For example, a positioning image generated for a slice of the sagittal plane of the subject SU is displayed. Then, when the operator observes the positioning image generated for the subject SU and the operator inputs the position of the slice region using the pointing device of the operation unit 32, the slice position image indicating the position of the slice region is displayed. And displayed on the positioning image.

  In addition, the display unit 33 displays an operation image indicating input items for the operator to input operation data on the display screen. Specifically, a menu image indicating input items to be input for scan parameters when performing the main scan for the subject SU is displayed on the display screen. In addition, a menu image indicating input items to be input regarding the image contrast of the magnetic resonance image generated as the main scan image is displayed on the display screen. In addition, a menu image indicating input items to be input regarding the types of diseases included in the slice region where the main scan is performed in the subject is displayed on the display screen.

  In addition, the display unit 33 receives the image data of the magnetic resonance image generated for the subject SU from the data processing unit 31 and displays it on the display screen. In the present embodiment, the display unit 33 displays the preview image generated by the preview image generation unit 313 on the display screen before performing the main scan. In addition, after the main scan is performed, the display unit 33 displays the main scan image generated by the main scan image generation unit 314 on the display screen.

  The storage unit 34 includes a memory and stores various data. The storage unit 34 is accessed by the control unit 30 as necessary for the stored data.

  In the present embodiment, the storage unit 34 stores data in which image contrast is associated with scan parameters for obtaining the image contrast. When the image contrast setting unit 311b sets the image contrast, Scan parameter data corresponding to the image contrast is extracted and output to the main scan condition setting unit 311.

  In the present embodiment, the storage unit 34 stores characteristic data at each position of the subject SU. Here, the memory | storage part 34 has memorize | stored the characteristic data which linked | related each position and characteristic value of the subject SU in the case of a healthy body. Further, characteristic data in which the position of each disease is associated with the characteristic value of each disease is stored. Specifically, characteristic values such as T1 value, T2 value, T2 * value, velocity vector, diffusion coefficient, and water-to-fat ratio are stored in association with each position of the subject SU. When the slice position for performing the main scan is set in the subject SU, the storage unit 34 outputs characteristic data corresponding to the slice position to the preview image generation unit 313.

(Operation)
Hereinafter, the operation when imaging the subject SU using the magnetic resonance imaging apparatus 1 of the present embodiment will be described.

  FIG. 3 is a flowchart showing an operation when imaging is performed on the subject SU in the embodiment according to the present invention.

  First, as shown in FIG. 3, the main scanning conditions are set (S11).

  Here, the main scan condition when performing the main scan for the subject SU is set by the main scan condition setting unit 311 based on the operation data input by the operator in the operation unit 32.

  Specifically, the position of the slice area where the main scan image is generated in the subject SU and the scan parameters when the main scan is performed on the subject SU are set as the main scan conditions.

  In the present embodiment, operation data is input by an operator using the operation image displayed on the display screen in the display unit 33, and the main scan condition is set based on the input operation data.

  FIG. 4 is a diagram showing an operation image displayed on the display screen when the position of the slice area is set as the main scan condition in the embodiment according to the present invention.

  When inputting operation data regarding the position of the slice area SA for generating the main scan image in the subject SU, as shown in FIG. 4, the operator observes the positioning image SL indicating the sagittal surface of the subject SU. . Then, on the displayed positioning image SL, the operator uses the pointing device of the operation unit 32 to select the position of the slice area SA for performing the main scan of the subject SU, so that the position of the slice area SA is determined. Coordinate data is input as operation data.

  For example, as shown in FIG. 4, a region corresponding to the head of the subject SU in the positioning image SL is selected to be a slice region SA, and coordinate data is input.

  Then, after the input coordinate data is received by the main scan condition setting unit 311 via the control unit 30, the position of the slice region SA for performing the main scan in the subject SU is set based on the coordinate data. .

  FIG. 5 is a diagram showing an operation image displayed on the display screen when setting the scan parameter as the main scan condition in the embodiment according to the present invention.

  As shown in FIG. 5, when the operation data is input regarding the scan parameters when the main scan is performed on the subject SU, it is displayed to determine the image contrast of the magnetic resonance image generated as the main scan image. A menu image M1 including a character string indicating a plurality of image contrast types is displayed and observed by the operator. Then, as shown in FIG. 5, the operator selects one of a plurality of image contrast types displayed in the menu image M1 using the pointing device of the operation unit 32, and the selected image contrast is selected. Enter the operation data of the type. Then, after the input data is received by the image contrast setting unit 311b via the control unit 30, the image contrast of the magnetic resonance image generated as the main scan image is determined based on the input data. 311b sets.

