JPH0191842A - Method for drawing flow of spinal fluid - Google Patents

Abstract

PURPOSE:To describe the flow of the spinal fluid without applying a pain to an examinee, by anchoring a region to be described at the almost center of the uniform space of the static magnetic field of a magnetic resonance imaging apparatus and executing a sequence having a short signal collecting interval at every different time phase with respect to one surface of the aforementioned region in synchronous relation to a cardioelectric waveform. CONSTITUTION:An examinee P is positioned so that the head HP being the extraction object of the flow of the spinal fluid is anchored at the almost center of the uniform space of the static magnetic field of a static magnetic field magnet 1 in order to set the median sagittal surface of the head. An electrocardiograph 13 generating a signal synchronous to a cardioelectric waveform consists of the induction electrode 13a applied to the examinee P and a synchronous signal generating part 13b and an R wave-R wave is divided into many waves to generate synchronous signals S1, S2, S3, S4, S5, S6 from the synchronous signal generating part 13b at every divided times and said signals are given to a computer system 11 to obtain an imaging start signal. Therefore, the time phase images in the signals S1, S2, S3, S4, S5, S6 are held in a display system to perform cinematic display. These operations can be simply performed without imparting a pain to the examinee P.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention produces a magnetic resonance phenomenon in a specific part of a subject placed in a static magnetic field, and detects the induced positive resonance signal. Using a magnetic resonance imaging device that reconstructs the slice image of the specific region to provide morphological and functional information of the specific region, we use a magnetic resonance imaging device to reconstruct the slice image of the specific region to provide morphological and functional information of the specific region. , spinal fluid in the neck, 9 thoracic vertebrae, and lumbar vertebrae (C8F
: Cerebro 3ptnat Fluid)
Concerning how to depict the flow of

(Prior Art) In order to diagnose hydrocephalus, which is a disease associated with outflow of spinal fluid into the skull, a method of depicting the flow of spinal fluid has been conventionally used. This is a method called X-ray minigraphy, and will be explained below. That is,
This is a method in which an iodine contrast agent is injected using a syringe into a region where spinal fluid is expected to leak, and after the region is contrasted with the iodine contrast agent, an X-ray image is performed. In images taken using this method, the spinal fluid is white-enhanced using an iodinated contrast agent, making it possible to clearly see where the flow of cerebrospinal fluid is blocked, and to diagnose disc herniation. effective. There is also an X-ray minigraphy CT in which a CT image is obtained by injecting a contrast agent in the same way as described above.

However, the above-mentioned XI! Minirography is a painful and dangerous method for the subject, in which an iodinated contrast agent is injected using a syringe into the area where spinal fluid is expected to leak, and it is not a simple diagnostic method. There wasn't.

(Problems to be Solved by the Invention) As described above, the conventional technique of X-ray minigraphy is a painful and dangerous method for the subject.
It was a problem.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method that can visualize the flow of spinal fluid without causing pain or risk to a subject.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a structure in which the following measures are taken to solve the above problems and achieve the object. That is, the present invention is a method for depicting the flow of spinal fluid using a magnetic resonance imaging device, in which a region to be depicted is placed approximately at the center of a uniform static magnetic field space of the magnetic resonance imaging device, and a receiving coil is placed in the region. A sequence with a short signal collection interval is synchronized with the electrocardiogram waveform and executed for each different time phase for one surface of the region, thereby obtaining a large number of slice images at different time phases. The flow of spinal fluid is visualized by displaying slice images in a high-speed cyclic manner to show changes in signal intensity.

(Function) By taking such measures, it is possible to collect signals from the imaged region with high sensitivity and at high speed, and by displaying a large number of slice images in a high-speed cyclic manner, changes in signal intensity appear.
This change depicts the flow of spinal fluid, which is non-invasive and does not cause pain or danger to the subject.

(Example) The method for depicting the flow of spinal fluid according to the present invention will be described below as an example of application to depicting the flow of spinal fluid within the skull.

FIG. 1 shows a magnetic resonance imaging apparatus used in this example.

