JP2015159916A - magnetic resonance imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MRI apparatus capable of reducing operation procedures by eliminating unnecessary measurement of positioning imaging, etc.SOLUTION: Using pointer devices 29 and 30 of an MRI apparatus placed in the upper part and on the right and left of a subject, a position and an inclination for targeting a feature part in the body of the subject as a measurement object is determined by moving/rotating first and second laser pointers while irradiating them to the subject. From the determined position and inclination, a measurement position and an amount of rotation in a measurement condition are automatically set. When the subject is placed on a base 27, the measurement position and the amount of rotation can be automatically set, thereby reducing burdens on an operator and the subject.

Description

  The present invention relates to a magnetic resonance imaging (hereinafter abbreviated as “MRI”) apparatus, and more particularly to a technique for automatically setting measurement conditions when imaging nuclear density distribution, relaxation time distribution, and the like.

  The MRI apparatus measures a nuclear magnetic resonance (hereinafter abbreviated as “NMR”) signal generated by a nuclear spin that constitutes the tissue of a subject, particularly a human body that is a subject, and the head, abdomen, limbs, etc. It is an apparatus that images forms and functions two-dimensionally or three-dimensionally. In imaging, a signal is given a phase encoding that varies depending on a gradient magnetic field, is frequency-encoded, and is measured as time-series data. The measured NMR signal is reconstructed into an image by two-dimensional or three-dimensional Fourier transform.

  Patent Document 1 that discloses a technique for acquiring image information while automatically irradiating a human body with a laser and automatically setting the irradiation position on the human body as a prior art document relating to automatic position setting in a medical device such as an MRI apparatus, There is Patent Document 2 that discloses a technique for acquiring an image and automatically correcting the current position and the position at the time of acquiring a reference image from the difference between the latest images.

JP 2012-101046 A JP 2003-319930 A

  Since Patent Document 1 described above is an automatic setting of the irradiation position on the human body surface, the setting of the depth direction of the human body in the target is not performed. Further, since Patent Document 2 is a technique for acquiring a reference image and automatically correcting the current position and the position at the time of acquiring the reference image from the difference between the latest images, acquisition of the reference image is essential.

  In general, in each examination using a medical device, the inclination and height of the subject's body are different, and therefore the inclination and depth cannot be set only by setting the pointer in one direction on the body surface. In addition, in order to measure the center line of a human organ such as the brain, which is the desired imaging site, the measurement is performed without considering the inclination of the human body as described above, and the operator sets the measurement position based on the measurement result. The measurement is performed again, and it is necessary to acquire an image that is not a desired measurement position, and the inspection time becomes longer.

  An object of the present invention is to solve the above-described problems, and to provide an MRI apparatus capable of setting an irradiation position including a depth direction and reducing examination time by reducing the number of imaging.

  In order to achieve the above object, in the present invention, a plurality of excitation pulses and gradient magnetic field pulses are applied to a subject via a magnetic field application unit and a magnetic field application unit based on a predetermined pulse sequence and received. There is provided an MRI apparatus configured to include a control unit that processes an echo signal from a subject and a plurality of pointer devices that set a characteristic part inside the subject as a measurement position.

  In order to achieve the above object, in the present invention, a plurality of excitation pulses and gradient magnetic field pulses are applied to a subject via a magnetic field application unit and a magnetic field application unit based on a predetermined pulse sequence. The control unit for processing the echo signal received from the subject, and a detection unit for detecting the appearance feature point of the subject, the control unit among the appearance feature points detected by the detection unit, Determine the appearance feature point corresponding to the test item of the subject, calculate the measurement position / rotation amount of the characteristic part inside the subject based on the determined appearance feature point, and based on the calculated measurement position / rotation amount An MRI apparatus configured to determine measurement conditions is provided.

  According to the MRI apparatus of the present invention, the measurement position and the rotation amount can be automatically set when the subject is placed, and the burden on the operator and the subject can be reduced.

