JP2012016459A - Mri apparatus, and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately set imaging condition to a region of interest indicated on image data.SOLUTION: The MRI apparatus 100 includes: a set region of interest selecting part 73 for selecting the desired set region of interest from at least one set region of interest of picture images taken by a pilot imaging mode; an imaging condition generating part 5 for generating an imaging condition corresponding to the set region of interest selected by the set region of interest selecting part 73; a display part 6 for displaying the imaging condition adjacent to the set region of interest; an imaging condition setting part 74 for setting the imaging condition displayed on the display part 6; and a control part 8 for performing MRI imaging by the imaging mode on the basis of the imaging condition set by the imaging condition setting part 74.

Description

  Embodiments described herein relate generally to an MRI apparatus and a control program that can easily set imaging conditions in various regions of interest set for image data.

  Magnetic resonance imaging (MRI) excites nuclear spins in a subject tissue placed in a strong static magnetic field with a high-frequency signal (RF pulse) having the Larmor frequency, and magnetic resonance generated by this excitation. This is an imaging method for generating image data by reconstructing a signal (MR signal).

  An MRI apparatus is an image diagnostic apparatus that generates image data based on MR signals detected from within a living body, and can obtain a lot of diagnostic information such as functional diagnostic information and biochemical information as well as anatomical diagnostic information. As a result, it is indispensable in the field of diagnostic imaging today.

  In the above-mentioned MRI, MRA (Magnetic Resonance Angiography) that enables observation of blood flow information has already been used in clinical settings, and in recent years, various types of blood flow information can be observed without using a contrast agent. Non-contrast-enhanced MRI has also been developed. In this non-contrast-enhanced MRI, one or a plurality of labeling pulse irradiation regions set for a diagnosis target region of a subject is irradiated with a labeling pulse, whereby MR signals obtained from blood in the blood vessel are surrounded by surrounding biological tissue. Is detected with higher sensitivity than the MR signal obtained from the above.

  For example, in non-contrast-enhanced MRI using a pulse sequence that combines a Time-SLIP (Time-Spatial Labeling Inversion Pulse) method and a True SSFP (Steady-State Free Precession) method, a region-selected IR pulse having a flip angle of 180 degrees is described above. After irradiating the irradiation region of the labeling pulse, high-speed MRI imaging by the True SSFP method is performed. By applying this Time-SLIP method, it becomes possible to observe the dynamics of blood flow in a desired blood vessel region without using a contrast agent.

JP 2008-289862 A

  Conventionally, the setting of imaging conditions for the above-described non-contrast MRI labeling pulse irradiation area and normal MRI imaging area has been performed using an imaging condition input sheet in which all imaging condition input fields are displayed in a list. . That is, doctors and examiners search for a desired imaging condition input field from many imaging condition input fields indicated on the imaging condition input sheet, and perform MRI imaging on the obtained imaging condition input field. A method of inputting suitable imaging conditions has been taken. For this reason, it takes a lot of time to set the imaging conditions, which not only lowers the examination efficiency but also places a heavy burden on doctors and examiners.

  In addition, in the setting of the imaging condition using the imaging condition input sheet described above, since a common imaging condition is set for the same type of irradiation area or imaging area, a plurality of these irradiation areas or imaging areas are set. In this case, it is impossible to set the imaging conditions for each area. Therefore, there is a problem that it is difficult to set optimal imaging conditions for these regions.

  The present disclosure has been made in view of the above-described problems, and an object thereof is to provide an MRI apparatus and a control program capable of easily setting imaging conditions of a region of interest indicated on image data. There is.

  The MRI apparatus according to the present embodiment performs MRI imaging in the main imaging mode based on the imaging conditions set in the pilot imaging mode. The MRI apparatus includes a region of interest selection unit, an imaging condition generation unit, a display unit, an imaging condition setting unit, and a control unit. The region-of-interest selection unit selects a desired region of interest from at least one region of interest in the image captured in the pilot imaging mode. The imaging condition generation unit generates an imaging condition corresponding to the region of interest selected by the region of interest selection unit. The display unit displays the imaging condition in the vicinity of the region of interest. The imaging condition setting unit sets the imaging condition displayed on the display unit. The control unit performs MRI imaging in the main imaging mode based on the imaging conditions set by the imaging condition setting unit.