  For example, as shown in FIG. 5, “T1 emphasis” is selected from character strings displayed as “T1 emphasis”, “T2 emphasis”, and “proton density emphasis”, and setting is performed.

  The main scan condition setting unit 311 receives the set image contrast data, and sets scan parameters for performing the main scan in the subject SU based on the data. Here, the scan parameter corresponding to the image contrast set by the image contrast setting unit 311b is extracted from the database stored in advance in association with the image contrast and the scan parameter, and the setting is performed.

  For example, in the pulse sequence of the spin echo method, when “T1 weighted” image contrast is set, the scan parameters are automatically set so that TR is 300 ms and TE is 10 ms. The set scan parameters are displayed on the operation image.

  Next, as shown in FIG. 3, the disease type is selected (S21).

  Here, the disease setting unit 312 sets the type of the disease included in the slice region where the main scan is performed on the subject based on the operation data input by the operator.

  FIG. 6 is a diagram illustrating an operation image displayed on the display screen when a disease type is selected and set in the embodiment according to the present invention.

  As shown in FIG. 6, a menu image M2 including a character string of the disease type displayed to determine the type of disease included in the slice region where the main scan is performed in the subject SU is displayed. Then, the operator selects one of the character strings of the disease type using the pointing device of the operation unit 32, and inputs the operation data of the selected disease type. Then, after the disease setting unit 312 receives the input data via the control unit 30, the type of disease to be displayed so as to be included in the preview image is set based on the input data.

  For example, when the slice area SA on which the main scan is performed is the head of the subject SU and includes a disease such as “cerebral infarction” and “brain tumor”, as shown in FIG. A character string indicating a disease included in the slice area SA such as “healthy body”, “cerebral infarction”, and “brain tumor” is displayed on the menu image M2. For this reason, for example, “cerebral infarction” is selected and set.

  In addition, when a disease image is not included in the preview image, “healthy body” is selected. In the above description, when the slice area SA set as the main scan condition is the head of the subject SU, but is not an area including a disease such as “cerebral infarction” or “brain tumor”, “healthy body” Is displayed on the menu image M2, and character strings indicating diseases such as “cerebral infarction” and “brain tumor” are not displayed.

  Next, as shown in FIG. 3, a preview image is generated (S31).

  Here, the preview image is generated by the preview image generation unit 313 simulating the main scan image generated as the magnetic resonance image when the main scan is performed under the main scan condition.

  In the present embodiment, a preview image is generated so as to correspond to the slice region and image contrast set as described above. Further, this preview image is generated so as to include a magnetic resonance image corresponding to the disease set as described above.

  FIG. 7 is a diagram for explaining how a preview image is generated in the embodiment according to the present invention.

  As shown in FIG. 7, in the present embodiment, the storage unit 34 stores characteristic data at each position (x, y, z) of the subject SU. Specifically, when the subject SU is a human body, T1 value, T2 value, T2 * value, velocity vector, diffusion coefficient, which are generally measured at each position (x, y, z) of the human body, An example of characteristic values such as the water-to-fat ratio is stored in advance as characteristic data. That is, data relating characteristic values measured in a general human body to a three-dimensional position is stored as characteristic data.

  Therefore, when the position (x, y, z) of the slice area SA where the main scan is performed in the subject SU is set as described above, the position (x, y, z) of the slice area SA is set. Corresponding characteristic data is output from the storage unit 34 to the preview image generation unit 313. Here, when the size of the subject SU on which the main scan is performed is different from the size of a general human body in which the characteristic data is stored, the slice region is determined based on the data of each size. Characteristic data corresponding to the position (x, y, z) of SA is extracted and output. For example, after the data on the size of the subject SU is input by the operator, the input data is compared with the data on the size of the human body in which the characteristic data stored in advance is measured. Based on this, the position information of the extracted characteristic data is adjusted.

  Then, based on the characteristic value at each position (x, y, z) of the slice area SA and the scan parameter set as described above, the preview image generating unit 313 generates a preview image.

For example, when a preview image is generated by a pulse sequence of the spin echo method, the value T ₁ (x, y, z) of T1, the value T ₂ (x of T2) as shown in the following formula (1) , Y, z), the respective pixel values S (x, y, z) are calculated from the characteristic values of the proton density values d (x, y, z) and the scan parameters of TR and TE. Here, the characteristic data is selected so as to correspond to whether the subject SU is a “healthy body” or includes a “disease”, and a preview image is generated. In this way, a simulation image generated according to the main scan condition is generated as a preview image.

  Next, a preview image is displayed as shown in FIG. 3 (S41).

  Here, the display unit 33 displays the preview image generated above on the display screen.