It is a figure which shows one Example of the whole structure of the MRI apparatus based on each Example. FIG. 3 is a three-view diagram illustrating an example of an external configuration of the MRI apparatus according to the first embodiment. It is a figure for demonstrating the movement and rotation of a pointer apparatus based on Example 1. FIG. It is a figure which shows the example of an operation | movement flow of measurement position setting and condition reflection based on Example 1. FIG. It is a figure which shows an example of the initial stage arrangement | positioning of the pointer apparatus based on Example 1. FIG. It is a figure explaining the measurement position change of AP direction based on Example 1. FIG. It is a figure explaining the in-plane rotation change of AP axis based on Example 1. FIG. It is a figure explaining the in-plane rotation change of the RL axis based on Example 1. FIG. It is a figure which shows the other example of the in-plane rotation change of the RL axis based on Example 1. FIG. It is a figure for demonstrating calculation of the measurement conditions based on Example 1. FIG. FIG. 6 is a three-view diagram illustrating an external configuration example of an MRI apparatus according to a second embodiment. It is a figure which shows the example of an operation | movement flow of measurement position setting and condition reflection based on Example 2. FIG. It is a figure for demonstrating the human body external appearance characteristic based on Example 2. FIG. It is a figure which shows an example of a test | inspection site | part and a human body external appearance characteristic based on Example 2. FIG. It is a figure which shows the other example of a test | inspection site | part and a human body external appearance characteristic based on Example 2. FIG.

  Hereinafter, preferred embodiments of the MRI apparatus of the present invention will be described in detail with reference to the accompanying drawings. In all the drawings for explaining various embodiments, the same reference numerals are given to those having the same function, and repeated explanation thereof is omitted.

  First, an overall outline of the MRI apparatus according to each embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the overall configuration of an embodiment of an MRI apparatus. This MRI apparatus uses a NMR phenomenon to obtain a tomographic image of a subject such as a subject. As shown in the figure, the MRI apparatus includes a static magnetic field generation system 2, a gradient magnetic field generation system 3, A transmission system 5, a reception system 6, a signal processing system 7, a sequencer 4, and a central processing unit (hereinafter abbreviated as “CPU”) 8 are configured. Among these, the static magnetic field generation system 2, the gradient magnetic field generation system 3, and the transmission system 5 form a magnetic field application unit of the MRI apparatus. The sequencer 4, the signal processing system 7, and the CPU 8 constitute a control unit of the MRI apparatus. The CPU 8 performs various controls and calculations by executing programs stored in a storage unit such as the ROM 21 and the RAM 22 in the signal processing system 7.

  If the static magnetic field generation system 2 in the magnetic field application unit is a vertical magnetic field system, it is uniform in the direction around the body axis in the space around the subject 1, and if it is a horizontal magnetic field system, it is uniform in the body axis direction. A static magnetic field is generated, and a permanent magnet type, normal conducting type or superconducting type static magnetic field generating source is arranged around the subject 1.

  The gradient magnetic field generation system 3 in the magnetic field application unit includes a gradient magnetic field coil 9 that applies a gradient magnetic field in the three-axis directions of X, Y, and Z, which are coordinate systems (stationary coordinate systems) of the MRI apparatus, and each gradient magnetic field coil. And the gradient magnetic field power supply 10 for driving each coil in accordance with a command from the sequencer 4 to be described later to drive the gradient magnetic field power supply 10 in each of the three axial directions of X, Y, and Z. , Gz. At the time of imaging, a slice plane gradient magnetic field pulse (Gs) is applied in the direction orthogonal to the slice plane, that is, the slice plane, the slice plane for the subject 1 is set, and the remaining planes orthogonal to the slice plane and orthogonal to each other The phase encoding direction gradient magnetic field pulse (Gp) and the frequency encoding direction gradient magnetic field pulse (Gf) are applied in the two directions, and position information in each direction is encoded in the echo signal.

  The sequencer 4 in the control unit is a control unit that repeatedly applies a high-frequency magnetic field pulse (hereinafter referred to as “RF pulse”) and a gradient magnetic field pulse in a predetermined pulse sequence, and operates under the control of the CPU 8. Various commands necessary for tomographic image data collection are sent to the transmission system 5, the gradient magnetic field generation system 3, and the reception system 6.