As shown in FIG. 1, the magnet assembly capable of accommodating the subject P therein includes a static magnetic field magnet (made of a permanent magnet, a normal conducting magnet, a superconducting magnet, or a combination thereof). A shim coil for static magnetic field correction may be added.) 1, a gradient magnetic field generating coil 2 that generates a gradient magnetic field for providing positional information of the induced site of the magnetic resonance signal, and a gradient magnetic field generating coil 2 that transmits a high-frequency magnetic field for excitation. It also has a probe 3 consisting of a coil, which is a transmitting/receiving system for detecting magnetic resonance signals induced therein.

Here, the subject P places the head HP approximately at the center of the static magnetic field uniform space of the static magnetic field magnet 1 in order to slice the head median sagittal plane, and the probe 3
Use a head coil or head and neck coil that can cover P.

If it is a superconducting system, it includes a refrigerant supply control system, and mainly controls the energization of the static magnetic field power source.
It is equipped with

Furthermore, the transmitter 8 provides power for generating a high-frequency magnetic field for excitation to the probe 3, and the signal from the receiving coil of the probe 0-73 is amplified to the extent that it can be applied to subsequent processing, and the output is converted into real and imaginary parts. and a receiver 9 that performs phase detection on each of the two, converts the phase detection output into a digital signal, and outputs an A/D conversion output.

In addition, for example, the data collection sequence shown in Figure 2 regarding protons (the angle at which the magnetization is flipped (flip angle) is 9
The computer system 1 includes a sequencer 10 that implements a gradient-end field echo method (gradient-end field echo method) with a value smaller than 0''.
Here, a slice image is reconstructed by, for example, a two-dimensional Fourier transform method, and displayed on a display system 12. The display system 12 is capable of holding a large number of images and is capable of high-speed cyclic display, that is, cine display, of the large number of held images.

The present embodiment also includes an electrocardiograph 13 that generates a signal synchronized with an electrocardiogram waveform. This electrocardiograph 13
It consists of an induction electrode 13a that is applied to When divided, the division interval is 50
msec. ), a synchronization signal 31 is sent at each division time,
$2.

83, 84, 85, 86~ are generated and given to the computer system 11 to be used as the Wi-Ang start signal.

With the apparatus configuration as described above, the method of this embodiment is performed as follows. That is, the electrocardiograph 13 outputs a synchronization signal 31°82.83.84.8 based on the electrocardiographic waveform of the subject P.
5.86~ are given to the computer system 11, and the computer system 11 receives these synchronization signals 81, 82.
,'83,'84.

85 and 86~ are given to the sequencer "IO" as a photographing start signal.

As a result, the sequencer 10 first executes the gradient-end field echo method data collection sequence shown in FIG. 7, the probe 3 and the gradient magnetic field generating coil 2 generate a predetermined magnetic field to excite the slice region Sr, and the induced magnetic resonance signal (echo signal) is detected by the probe 3 and the receiver 9. Then, the computer system 11 generates a temporal image IM at S1.
1 and displays a temporal image IM1 at $1 in the display system 12.
hold.

Next, at $2, the same gradient-end field echo method data collection sequence as above is executed, and the computer system 11 generates a temporal image IM at step S2.
2, and displays the temporal image IM2 at S2 in the display system 12.
hold. This is carried out at 83.84.85.86~, and the time phase images rM3, IM4, IM5, at 83.84.85.86~ are displayed in the display system 12.
Hold IM6~.

By the above procedure, 81 and 82 are displayed in the display system 12.

Temporal image IM1 at S3, S4, S5, S6 ~
゜1M2.1M3.1M4.1M5, 1M6~ are held, and then the time phase (*IM1.1M2.1M3.

1M4. High-speed cyclic display, ie, cine display, is performed on IM5, 1M6 and so on.

As described above, according to this embodiment, the temporal image IM1.1M2.1M3.1M4 is based on the electrocardiogram waveform.

By displaying 1M5, 1M6 and so on in cine, the observer can visually follow the change in signal intensity (vixel value) between time-phase images. Therefore, the signal strength changes depending on the flow velocity in the part where the flow table is, so by displaying the cine, it is possible to know the flow velocity of the spinal fluid C8F gushing out from the cerebral aqueduct, for example, as shown in Figure 3. Can be done.