The block diagram which shows the whole structure of the MRI apparatus in this embodiment. The figure which shows the pulse sequence which combined the Time-SLIP method and True SSFP method applied to the non-contrast MRI imaging of this embodiment. The figure which shows the longitudinal magnetization of the nuclear spin which changes with the area | region selection IR pulse irradiated in the non-contrast MRI imaging of this embodiment, and irradiation of this area | region selection IR pulse. The figure which shows typically the blood-flow information observed in the non-contrast MRI imaging of this embodiment. The figure which shows the imaging condition produced | generated by the imaging condition production | generation part of this embodiment. The figure which shows the imaging condition displayed with the image data for positioning in the display part of this embodiment. The figure which shows the arrangement position of the imaging condition with respect to the region of interest set to the image data for positioning of this embodiment. 5 is a flowchart showing a procedure for setting imaging conditions in the present embodiment. The figure which shows the several imaging condition displayed with the image data for positioning in the modification of this embodiment. The figure for demonstrating the imaging condition which shows the imaging | photography condition of the grid | lattice-like region of interest set to the image data for positioning in this modification of this embodiment, and this region of interest.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

  In the MRI apparatus according to the present embodiment, the irradiation region (labeling pulse irradiation region) of the region selection IR pulse used in the non-contrast MRI imaging is included in the positioning image collected in the pilot imaging mode preceding the main imaging mode. At least one region of interest shown is superimposed and displayed on the display unit. When a desired region of interest is selected from the displayed regions of interest, the imaging region temporarily set for the selected region of interest (for example, the region of interest temporarily set using standard imaging conditions etc. is irradiated) Imaging conditions indicating a region selection IR pulse irradiation condition to be generated) and the obtained imaging conditions are arranged in the vicinity of the region of interest superimposed on the positioning image data and displayed on the display unit. Next, by updating the displayed imaging conditions as necessary, suitable imaging conditions are set for the selected region of interest, and MRI imaging in the main imaging mode is performed based on the obtained imaging conditions.

  In the following description, two regions of interest corresponding to the labeling pulse irradiation region of non-contrast MRI imaging are set for the positioning image acquired in the pilot imaging mode and selected from these regions of interest. Although the case where an imaging condition suitable for the region of interest is set based on the imaging condition displayed in the vicinity of the desired region of interest will be described, the imaging condition is not limited to the labeling pulse irradiation condition, and an imaging section is set. It may be imaging conditions or the like.

  The configuration and function of the MRI apparatus according to the embodiment of the present disclosure will be described with reference to FIGS. FIG. 1 is a block diagram showing the overall configuration of the MRI apparatus.

  The MRI apparatus 100 shown in FIG. 1 irradiates the subject 150 with RF pulses by generating a static magnetic field generator 1 and a gradient magnetic field generator 2 that generate a magnetic field for the subject 150, and the subject 150. The transmission / reception unit 3 for detecting the MR signal and the MR signal (MR data) collected in the non-contrast MRI imaging in the pilot imaging mode and the main imaging mode for the subject 150 are reconstructed to perform positioning image data and diagnostic image. An image data generation unit 4 that generates data, an imaging condition generation unit 5 that generates an imaging condition corresponding to a region of interest set for the positioning image data, and a positioning image to which the region of interest and the imaging condition are added A display unit 6 for displaying data and diagnostic image data in the main imaging mode is provided.

  Furthermore, the MRI apparatus 100 includes an input control unit 7 that performs input of subject information, selection of an imaging mode / imaging condition setting mode, selection of a region of interest, setting of imaging conditions, input of various command signals, and the like. , A top plate moving mechanism unit 10 for moving the top plate 9 in the body axis direction (z-axis direction) of the subject 150, and a control unit for controlling the above-described units of the MRI apparatus 100. 8 is provided.

  The static magnetic field generation unit 1 includes a main magnet 11 composed of a normal conducting magnet or a superconducting magnet, and a static magnetic field power source 12 for supplying current to the main magnet 11, and is disposed in an imaging field in the center of the gantry (not shown). A strong static magnetic field is formed on the subject 150. The main magnet 11 may be constituted by a permanent magnet.

  On the other hand, the gradient magnetic field generator 2 is a gradient magnetic field coil that forms a gradient magnetic field in the body axis direction (z-axis direction in FIG. 1) of the subject 150 and the x-axis direction and the y-axis direction orthogonal to the body axis direction. 21 and a gradient magnetic field power supply 22 for supplying a pulse current to each of the gradient magnetic field coils 21.

  The gradient magnetic field coil 21 and the gradient magnetic field power source 22 add position information to the imaging field in the center of the gantry where the subject 150 is placed. That is, the gradient magnetic field power supply 22 controls the pulse current supplied to the gradient magnetic field coil 21 in the x-axis direction, the y-axis direction, and the z-axis direction based on the sequence control signal supplied from the control unit 8 to thereby change the direction of each direction. To form a gradient magnetic field. The gradient magnetic fields in the x-axis direction, the y-axis direction, and the z-axis direction are combined to form slice selection gradient magnetic fields, phase encoding gradient magnetic fields, and frequency encoding (reading) gradient magnetic fields that are orthogonal to each other, and these The gradient magnetic field is applied to the subject 150 while being superimposed on the static magnetic field formed by the main magnet 11.

  Next, the transmitter / receiver 3 irradiates the subject 150 with an RF pulse and detects an MR signal generated from the subject 150, and a transmitter 32 and a receiver 33 connected to the transmitter / receiver coil 31. It has. However, the transmission / reception coil 31 may be configured by a transmission-only coil and a reception-only coil.