  The transmission system 5 in the magnetic field application unit irradiates the subject 1 with an RF pulse in order to cause nuclear magnetic resonance to occur in the nuclear spins of the atoms constituting the living tissue of the subject 1. And a modulator 12, a high-frequency amplifier 13, and a high-frequency coil (transmission coil) 14a on the transmission side. The RF pulse output from the high-frequency oscillator 11 is amplitude-modulated by the modulator 12 at a timing according to a command from the sequencer 4, and the amplitude-modulated RF pulse is amplified by the high-frequency amplifier 13 and then placed close to the subject 1. By supplying the high frequency coil 14a, the subject 1 is irradiated with RF pulses.

  The receiving system 6 detects an echo signal (NMR signal) emitted by nuclear magnetic resonance of nuclear spins constituting the biological tissue of the subject 1, and includes a receiving-side high-frequency coil (receiving coil) 14b and a signal amplifier. 15, a quadrature phase detector 16, and an A / D converter 17. The NMR signal of the response of the subject 1 induced by the electromagnetic wave irradiated from the high frequency coil 14a on the transmission side is detected by the high frequency coil 14b arranged close to the subject 1 and amplified by the signal amplifier 15. Thereafter, the signals are divided into two orthogonal signals by the quadrature phase detector 16 at a timing according to a command from the sequencer 4, converted into digital quantities by the A / D converter 17, and sent to the signal processing system 7.

  The signal processing system 7 in the control unit performs various data processing and display and storage of processing results, and includes an external storage device such as an optical disk 19 and a magnetic disk 18 and a display 20 including a CRT. When data from the receiving system 6 is input to the CPU 8 in the control unit, the CPU 8 executes processing such as signal processing and image reconstruction, and displays a tomographic image of the subject 1 as a result on the display 20. At the same time, the data is recorded on the magnetic disk 18 of the external storage device.

  The operation unit 25 inputs various control information of the MRI apparatus and control information of processing performed by the signal processing system 7 and includes a trackball or mouse 23 and a keyboard 24. The operation unit 25 is arranged in the vicinity of the display 20, and the operator controls various processes of the MRI apparatus interactively through the operation unit 25 while looking at the display 20.

  In FIG. 1, the high-frequency coil 14a and the gradient magnetic field coil 9 on the transmission side are located in the static magnetic field space of the static magnetic field generation system 2 in which the subject 1 is inserted. Oppositely, if it is a horizontal magnetic field system, it is installed so as to surround the subject 1. The high-frequency coil 14b on the receiving side is installed so as to face or surround the subject 1.

  Currently, the imaging target nuclide of the MRI apparatus is a hydrogen nucleus (proton) which is a main constituent material of the subject as widely used clinically. Information on the spatial distribution of the proton density and the spatial distribution of the relaxation time of the excited state is imaged, thereby imaging the form or function of the human head, abdomen, limbs, etc. two-dimensionally or three-dimensionally.

  Subsequently, an example of a characteristic configuration of the MRI apparatus according to the first embodiment will be described. This embodiment applies a plurality of excitation pulses and gradient magnetic field pulses to a subject via a magnetic field application unit and a predetermined pulse sequence, and receives an echo signal from the subject. 3 is an example of an MRI apparatus including a control unit that performs the above-described processing and a plurality of pointer devices that set a characteristic part inside a subject as a measurement position. In the configuration of the present embodiment, a plurality of pointer devices are further installed in the MRI apparatus outlined in FIG.

  FIG. 2 shows a three-view diagram of a configuration example of an MRI apparatus in which a plurality of pointer devices of this embodiment are installed. The three views are a front view on the right side of FIG. 2, a side view on the upper left side, and a plan view on the lower left side. In the figure, 26 is a gantry of the MRI apparatus, 27 is a bed base, 28 is a bed body, 29 is an upper pointer device, 30 is a left / right pointer device, and 31 is a movement amount encoder. As is clear from the figure, pointer devices 29 and 30 are arranged at the upper position and the left and right positions of the gantry 26. In FIG. 2, these three pointer devices 29, 30 are attached to the entrance side of the gantry 26, but may be installed inside the gantry 26. These pointer devices 29 and 30 can project orthogonal linear laser beams, and can be moved and rotated by a built-in moving mechanism and rotating mechanism. The moving amount and rotating amount can be detected by an attached encoder or the like. It is configured.

