JPH06121791A - X-ray determination device and x-ray determination method - Google Patents

Abstract

PURPOSE:To accurately carry out the determination of a body consisting of at least three substances by irradiating the body with the X-rays having at least three energy bands while maintaining sufficient number of photons. CONSTITUTION:A X-ray determination device is provided with a tube-voltage changeover device 12 of a X-ray tube 11, a K-absorption edge filter 13, and a CdTe semiconductor X-ray detector 14, and two-dimensional transmission information is obtained by synchronously moving these devices. The fan beam X-rays 21 emitted from the X-ray tube 11 are separated into two energy bands by the K-absorption edge filter 13. Further, by changing over the tube voltage for each line, X-rays of different spectra are emitted from the X-ray tube 11, and they are separated by the K-absorption edge filter 13 to obtain at least another one different energy band. The amounts of transmission of the X-rays of these three or more energy bands are measured by the CdTe semiconductor X-ray detector 14, and by using these measured transmission amounts, calculation is carried out by means of a calculation unit 17, so that the determination of at least three substances in a subject 15 is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray quantification device and an X-ray quantification method for quantifying a substance by X-rays, and in particular, a body component analysis device for quantifying bone mineral content, fat mass and bone density of human body. And a method for analyzing body composition.

[0002]

2. Description of the Related Art Conventionally, as a method for quantifying a specific substance contained in an object, an energy difference method utilizing X-ray transmission intensity consisting of a plurality of energy bands has been used.

FIG. 6 is a sectional view of an object containing two substances to be measured. In FIG. 6, when the object 1 to be measured is composed of two substances A and C,
A specific substance is quantified as follows.

First, since the energy difference method is used, 2
The X-ray 2 having the energies E1 and E2 of various kinds is applied to the object 1 to be measured, and the energies E1 and E2 at each position
The transmission intensities I ₁ and I ₂ are measured.

Intensities I _x1 and I _x2 of the two kinds of X-rays 2 having energies E1 and E2 after passing through the object at the position X shown in FIG.
Is represented by (Equation 1) and (Equation 2).

(Expression 1) I _x1 = I ₀₁ exp (−μ _A1 ρ _A T _A −μ _C1 ρ _C T _C ')

(Formula 2) I _x2 = I ₀₂ exp (−μ _A2 ρ _A T _A −μ _C2 ρ _C T _C ′) Further, the intensity I _Y1 , I after transmission at the position Y shown in FIG.
_Y2 is represented by ( _Equation 3) and (Equation 4).

(Equation 3) I _Y1 = I ₀₁ exp (-μ _C1 ρ _C T _C )

(Formula 4) I _Y2 = I ₀₂ exp (−μ _C2 ρ _C T _C ) where μ _A1 , μ _A2 , μ _C1 , and μ _C2 are mass attenuation coefficients of the substances A and C at energies E1 and E2, I ₀₁ and I ₀₂ are X-ray intensities of energies E1 and E2 with which the substance is irradiated,
ρ _A and ρ _C represent the densities of the substances A and C, and T _A and T _C represent the thicknesses of the substances A and C. T _C 'is the substance C at position X
The thickness is (Equation 5).

(Equation 5) The density of the substance A is obtained based on the energy difference calculation formula (Equation 6) for eliminating T _C '= T _C -T _A T _C.

(Equation 6) S = R _C * ln (I ₂ / I ₀₂ ) -ln (I ₁ / I ₀₁ ) where R _C = μ _{C 1} / μ _{C 2} .

At the position X, the transmission intensity is expressed by (Equation 1) and (Equation 2), so the calculation result of (Equation 6) is as shown in (Equation 7).

(Equation 7) S = _RC · ln (I _a2 / I ₀₂ ) -ln (I _a1 / I ₀₁ ) = (μ _A1 −μ _A2 R _C ) ρ _A T _A As a result, the unit of substance A The density m _A per area is obtained as (Equation 8).

(Equation 8) Further, at the position Y, the transmission intensity is represented by (Equation 3) and (Equation 4), so the calculation result of S in (Equation 6) is 0. Therefore, the presence of the substance A at each position of the object can be identified by the difference calculation of (Equation 6), and the density can be quantified.
Further, the calculation result can be displayed as an image to obtain an image proportional to the density of the substance A.