  The transmission unit 32 has a function of supplying a pulse current to the transmission / reception coil 31 in the pilot imaging mode for collecting positioning image data and the main imaging mode for collecting diagnostic image data. A reference signal generator, a modulator, a power amplifier, and the like. The reference signal generator generates a reference signal having the same frequency as the magnetic resonance frequency (Larmor frequency) determined by the static magnetic field strength of the main magnet 11, and the modulator converts the reference signal into a predetermined selective excitation waveform. Modulate to generate a pulse current.

  Then, the obtained pulse current is supplied to the transmission / reception coil 31 via the power amplifier, and the subject 150 is irradiated with the RF pulse. In particular, in the non-contrast-enhanced MRI imaging of the present embodiment using a pulse sequence that combines the Time-SLIP method and the True SSFP method, two area selection IR (Inversion Recovery) having a flip angle of 180 degrees is required when collecting one image data. ) A pulse, a 90 degree pulse and a plurality of 180 degree pulses are supplied to the transmitting / receiving coil 31 in a predetermined order.

  On the other hand, the receiving unit 33 generates intermediate frequency conversion, phase detection, low frequency amplification, filtering, A / D for the MR signal generated in the subject 150 irradiated with the RF pulse and detected by the transmission / reception coil 31. Signal processing such as conversion is performed to generate k-space MR data.

  Next, non-contrast-enhanced MRI imaging according to this embodiment capable of collecting image data in which a desired vascular system is emphasized in time series by combining the Time-SLIP method and the True SSFP method is shown in FIGS. Will be described. Note that FIG. 2 shows that the region selection IR pulse PI1 (the first labeling pulse irradiation region) is set with respect to the labeling pulse irradiation region S1 (first labeling pulse irradiation region) set in the imaging region of the subject 150 prior to the acquisition of the MR signal. The non-contrast-enhanced MRI imaging pulse that irradiates the region selection IR pulse) and irradiates the labeling pulse irradiation region S2 (second labeling pulse irradiation region) with the region selection IR pulse PI2 (second region selection IR pulse). A sequence is shown.

  On the other hand, FIG. 3 shows temporal changes in longitudinal magnetization of nuclear spins of biological tissue in the labeling pulse irradiation region S1 irradiated with the region selection IR pulse PI1 and the labeling pulse irradiation region S2 irradiated with the region selection IR pulse PI2. Show. FIG. 4 shows a non-contrast image by irradiation of the labeling pulse irradiation region S1 and the labeling pulse irradiation region S2 set for the imaging region Rx of the subject 150 and the region selection IR pulses PI1 and PI2 for these irradiation regions. The blood flow information of the blood vessel region that can be observed is schematically shown.

  2A, FIG. 2A shows an RF pulse applied to the imaging region of the subject 150 including the above-described labeling pulse irradiation region, and FIGS. 2B to 2D show the imaging region. A slice selective gradient magnetic field (Gs), a phase encode gradient magnetic field (Ge), a frequency encode (read) gradient magnetic field (Gr) applied to the image, and FIG. The MR signals generated from are respectively shown.

  In the pulse sequence of non-contrast MRI imaging shown in FIG. 2, first, a region selection IR pulse PI1 having a flip angle of 180 degrees is irradiated to the labeling pulse irradiation region S1 of the subject 150 at time t1, and then the time At time t2 subsequent to t1, the region selection IR pulse PI2 having the same flip angle is irradiated to the labeling pulse irradiation region S2. Then, after a 90-degree pulse is irradiated at a time t3 when a predetermined time TI1 (or a predetermined time TI2 from the irradiation time t2 of the region selection IR pulse PI2) has elapsed since the irradiation time t1 of the region selection IR pulse PI1, True SSFP method Acquisition of MR signals based on the pulse sequence is started.

  FIG. 3 shows the irradiation timing of the region selection IR pulse PI1 and the region selection IR pulse PI2 (FIG. 3A) and the time of longitudinal magnetization possessed by the nuclear spins in the labeling pulse irradiation region S1 irradiated with the region selection IR pulse PI1. FIG. 3B shows a temporal change (FIG. 3C) of the longitudinal magnetization of the nuclear spins in the nuclear pulse of the labeling pulse irradiation region S2 irradiated with the region change IR pulse PI2 and FIG. Longitudinal magnetization of the labeling pulse irradiation regions S1 and S2 inverted by 180 degrees from positive longitudinal magnetization (Mo) to negative longitudinal magnetization (-Mo) by irradiation of the region selective IR pulse PI1 and irradiation of the region selective IR pulse PI2 at time t2. Tries to return to the original longitudinal magnetization (Mo) according to the longitudinal relaxation time T1 of the biological tissue or blood in the blood vessel.

  When a 90-degree pulse is applied to the imaging region including the labeling pulse irradiation regions S1 and S2 at time t3 of such a recovery process, the imaging region that has not been irradiated with the region selection IR pulses PI1 and PI2 (hereinafter, referred to as the imaging region). In the labeling pulse non-irradiation region, MRI imaging is performed by applying a true SSFP pulse sequence to a biological tissue and blood in the blood vessel having longitudinal magnetization Mo. In the labeling pulse irradiation regions S1 and S2, longitudinal magnetization is performed. The above-described MRI imaging is performed on a living tissue and longitudinal blood having longitudinal magnetization M1 or M2 smaller than Mo.