  FIG. 3 shows a specific configuration example of the pointer devices 29 and 30 of the present embodiment. In the figure, the pointer device 29 attached to the upper position of the gantry 26 will be described as an example, but the pointer device 30 attached to the left and right positions also has the same configuration. In the figure, the pointer device 29 can be moved in the left-right direction by the moving mechanism, and the moving amount encoder 31 can detect the moving amount. Further, the pointer device 29 is provided with a rotation mechanism, and the rotary encoders 33 and 34 can detect the tilt of the axis of the laser beam transmitted from the pointer device 29 and the amount of rotation of the shaft.

  In other words, the movement amount encoder 31 and the rotary encoders 33 and 34 function as a measurement unit that measures the position movement amount and the rotation amount of the pointer device. In the drawing, reference numerals 35 and 36 denote linear first and second lasers projected by the pointer device, respectively. Reference numerals 37 and 38 respectively denote a first linear laser beam and a second linear laser beam irradiated onto the body surface of the subject by the first laser 35 and the second laser 36, respectively.

  Next, the operation of the MRI apparatus according to the first embodiment will be described with reference to the flowchart of FIG. When the operation starts (40), the subject 1 is placed at a predetermined position using the base 27 of the MRI apparatus (41), and the orthogonal linear laser beams from the plurality of pointer devices 29, 30 are directed to the subject. Irradiated. Then, in order to determine the measurement position in the body of the subject while the operator observes the position of the laser linear light irradiated to the subject 1, the measurement position change in the AP direction (42), the surface of the AP axis The internal rotation change (43) and the RL axis in-plane rotation change (44) are performed. This position / rotation change will be described later in detail with reference to FIGS.

  After the position / rotation change, the movement amount / rotation amount of the upper pointer device 29 and the left / right pointer device 30 is detected by the movement amount encoder 31 and the rotary encoders 33 and 34 shown in FIG. 3 (45). . Then, using the detection data of the movement amount / rotation amount, the measurement conditions of the MRI apparatus are reflected and set (46). If it is determined that the setting is completed or not (47), a measurement start instruction (48) is issued, and measurement of the NMR signal of the subject is started (49). In other words, according to the configuration of the present embodiment, when changing the measurement position in the AP direction and setting each in-plane rotation, the movement amount / rotation amount of the upper pointer device 29 and the left / right pointer device 30 which are measured by the measurement unit including each encoder. Based on the above, the measurement center position / rotation amount is calculated, and the calculation result is reflected in the measurement conditions. Until the setting of the measurement position / tilt is completed, the reflection to the setting / condition is repeated (47).

  FIG. 5 shows an example of the reference position before setting when setting the inspection position of the subject 1 by the MRI apparatus. 5 to 8 show three views, respectively. The front view, the side view, and the plan view of the three views are the same as those in FIG. H and F shown in the side view and the plan view mean the head and the foot, respectively. As is apparent from the figure, a left and right pointer device 30 incorporating a moving mechanism is provided with a moving amount encoder 32.

  Similarly, FIGS. 6, 7, and 8 illustrate the change of the measurement position in the AP direction (42), the change of the in-plane rotation of the AP axis (43), and the change of the in-plane rotation of the RL axis (44), respectively. FIG. In these drawings, some of the same numbers as those in FIG. 5 are partially omitted. As apparent from FIG. 6, the measurement center adjustment in the AP direction is realized by moving the position of the pair of left and right pointer devices 30. By the position movement of these left and right pointer devices 30, the measurement position can be positioned in the depth direction from the body surface of the subject. An arrow 50 in the figure indicates the moving direction, and the moving amount can be measured by the moving amount encoder 32. In the measurement position change (42) in the AP direction in the present embodiment, the depth position is set by the pair of left and right pointer devices 30 moving in synchronization.

