JPS6264346A - Nuclear magnetic resonance image pickup apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a nuclear magnetic resonance imaging apparatus (hereinafter referred to as nuclear magnetic resonance).
In particular, the present invention relates to improvements in the means for obtaining a cumulative image of the relaxation time TI+T2j3 and the proton density ρ.

(Prior Art) Conventionally, NMR imaging devices have been used to produce images that are fsQ (TI edge) to the longitudinal relaxation time TI value, which are considered medically useful, and images that jump to the transverse relaxation time T2 value (T
There was a technique to find 2 images).

(Problems to be Solved by the Invention) However, the TI image and the D2 image have been obtained by different methods as follows.

(2) The Ti image is calculated as follows, for example. The inversion recovery method (lnversio) as shown in FIG.
The rR3E method is a combination of the spin echo method (abbreviated as the spin echo method) and the spin echo method (abbreviated as the SE method), and the saturation recovery method as shown in Figure 10.
coverage: hereinafter abbreviated as SR method) and SE method are 01
One original image is obtained using the SR3E method applied in the previous section, and calculations are performed using these two images and an approximation formula for signal strength.

SRS E FA is a pulse sequence in which an echo signal is obtained by applying a 90° pulse and then a 180° pulse, as shown in Figure 10.
The time from the application of the 90° pulse to the application of the 90″ pulse in the next view is T.
It is set as r.

In addition, the IR8E method is as shown in FIG.
A pulse sequence in which a 180° pulse for inversion/recovery is applied at the beginning of each 90' pulse of the 8E method, and the time from application of a 180° pulse for inversion/recovery to application of a 90° pulse is Td19
The time from the 0° pulse to the center of the echo signal is Ts, and the time from the application of the 1806 pulse for inversion/recovery to the application of the 180° pulse in the next view is Tr.
It is said that

Theoretical formula for signal strength in the SR8E method
The theoretical formula I for the signal strength in the law is
~Ts/Ding-)(,(-z・4!fiP (-T(L)
/ T +9+2・ku≧nip(-Ts/T+juice Ts/2
1+)-<xP(-Ts/T+)).

For this theoretical formula, here, Tr:'! If we take 'T+ (3Xl'+ <-Tr/T+ > =O,
ISR hand Io・P (Ts / Tz) Therefore, ■u/ ISR= l−2・wp (−god−/T
l) Ding + ”T, g, /1m (2ISR Bing SR-I
t<)t Find the II value from this formula.

■When obtaining a T2 image, for example, please refer to the publication [Video Information (
M) J June 1984 issue (Vo 1.16 No.

CP described on pages 570 to 576 of 11)
By MG method? ! The T2 value is determined by eliminating TI+ρ from several pieces of echo data and using the method of least squares.

In addition, in the CP method, in which multiple pieces of echo data are continuously taken out in one data collection and the T2 value is calculated by 1g, if the length of the applied pulse is incomplete, the error will cause an error in the echo. However, a pulse sequence called the CPMG method solves this problem, and as shown in Figure 7, a 90° pulse is followed by a 180° pulse. This is a pulse sequence in which n echoes are generated by repeatedly applying n times.

Conventional methods using such techniques have the following drawbacks.

(1) The TI image and the T2 image are obtained separately, and the calculation images of T I s T2 and ρ cannot be obtained at the same time.

(2) An accurate value cannot be determined because an approximate formula is used.

(3) Tr) Due to the TI condition, the Tr must be made long, and the total scan time is long.

(4) The scan parameters of the original image are not Wi-optimized, and the best calculated image cannot be found under the given conditions.

(5) There is a systematic error due to the influence of the slice shape.

(II;) There is a systematic error due to the 90° pulse error.

In view of these points, an object of the present invention is to process a plurality of original images obtained in a short time using an NMRI imager.
jaI: KT + , T2 , pHtl image Wonor
The object of the present invention is to provide an NMR imaging device that can determine k-.

(Means for Solving the Problems) In order to achieve such an object, the present invention devises a new pulse sequence for computational images in a nuclear magnetic resonance imaging device, and performs imaging using the IRn5flX and SRmSE methods. It is assumed that (n+m) images are obtained from the i image and that a T + + T 21ρ image can be calculated from this image, and each scan parameter in the IRnSE method and SRmSE method in this case is T + r 72 in the range of interest.
It is characterized in that the evaluation function of the +ρ calculation image is selected to be the best.

