KR20150115316A - Method and apparatus for adjusting parameter of magnetic resonance image - Google Patents

Abstract

Disclosed are a method and an apparatus for adjusting a parameter of a magnetic resonance image. According to a proper embodiment of the present invention, as a method for adjusting a contrast in an imaging device, provided is the method for adjusting a parameter of a magnetic resonance image, comprising the following steps: (a) storing magnetic resonance (MR) data according to a preset sequence; (b) calculating a constant value using the MR data; and (c) when a user control exists, outputting magnetic resonance images of different contrasts in real time using a parameter adjusted by the control, and the constant value.

Description

METHOD AND APPARATUS FOR ADJUSTING PARAMETER OF MAGNETIC RESONANCE IMAGE < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for adjusting parameters of a magnetic resonance image, and more particularly, to a method and an apparatus for easily changing parameters of a magnetic resonance image in a diagnostic process using a magnetic resonance image.

Magnetic Resonance Imaging (MRI) is a magnetic resonance imaging (MRI) system that incorporates a large magnet that generates a magnetic field to generate a high frequency to resonate the hydrogen nuclei in the body to measure the difference in signal from each tissue reconstruction through computer Respectively.

This means that when an echo signal is emitted from a human body by radiating a high frequency to a human body in a device composed of magnets, the echo signal is converted and converted into digital information for imaging.

Magnetic resonance imaging is one of the important advantages that it is virtually harmless to the human body because it is an examination using X-ray, simple x-ray, or CT using high frequency which is non-ionizing radiation. The contrast of the body soft tissue is superior to that of CT without contrast agent by using a harmless magnetic field and non-ionizing radiation, and the information about the biochemical characteristics of a tissue containing a hydrogen atom nucleus can be obtained.

It is similar to CT in that it shows the human body in cross-section, but in CT, the cross-sectional image, which is the cross-cut shape of the human body, is predominant. Magnetic resonance imaging, however, There is also an advantage that images such as directions can be obtained freely.

MRI can be obtained through various techniques. For example, T1 weighted images, T2 weighted images, and FLAIR (Fluid-Attenuated Inversion-Recovery) exist.

T1-weighted images are images obtained by spin echo technique using short TR (Repitition Time) and short TE (Echo Time), and images obtained by reflecting the difference of T1 relaxation time as signal difference. Using short TR results in a significant difference in the recovery of longitudinal axis magnetization between tissues and can be reflected in the signal to obtain T1-weighted images.

T2-weighted images were obtained by spin echo technique using long TR and TE, and images were obtained by reflecting difference of tissue T2 relaxation time as signal difference. Using long TE, the collapse of transverse magnetization between tissues is greatly differentiated, and T2 - weighted images can be obtained by reflecting this in signals.

FLAIR is an image obtained by Inversion Recovery technique applying a 180-degree reversal pulse.

The doctor diagnoses the condition of the patient through the imaging device using the image obtained through one of the various techniques (sequences) as described above.

However, since the method of diagnosing the patient's condition using one image according to the magnetic resonance image acquisition technique and the method using the image obtained through the other technique are used in case of insufficient use, the patient is photographed according to various sequences in order to diagnose the patient There is a hassle to perform repeatedly.

In order to solve the problems of the prior art as described above, the present invention proposes a method and an apparatus for adjusting parameters of a magnetic resonance image in a diagnostic process.

According to a preferred embodiment of the present invention, there is provided a method of adjusting parameters in an imaging apparatus, the method comprising: (a) storing MR (Magnetic Resonance) data according to a preset sequence; (b) calculating a constant value using the MR data; And (c) outputting a magnetic resonance image of different contrast degrees using the parameters and the constant values adjusted according to the operation, when there is a user operation.

The constant value is at least one of Mo (proton density), T1 time constant, T2 time constant, T2 *, T1ρ, B1, ΔBo, Diffusion coefficient and Susceptibility, Time, TE (Echo Time), TI, and FA (Flip Angle).

Wherein the user operation is performed through a mouse having a first button, the parameter includes a first parameter and a second parameter, and when the first button is pressed or pressed, the mouse is moved in the left- 1 parameter is adjusted, and the second parameter can be adjusted when the mouse is moved in the vertical direction.

The mouse includes a second button, and when the second button is input, the first and second parameters at the time when the second button is input can be stored.