An X-ray quantification device based on this method detects an X-ray tube as an X-ray irradiation device, a K absorption edge filter for separating an X-ray spectrum into two energy bands, and an X-ray transmitted through an object. It is composed of an X-ray detector.
These are mutually supported by a support and can be moved in synchronization by a moving device, and the transmission intensity in a two-dimensional region can be measured. The K absorption edge filter is made of a metal such as gadolinium or erbium or a combination thereof, and when the X-ray emitted from the X-ray tube is transmitted,
It is separated into two high and low energy bands. The transmission intensity of the X-ray in the two energy bands of the object is measured, and a specific substance in the object, for example, the amount of bone mineral in the human body is quantified by the above-mentioned energy difference formula.

As another device, an X-ray tube as an X-ray irradiation device, a voltage control device for switching the tube voltage of the X-ray tube, a reference substance having the same X-ray attenuation coefficient as the substance in the subject, There is a device including an apparatus for selecting a reference substance and an X-ray detector for detecting X-rays transmitted through an object. These are mutually supported by a support and can be moved in synchronization by a moving device, and the transmission intensity in a two-dimensional region can be measured. In this apparatus, in order to irradiate X-rays having different energies, the tube voltage is temporally switched to sequentially generate X-rays having spectra as shown in a and b of FIG. 7a shows a tube voltage of 70 kV,
b is a spectrum of a tube voltage of 140 kV, and effective energies thereof are 40 keV and 100 keV, respectively. The X-ray transmission intensities of these two spectra are respectively measured and quantified by the method described above. However, in the case of this method, X
Since the spectral width of the line spectrum is wide and sufficient quantitative accuracy cannot be obtained when treated as a monochromatic X-ray, it is necessary to perform calibration using a reference substance. When quantifying bone mineral in the human body, a substance having an attenuation coefficient close to that of bone mineral and soft tissue is used as a reference substance.

Next, when the object to be measured is composed of three kinds of substances and the X-rays are overlapped so as to pass through all the three kinds of substances, X-rays having three energy bands are used. .

Here, a case of measuring an object 3 composed of three substances A, B and C shown in FIG. 8 will be described. Since the energy difference method is used, X-rays 4 having three types of energy E1, E2, and E3 are irradiated. Intensities I _aa1 of the three kinds of X-rays 4 of these energies E1, E2 and E3 after passing through the object at the position aa shown in FIG.
I _{aa 2} and I _aa3 are represented by ( _Equation 9), ( _Equation 10), and (Equation 11), respectively.

( _Equation 9) I _aa1 = I ₀₁ exp (−μ _A1 ρ _A T _A −μ _B1 ρ _B T _B −μ _C1 ρ _C T _C ′)

( _Formula 10) I _aa2 = I ₀₂ exp (−μ _A2 ρ _A T _A −μ _B2 ρ _B T _B −μ _C2 ρ _C T _C ′)

( _Equation 11) I _aa3 = I ₀₃ exp (−μ _A3 ρ _A T _A −μ _B3 ρ _B T _B −μ _C3 ρ _C T _C ′) Further, the intensity after transmission at the position cc shown in FIG. I _cc1, I _cc2, I _cc3, respectively (equation 12), (Equation 13) is expressed by equation (14).

(Equation 12) I _CC1 = I ₀₁ exp (−μ _C1 ρ _C T _C )

(Equation 13) I _CC2 = I ₀₂ exp (−μ _C2 ρ _C T _C )

(Equation 14) I _CC3 = I ₀₃ exp (−μ _C3 ρ _C T _C ) Similarly, the intensity I after transmission at the position bb shown in FIG.
_bb1 , I _bb2 , and I _bb3 are ( _Equation 15) and ( _Equation 1), respectively.
6) and (Expression 17).

( _Equation 15) I _bb1 = I ₀₁ exp (−μ _B1 ρ _B T _B −μ _C1 ρ _C T _C ″)

( _Equation 16) I _bb2 = I ₀₂ exp (−μ _B2 ρ _B T _B −μ _C2 ρ _C T _C ″)

( _Equation 17) I _bb3 = I ₀₃ exp (-μ _B3 ρ _B T _B −μ _C3 ρ _C T _C ″) where μ _A1 , μ _A2 , μ _A3 , μ _B1 , μ _B2 , μ _B3 , μ _C1 ,
μ _C2 and μ _C3 are the energies E1 and E2 of substances A, B and C,
Mass attenuation coefficient at E3, I ₀₁ , I ₀₂ , I ₀₃ energy X-ray intensity of energy E1, E2, E3 irradiated to the substance, ρ
_A , ρ _B and ρ _C are the densities of substance A, substance B and substance C,
T _A , T _B and T _C represent the thicknesses of the substances A, B and C.
T _C 'and T _C "are (Equation 18) and (Equation 19), respectively.