  By this MRI imaging, high-sensitivity MR signals proportional to the magnitude of the longitudinal magnetization M0 are collected from the labeling pulse non-irradiated region, and the longitudinal magnetization M1 (M1 <M0) or the longitudinal magnetization M1 from the labeling pulse irradiated regions S1 and S2. A low-sensitivity MR signal proportional to the magnitude of the magnetization M2 (M2 <M0) is collected.

  Next, blood flow information obtained by MRI imaging of the Time-SLIP method using the region selection IR pulses PI1 and PI2 will be described with reference to FIG. FIG. 4 shows, for example, labeling pulse irradiation regions S1 and S2 set for positioning image data collected in the pilot imaging mode performed prior to non-contrast MRI imaging of the subject 150.

  The labeling pulse irradiation regions S1 and S2 are irradiated with the region selection IR pulse PI1 at time t1 and the region selection IR pulse PI2 at time t2, and TI1 from time t1 or TI2 from time t2 has elapsed. When MRI imaging using the True SSFP method pulse sequence is started at time t3, low sensitivity MR signals are emitted from the living tissue and blood in the labeling pulse irradiation regions S1 and S2 in which the longitudinal magnetization of the nuclear spins is significantly reduced. Are collected.

  On the other hand, since the intravascular blood in which the longitudinal magnetization M0 is maintained in the labeling pulse non-irradiation region adjacent to the labeling pulse irradiation regions S1 and S2 moves to the blood vessel regions R1 and R2 indicated by the oblique lines in FIG. Highly sensitive MR signals can be collected from the blood vessel regions R1 and R2. That is, according to the above-described method, the blood vessel region R1 and the labeling pulse irradiation region of the labeling pulse irradiation region S1 are performed by performing high-speed MRI imaging by the True SSFP method after a predetermined time has elapsed from the irradiation of the region selection IR pulses PI1 and PI2. It becomes possible to observe blood flow information in the blood vessel region R2 of S2 with high sensitivity. In addition, the arrow of FIG. 4 has shown the blood flow direction.

  Next, the image data generation unit 4 of FIG. 1 includes an MR data storage unit 41, a high-speed calculation processing unit 42, and an image data storage unit 43. The MR data storage unit 41 includes a slice selection gradient magnetic field and a phase encoding gradient magnetic field. Are sequentially updated, and MR signals in the pilot imaging mode and the main imaging mode collected from the subject 150 in time series are stored as MR data in the k space.

  On the other hand, the high-speed arithmetic processing unit 42 performs reconstruction processing by Fourier transform on the k-space MR data read from the MR data storage unit 41 to generate real-space image data. The image data in the imaging mode is temporarily stored in the image data storage unit 43.

  Next, the imaging condition generation unit 5 includes an imaging condition storage unit and a data extraction unit (not shown). In this imaging condition storage unit, various regions of interest indicating an RF pulse irradiation area, an image data collection area, and the like are displayed. The preset standard imaging conditions, the imaging conditions used in the past MRI examination, and the like are stored as identification information of the region of interest as supplementary information. Then, in an imaging condition setting mode for setting the imaging condition of the region of interest, a desired one of a plurality of regions of interest (for example, two regions of interest indicating labeling pulse irradiation regions S1 and S2) indicated on the positioning image data is desired. When the input control unit 7 selects the region of interest (for example, the region of interest indicating the labeling pulse irradiation region S1), the data extraction unit is stored in the imaging condition storage unit based on the identification information of the selected region of interest. The imaging conditions corresponding to the labeling pulse irradiation area S1 are read out from the various imaging conditions. Then, an imaging condition of a predetermined format in which the obtained imaging conditions are displayed as a list is created.

  FIG. 5 shows the generation of imaging conditions when the region of interest SR1 is selected in the imaging region Rx of the positioning image data in which the region of interest SR1 indicating the labeling pulse irradiation region S1 and the region of interest SR2 indicating the labeling pulse irradiation region S2 are superimposed. A specific example of the imaging conditions generated by the unit 5 is shown. The imaging conditions include, for example, the inversion time (TI) of the region selection IR pulse PI1 temporarily set according to the standard imaging conditions and the like, the flip angle (α ), The slice thickness (d), and the echo time (TE) and repetition time (TR) in MRI imaging using the region selection IR pulse PI1 are shown as necessary. A button for updating (increasing / decreasing) the value of the above-described temporarily set imaging condition is added to the right end portion.