<Example> The present invention will be described in detail below using the drawings. FIG. 1 is a partial block diagram showing an example of a solid stripe of the NMR 1fi imager according to the present invention. In the figure, reference numeral 1 denotes a magnet assembly, inside of which a space (hole) is provided for inserting a target object. A main magnetic field coil 2 for applying, and a gradient magnetic field coil 3 for generating a gradiometer is (X gradient r! configured to be able to individually generate a gradient magnetic field).
& field coil, y-gradient field coil, and 2-gradient magnetic field coil), a transmitter coil 4 that provides a high-frequency pulse to excite the spins of atomic nuclei in the object, and an NMR signal from the object. A receiving coil 5 and the like are arranged to detect the.

The main 11 field coil is connected to the static magnetic field control circuit 15, G
Each of the y and Gz gradient magnetic field coils is connected to the gradient magnetic field control circuit 14,
The RF transmitting coil is connected to a power amplifier 18, and the NMR signal receiving coil is connected to a preamplifier 19.

Reference numeral 13 denotes a controller 1, which controls the sequence of generation of gradient magnetic fields and high-frequency magnetic fields.

17 is a gate modulation circuit, and 16 is a high frequency oscillator that generates a high frequency (no. RF power amplifier 1 generates a high frequency pulse.
8 through R' is applied to the transmitter coil 4.

19 is a preamplifier that amplifies the NMR signal received from the detection coil 5; 20 is a phase detection circuit that detects the phase of the NMR signal by referring to the output signal of the high frequency oscillator; and 21 is a preamplifier that amplifies the NMR signal received from the detection coil 5; A waveform memory that stores waveform signals and includes a Δ7/D transformer.

11 is a computer that receives the signal from the waveform memory 21 and performs predetermined signal processing to obtain a tomographic image; 12 is a computer that receives the signal from the waveform memory 21; It is a display device like a television monitor that displays the J image.

Reference numeral 30 denotes an operation console, which is connected to the computer 11 and is an input means for inputting various information necessary for the apparatus.

Next, a procedure for creating a calculation image based on such a configuration will be described.

Here, three images obtained using the IR3SE method and the SRJSE
From the fft 7 images of 4 images obtained by the method, T I
, T2, and the case where the ρ image is calculated will be explained as an example.

In addition, as shown in FIG. 2, the IR3SE method uses rR8E
This is a pulse sequence based on the SR4SE method, but it is applied three times in 180" (repeat 2 pulses) sections in one pico, so that three echo signals are received. As shown in Figure 3, the law is SR3E
It is a multi-echo method in which a 180° (2) pulse is applied four times to obtain an echo signal of 4 meters per pico.

(1) Pulse Sequence The pulse sequences shown in FIGS. 2 and 3 will be explained in more detail as follows.

Distance Ts between the 90° pulse and the center of the first echo 1=
l, center interval T5 of each echo signal after the first echo signal
2. Distance T between 180° (1) pulse and 90” pulse
d and repetition time T can be selected arbitrarily.

At these times, lX1l management is performed by the controller 13,
The time setting can be performed using the operating vehicle 30.

The 180° (1) pulse is a 180° pulse for spin anti-private use, and the 180° (2) is a 1806 pulse for spin echo.
Both are 90”-45- to reduce pulse error.
・ 270” 4-5 ・90-6 composite pulse is used.

The number of 180° pulses for each view is IR3SEl, SR
Both 4S[E methods are @ numbers.

Note that the fixed value attached to the frequency of the composite pulse represents a difference of 1 (1) from the 90° pulse for excitation, and these pulses are non-selective pulses.

The 90° excitation pulse is a selective pulse and is Gaussian modulated.

The application of such 90° pulses to 180° pulses is performed as follows. In other words, controller 1 to roller 1
3, a predetermined 90° pulse or 180° pulse signal is applied to the RF transmitting coil 4 via the power amplifier 18 through the gate modulation circuit 17 to generate an RF magnetic field to be applied to the object. .

On the other hand, the gradient magnetic field is as follows. The gradient magnetic field Gx in the X direction is a progeexi gradient, and a is 180°
This is a groove for eliminating noise outside the slice plane due to pulses.

The two-directional gradient position aiEI G z is outside the slice plane, the y-direction gradient la field G y is a warb gradient, and b is a spoiler for eliminating artifacts due to 180° pulse error. Further, C is a spoiler for removing correlation between views.

The application of each gradient magnetic field is controlled by a controller 13.

Each echo signal generated by the above pulse sequence is detected by the receiving coil 5. The spin echo signal detected by the receiving coil is stored in a waveform memory 21 via a preamplifier 191 and a phase detection circuit 20.