(C) outputting the magnetic resonance image on a diagnostic interface, wherein the diagnostic interface comprises an image loading menu, a video output area, a parameter control bar, a parameter adjustment input window, a storage parameter display area, And a menu.

The parameter adjustment can be performed according to the parameter adjustment process in the parameter control bar or the parameter input process in the parameter adjustment input window.

Wherein the user operation is performed through a touch operation, the parameter includes a first parameter and a second parameter, the first parameter is adjusted when moving in the left-right direction after touching the user, The parameters can be adjusted.

According to another aspect of the present invention, there is provided a computer-readable recording medium on which a program for performing the above-described method is recorded.

According to another aspect of the present invention, there is provided an apparatus for adjusting a magnetic resonance imaging parameter, comprising: an MR data storage unit for storing MR data according to a preset sequence; A controller for calculating a constant value using parameters in the sequence and generating a magnetic resonance image corresponding to the MR data; And a display unit for outputting a diagnostic interface including the generated magnetic resonance image, wherein, when there is a user operation, the controller uses magnetic resonance images of different contrast degrees using the parameter adjusted according to the operation and the constant value, There is provided an apparatus for adjusting parameters of a magnetic resonance image which controls an image to be output through the display unit.

According to the present invention, it is possible to easily change parameters using a mouse or the like, and to confirm magnetic resonance images of different contrast degrees.

1 is a flowchart of a parameter adjustment process of a magnetic resonance image according to a preferred embodiment of the present invention.
FIG. 2 is a diagram for explaining a process of acquiring T1 and T2 through exponent adjustment of relaxation data; FIG.
FIG. 3 is a diagram for explaining the acquisition process of T1 and T2 through magnetic resonance fingerprinting; FIG.
4 is a diagram illustrating a diagnostic interface output from a video apparatus according to an embodiment of the present invention.
5 to 6 are diagrams illustrating a state in which magnetic resonance images of different contrast degrees are output through a diagnostic interface according to an embodiment of the present invention.
FIGS. 7 to 8 illustrate a process of discriminating an organization through different contrast image images. FIG.
9 is a block diagram showing a configuration of a video apparatus according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

FIG. 1 is a flowchart of a parameter adjustment process of a magnetic resonance image according to a preferred embodiment of the present invention.

The process shown in FIG. 1 can be performed in a video device capable of outputting a magnetic resonance image.

Referring to FIG. 1, MR (Magnetic Resonance) data is acquired according to a predetermined technique (sequence) (step 100).

Here, the MR data is data relating to various parameters in the photographing sequence and signals emitted during relaxation after application of a high-frequency pulse.

The imaging techniques used in step 100 may vary, and the magnetic resonance images obtained thereby may be, but are not limited to, T1-weighted images, T2-weighted images, and FLAIR images.

Then, the imaging device calculates T1 and T2 using the obtained MR data (step 102).

Magnetic resonance imaging is obtained by measuring the pattern in which a hydrogen nucleus interacts with a magnetic field in a magnetic field and absorbs and emits electromagnetic waves of a specific frequency. In adults, about 60% of body weight is body fluids, most of which is water. Proton, a nucleus of water 's hydrogen atom, has a spin in any direction. When placed in a strong magnetic field, the spin direction of a portion of the hydrogen nucleus lies along the direction of the magnetic field.

A high-frequency pulse in the vertical direction absorbs the energy of the hydrogen atom nucleus and changes the spin direction in the direction opposite to the magnetic field. When the pulse is interrupted, the hydrogen nucleus with reverse spin returns to its original state, producing weak electromagnetic waves. And the image can be formed by detecting the electromagnetic wave and estimating the position of the hydrogen nucleus from which the electromagnetic wave is emitted.

And the time (relaxation time) that the hydrogen nucleus with reverse spin returns to its original state has two values of T1 and T2 depending on the relaxation factor of spin.

A spin-spin relaxation in which the spin of a hydrogen nucleus is relaxed by interaction with a spin nucleus of the surrounding hydrogen nucleus is referred to as a time constant T2.

On the other hand, spin-lattice relaxation refers to relaxation of spin by interaction with the lattice structure of the surrounding tissue, and this time constant is referred to as T1.

FIG. 2 is a diagram for explaining the acquisition process of T1 and T2 through exponent adjustment of relaxation data.

