JP2008055023A - Magnetic resonance imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic resonance imaging apparatus improving spatial resolution and suppressing artifact by supplementing image data and reconstructing an image stored in database. <P>SOLUTION: This magnetic resonance imaging apparatus selects an image stored in the database and creates and displays a list of changeable parameters based on sequence parameters in imaging attached to the image (steps 101 and 102). This apparatus creates a pulse sequence based on the additional measurement parameters set in the step 102 and measures the additional data using the pulse sequence created in the step 103 by a measurement command (steps 103 and 104). Raw Data in the data set stored in the database are connected to the data additionally acquired in the step 104 and the Raw Data created in the step 105 are Fourier-transformed into an image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic resonance imaging apparatus that obtains a tomographic image of an examination site of a subject using a nuclear magnetic resonance phenomenon.

  In a magnetic resonance imaging apparatus (MRI apparatus), a predetermined number of pulse sequences including a series of operations of irradiation RF pulses and gradient magnetic field pulses are repeated in order to acquire all echo signals necessary for image reconstruction. . Since the contrast of the image is determined by the relaxation time of proton molecules as the main signal source, the repetition time of the pulse sequence is limited by this relaxation time.

  As a result, the MRI apparatus has a longer imaging time than the X-ray CT or ultrasonic diagnostic apparatus, and there is a problem that artifacts are mixed in the image due to the movement of the subject during imaging.

  In order to reduce the artifact caused by this body movement, it is effective to shorten the photographing time. As an imaging time shortening method, there is a multi-echo measurement method (echo planar method, fast spin echo method or the like) in which a plurality of echo signals are acquired by one excitation when excitation is performed using a high-frequency magnetic field pulse.

  Patent Document 1 describes the following technique. That is, the measurement data being measured is stored, and the gradient magnetic field application pattern is stored in the memory in relation to the measurement time. Then, when the body movement of the subject is recognized, the application of the gradient magnetic field and the imaging are temporarily stopped, a part of the measurement data is removed, and the remeasurement time is calculated. Based on the calculated remeasurement time, measurement is restarted from the gradient magnetic field application pattern stored in the memory.

  According to the technique described in Patent Document 1, it is possible to make the measurement data before body movement effective and shorten the measurement time.

JP 7-194575 A

  However, in the conventional MRI apparatus, it takes time from the start of imaging until the imaging is completed and the image is displayed, and parameter setting errors and artifacts may be determined only after the final image is obtained. For this reason, there is a problem that it takes a lot of time to retake the image and the imaging efficiency is low.

  In addition, the multi-echo measurement method can acquire multiple echo signals with a single excitation, so the imaging time can be shortened, but the problem that the stability of hardware greatly affects the image quality and the shape of the pulse sequence are limited. For this reason, there is a problem that it is difficult to obtain a desired contrast.

  With the technique described in Patent Document 1, data before the occurrence of body movement can be used effectively, but insufficient image quality, an imaging section setting error, etc. cannot be determined until after the imaging is completed. Had to retake the image.

  Further, once the measurement is completed and the image is stored in the database, data to be added later cannot be acquired, and if the conditions are changed, it is necessary to perform imaging again from the beginning.

  An object of the present invention is to realize a magnetic resonance imaging apparatus capable of improving spatial resolution and suppressing artifacts by supplementing image data to an image stored in a database and reconstructing the image.

  The magnetic resonance imaging apparatus of the present invention reconstructs and displays an image of a subject based on echo signals received by a static magnetic field generating means, a gradient magnetic field generating means, a high frequency signal transmitting / receiving means, and a high frequency signal transmitting / receiving means. A signal processing display unit; and a control unit that controls the static magnetic field generation unit, the oblique magnetic field generation unit, the high-frequency signal transmission / reception unit, and the signal processing display unit.

  The magnetic resonance imaging apparatus includes data storage means for storing the image reconstructed by the signal display processing means and supplementary information related to the image capturing, and the control means includes the image stored in the data storage means and the supplementary information. Information is read in accordance with the operator's command, and additional shooting data is created on the signal processing display means based on the additional measurement shooting parameter specified by the operator, and is combined with the image read by the operator's command. .