(2) Regarding the signal strength formula ■ The signal strength formula for the R38E method is
T (i / crush) ÷ 2 zo fup (Ti- / 1 inch Tsl /
”L+3TSZ/2Ti)-2e+P(-7h
/T + Juryos+ /Tl + Ts, 72-cho1)
12+xP (-Th/'T+, the first echo is 1o-eXp(-Ts I/T2) The second echo is 1o ・f3XD (-Ts + z'T2-TS
27'T2) The third echo is 1o ・eXI) (-Ts + /T2-2T52
/T2.

(2) The signal strength formula of the SR4SE method is IsQ C$ bet 4 (Tt /T?) [1-14Np
(-TN/TI +TRI/Tl 15 Ts, / 2
T+ ) 12mo x P 咋/Tl 10T, , /7. Doyours
z / Z million 2-2 (XP(T)-/T1ki1s1/τ
, +TS2 /ZT1) Sat Ze%F'(=Ts/T+Sat Ts + 10 ZT & ) - ε Naka(Th/1,000)]・P, the first echo is 1o-Qxp(Ts +/T2) second The echo is Jo-OXp(Ts+/T2-TS2/T2)
The third echo is 1o-exp(TSI/′T2 2T52/”T2) The fourth echo is 1o-QX[) (Ts + /T2-3TS 2
/'T2).

Here, C1 and C5124 are functions representing the influence of the slice shape, and are determined as follows.

The signal strength equation, which does not include the influence of slice shape, is expressed as “n(T1
, Ts+m>TxzP).

b) The angle at which the magnetization falls due to the 90° pulse is α.

(No. 3 intensity is 900 with one pulse sequence)
If it is composed of a pulse and one 180° pulse, then the following is true.

(Note) If a Gaussian 90゛ pulse is used, α at a point at a distance wiz from the center of the slice is a= (π/2)exp (-Z”)
, 1. (2) becomes.

C) By integrating equation (1) by 2 using equation (2), the signal strength including the influence of the slice shape can be obtained, and the following equation is obtained.

-''(3) Since the integral of equation (3) is an i!1 number of only (T+/'Tr), this value is often referred to as CA (T+/Tτ).

2) Since G and u are functions only of T+/Tr, C0 can be obtained by numerical integration within the required range of Tl/Tr, and from this value, C0 and L can be obtained as a polynomial of T+/Tr.

From the above, the signal strength formula F including the influence of slice shape
s (T; 7Ts7T+zTz, P ) is determined as the product of n and a coefficient Cod representing the influence of the slice shape.

F s (TI-1T;/Tl, T2.P )=F
n (Ti-Js汀uTz)P) Coda
(T I /' T r )Here, Co(
LL is, for example, 0.2<T, /Ty<1
0, O, CcxjJ, −8,1537E −6(TI /T
r)'=2.95086E-4(T+7'
Ta) S+ 4.27675E -3(T + %T
T>'-3,17902E-2(T+,'T
) ko + 1.29262E i (T + /
T r ) 2- 2,8554 E -1(T +
/Tt ) + 1.0557 Pulse sequence consists of one 90° pulse and an even number of 18
In the case of JJJ, which is composed of 0° pulses, if the signal strength formula that does not take into account the influence of the slice shape is Fn, the signal strength when the angle at which the magnetization falls is α° is as follows. It is possible to calculate the amount in the same way as in the case.

For example, if Gaussian 906 pulses are used, 0.
2<T+/T2 This 10,0 does not represent the influence of the slice shape, and the coefficient C<yeh is Civ, 2N −=2.4203[E −5(Tl
,'Tr)'+-5,68GI
E-4(T+/Tr)
'-3,6523E 3 (T + , 'Tr)
Co 1.0071 E -2 (Tl %Tr > 2+
3.2162 E 1 (Tl 7'Tr )+
It is 0J178.

By using the signal strength α equation that includes the influence of the slice shape determined here, systematic errors due to the slice shape can be removed.

The above is the 31 calculation when using a Gaussian 90° pulse, but even when using other 90" pulses, if you can find the angle α at which the magnetization falls due to the 90° pulse at a distance @2 from the center of the slice, It can be calculated similarly.

(3) 90° regarding systematic errors due to 90' pulse error
The pulse became a β° pulse due to RF pulse non-uniformity. In case A, the obtained signal strength can be found by performing zr integration of equation (1) or equation (4) using equation (5) in the same manner as in case (2) above.