  FIG. 7 shows the in-plane rotation adjustment 1 by the upper pointer device 29, and the rotation adjustment in the plane perpendicular to the AP axis is realized by the rotation mechanism of the pointer device. As is clear from the plan view on the lower left side of the figure, the upper pointer device 29 is rotated in the direction of the arrow 51 around the AP axis, and the amount of rotation is detected by the rotary encoder 34 shown in FIG. Is done.

  FIG. 8 shows in-plane rotation adjustment 2 by the left and right pointer device 30, and the arrow 54 in the plane perpendicular to the RL axis is clearly shown in the upper left side view of the same figure by the rotation mechanism of the pointer device. Directional rotation adjustment is achieved (44). In changing the inclination of the measurement surface by rotating the surface of the RL axis, the measurement center position is maintained by moving and rotating the upper pointer device 29 in the directions of the arrows 52 and 53 in synchronization with the rotation of the left and right pointer devices 30 in the direction of the arrow 54. Set as is. The rotation of the upper pointer device 29 in the direction of the arrow 53 at this time means adjustment of the inclination of the shaft, and the amount of inclination of the shaft is detected by the rotary encoder 33 shown in FIG.

  Here, an example of setting of the pointer device, measurement position calculation, and measurement condition calculation results when adjusting the measurement center position and adjusting the inclination of the measurement surface will be described with reference to FIGS. As shown in FIG. 9, when the upper pointing device 29 moves in the direction of the arrow 52 and the shaft rotates in the clockwise direction as indicated by the arrow 53, the left and right pointer devices 30 are synchronized with the clockwise arrow 54. In this configuration, a case where the measurement center position moves in the direction of the arrow 55 on the AP axis of the upper pointer device 29 will be described.

  FIG. 10 schematically shows the relationship between the movement amount and the rotation amount in the case of the AP measurement center position adjustment and the measurement surface tilt adjustment exemplified in FIG. In the figure, Y indicates the distance between the upper pointer device 29 and the left and right pointer devices 30 at the standard position. Then, the upper pointer device 29 and the left and right pointer devices 30 are moved from the standard position by adjustment. The upper pointer device 29 moves from the standard position in the direction of the arrow 52 and rotates in the direction indicated by the arrow 54 around the RL axis. Then, the movement amount z is detected by the movement amount encoder 31 of the upper pointer device 29, and the rotation amount α is detected by the inclination detection rotary encoder 33 which similarly detects the inclination amount of the axis of the upper pointer device 29. The detected movement amount z is synchronized with the movement amount / rotation amount of the RL side pointer device 30, and the rotation amount α is synchronized with the rotation amount of the RL side pointer device 30.

  On the other hand, due to the above adjustment, the RL side pointer device 29 moves in the direction of the arrow 55 in synchronization with the movement amount / rotation amount of the upper pointer device 29, and around the RL axis in synchronization with the inclination of the upper pointer device 29. To rotate in the direction of arrow 56. Then, the movement amount y is detected from the movement amount encoder 31 of the left and right pointer device 29, and the rotation amount α is detected by the shaft rotation rotary encoder 34. Based on the numerical values detected from the encoder as described above, the reflection (46) in the flowchart measurement conditions of FIG. 4 is performed, and an example of the measurement conditions is shown in the lower part of FIG.

  According to the MRI apparatus of the first embodiment described in detail above, a plurality of pointer devices can be used to set a characteristic part inside the subject as a measurement position, and the examination time can be shortened by reducing the number of imaging, and the accumulated SAR on the human body. Can be reduced, and the burden on the subject can be reduced. In addition, since the measurement position / measurement condition can be automatically set based on the position / rotation amount information of the pointer device obtained by various encoders, it is possible to reduce the work of the operator.