  Returning to FIG. 1, the display unit 6 of the MRI apparatus 100 includes a display data generation unit, a data conversion unit, and a monitor (not shown). The display data generation unit is for positioning generated by the image data generation unit 4 in the pilot imaging mode. Regions of interest SR1 and SR2 indicating labeling pulse irradiation regions S1 and S2 are superimposed on the image data, and further, for example, the region of interest SR1 is selected from the regions of interest SR1 and SR2 by the input control unit 7 in the imaging condition setting mode. In this case, the imaging condition generated by the imaging condition generation unit 5 based on the identification information of the selected region of interest SR1 is added close to the region of interest SR1 on the positioning image data to generate display data. Next, the data conversion unit performs conversion processing such as D / A conversion and television format conversion on the display data and displays it on the monitor. Further, the display data generation unit generates display data by adding subject information, imaging conditions, and the like to the diagnostic image data generated by the image data generation unit 4 in the main imaging mode, and displays the display data via the data conversion unit. indicate.

  On the other hand, the input control unit 7 is connected to various input devices such as a display panel, a switch, a keyboard, or a mouse, for example, and forms an interactive interface when combined with the display unit 6. The input control unit 7 is a mode selection unit 71 that selects an imaging mode / imaging condition setting mode based on an input result from the input device described above, and a region of interest setting unit 72 that sets a region of interest for positioning image data. A region-of-interest selection unit 73 for selecting a desired region of interest from one or a plurality of regions of interest set for the positioning image data, and a region of interest on the positioning image data. It functions as an imaging condition setting unit 74 that sets an imaging condition suitable for the region of interest using the indicated imaging conditions. In addition, input of subject information, setting of MR signal acquisition conditions including pulse sequences of Time-SLIP method and True SSFP method, setting of image data generation conditions and image data display conditions, and input of various command signals, etc. This is performed using the display panel or the input device described above.

  The top board 9 is slidably attached to the body axis direction (z-axis direction) of the subject 150 on the upper surface of a bed (not shown), and the subject 150 placed on the top board 9 is moved in the z-axis direction. Thus, the imaging area is set to a desired position in the imaging field. On the other hand, the top plate moving mechanism unit 10 is attached to, for example, the end or lower portion of the bed, and generates a drive signal for moving the top plate 9 based on the top plate movement control signal supplied from the control unit 8. . A wide range of image data can be collected by performing MRI imaging at predetermined intervals while sequentially moving the top plate 9 in the body axis direction of the subject 150.

  Next, the control unit 8 includes a main control unit 81, a sequence control unit 82, and a top board movement control unit 83. The main control unit 81 includes, for example, a CPU and a storage unit (not shown), and has a function of controlling each unit of the MRI apparatus 100 in an integrated manner. In the storage unit of the main control unit 81, various types of information input through the above input device are stored. On the other hand, the CPU of the main control unit 81 sets the magnitude, polarity, supply time, supply timing, etc. of the pulse current to be supplied to the gradient magnetic field coil 21 and the transmission / reception coil 31 based on the above-described MR signal acquisition conditions, and sequence By supplying to the control unit 82, non-contrast MRI imaging of the subject 150 is executed.

  The sequence control unit 82 includes, for example, a CPU and a storage unit (not shown). The sequence control unit 82 temporarily stores the MR signal collection conditions supplied from the main control unit 81 in the storage unit, and then based on these information, the Time-SLIP A sequence control signal for non-contrast-enhanced MRI imaging combining the method and the True SSFP method is generated, and the gradient magnetic field power source 22 of the gradient magnetic field generator 2 and the transmitter 32 of the transmitter / receiver 3 are controlled. On the other hand, the top board movement control unit 83 generates a top board movement control signal based on the top board movement instruction signal supplied from the input control unit 7 via the main control unit 81 and supplies the top board movement control signal to the top board movement mechanism unit 10. .

  Next, when the imaging condition setting mode is selected by the input control unit 7, the imaging condition displayed together with the positioning image data on the monitor of the display unit 6 and the setting of the imaging condition performed using this imaging condition are shown in FIG. Will be described.

  As shown in FIG. 6, when the mode switching function of the input control unit 7 is used to switch the mode from the pilot imaging mode to the imaging condition setting mode, the display unit 6 displays the positioning information collected in the pilot imaging mode. Display data generated by superimposing the region of interest SR1 and the region of interest SR2 indicating the labeling pulse irradiation region S1 and the labeling pulse irradiation region S2 on the image data is displayed on its own monitor. At this time, the size, position, and direction of the region of interest SR1 and the region of interest SR2 are set based on standard irradiation region information set in advance for each imaging method.

  Next, when the imaging condition of the region of interest SR1 superimposed on the positioning image data displayed on the monitor of the display unit 6 is to be updated, the operator uses the input device connected to the input control unit 7 for positioning. The region of interest SR1 on the image data is selected (click selected). On the other hand, the imaging condition generation unit 5 that has received the selection signal and the identification information of the region of interest SR1 from the input control unit 7 via the main control unit 81 includes various imaging conditions stored in its own imaging condition storage unit. The imaging conditions of the region of interest SR1 are read out from the above, and imaging conditions (see FIG. 5) in which these imaging conditions are temporarily set are generated and supplied to the display unit 6. The display unit 6 adds the imaging condition supplied from the imaging condition generation unit 5 in the vicinity of the region of interest SR1 on the positioning image data, and displays it on its own monitor.