α-β・8Xp(-Z2) ・ ・ ・
(5) If the coefficient expressing this influence is Cf, then Cod
i.

Similar to Ceveh, cβ is a function only of (T+/Tr), and its shape is determined by whether the number of 180° pulses is even or odd.

I R3S E ToS R4S E 17) 180”
The number of pulses (both sides are even numbers, so if Tr is made equal, I
The Cf of R3SE and SR4SE match. Therefore, the influence of the 9° pulse error is multiplied by Cf for all images, and the influence on T 1 + T 2 *ρ measurement is only multiplied by Cf on the ρ value.

From the above, if IR3SE and SR4SE(1)Tr are made equal, the systematic error due to the 90° pulse error to the s Tl *72 value can be removed.

Other effects of making Tr equal are as follows. Coefficient C (V4A and I
Since R3SE and SR4SE match, the systematic error due to the slice shape is only the ρ value multiplied by CfVQ. Therefore, ρ1 direct is m3! If there is no need to obtain a detailed signal strength formula, a normal signal strength formula that does not include the influence of the slice shape may be used. It is also effective when the slice shape is unknown.

(4) Optimization of scan parameters T1 of human body. T
2. The scan parameters that give the best evaluation l1lli function of the ρS1 numb image are calculated using the law of error propagation. The signal strength formula (2) above is used as the signal strength formula.

Here, the theoretical formula for signal strength and the required Tl, T2,
A method for determining scan parameters that optimize the evaluation function of a sieve image from the ρ value will be explained. Here 5f
f' The sum of standard deviations normalized as a fi function, i.e., σ7. / T I→-72/T2+σρ7/ρ However, Shun 1, 72. σ is Tl, T2. Use the standard deviation of ρ.

PI/PS scanned the 7 images,...
71P7, the signal strength formula is F+ , F2 , , , , F?
Then, TI+T calculated from the image by the least squares method
Direct covariance matrix VTi Tz P of elρ is VT+Tz
P= (△7 V, 2. A)-Madashi, Vn
v is the covariance matrix of the original image, and the variance σ2 of the original image is
Let n be the average directivity and Ta be the sampling time, σ2”
n −' Ta −' Ta Lisah, and Δ are as follows.

Therefore, the variance of the value of T I + 72 *ρ can be found as the diagonal element of V square 2p.

From the above, the evaluation function of the calculated image is W t E /...
No bribe NO TO-+, Go'(u/”'/τ'IIL'?'
4℃lz'hz)'''/ It is found as a function of K7.

Based on this principle, appropriate scan parameters are determined by the following procedure.

■Define the theoretical formula for signal strength.

■Theoretical formula and the range of T+, T2, and ρ that you want to measure,
From the variance of the original image, the evaluation function of the calculated image is determined as a function of the skin parameter.

■In the above ■, the evaluation 1iIIIi function of δi calculation iia @ was found as a multivariable function of the scan parameter, so the scan parameter that gives the best evaluation PA number is determined by a method (such as the simplex method) that finds the extreme value of the multivariable rlQ number. demand.

An example of the scan parameters obtained in this manner is as follows. Note that the Tr in the IR3SE method and the SR4SE method are made equal.

■When scanning with a total scan time of 600 seconds, in the lRa5E method, Tr = 2.3G seconds Td = 0.579 seconds, , = 0.02 seconds Ts 2 = 0.02 seconds Average number of times (AVE) - 1 In the SRJSE method, Tr = 2.36 seconds Ts, -0,02 seconds Ts 2 = -0,079 seconds Average number of times (AVEE>=1 ■Also, if the total scan time is 300 seconds and scans In the IR3SE method, Tr-1, 18 seconds Td = 0.414 seconds Ts, = 0.02 seconds Ts 2 = 0.02 seconds Averager a (AVE) = 1 In the SRJSE method, Ty = t, 18 seconds Ts + = 0 .02 seconds 52 = 0.074 seconds averager a(AVE) = 1 (S) Imaging is performed using the ``1!'' parameter in (4) above.

That is, in the IR3SE method, scanning is performed with the above parameters over different predetermined views (the number of views is, for example, 127) of the warp gradient (l G y in the gradient magnetic field J), and the echo signal is measured. The measured echo signals are divided into first, second, and third echo signal groups, and each is re-formed (thinned) into two-dimensional images using the computer 11 to obtain three original images.