Next, a second embodiment will be described with reference to the drawings. In this embodiment, a plurality of excitation pulses and gradient magnetic field pulses are applied to a subject via a magnetic field application unit and a magnetic field application unit based on a predetermined pulse sequence, and received echoes from the subject are received. A control unit that performs signal processing and a detection unit that detects an appearance feature point of the subject, and the control unit has an appearance corresponding to the inspection item of the subject among the appearance feature points detected by the detection unit. Implementation of an MRI apparatus that determines feature points, calculates the measurement position / rotation amount of the characteristic part inside the subject based on the determined appearance feature point, and determines measurement conditions based on the calculated measurement position / rotation amount It is an example.
The difference from the first embodiment is that the external shape of the human body is acquired by using the scan laser device and the camera device constituting the detection unit without using the upper / left and right pointer devices, and the feature points of the external shape are automatically detected. Thus, the measurement position / rotation amount is calculated and reflected in the measurement conditions of the MRI apparatus. In the configuration of this embodiment, a plurality of pairs of laser detection camera devices 57 and a scan laser irradiator 58 constituting a detection unit are arranged in the MRI apparatus described with reference to FIG.

  FIG. 11 shows a configuration in which a plurality of laser detection camera devices 57 and a plurality of scan laser irradiators 58 are arranged in the MRI apparatus of the second embodiment. Hereinafter, only the parts of the apparatus configuration and operation of the first embodiment will be described, and the description of the same parts will be omitted. Instead of the pointer device, a pair of a laser detection camera device 57 and a scan laser irradiator 58 are installed at the upper position and the left and right positions of the gantry 26 of the MRI apparatus.

  Also in the MRI apparatus of this configuration, the operation is performed according to the flowchart of FIG. 12 by a program executed by the CPU 8 constituting the control unit. Similar to the first embodiment, after the start (40) and the placement of the subject (41), the operation specific to the present embodiment is performed. First, a scan of the external shape of the human body that is the subject is performed using the scan laser irradiator 58 (59). The laser beam scanned by the subject is detected by the laser detection camera device 57, and the external feature of the external shape of the human body is detected using the output signal (60). In other words, a plurality of pairs of laser detection camera devices 57 and scan laser irradiators 58 constitute an external feature detection unit for the external shape of the human body. FIG. 13 shows a specific example of the human body appearance feature related to the subject's head. As apparent from FIG. 13, the human body appearance features 66 of the human head 65 include the corners of the eyes, ear holes, under the chin, and tilt of the neck.

  Subsequently, in FIG. 12, the appearance characteristics corresponding to the desired inspection item are determined using the output signals of the plurality of laser detection camera devices 57 (61). At this time, the inspection item and the appearance feature correspondence table are used (62). As the inspection item and appearance feature correspondence table, examples of cerebral inspection and cervical spine inspection are shown in FIGS. 14 and 15, respectively. Such an inspection item and appearance feature correspondence table, in other words, a table showing appearance feature points corresponding to the inspection item is stored in advance in a storage unit such as the magnetic disk 16, ROM 21, RAM 22 in the control unit of FIG. .

  As shown in FIG. 14, when the examination site is the cerebrum, the human body appearance feature 67 used is the corner of the eye or the upper edge of the ear hole. Further, when the examination site is the cervical spine, the human body appearance feature 68 to be used uses a chin bottom, a neck inclination, or the like. Then, the measurement location / rotation is calculated based on the determined appearance feature (63) and reflected in the measurement conditions (64). The reflection (64) on the measurement condition can be automatically performed in the same manner as the reflection (46) on the measurement condition in FIG. Thereafter, as in the first embodiment, measurement is started (49) by a measurement start instruction (48).

  According to the MRI apparatus of the present embodiment, after the subject is placed, the external shape of the inspection object is measured by the detection unit composed of a plurality of pairs of the laser detection camera device 57 and the scan laser irradiator 58, The feature point is detected, and the control unit determines a feature point corresponding to the inspection item from the detected feature points, and using the determined feature points as a reference, the measurement position of the feature part inside the subject The amount of rotation can be calculated automatically. In addition, the control unit can automatically reflect the calculated measurement position and rotation amount in the measurement conditions, and in addition to the effects of the first embodiment, the burden on the operator can be further reduced and the inspection time can be shortened. it can.