Referring to FIGS. 2A and 2B, since the relaxation signal (MR data) obtained through a predetermined sequence has an exponential shape, a quantitative value of T1 and T2 can be obtained through fitting through c and d as shown in FIG. 2 .

However, in the method shown in FIG. 2, values such as T1 and T2 can not be obtained simultaneously, and a plurality of pieces of data are required to obtain an exponential curve.

FIG. 3 is a view for explaining a process of acquiring T1 and T2 through magnetic resonance fingerprinting.

FIG. 3 is a graphical representation of the < RTI ID = 0.0 > "Magnetic resonance fingerprinting." Nature 495.7440 (2013): 187-192.), Which is a method for generating quantitative multi-parameters after generating a preliminary Forward modeling (Dictionary) based on the following Bloch Equation and comparing it with the obtained signal.

)는 proton density(특정 조직에서의 물의 함량)이다. Where x and y are the voxel indices representing the position of the voxel, TE is the echo time, TR is the iteration time, Mo (

) Is the proton density (the amount of water in a particular tissue).

In a magnetic resonance image, TR and TE can be divided into several sets (for example, (TR1 = 3000, TE1 = 200, TR2 = 400, TE2 = 400) .

)와 같은 상수값이 계산될 수 있으며, 그밖에 아래의 수학식 2 내지 3에서와 같이, 상수값은 delB B0(△BO), B1, 확산 계수(Diffusion coefficient) 및 자화율(Suscepbility), T2*(free induction decay rate), T1ρ 등을 포함할 수 있다. Through the above-described equation (1), T1 and T2 and Mo (proton density,

), And constant values such as DELB B0 (DELTA BO), B1, diffusion coefficient and susceptibility, and T2 * ( free induction decay rate, T1ρ, and the like.

here,

TI is a time interval between a 180-degree RF pulse and a 90-degree RF pulse in a suppression sequence. When TI (inversion time) = 0, , And becomes equal to Equation (1).

_

_

Here, FA (Flip Angle) is an angle that rotates the magnetization to the transverse plane.

Me is a 3 × 1 vector, where Me (1) is the first component and Me (2) is the second component.

Here, [Delta] B0 is a B0 inhomogeneity, a parameter indicating the nonuniformity of B0, and B1 is a parameter indicating a B1 field. The diffusion coefficient is a diffusion constant in which protons (water) move within the tissue, and the magnetic susceptibility is a numerical value indicating the degree of magnetization of the object in the MRI.

T1ρ is defined as the spin-lattice relaxation time constant in the rotating frame.

T1ρ imaging is used to monitor proton absense, Alzheimer's disease, and fluidity of the fat.

After the constant values such as T1 and T2 are calculated as described above, the video apparatus determines whether there is an operation by the user (step 104).

And outputs images of various contrast degrees to a predetermined area of the diagnostic interface while adjusting one or more parameters according to user's operation (step 106).

The parameter adjustment according to an embodiment of the present invention may be performed by a mouse operation of a user and a magnetic resonance image corresponding to a parameter adjusted in real time according to a user's mouse operation is output to a predetermined area of the diagnostic interface.

4 is a diagram illustrating a diagnostic interface output from a video apparatus according to an embodiment of the present invention.

4, the diagnostic interface according to an exemplary embodiment of the present invention includes an image loading menu 400, a video output area 402, a parameter control bar 404, a parameter adjustment input window 406, A display area 408, an image selection menu 410, and a calculation parameter menu 412.

When the user selects the image loading menu 400, a magnetic resonance image corresponding to the MR data acquired through the predetermined sequence is output to the image output area 402.

In the image output area 402, a magnetic resonance image obtained through TR and TE set in advance is output, and constant values such as T1 and T2 in the corresponding sequence are calculated in advance.

According to a preferred embodiment of the present invention, when there is a user operation, parameters such as TR and TE are adjusted in the image output area 402, and the magnetic resonance generated using the adjusted parameter and the previously calculated constant value Video is output.

Preferably, the parameter adjustment according to an embodiment of the present invention can be performed through a mouse operation.

In the following description, TR and TE among the plurality of parameters are adjusted to output different contrast images.

According to an embodiment of the present invention, it is possible to easily adjust the parameters according to the input of the left click or right button provided on the mouse and the movement of the mouse.