Next, 5) In the 14SE method, the warb gradient (gradient magnetic field G
y) different predetermined views (the number of views is, for example, 1
27) with the above parameters, and similarly measure the echo signal and store it in the waveform memory 21. 19
The first, second, ! 53 and the fourth echo signal group, and similarly reconstructed into two-dimensional images using the computer 11 to obtain four original images (9°9°(6) 7 Using the original images, TI, T2, and ρ images (planned images) are obtained by the nonlinear least squares method (calculated by the computer 11).

In the above method, gradient magnetic fields Gx, Gy, G
The relationship between 2 and slice, brochure, and warp is f
'E will.

Through the above procedure, the divided images of T+ and T2+ρ can be obtained accurately and simultaneously.

Figures 4 to 6 show the results of an experiment using a phantom in which an aqueous NLC12 solution and heavy water were appropriately mixed. Value determined by analytical method (measured T+ r T
2 * ρ) and [(calcula
tedT+, ding2. ρ) agreed within the measurement error, demonstrating the high precision of 51 calculations.

(Other Embodiments) J3. The present invention is not limited to the above embodiments, but can be implemented as follows.

(1) As a pulse sequence, in the embodiment, the interval from the 90'' pulse to the first echo signal is TS1, and the interval of each echo signal after the first echo is received is TS2. The interval to the first echo signal and the interval from the first echo signal to the second echo signal are respectively T.
S l , the interval from the second echo (g to the third echo (Δ11) and the interval from the third echo (g to the fourth echo signal) is T52, and the interval from the (2n-2)th echo signal to the subsequent (2n-2)th echo signal < 2n-1) Interval until echo j and the (
2n-1>L from the echo signal to the 20th echo signal
! Let li (where n≧3) be Tsn. In this case 18
0° pulse error can be removed by even echoes.

Furthermore, the interval between each echo signal may be completely arbitrary.

(2) Gaussian modulated 90° pulse, composite 1
The 80' pulse is not limited to the actual flow example, and other 90° pulses and 180° pulses may be used, and calculated images can be obtained in the same way.

(3) In the example, 1q of seven images were obtained from eye movements by the IRGSE method and the SR4SE method, and these were later TI.

T2. Although we have shown the case where each calculation image of ρ is obtained, without being limited to this, in general, (n - + - m) images are obtained from the images obtained by the IRnSE method and the SRmSE method. Each t1 calculation image of +T2 +ρ may be obtained.

<Effects of the Invention> As explained above, the present invention has the following effects.

■Accurate values can be obtained because no approximation formulas are used.

(2) By using scan parameters that minimize the variance of the calculated image, the best calculated image can be found in a predetermined image time.

■The combination of IRnSE method and SRmSE method both 180
By setting the number of pulses to an even number, the standard deviation of the calculated image can be reduced. FIG. 7 shows the normalized standard deviation kl B] at representative points of T1 and T2 values of the human body for various combinations of pulse sequences. As is clear from this graph, the IRnSE method,
When the number of 18-cis pulses is even in both SRmStE methods, search t1! It can be seen that the difference is small. In other words, fRJsE
IR38E method, SRJ than the case of SRJSE method.
It turns out that the SE method is better.

■Since multi-echo is used, the number of strokes a used for calculations can be increased without increasing the interval between leaps and bounds. As a result, high quality images can be obtained in a short imaging time.

As seen in Fig. 7, the X mark in the case of the combination of the R35E method and the SRJSE method is 1Ijll'j1 hour, which is half the time in the sunspot, but the combination of the SR8E method and the SR23E method and the fR3E method The sum of normalized standard deviations is smaller than that of the combination of
It can be seen that the calculated image is multiplied by 1q.

- By using multi-echo, dispersion can be reduced over a wide range of TI and T2. Figure 8 is TI
, is a diagram showing the normalized sum of (7 standard deviations) for the T2 value.

(2) By making Tr equal to the even/odd number of 180° pulses in the IRnSE method and the SRmSE method, systematic errors to T1 and TzllfI due to 90' pulse errors can be removed.

(2) Systematic errors due to slice shape can be removed by using a signal strength equation that includes the influence of slice shape.