  Next, the operator sets an imaging condition suitable for the region of interest by updating the above imaging condition using a button added to the imaging condition displayed on the display unit 6, and sets the imaging condition. When is finished, the main imaging mode is selected. The newly set imaging conditions are supplied to the sequence control unit 82 via the main control unit 81 by the selection signal for the main imaging mode, and MRI imaging in the main imaging mode is started.

  Note that imaging conditions temporarily set immediately after a desired region of interest is selected include imaging conditions based on MR signal acquisition conditions initially set for the MRI imaging, standard imaging conditions set in advance, and Although it may be based on the imaging conditions set in the past MRI imaging, it is not particularly limited. On the other hand, when the size, position, and direction of the region of interest SR1 or region of interest SR2 superimposed on the positioning image data are inappropriate, the region of interest may be updated using an input device connected to the input control unit 7. You may update using the above-mentioned imaging conditions. In this case, information regarding the position and direction of the region of interest is added to the imaging condition.

  Next, the display position of the imaging condition for the region of interest will be described with reference to FIG. FIG. 7 shows a case where the region of interest SR1 indicating the labeling pulse irradiation region S1 and the region of interest SR2 indicating the labeling pulse irradiation region S2 are arranged adjacent to each other in the horizontal direction, and imaging added to the positioning image data. The position of the condition is determined by the click position of the input device used in selecting the region of interest.

  For example, when the region of interest SR1 is selected using an input device connected to the input control unit 7, the imaging condition corresponding to the region of interest SR1 is a region adjacent to the region of interest SR1 by clicking on the upper left region of the region of interest SR1. The imaging conditions when the upper right region of the region of interest SR1 is clicked are arranged in the region D and are arranged in the region D. The imaging conditions when the lower left region of the region of interest SR1 is clicked are arranged in the region B or the region C, and the imaging conditions when the lower right region of the region of interest SR1 is clicked are arranged in the region E or the region F.

  Similarly, the imaging condition when the upper left region of the region of interest SR2 is clicked is arranged in the region G, and the imaging condition when the upper right region of the region of interest SR2 is clicked is arranged in the region J. The imaging conditions when the lower left region of the region of interest SR2 is clicked are arranged in the region H or the region I, and the imaging conditions when the lower right region of the region of interest SR2 is clicked are arranged in the region K or the region L. In this case, when there is a margin in the vertical width of the monitor provided in the display unit 6, the arrangement in the region C, the region F, the region I, and the region L is preferable, but is not particularly limited.

  Next, an imaging condition setting procedure in this embodiment will be described with reference to the flowchart of FIG.

  Prior to MRI imaging in the pilot imaging mode for the subject 150, the input control unit 7 inputs subject information or pilots based on the operation of the input device by a doctor, an examiner, or the like (hereinafter referred to as an operator). MR signal acquisition conditions, image data generation conditions, and image data display conditions in the imaging mode and the main imaging mode are set (step S1 in FIG. 8).

  When the above initial setting is completed, the input control unit 7 selects a pilot imaging mode and inputs an imaging start command based on the operation of the input device by the operator. Next, the main control unit 81 of the control unit 8 that has received this command signal controls each unit of the MRI apparatus 100, for example, positioning image data in a coronal section (vertical section viewed from the front) of the subject 150. Is generated (step S2 in FIG. 8). Then, the display unit 6 superimposes the region of interest SR1 indicating the labeling pulse irradiation region S1 and the region of interest SR2 indicating the labeling pulse irradiation region S2 set in advance on the obtained positioning image data and displays them on the monitor (FIG. 8 step S3).

  When the generation and display of the positioning image data is completed, the input control unit 7 selects the imaging condition setting mode based on the operation of the input device by the operator (step S4 in FIG. 8). When the positions and sizes of the region of interest SR1 and the region of interest SR2 displayed together with the positioning image data on the monitor are inappropriate, correction is performed using the input device of the input control unit 7. Next, the input control unit 7 selects a region of interest (for example, a region of interest SR1) that needs to be updated in imaging conditions based on the operation of the input device by the operator (step S5 in FIG. 8).

  On the other hand, the imaging condition generation unit 5 that has received the selection signal and the identification information of the selected region of interest SR1 from the input control unit 7 via the main control unit 81 performs various imaging stored in its own imaging condition storage unit. The imaging conditions of the region of interest SR1 are read from the conditions, and imaging conditions in which these imaging conditions are temporarily set are generated and supplied to the display unit 6. Then, the display unit 6 adds the imaging condition supplied from the imaging condition generation unit 5 to the vicinity of the region of interest SR1 superimposed on the above-described positioning image data and displays it on its own monitor (step S6 in FIG. 8). ).