For example, when the user operates the mouse while holding the right button of the mouse after placing the mouse cursor in the image output area 402, the video device sets the parameter according to the size of the movement in the left-right direction or the upward direction of the mouse And displays a magnetic resonance image corresponding to the adjusted parameter in the image output area 402 in real time.

For example, the movement of the mouse in the lateral direction can be set by the TE parameter adjustment, and the movement in the vertical direction can be set by the TR parameter adjustment. Of course, the opposite can also be included in the scope of the present invention.

If there is parameter adjustment according to the mouse operation, the parameter at the current mouse position is displayed in the parameter control bar 404 and the parameter adjustment input window 406.

Meanwhile, according to the embodiment of the present invention, not the mouse operation but the parameters TR and TE in the parameter control bar 404 or the parameters TR and TE in the parameter adjustment input window 406 Adjustment can be made.

According to an embodiment of the present invention, when the user operates the mouse while pressing the right-click button and then presses the left-click button, the current parameter value is stored.

That is, according to an embodiment of the present invention, the input of the first button provided on the mouse can be set to the adjustment of the parameter, and the input of the second button can be set to the storage of the parameter.

The stored parameter is output to the storage parameter display area 408.

In addition, a magnetic resonance image corresponding to the currently stored parameter is output to the image display area 402. [

In the above description, the two parameters TR and TE are adjusted through the movement of the mouse in the left-right direction or the up-down direction. However, when additional parameters are present, adjustment of additional parameters This is possible.

For example, if the proton density of Equation 1 is included as an adjustable parameter, adjustment of the proton density may be possible through the scrolling portion of the mouse.

Additional parameters may include TI parameters or FA (Flip Angle) in addition to TR and TE. STIR and FLAIR are used to view except CSF and Fat parts of the organization. TI parameters are used in the sequence used to see only the tissues that help diagnosis.

Further, it is possible to provide additional buttons in addition to the right-click button and the left-click button of the mouse, and to adjust parameters when an additional button is pressed or the mouse is moved in the left-right direction or the up-down direction while being pressed.

5 to 6 are views showing states in which MRI images of different contrast degrees are output through a diagnostic interface according to an embodiment of the present invention.

FIG. 5 shows a state in which a magnetic resonance image in which the TR is adjusted to 300.8 ms and the TE is adjusted to 14.6667 ms is shown. FIG. 6 shows a state in which a magnetic resonance image in which TR is adjusted to 3852.8 ms and TE is adjusted to 17.6667 ms Fig.

As shown in FIGS. 5 to 6, the parameter adjustment can be easily adjusted through the diagnostic interface according to the present embodiment, and the magnetic resonance images of different contrast degrees can be easily confirmed through the parameter adjustment.

FIGS. 7 to 8 illustrate a process of discriminating an organization through different contrast images.

FIG. 7 is a view showing a state in which a magnetic resonance image in which TR is adjusted to 1625.6 ms and TE is adjusted to 14.6667 ms is outputted, and FIG. 8 is a view showing a state in which a magnetic resonance image adjusted to TR of 3724.8 ms and TE is adjusted to 197.3333 ms Fig.

Referring to FIGS. 7 to 8, in the magnetic resonance image of FIG. 5, the structure of the inside of the circle 700 is not discriminated, but when a magnetic resonance image as shown in FIG. 6 is output through parameter adjustment, The organization can be identified.

As described above, when the diagnostic interface according to the embodiment of the present invention is used, it is possible to accurately diagnose the state of the patient by easily changing the contrast degree without further photographing.

9 is a block diagram illustrating the configuration of a video apparatus according to an exemplary embodiment of the present invention.

9, the imaging apparatus according to the present invention may include an MR data storage unit 900, a control unit 902, a display unit 904, and a user operating unit 906.

The MR data storage unit 900 stores MR data obtained through a predetermined sequence.

The control unit 902 calculates a constant value such as parameters T1 and T2 of the MR data stored in the MR data storage unit 900. [

The calculated constant value is stored in advance.

In addition, the controller 902 controls the display unit 904 to output a diagnostic interface including a video output area as shown in FIG. 4 when the user requests it.

The display unit 904 displays a magnetic resonance image generated by using the MR data stored in the MR data storage unit 900 in the image output area 904 when there is a data loading request, 402.