■Composite pulse 9〇- to 180° (2) pulse
By using 云270ν ・9026 and setting the interval between each echo Shintan so that two adjacent echoes are equal, the 180° pulse error can be removed with an even number of echoes. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main part of an embodiment of the NMRm imaging stomach according to the present invention, FIG. 2 is a diagram showing the pulse sequence of the rR3S E method, and FIG. 3 is a diagram showing the pulse sequence of the SR48E method. The figures shown in FIGS. 4 to 6 are T I + 7
2 * A diagram comparing the value of ρ determined by the analytical method and the value determined from the Ji Tan images according to the present invention,
Fig. 7 is a diagram showing the sum of normalized standard deviations at representative points of D + and T2 Ill of the human body for various pulse sequence combinations, and Fig. 8 shows T1 and T2 values for various pulse sequence combinations. 9 to 11 are diagrams showing an example of a conventional pulse sequence. 7... Magnet 1~assembly, 2... Main magnetic field coil, 3... Gradient magnetic field coil, 4... R "transmission coil, 5... Receiver (ffl coil, 11... Computer, 12...Display device, 13...Controller, 14
... Gradient device 1 JQ control υ■ circuit, 15 ... Static magnetic field control circuit, 16 ... High frequency oscillator, 17 ... Gate modulation circuit, 18 ... Power amplifier, 1 ... Preamplifier, 20... Phase detection circuit, 21... Waveform memory, 3
0...Operation console. CCLkttl (lted T2 (ms) sacrifice) 2 瀘 宕 宕つり decrepit

To K Ward C (l1
2cul(lted Tz (ms＞Fig. 7 measuredβ Fig. 7 Σ(Mu△+Go) 10,000 Tz f

Claims (1)

[Claims] 1) A nuclear magnetic resonance imaging device that applies high-frequency pulses and a magnetic field to an object to generate a nuclear magnetic resonance signal, and uses this signal to obtain an image of the tissue of the object, It is characterized by comprising a control/calculation means having the following functions (a) to (c) for obtaining a calculated image regarding at least one of relaxation time (T_1, T_2) or proton density (ρ). Nuclear magnetic resonance imaging device. Note (a) IRnSE method (n is an integer) and SRm that provide the best evaluation function for T_1, T_2, and ρ calculation images in the range of interest
Find scan parameters for the SE method (m is an integer). (b) Imaging is performed using the scan parameters determined in (a) using a pulse sequence using the IRnSE method and the SRmSE method. (c) Calculate T_1, T_2, and ρ images from (n+m) images obtained from imaging using the IRnSE method and the SRmSE method. 2) The control/calculation means uses the IRnSE method and the SRmS method.
2. The nuclear magnetic resonance imaging apparatus according to claim 1, wherein the 180° pulse is applied an even number of times in the pulse sequence in both the E method and the E method. 3) The control/calculation means uses the IRnSE method and the SRmS method.
Nuclear magnetic resonance according to claim 1, characterized in that both E methods include a function of controlling the number of 180° pulses in the pulse sequence to be even or odd, and to make both repetition times T_r equal. Imaging device. 4) The control/calculation means uses the IR3SE method and the SR4SE method.
2. The nuclear magnetic resonance imaging apparatus according to claim 1, wherein the nuclear magnetic resonance imaging apparatus is configured to perform imaging according to the method to obtain seven images, and calculate T_1, T_2, and ρ images from these seven images. 5) The control/calculation means uses the IR3SE method and the SR4SE method.
According to the first aspect of the present invention, the method is configured such that seven images are obtained by imaging according to the method, T_1, T_2, and ρ images are calculated from these seven images, and the following values are used as scan parameters. The nuclear magnetic resonance imaging device described in Section 1. (1) In the IR3SE method, a predetermined number of views are scanned with T_r=2.36 seconds T_d=0.58 seconds T_s_1=0.02 seconds T_s_2=0.02 seconds. (2) In the SR4SE method, a predetermined number of views are scanned with T_r=2.36 seconds T_s_1=0.02 seconds T_s_2=0.079 seconds. (3) The seven images to be obtained are the IR3SE method and the SR4SE method.
Average the modulus in a 1:1 ratio. 6) The control/programming means is based on the IR3SE method and the SR4SE method.
According to the first aspect of the present invention, the method is configured such that seven images are obtained by imaging according to the method, T_1, T_2, and ρ images are calculated from these seven images, and the following values are used as scan parameters. The nuclear magnetic resonance imaging device described in Section 1. (1) In the IR3SE method, a predetermined number of views are scanned with T_r=1.18 seconds T_d=0.41 seconds T_s_1=0.02 seconds T_s_2=0.02 seconds. (2) In the SR4SE method, a predetermined number of views are scanned with T_r=1.18 seconds T_s_1=0.02 seconds T_s_2=0.074 seconds. (3) The seven images to be obtained are the IR3SE method and the SR4SE method.
Average the modulus in a 1:1 ratio.