  According to the present invention, the image stored in the database can be supplemented with image data and reconstructed to improve spatial resolution and suppress artifacts.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of an MRI apparatus to which the present invention is applied. In FIG. 1, a magnetic resonance imaging apparatus obtains a tomographic image of a subject using a nuclear magnetic resonance (NMR) phenomenon, and 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 (CPU) 8 are provided.

  The static magnetic field generation system 2 generates a uniform static magnetic field in a body axis direction or a direction perpendicular to the body axis in a space around the subject 1, and a permanent magnet system or a normal conduction system around the subject 1. Alternatively, a superconducting magnetic field generating means is arranged. The gradient magnetic field generation system 3 includes a gradient magnetic field coil 9 wound in three axial directions of X, Y, and Z, and a gradient magnetic field power source 10 that drives each gradient magnetic field coil. The gradient magnetic field power supply 10 applies the gradient magnetic fields Gs, Gp, and Gf in the three-axis directions of X, Y, and Z to the subject 1 by driving each coil in accordance with a command from the sequencer 4 described later.

  More specifically, a slice direction gradient magnetic field pulse (Gs) is applied in one of X, Y, and Z to set a slice plane for the subject 1, and the phase encode direction gradient magnetic field is applied in the remaining two directions. A pulse (Gp) and a frequency encoding direction gradient magnetic field pulse (Gf) are applied, and position information in each direction is encoded in the echo signal.

  The sequencer 4 is a control unit that repeatedly applies a high-frequency magnetic field pulse (RF pulse) and a gradient magnetic field pulse in a predetermined pulse sequence. The sequencer 4 operates under the control of the CP 8 and sends various commands necessary for collecting tomographic image data of the subject 1 to the transmission system 5, the gradient magnetic field generation system 3, and the reception system 6.

  The transmission system 5 irradiates an RF pulse to cause nuclear magnetic resonance to the atomic nuclear spin constituting the biological tissue of the subject 1, and includes a high-frequency oscillator 11, a modulator 12, a high-frequency amplifier 13, A high-frequency coil 14a on the transmission side.

  The high-frequency 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 after the amplitude-modulated high-frequency pulse is amplified by the high-frequency amplifier 13, the high-frequency pulse is arranged close to the subject 1. Is supplied to the high frequency coil 14a. Thereby, the subject 1 is irradiated with electromagnetic waves (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. The reception system 6 includes a reception-side high frequency coil 14 b, an amplifier 15, a quadrature phase detector 16, and an A / D converter 17. The response electromagnetic wave (NMR signal) of the subject 1 induced by the electromagnetic wave irradiated from the transmission-side high frequency coil 14 a is detected by the high frequency coil 14 b disposed in the vicinity of the subject 1. Then, after being amplified by the amplifier 15, it is divided into two orthogonal signals by the quadrature phase detector 16 at a timing according to a command from the sequencer 4, and each is converted into a digital quantity by the A / D converter 17, It is sent to the signal processing system 7.

  The signal processing system 7 includes an external storage device such as an optical disk 19 and a magnetic disk 18 and a display 20 made up of a CRT or the like. When the data from the reception system 6 is input to the CPU 8, the signal processing system 7 performs processing such as signal processing and image reconstruction, and displays the tomographic image of the subject 1 as a result of the display 20. And recorded on the magnetic disk 18 or the like of the external storage device.

  The operation unit 25 is used to input 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 disposed 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 coils 14 a and 14 b and the gradient magnetic field coil 9 on the transmission side and the reception side are installed in the static magnetic field space of the static magnetic field generation system 2 arranged in the space around the subject 1. .

  At present, the spin species to be imaged by the MRI apparatus are protons, which are the main constituents of the subject, as widely used clinically. By imaging the spatial distribution of the proton density and the spatial distribution of the relaxation phenomenon in the excited state, the form or function of the human head, abdomen, limbs, etc. is photographed two-dimensionally or three-dimensionally.