  FIG. 8 is a diagram showing how a preview image is displayed in the embodiment according to the present invention.

  For example, as shown in FIG. 8, the preview image P generated as a slice image for the set slice region is displayed side by side on the positioning image SL.

  Next, as shown in FIG. 3, it is determined whether or not it is necessary to reset the main scan conditions (S51).

  Here, the operator observes the preview image displayed on the screen of the display unit 33 and determines whether or not a desired image is obtained. For example, it is determined whether or not the preview image is generated with a desired image contrast.

  If the preview image is not a desired image and it is necessary to reset the main scan condition (Yes), the main scan condition is adjusted as shown in FIG. 3 (S61).

  Here, the operator inputs operation data so as to adjust the slice position and the scan parameter. For example, the numerical values are input so that the values of the scan parameters TR and TE are changed from the value set above to another value.

  Thereafter, in the same manner as described above, a preview image is generated so as to correspond to the adjusted scan condition (S31), the generated preview image is displayed (S41), and it is necessary to reset the main scan condition. The determination (S51) is repeated.

  On the other hand, if the preview image is a desired image and it is not necessary to reset the main scan condition (No), the main scan is started as shown in FIG. 3 (S71).

  Here, after the operation data for starting execution of the main scan is input by the operator, the scan unit 2 performs the main scan on the subject SU so as to correspond to the main scan conditions set as described above.

  Next, as shown in FIG. 3, a main scan image is generated (S81).

  Here, the main scan image generation unit 314 generates magnetic scan signals collected by performing the main scan as raw data as the main scan image.

  Next, as shown in FIG. 3, the main scan image is displayed (S91).

  Here, the display unit 33 displays the main scan image generated above on the display screen.

  As described above, the present embodiment generates a preview image by simulating the main scan image generated when the main scan is performed under the main scan condition before the main scan is performed. Then, the preview image is displayed on the display screen before the main scan is performed. For this reason, in the present embodiment, it is possible to predict whether or not a magnetic resonance image having a desired image quality is generated as a main scan image by observing the preview image. Therefore, in the present embodiment, it is possible to confirm whether or not the main scan condition is accurately set before the main scan is performed. Therefore, it is possible to improve the imaging efficiency for imaging the subject.

  In the present embodiment, the main scan condition is set so as to correspond to the image contrast, and the preview image generated under the main scan condition is simulated. For this reason, in the present embodiment, when obtaining a magnetic resonance image having a desired image contrast such as a T1-weighted image, a T2-weighted image, or a proton density-weighted image, the main scan condition can be easily set, and thus the subject is imaged. Imaging efficiency can be improved.

  Further, in the present embodiment, a main scan image generated as a magnetic resonance image when a disease is included in a slice region is generated as a preview image by simulation and displayed on a display screen. For this reason, in the present embodiment, even when a disease is included in a slice region, it is easy to accurately input operation data so as to generate a desired magnetic resonance image, as described above. The imaging efficiency for imaging the subject can be improved.

  In the above embodiment, the magnetic resonance imaging apparatus 1 corresponds to the magnetic resonance imaging apparatus of the present invention. The display unit 33 in the above embodiment corresponds to the preview image display unit of the present invention. Further, the operation console unit 3 of the above embodiment corresponds to the preview image display device of the present invention. Moreover, the display part 33 of the said embodiment is corresponded to the display part of this invention. In addition, the storage unit 34 in the above embodiment corresponds to the storage unit of the present invention. Further, the main scan condition setting unit 311 of the above embodiment corresponds to the main scan condition setting unit of the present invention. The image contrast setting unit 311b in the above embodiment corresponds to the image contrast setting unit of the present invention. Moreover, the disease setting unit 312 of the above embodiment corresponds to the disease setting unit of the present invention. Further, the preview image generation unit 313 of the above embodiment corresponds to the preview image generation unit of the present invention.

  In implementing the present invention, the present invention is not limited to the above-described embodiment, and various modifications can be employed.

FIG. 1 is a configuration diagram showing a configuration of a magnetic resonance imaging apparatus 1 in an embodiment according to the present invention. FIG. 2 is a block diagram showing the data processing unit 31 in the embodiment according to the present invention. FIG. 3 is a flowchart showing an operation when imaging is performed on the subject SU in the embodiment according to the present invention. FIG. 4 is a diagram showing an operation image displayed on the display screen when the position of the slice area is set as the main scan condition in the embodiment according to the present invention. FIG. 5 is a diagram showing an operation image displayed on the display screen when setting the scan parameter as the main scan condition in the embodiment according to the present invention. FIG. 6 is a diagram illustrating an operation image displayed on the display screen when a disease type is selected and set in the embodiment according to the present invention. FIG. 7 is a diagram for explaining how a preview image is generated in the embodiment according to the present invention. FIG. 8 is a diagram showing how a preview image is displayed in the embodiment according to the present invention.