  Next, the input control unit 7 updates the imaging condition temporarily set by using the buttons shown in the imaging condition displayed on the display unit 6 based on the operation of the input device by the operator. An imaging condition suitable for the region of interest is set (step S7 in FIG. 8). When the imaging condition needs to be updated for the region of interest SR2 superimposed on the positioning image data, the imaging condition for the region of interest SR2 is updated by repeating the above steps S5 to S7. Performed (steps S5 to S7 in FIG. 8).

  When the setting of the imaging conditions for the region of interest SR1 and the region of interest SR2 indicated in the positioning image data is completed, the input control unit 7 selects the main imaging mode based on the operation of the input device by the operator. And an imaging start command are input (step S8 in FIG. 8). At this time, the imaging conditions of the region of interest SR1 and the region of interest SR2 temporarily set or newly set in the imaging condition setting mode are supplied to the sequence control unit 82 based on the selection signal of the main imaging mode, and the imaging start command is mainly used. By being supplied to the control unit 81, MRI imaging in the main imaging mode based on the imaging conditions described above is started (step S9 in FIG. 8).

  According to the present embodiment described above, it is possible to easily set the imaging condition of the region of interest superimposed on the positioning image data in the pilot imaging mode. For this reason, not only examination efficiency improves, but the burden of a subject, a doctor, etc. can be reduced.

  In particular, when a plurality of regions of interest are set for the positioning image data, it is possible to set the imaging conditions in each region of interest independently, so that the imaging conditions suitable for the MRI imaging can be accurately and accurately set. It can be set in a short time.

  In addition, the imaging condition used for setting the imaging condition can be prevented from being set erroneously because it is arranged in the vicinity of the corresponding region of interest, and the imaging condition can be controlled by operating a button added to the imaging condition. Setting is even easier.

  As mentioned above, although embodiment of this indication has been described, this indication is not limited to the above-mentioned embodiment, and it can change and carry out. For example, in the above-described embodiment, two regions of interest corresponding to the labeling pulse irradiation region of non-contrast MRI imaging are set for the positioning image data acquired in the pilot imaging mode, and selected from these regions of interest. In the above description, the imaging condition suitable for the region of interest is set based on the imaging condition displayed in the vicinity of the desired region of interest. However, the imaging condition is not limited to the irradiation condition of the labeling pulse. The imaging conditions for setting the imaging section may be used.

  In addition, the case where two regions of interest indicating the irradiation region (labeling pulse irradiation region) of the first region selection IR pulse and the second region selection IR pulse are set for the positioning image data has been described. The number of regions of interest set in the image data may be one or three or more.

  Furthermore, a case has been described in which one region of interest is selected from a plurality of regions of interest set in the positioning image data, and imaging conditions suitable for the region of interest are set using the imaging conditions of the selected region of interest. However, two or more regions of interest may be simultaneously selected from a plurality of regions of interest. For example, as shown in FIG. 9, when the region of interest SR1 and the region of interest SR2 are selected at the same time, the imaging condition Do1 indicating the imaging condition of the region of interest SR1 is displayed in the vicinity of the region of interest SR1, and the imaging condition of the region of interest SR2 Is displayed in the vicinity of the region of interest SR2. Based on the imaging conditions Do1 and Do2 displayed in this way, suitable imaging conditions are set for the region of interest SR1 and the region of interest SR2. When the same imaging condition is set for the region of interest SR1 and the region of interest SR2, the imaging condition of the region of interest SR1 (region of interest SR2) input to the imaging condition Do1 (Do2) is set as the imaging condition Do2 (Do1). It is also possible to set the imaging condition of the region of interest SR2 (region of interest SR1) by copying and pasting.

  In the above-described embodiment, the case where the region of interest superimposed on the positioning image data is inappropriate, the region of interest is updated using the input device of the input control unit 7 is described. However, the region of interest may be updated using the above imaging conditions. In this case, information regarding the size, position, direction, and the like of the region of interest is added to the imaging condition.

  Furthermore, the case where the same type of region of interest indicating the labeling pulse irradiation region is superimposed on the positioning image data has been described. For example, different regions such as the region of interest indicating the labeling pulse irradiation region and the region of interest indicating the saturation pulse irradiation region may be used. May be superimposed on the same positioning image data.

  On the other hand, in the above-described embodiment, the setting of the imaging condition in the imaging condition setting mode has been described, and the case of shifting to the main imaging mode in which diagnostic image data is generated using the set imaging condition has been described. An evaluation mode for confirming the validity of the imaging condition set by generating and displaying evaluation image data using the imaging condition may be provided between the imaging condition setting mode and the main imaging mode. If the imaging condition set in the imaging condition setting mode is found to be inappropriate by observing the evaluation image data generated in this evaluation mode, the imaging condition setting mode and the evaluation mode are repeated to further improve the imaging condition. Can be set.

  Moreover, although the irradiation conditions of Time-SLIP were described as imaging conditions, it is not limited to this, for example, irradiation of saturation pulses, SPAMM (Spatial modulation of magnetization) pulses, water selective excitation pulses, fat suppression pulses, etc. Condition may be sufficient.