  Next, an example of the imaging pulse sequence will be described. FIG. 2A shows a gradient echo pulse sequence. RF, Gs, Gp, Gr, and AD / Echo in FIG. 2A represent the axes of the RF pulse, slice gradient magnetic field, phase encode gradient magnetic field, frequency encode gradient magnetic field, and AD conversion / echo signal, respectively. Reference numeral 201 denotes an RF pulse, 202 denotes a slice selective gradient magnetic field pulse, 203 denotes a phase encode gradient magnetic field pulse, 204 denotes a frequency encode gradient magnetic field pulse, 205 denotes a sampling window, and 206 denotes an echo signal.

  The measurement of the echo signal is repeatedly executed at a time interval 208 (repetition time TR), and each echo signal is generated at a time 207 (echo time TE). The acquired echo signal 206 is placed in the K space 209.

  The horizontal axis Kx in FIG. 2B corresponds to the time of the echo signal sampling window 205, and the vertical axis Ky corresponds to the amount of the phase encoding gradient magnetic field pulse 203 applied to the Gp axis.

  As shown in FIG. 2 (a), the MRI apparatus normally acquires one echo signal for each RF pulse irradiation 201 and repeats it at a repetition time interval TR (208), which is necessary for image reconstruction. Get all echo signals. Therefore, the time required to acquire data is TR · N, where N is the number of echoes.

  In the MRI apparatus, when an object moves during measurement, an artifact occurs in an image. A method for detecting the movement of the object has been proposed. In particular, by additionally acquiring an echo signal (navigator echo) for detecting the body movement of the subject, the body movement of the subject can be easily detected.

  FIG. 2C is a diagram showing an example of a pulse sequence with the navigator echo signal. The difference between the example shown in (c) of FIG. 2 and the example shown in (a) of FIG. 2 is that, in the example of (c) of FIG. 2, before acquiring the echo signal 206 for an image, That is, there are readout gradient magnetic field pulses 210 and AD 211 for acquiring the navigator echo 212. Since the navigator echo signal 212 is acquired at every repetition time 208, it is determined whether the subject has moved by comparing changes in the navigator echo signal.

  In FIG. 2C, the navigator echo is read out and acquired in the gradient magnetic field direction. However, the navigator echo signal can be acquired in the direction in which the body motion is desired to be detected. Axis can be acquired simultaneously. Alternatively, it can be acquired in the direction in which the axes are combined.

  Next, a real-time reconstruction method during sequence execution will be described.

  FIGS. 3A and 3B are diagrams schematically showing echo signals arranged in the measurement space, and FIG. 3A is a state of filling the measurement space of a general MRI apparatus. In this case, as shown by the echo signal arrangements 601-1 to 601-4, the echo signals are sequentially acquired from the end of the measurement space (the highest frequency region) as the measurement progresses. By repeating this until the entire measurement space is filled, all echo signals necessary for image reconstruction are acquired.

  On the other hand, as shown by echo signal arrangements 602-1 to 602-4 in FIG. 3B, echo signals are sequentially sent from the center of the measurement space (0 phase encoding) to the outside (high frequency region). You can also set the sequence to place them. If there is low frequency data in the measurement space, it is possible to reconstruct the image and obtain the shape of the subject (however, there is no high frequency data, resulting in a blurred image). For this reason, as shown in FIG. 3B, by arranging the echo signal, image reconstruction can be performed every time the echo signal is acquired.

  603-1 to 603-4 shown in (c) of FIG. 3 schematically show images reconstructed using the echo signals 602-1 to 602-4 of (b) of FIG. 3. In this way, it is possible to monitor how the image gradually becomes higher in image quality each time an echo signal is acquired.

  The present invention has been made on the premise of the above principle. Next, an embodiment of the present invention will be specifically described.

(First embodiment)
In the first embodiment of the present invention, data measurement and calculation processing are additionally performed on an already measured image, and image quality improvement, photographing cross-sectional area correction, and the like can be executed.

  In the first embodiment of the present invention, as shown in FIG. 4A, for each image 301 that has already been measured, sequence information 302 at the time of shooting, RawData (measurement data) 303, and position information A data set 304 that includes 309 and additional data (such as navigator echo) 312 is stored. Thereby, it is possible to calculate the selected image data and the additionally acquired data.

  FIG. 5 is an operation flowchart of the first embodiment of the present invention.