Explanation of symbols

1: magnetic resonance imaging apparatus (magnetic resonance imaging apparatus), 2: scanning section, 3: operation console section (preview image display apparatus), 12: static magnetic field magnet section, 13: gradient coil section, 14: RF coil section, 15 : Subject moving unit, 22: RF drive unit, 23: gradient drive unit, 24: data collection unit, 30: control unit, 31: data processing unit, 32: operation unit, 33: display unit (display unit), 34 : Storage unit (storage unit), 311: main scan condition setting unit (main scan condition setting unit), 311b: image contrast setting unit (image contrast setting unit), 312: disease setting unit (disease setting unit), 313: preview Image generation unit (preview image generation unit), 314: main scan image generation unit

Claims (10)

The main scan for collecting magnetic resonance signals from the subject in the static magnetic field space is performed so as to correspond to the main scan conditions, and the magnetic resonance image is scanned based on the magnetic resonance signals collected in the execution of the main scan. A magnetic resonance imaging apparatus for generating an image,
A preview image generating unit that generates a simulation image simulated for a main scan image generated when the main scan is performed so as to correspond to the main scan condition;
A display unit that displays the preview image generated by the preview image generation unit on a display screen before the main scan is performed;
A storage unit storing characteristic data representing characteristic values generally measured in a human body in association with each position of the subject;
Have
The magnetic resonance imaging apparatus, wherein the preview image generation unit generates the preview image using the characteristic data. A main scan condition setting unit for setting the main scan condition;
The main scan condition setting unit sets, as the main scan condition, a position of a slice region that generates the main scan image in the subject based on a command input by an operator,
The preview image generation unit generates the preview image for the slice region set by the main scan condition setting unit;
The magnetic resonance imaging apparatus according to claim 1. An image contrast setting unit configured to set an image contrast of the magnetic resonance image generated as the main scan image based on a command input by an operator;
The main scan condition setting unit sets the main scan condition so that the main scan image is generated with the image contrast set by the image contrast setting unit,
The preview image generation unit generates the preview image based on the main scan condition set by the main scan condition setting unit so as to correspond to the image contrast set by the image contrast setting unit;
The magnetic resonance imaging apparatus according to claim 2. A disease setting unit for setting a disease included in the slice region set by the main scan condition setting unit based on a command input by an operator;
The preview image generation unit generates, as the preview image, a simulation image that is simulated for a main scan image that is generated when the disease set by the disease setting unit is included in the slice region.
The magnetic resonance imaging apparatus according to claim 2 or 3.   The characteristic value includes at least one of a T1 value, a T2 value, a T2 * value, a velocity vector, a diffusion coefficient, and a water-to-fat ratio. The magnetic resonance imaging apparatus described. A book generated based on the magnetic resonance signal collected in the execution of the main scan when the main scan for collecting the magnetic resonance signal from the subject in the static magnetic field space is performed so as to correspond to the main scan condition. A preview image generation unit that generates a simulation image simulated for a scan image as a preview image;
A display unit that displays the preview image generated by the preview image generation unit on a display screen before the main scan is performed;
A storage unit storing characteristic data representing characteristic values generally measured in a human body in association with each position of the subject;
Have
The preview image display device generates the preview image using the characteristic data. A main scan condition setting unit for setting the main scan condition;
The main scan condition setting unit sets, as the main scan condition, a position of a slice region that generates the main scan image in the subject based on a command input by an operator,
The preview image generation unit generates the preview image for the slice region set by the main scan condition setting unit;
The preview image display device according to claim 6. An image contrast setting unit configured to set an image contrast of the magnetic resonance image generated as the main scan image based on a command input by an operator;
The main scan condition setting unit sets the main scan condition so that the main scan image is generated with the image contrast set by the image contrast setting unit,
The preview image generation unit generates the preview image based on the main scan condition set by the main scan condition setting unit so as to correspond to the image contrast set by the image contrast setting unit;
The preview image display device according to claim 7. A disease setting unit for setting a disease included in the slice region set by the main scan condition setting unit based on a command input by an operator;
The preview image generation unit generates, as the preview image, a simulation image that is simulated for a main scan image that is generated when the disease set by the disease setting unit is included in the slice region.
The preview image display device according to claim 7 or 8.   The characteristic value includes at least one of a T1 value, a T2 value, a T2 * value, a velocity vector, a diffusion coefficient, and a water-to-fat ratio. The preview image display device described.

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