The control unit 902 according to this embodiment adjusts the parameters according to the input signals of the user operating unit 906 and controls the magnetic resonance images corresponding to the adjusted parameters to be output.

The user operation unit 906 according to the present embodiment may be a mouse, and as described above, parameters may be adjusted through input of a button provided on the mouse and mouse movement.

However, if the display unit 904 is provided as a touch screen without being limited thereto, the parameters may be adjusted according to the touch operation of the user.

For example, the TE parameter can be adjusted when the user moves in the left-right direction while being touched, and the TR parameter can be adjusted when moving in the up-down direction.

In addition, if one hand touches the other hand and touches it in the left or right direction or the up and down direction, the parameter can be adjusted correspondingly.

Embodiments of the present invention may be implemented in the form of program instructions that can be executed on various computer means and recorded on a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and configured for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Examples of program instructions, such as magneto-optical and ROM, RAM, flash memory and the like, can be executed by a computer using an interpreter or the like, as well as machine code, Includes a high-level language code. The hardware devices described above may be configured to operate as at least one software module to perform operations of one embodiment of the present invention, and vice versa.

It will be apparent to those skilled in the relevant art that various modifications, additions and substitutions are possible, without departing from the spirit and scope of the invention as defined by the appended claims. The appended claims are to be considered as falling within the scope of the following claims.

Claims (12)

A method of adjusting parameters in a video device,
(a) storing MR (Magnetic Resonance) data according to a preset sequence;
(b) calculating a constant value using the MR data; And
(c) outputting, when there is a user operation, a magnetic resonance image of different contrast degrees in real time using parameters adjusted according to the operation and the constant value. The method according to claim 1,
The constant value is at least one of Mo (proton density), T1 time constant, T2 time constant, T2 *, T1ρ, B1, ΔBo, Diffusion coefficient and Susceptibility, Time), TE (Echo Time), TI, and FA (Flip Angle). The method according to claim 1,
Wherein the user operation is via a mouse having a first button, the parameter comprises a first parameter and a second parameter,
Wherein the first parameter is adjusted when the mouse is moved in the left or right direction while the first button is pressed or pressed, and the second parameter is adjusted when the mouse is moved in the vertical direction. The method of claim 3,
The mouse including a second button,
Wherein when the second button is input, the first and second parameters at the time when the second button is input are stored. The method according to claim 1,
(C) outputting the magnetic resonance image on a diagnostic interface, wherein the diagnostic interface comprises an image loading menu, a video output area, a parameter control bar, a parameter adjustment input window, a storage parameter display area, The method comprising the steps of: 6. The method of claim 5,
Wherein the parameter adjustment is performed according to a parameter adjustment process in the parameter control bar or a parameter input process in the parameter adjustment input window. The method according to claim 1,
Wherein the user operation is performed through a touch operation, the parameter includes a first parameter and a second parameter,
Wherein the first parameter is adjusted when the user moves in the left and right direction after touching the user, and the second parameter is adjusted when the user moves in the up and down direction. A computer-readable recording medium on which a program for performing the method according to claim 1 is recorded. An apparatus for adjusting a magnetic resonance imaging parameter,
An MR data storage unit for storing MR data according to a preset sequence;
A controller for calculating a constant value using parameters in the sequence and generating a magnetic resonance image corresponding to the MR data; And
And a display unit for outputting a diagnostic interface including the generated magnetic resonance image,
Wherein the controller controls the magnetic resonance images of different contrast degrees to be output through the display unit in real time using the parameters and the constant values adjusted in accordance with the operation when there is a user operation. 10. The method of claim 9,
The constant value is at least one of Mo (proton density), T1 time constant, T2 time constant, T2 *, T1ρ, B1, ΔBo, Diffusion coefficient and Susceptibility, Time), TE (Echo Time), TI, and FA (Flip Angle). 10. The method of claim 9,
Wherein the user operation is via a mouse having a first button, the parameter comprises a first parameter and a second parameter,
Wherein the first parameter is adjusted when the mouse is moved in the left or right direction while the first button is pressed or pressed, and the second parameter is adjusted when the mouse is moved in the vertical direction. 10. The method of claim 9,
The mouse including a second button,
Wherein the first and second parameters at the time when the second button is input are stored when there is an input of the second button.

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