  In the image selection step 101 of FIG. 5, an image 301 stored in a database in the magnetic disk 18 is selected. Next, in a measurable parameter display step 102, a changeable parameter list is created and displayed based on the sequence parameter 302 at the time of shooting attached to the image. An example of the operation screen (display 20) used in step 102 is shown in FIG.

  In FIG. 4B, reference numeral 305 denotes a parameter setting screen, reference numeral 306 denotes a selected image, and reference numerals 307-1 to 307-3 denote parameter lists that can be changed by additional measurement.

  The sequence setting step 103 creates a pulse sequence based on the additional measurement parameter set in step 102. In the additional data measurement step 104, additional data is measured using the pulse sequence created in step 103 in accordance with a measurement instruction. The measurement instruction can be issued by using the Start 313, Stop button 314, etc. prepared on the operation screen.

  In the data combining step 105, the RawData 303 in the data set 304 stored in the database is combined with the data additionally acquired in Step 104.

  In the image creation step 106, the RawData created in Step 105 is Fourier transformed into an image. At this time, the data set 304 including the image is stored. If the result image display area 308 is on the operation screen, the created image is displayed.

  Note that the parameter list that can be set in step 102 differs depending on the sequence parameter set when the image in the database is measured. FIG. 6 is a diagram illustrating an example of setting a measurement space when performing additional measurement. In each of FIGS. 6A to 6E, the left side indicates RawData 303 in the database, the right side indicates additional measurement data, and the areas not shown in black are areas where echo signals exist, respectively. is there.

  FIG. 6A shows the case of additional measurement of the number of phase encodings (number of data points in the Ky direction). In this case, data 501 near the center of the measurement space is acquired in RawData 303 in the database. In the additional measurement, the high-frequency regions 502-1 and 502-2 of the measurement space are acquired, thereby covering a wide region of the measurement space and improving the spatial resolution of the image.

  FIG. 6B is another example when the number of phase encodes is small, and shows a measurement space in the case of half scan. In the half scan, an echo signal is acquired from the center of the measurement space as in the measurement data 503 toward the high frequency region in one direction. In reconstruction, data in a non-measurement area is estimated by performing data estimation processing. However, if there is a gradient magnetic field offset shift, a gradient magnetic field output error, etc., and the echo peak shifts to the non-measurement region side of the measurement space, the data estimation process cannot be performed correctly, and an artifact occurs in the image.

  In such a case, artifacts can be eliminated by acquiring high-frequency region data 504 on the other direction side in additional measurement. In FIG. 6B, the additional measurement area 504 is shown to measure all of the non-measurement areas 503, but it is not always necessary to acquire all of them.

  FIG. 6C is a diagram illustrating an example of a parallel imaging measurement space. In parallel imaging, a measurement space is thinned out at a predetermined interval as in measurement data 505-1 to 505-8, and the aliasing generated in the image is developed based on the sensitivity distribution of the receiving coil. Since parallel imaging can be measured by thinning out the measurement space, the imaging time can be shortened.

  However, if the sensitivity distribution of the receiving coil is not suitable for parallel imaging, artifacts occur when removing the aliasing of the image. In such a case, an image free from artifacts can be obtained by additionally measuring the thinned areas 506-1 to 506-7 as additional measurement.

  FIG. 6D is a diagram illustrating an example of addition of the measurement space. When the SNR (signal-to-noise ratio) of the image 301 in the database is insufficient, the SNR can be improved by performing additional measurement under the same imaging conditions and adding these two RawData 507 and 508 together.

  Also, in the steady state pulse sequence that can change the image quality by changing the phase of the irradiation RF, the phase of the irradiation RF when the RawData 507 in the database is acquired and the phase of the irradiation RF of the additional measurement are changed, RawData 508 in different states can be obtained. By adding these two pieces of data 507 and 508 to each other, it is possible to reduce a signal having an arbitrary frequency (for example, a fat signal) or to reduce signal loss artifacts generated in an image.

  (E) of FIG. 6 is a figure which shows the example which changed the phase encoding direction as addition variation of measurement space. At the time when RawData 509 in the database is measured, the phase encoding direction is set to the vertical direction. In the MRI apparatus, when the subject has a body motion or a fluid, the data in the phase encoding direction becomes discontinuous, and thus an artifact is likely to occur in the phase encoding direction.