  While various embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, in the above description, the MRI apparatus is used for explanation. However, the present invention relating to automatic setting of the measurement position / measurement condition using the pointer apparatus is applicable to apparatuses such as an X-ray CT apparatus in addition to the MRI apparatus. Is available. Further, the above-described embodiments have been described in detail for better understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Further, the above-described configuration, function, control unit, and the like have been described as an example of creating a program that realizes a part or all of them. Needless to say, it can be realized with this.

DESCRIPTION OF SYMBOLS 1 Subject 2 Static magnetic field generation system 3 Gradient magnetic field generation system 4 Sequencer 5 Transmission system 6 Reception system 7 Signal processing system 8 Central processing unit (CPU)
9 Gradient Magnetic Field Coil 10 Gradient Magnetic Field Power Supply 11 High Frequency Transmitter 12 Modulator 13 High Frequency Amplifier 14a High Frequency Coil (Transmission Coil)
14b High frequency coil (receiver coil)
15 Signal amplifier 16 Quadrature detector 17 A / D converter 18 Magnetic disk 19 Optical disk 20 Display 21 ROM
22 RAM
23 trackball or mouse 24 keyboard,
25 Operation unit 26 Gantry 27 Base 28 Bed body 29 Upper pointer device 30 Left and right pointer devices 31, 32 Movement amount encoder 33 Inclination amount detection rotary encoder 34 Rotation amount detection rotary encoder 35 First laser pointer 36 Second laser pointer 37 First Linear laser beam 38 Second linear laser beam 50, 52, 55 Moving direction 51, 53, 54, 56 Rotating direction 57 Laser detection camera device 58 Scan laser irradiator

Claims (10)

Based on a magnetic field application unit and a predetermined pulse sequence, a plurality of excitation pulses and gradient magnetic field pulses are applied to the subject via the magnetic field application unit, and the received echo signal from the subject is processed And a plurality of pointer devices that set the characteristic part inside the subject as a measurement position,
A magnetic resonance imaging (hereinafter referred to as MRI) apparatus. The MRI apparatus according to claim 1,
The control unit sets measurement conditions from information on the position / rotation amount of the pointer device when setting the measurement position.
An MRI apparatus characterized by that. The MRI apparatus according to claim 2, wherein
The operator can arbitrarily set the position / rotation amount of the pointer device,
An MRI apparatus characterized by that. The MRI apparatus according to claim 2, wherein
A measuring unit for measuring a position movement amount and a rotation amount of the pointer device;
An MRI apparatus characterized by that. The MRI apparatus according to claim 2, wherein
The pointer device comprises an upper pointer device that can be placed on the subject and a pair of left and right pointer devices that can be placed on the left and right of the subject.
An MRI apparatus characterized by that. The MRI apparatus according to claim 5, wherein
The upper pointer device and the left and right pointer devices move and rotate synchronously when setting the measurement position,
An MRI apparatus characterized by that. The MRI apparatus according to claim 5, wherein
The left and right pointer devices move in synchronization when moving the measurement position in the depth direction of the subject.
MRI equipment that specializes in that. Based on a magnetic field application unit and a predetermined pulse sequence, a plurality of excitation pulses and gradient magnetic field pulses are applied to the subject via the magnetic field application unit, and the received echo signal from the subject is processed And a control unit for detecting the appearance feature point of the subject,
The control unit determines an external feature point corresponding to the inspection item of the subject among the external feature points detected by the detection unit, and uses the determined external feature point as a reference for the inside of the subject. Calculate the measurement position / rotation amount of the characteristic part, and determine measurement conditions based on the calculated measurement position / rotation amount.
An MRI apparatus characterized by that. The MRI apparatus according to claim 8, wherein
The detection unit includes a scan laser irradiator that irradiates the subject with a scan laser, and a laser detection camera device that images the subject irradiated with the scan laser irradiator.
An MRI apparatus characterized by that. The MRI apparatus according to claim 8, wherein
The control unit includes a storage unit that stores a table indicating appearance feature points corresponding to the inspection items.
An MRI apparatus characterized by that.

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