In addition, in this example, although image acquisition is performed within each division interval of electrocardiographic synchronization, the gradient-end field echo method is applied as the image acquisition sequence, in which the echo time te is short but the SlN is high. , and the flip angle is set to an angle smaller than 90'. Therefore, changes in the temporal image within each division interval are emphasized only by changes in the signal intensity (vixels (ia)) between the temporal images with respect to the flow velocity of the spinal fluid moving in response to the heartbeat.
By displaying multiple temporal images in cine, only the flow of spinal fluid can be clearly shown.

Further, the head HP, which is the object of depicting the flow of spinal fluid, is placed approximately at the center of the static magnetic field uniform space of the static magnetic field magnet 1, and a head coil or a head and neck coil capable of covering the head HP is installed. Therefore, the receiving sensitivity is high and a good image can be generated.

The above movements are non-invasive movements for the subject P, so they do not cause any pain to the subject P, and there is no danger.
It is a diagnostic method that can be easily performed.

The present invention has other embodiments as follows. In other words, the slice site for depicting the flow of spinal fluid is not limited to the midsagittal plane of the head mentioned above, but also the acal plane at the lateral brain drip level, the third ventricle level, the fourth brain solstice level, and the cervical midsagittal plane. Can be set.

Further, in the above example, an example was described in which the flow of cerebrospinal fluid in the skull and neck is depicted, but the thoracic vertebrae is effective in diagnosing diseases such as intervertebral disc herniation.

It can also visualize the flow of spinal fluid in the spinal cord in areas such as the lumbar vertebrae. In other words, the desired diagnosis area of the lower back is
The field magnet 1 is placed approximately at the center of the uniform static magnetic field space, and the partial surface coil is applied to the diagnosis site to obtain a large number of time-phase images in synchronization with the electrocardiogram waveform as in the example above, which are then used as a cine. It is to be displayed. This cine display allows you to clearly see that the flow of spinal fluid is obstructed.

In general, the image acquisition sequence is not limited to the gradient-end field echo method, and various sequences, particularly high-speed sequences, can be implemented. In the spin echo method, each of the flowing protons is focused! 1
11! Assume that l has been adjusted.

Furthermore, it does not specify the configuration of each element or electrocardiograph of the magnetic resonance imaging apparatus.

The invention can be modified in various ways without departing from the gist of the invention.

[Effects of the Invention] As described above, in the present invention, the imaged region of the subject is placed approximately at the center of the static magnetic field uniform space of the magnetic resonance imaging apparatus, the receiving coil is arranged at the region, and the imaged region is placed on one surface of the region. On the other hand, by synchronizing a sequence with a short signal collection interval with the electrocardiogram waveform and executing it for each different time phase, many slice images of different time phases are obtained, and by displaying these many slice images in a high-speed cyclic manner, Signals can be collected from the visualized area with high sensitivity and at high speed, and changes in signal intensity appear by displaying many slice images at high speed,
This change depicts the flow of spinal fluid, which has the effect of being non-invasive, causing no pain to the subject, and having no danger.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an apparatus capable of carrying out an embodiment of the method for depicting the flow of spinal fluid according to the present invention, and FIG. 2 is a diagram showing an image acquisition sequence used in the configuration of FIG. 1.
FIG. 3 is a diagram showing an example of image collection and display in the same embodiment. 1... Static S magnet, 2... Gradient magnetic field generating coil, 3
... Probe, 4... Static magnetic field control system, 5.6.7.
...X-axis, Y-axis, Z-axis gradient magnetic field N source, 8... transmitter,
9... Receiver, 10... Sequencer, 11... Computer system, 12... Display system, 13... Electrocardiograph. Applicant's Representative Patent Attorney Takehiko Suzue Procedural Amendments Showa Condolences 2.1 Power 28th

Claims (1)

[Claims] In a method for depicting the flow of spinal fluid using a magnetic resonance imaging device, a region to be depicted is placed approximately at the center of a uniform static magnetic field space of the magnetic resonance imaging device, a receiving coil is placed at the region, and a receiving coil is placed at the region. By synchronizing sequences with short signal acquisition intervals for one plane and executing them for each different time phase in synchronization with the electrocardiogram waveform, many slice images of different time phases are obtained, and these many slice images are displayed in a high-speed cyclic manner. A method for depicting the flow of spinal fluid that depicts the flow of spinal fluid by expressing changes in signal intensity.