  For this reason, in the additional measurement, the phase encoding direction is obtained by reversing 90 degrees from the data 509 as in 510, and by adding these two data 509 and 510, the artifact is dispersed and the artifact is reduced. An image can be obtained.

  Preferably, by storing the position information 309 in the data set 304 for each image, the same shooting position as that at the time of image acquisition can be automatically set at the time of image selection, and the operation can be simplified.

  According to the first embodiment of the present invention, by measuring and acquiring additional data from the measurement image in the database and reconstructing the image, the image quality is improved without wasting already acquired data. can do.

  In addition, it is possible to acquire an image with a small number of phase encodes in advance to check the rough image quality and contrast, and to improve the spatial resolution and SNR by additional measurement to be performed later. It is possible to solve the problems of the prior art in which a setting error is found.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the second embodiment, the image quality is improved by excluding the phase-encoded region where the data has deteriorated from the image in the database and performing re-measurement. FIG. 7 is a process flowchart of the second embodiment of the present invention.

  The difference from the flowchart shown in FIG. 5 is that there is an effective data area selection step 107 between steps 102 and 103 in the flowchart shown in FIG.

  In the effective data area selection step 107, an area in which a defective data area that causes an artifact in the reconstructed image is excluded from the selected image in the database. In the effective data area, an arbitrary width 310 is set with respect to the center of the measurement space, as shown in FIG.

  As a method for setting the effective data area 310, the position of the scroll bar 315 shown in FIG. 4B is associated with the effective data area 310 using, for example, a linear function 311 as shown in FIG. Let me change it. Further, every time the scroll bar 315 is changed, an image is created only by the effective data area 310, and the created image is drawn in the image display area 308 (FIG. 4B) as needed, thereby mixing artifacts. It is possible to visually identify a data range from which bad data is excluded. In this case, in the image creation process, it is desirable to perform processing similar to normal reconstruction, such as half-scan and parallel imaging reconstruction, and phase correction processing.

  A sequence setting step 103 in FIG. 7 sets a sequence so that an area other than the effective data area set by the scroll bar 315 is measured. Thereafter, steps 104 to 106 are performed in the same manner as in the first embodiment.

  In addition, as a method for selecting defective data, a pulse sequence with a navigator echo signal as shown in FIG. 2C is executed to determine defective data by comparing navigator echo signals and set an effective data area. can do. In this case, the data set 304 to be stored in the database together with the image includes an additional data group 312 in addition to RawData, in which the navigator echo signal is stored. Thereby, the navigator echo signal can also be selected at the time of the image selection step 101 in FIG.

  According to the second embodiment of the present invention, by acquiring the additional data by excluding the artifact region generated in the image, it is possible to obtain an image free from artifacts by minimizing the amount of data to be acquired.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  In the third embodiment, the image quality is improved by displaying the reconstructed image in real time during the execution of the sequence, interrupting the measurement at an arbitrary timing, and removing the illegal data area and performing the remeasurement. FIG. 8 is a process flowchart of the third embodiment of the present invention. In the third embodiment, the operation screen shown in FIG. 4B can be used as in the first and second embodiments.

  In the shooting parameter setting step 701 in FIG. 8, parameters for obtaining a desired contrast are set as in normal shooting.

  Next, in a data measurement step 702, an echo signal is obtained by executing a pulse sequence based on the set imaging parameters.

  Subsequently, in a real-time image creation step 703, an image is created and displayed using the acquired echo signal and the already acquired echo signal group. For example, an image 306 shown in FIG. 4B is used as the display area, and the image can be paused at an arbitrary timing after the user confirms this image. As a Pause trigger, for example, a Stop button 314 on the screen is used.

  Next, if it is determined in step 704 that the pause has been made, the process proceeds to a data range setting step 705. The designation of the data range in step 705 can be performed in the same manner as in step 107 of the second embodiment. By moving the scroll bar 315 on the operation screen, the effective data area of the measurement space is changed and the screen 308 is changed. An image created with only the valid data area is displayed at any time.