  For example, when imaging cerebrospinal fluid (CSF) by non-contrast-enhanced MRI, as shown in FIG. 10, a lattice indicating a saturation region with respect to positioning image data collected on the head of a subject Is set as the region of interest SR3. Then, using the imaging condition Do3 displayed in the vicinity of the region of interest SR3, an imaging region condition suitable for the region of interest SR3 (that is, the irradiation condition of the SPAMM pulse irradiated to the region of interest SR3) is set.

  In this case, in the positioning image data, the gradient magnetic field strength Gd and the RF pulse interval Δτ that determine the lattice interval D and the lattice width ΔD are temporarily set as imaging conditions, and further, the inversion time (TI), the flip angle α, the echo An imaging condition Do3 in which the time (TE) and the repetition time (TR) are temporarily set as necessary is added. Then, the operator sets a suitable imaging condition for the region of interest SR3 by updating the temporarily set imaging condition described above. Note that the shape of the region of interest set on the subject's head for the purpose of imaging cerebrospinal fluid is not limited to the lattice shape, and may be a stripe or radial region of interest.

  Note that a part of the MRI apparatus according to the embodiment of the present invention can be realized by using, for example, a computer as hardware. That is, the control unit, the input control unit, and the like of the MRI apparatus can be realized by causing a processor (CPU or the like) mounted on the computer to execute a program. At this time, the MRI apparatus may be realized by installing the above-described program in a computer in advance, or may be stored in a computer-readable storage medium or distributed through the network, and this program You may implement | achieve by installing in a computer suitably.

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

DESCRIPTION OF SYMBOLS 1 ... Static magnetic field generation part 11 ... Main magnet 12 ... Static magnetic field power supply 2 ... Gradient magnetic field generation part 21 ... Gradient magnetic field coil 22 ... Gradient magnetic field power supply 3 ... Transmission / reception part 31 ... Transmission / reception coil 32 ... Transmission part 33 ... Reception part 4 ... Image Data generation unit 5 ... Imaging condition generation unit 6 ... Display unit 7 ... Input control unit 8 ... Control unit 81 ... Main control unit 82 ... Sequence control unit 83 ... Top plate movement control unit 9 ... Top plate 10 ... Top plate movement mechanism unit 100 ... MRI system

Claims (10)

A region-of-interest selecting unit that selects a desired region of interest from at least one region of interest in the image captured in the pilot imaging mode;
An imaging condition generation unit that generates an imaging condition corresponding to the region of interest selected by the region of interest selection unit;
A display unit for displaying the imaging condition in the vicinity of the region of interest;
An imaging condition setting unit configured to set the imaging condition displayed on the display unit;
A control unit that performs MRI imaging in the main imaging mode based on the imaging conditions set by the imaging condition setting unit;
An MRI apparatus characterized by comprising:   The imaging condition generation unit generates the imaging condition based on the imaging condition temporarily set in the region of interest, and the imaging condition setting unit updates the imaging condition temporarily set by the imaging condition generation unit 2. The MRI apparatus according to claim 1, wherein the imaging condition is set as described above.   The MRI apparatus according to claim 2, wherein the imaging condition setting unit includes a button for updating the temporarily set imaging condition.   The MRI apparatus according to claim 2, wherein the imaging condition generation unit generates the imaging condition based on a preset standard imaging condition or an imaging condition set in past MRI imaging.   The MRI apparatus according to claim 1, wherein the imaging condition setting unit sets an imaging condition of the region of interest indicating a labeling pulse irradiation region.   The MRI according to claim 1, wherein the imaging condition setting unit sets at least one irradiation condition of Time-SLIP, saturation pulse, SPAMM pulse, water selective excitation pulse, and fat suppression pulse as the imaging condition. apparatus.   An imaging condition evaluation unit that evaluates an imaging condition set by the imaging condition setting unit is further provided, and the control unit starts MRI imaging in the main imaging mode based on an evaluation result of the imaging condition evaluation unit. The MRI apparatus according to claim 1, wherein   A mode selection unit that selects an imaging condition setting mode for setting the imaging condition based on the imaging condition; and the display unit includes the region of interest and the region of interest in the image based on selection information of the imaging condition setting mode. The MRI apparatus according to claim 1, wherein the imaging condition is added and displayed.   When a plurality of regions of interest are selected by the region of interest selection unit, the imaging condition setting unit is selected using the imaging condition set in at least one region of interest of the plurality of selected regions of interest. The MRI apparatus according to claim 1, wherein imaging conditions for the remaining regions of interest of the plurality of regions of interest are set. A region-of-interest selector that selects a desired region of interest from at least one region of interest shown in an image captured in the pilot imaging mode;
An imaging condition generation unit that generates an imaging condition corresponding to the region of interest selected by the region of interest selection unit;
A display unit for displaying the imaging condition in the vicinity of the region of interest;
An imaging condition setting unit for setting the imaging condition displayed on the display unit;
A control program for causing a computer to function as a control unit that performs MRI imaging in a main imaging mode based on the imaging conditions set by the imaging condition setting unit.

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