  Next, it is determined whether or not Resume has been performed in Step 706. If not, the process returns to Step 705. If Resume is performed in Step 706, the process proceeds to an imaging parameter update step 707. In step 707, the imaging parameters of the pulse sequence are updated so as to acquire the data range specified in step 705, and the process returns to data measurement step 702.

  Steps 702 to 707 are repeated until it is determined in step 708 that the final data has been acquired. After it is determined that the final data has been acquired, an image is created in step 709. At this time, the data set 304 is stored along with the image.

  In the third embodiment of the present invention, while reconstructing an image being shot in real time, the image quality is monitored to check the state of occurrence of the artifact, and shooting is interrupted when defective data is entered, By changing the effective data range so as to eliminate it and performing measurement again, it is possible to obtain an image free from artifacts with minimal data recovery. In this case as well, it is desirable to perform processing similar to normal reconstruction, such as half-scan and parallel imaging reconstruction, and phase correction processing, in the image creation process.

  The first to third embodiments have been described separately for the sake of simplicity, but these embodiments can be combined with each other. It is also possible to implement these recursively.

  Furthermore, although the case of the gradient echo sequence is shown in the above-described example, the present invention can be applied to a spin echo sequence, a fast spin echo sequence that is a multi-echo type sequence, and an echo planar sequence. Moreover, it can be applied not only to two-dimensional imaging but also to three-dimensional imaging.

It is a figure showing the whole M rule device composition to which the present invention is applied. It is a figure explaining the pulse sequence of a general gradient echo. It is a figure explaining the real-time reconstruction method. It is a figure explaining the data structure and operation screen of this invention. It is a processing flowchart of a 1st embodiment of the present invention. It is a figure which shows the data addition method in this invention. It is a process flowchart of the 2nd Embodiment of this invention. It is a process flowchart of the 3rd Embodiment of this invention.

Explanation of symbols

  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, l1 ... High frequency oscillator, 12 ... Modulator, 13 ... High frequency amplifier 14a, 14b ... high frequency coil, 15 ... amplifier, 16 ... quadrature phase detector, 17 ... A / D converter, 18 ... magnetic disk, 19 ... optical disc, 20. ..Display, 23 ... Track ball (mouse), 24 ... Keyboard, 301 ... Image data already measured, 302 ... Sequence parameter, 303 ... RawData, 304 ... Data set 305 ... Parameter setting screen 306 ... select the image 307 ... parameter 308 ... image display area, 309 ... position information, 310 ... effective data area, 312 ... additional data group

Claims (5)

Static magnetic field generation means, gradient magnetic field generation means, high frequency signal transmission / reception means, signal processing display means for reconstructing and displaying an image of a subject based on echo signals received by the high frequency signal transmission / reception means, and the static magnetic field In a magnetic resonance imaging apparatus having a generating means, a gradient magnetic field generating means, a high-frequency signal transmitting / receiving means, and a control means for controlling a signal processing display means,
A data storage means for storing the image reconstructed by the signal display processing means and incidental information relating to the image photographing;
The control means reads the image and supplementary information stored in the data storage means in accordance with an operator command, and creates additional imaging data based on the additional measurement imaging parameters designated by the operator in the signal processing display means. And a magnetic resonance imaging apparatus, wherein the magnetic resonance imaging apparatus synthesizes the image read out in accordance with an instruction from the operator.   2. The magnetic resonance imaging apparatus according to claim 1, wherein the incidental information includes an imaging parameter and a received echo signal.   The magnetic resonance imaging apparatus according to claim 2, wherein the control unit performs additional measurement using a range of a measurement space used for creating an image, which is set by an operator, among echo signals as the incidental information, A magnetic resonance imaging apparatus characterized in that images are sequentially generated and displayed on the signal processing display means.   2. The magnetic resonance imaging apparatus according to claim 1, wherein the control unit changes a phase encoding amount from a low spatial frequency region to a high spatial frequency region side of the measurement space.   5. The magnetic resonance imaging apparatus according to claim 4, wherein the signal processing display means creates and displays an image every time an echo signal is acquired, and the control means sets an image among the acquired echo signals set by an operator. A magnetic resonance imaging apparatus characterized in that images are sequentially created using a range of a measurement space used for creation and displayed on the signal processing display unit, and photographing is performed for an additional photographing region designated by an operator.

Images