[0028] (number _{18) T C '= T C} -T A -T B

(Formula 19) T _C ″ = T _C −T _B (Formula 9) to (Formula 11) The logarithm of both sides is taken and expressed as the following formula.

( _Equation 20) L _aa1 = −μ _A1 ρ _A T _A −μ _B1 ρ _B T _B −μ _C1 ρ _C T _C '

( _Formula 21) L _aa2 = −μ _A2 ρ _A T _A −μ _B2 ρ _B T _B −μ _C2 ρ _C T _C '

(Equation 22) L_aa3= -Μ_A3ρ_AT_A-Μ_B3ρ_BT_B-Μ_C3ρ_CT_C'However, L_aa1= Ln (I_aa1/ I₀), L_aa2= Ln
(I_aa2/ I₀), L _aa3= Ln (I_aa3/ I₀)
It

From these three equations, when T _B and T _C ′ are erased and T _A is solved, the equation (23) is obtained.

(Equation 23) m _A = ρ _A T _A = D _A / D

(Equation 24) m _B = ρ _B T _B = D _B / D

(Equation 25) m _C = ρ _C T _C = D _C / D where D _A , D _B , D _C and D are

(Equation 26) D _A = L ₁ μ _B2 μ _C3 + μ _B1 μ _C2 L ₃ + μ _C1 L ₂ μ _C3 −μ _C1 μ _B2 L ₃ −L ₁ μ _C2 μ _B3 −μ _B1 L ₂ μ _C3

(Equation 27) D _B = μ _A1 L ₂ μ _C3 + L ₁ μ _C2 μ _A3 + μ _C1 μ _A2 L ₃ −μ _C1 L ₂ μ _A3 −μ A ₁ μ _C2 L ₃ −L ₁ μ _A2 μ _C3

[0039] (number _{28) D C = μ A1 μ} B2 L 3 + μ B1 L 2 μ A3 + L 1 μ A2 μ C3 -L 1 μ B2 μ A3 + μ A1 L 2 μ B3 + μ B1 μ A2 L 3

(Equation 29) D = −μ _A1 μ _B2 μ _C3 −μ _B1 μ _C2 μ _A3 −μ _C1 μ _A2 μ _C3 + μ _C1 μ _B2 μ _A3 + μ _A1 μ _C2 μ _B3 + μ _B1 μ _A2 μ _C3 .

At the positions cc and bb in FIG. 8, the substance A is not included in the X-ray transmission path, and the X-ray transmission intensity is (Equation 12)-
It is represented by (Equation 17). Logarithmic ratio of transmission intensity (Equation 23)
Then, m _A becomes 0 at the positions cc and bb.

Similarly, the densities m _B and m _c of the substance B and the substance C per unit area are also obtained from (Equation 24) to (Equation 25). If this is applied to the human body, the basic components of bone, fat and muscle can be quantified.

In the case of quantifying a substance by using X-ray transmission information, it is necessary to irradiate X-rays having energy bands as many as the number of substances contained in the target object.
To perform a quantitative analysis of an object composed of 3 types of substances 3
An X-ray irradiation device having two energy bands is required.

[0044]

However, it is difficult to irradiate X-rays having three energy bands with the above conventional structure.

That is, using the K-edge filter, 3
To separate into two energy bands, two elements with different K absorption edges are used in superposition, and each element is thickened in order to make the boundaries of the energy bands clear, and two energy bands are obtained. Compared with the case, the X-ray dose to be transmitted is extremely small. Therefore, sufficient quantitative accuracy cannot be obtained.

In addition, in the method of switching the X-ray tube voltage, if switching is performed three times, it takes too much time. Therefore, when a human body is measured, the influence of body movement or the like becomes large. Further, three kinds of reference substances are also required, which makes the calibration of data in calculation too complicated.

As described above, there has been a problem that it is impossible to quantify an object composed of three or more substances, for example, quantify bone in a human body without the influence of fat. The present invention solves the above-mentioned conventional problems, and an X-ray quantification apparatus and an X-ray quantification method capable of irradiating X-rays having three energy bands easily and with a sufficient number of photons to obtain accuracy. The purpose is to provide.

[0048]

In order to solve the above problems, the X-ray quantification device of the present invention irradiates X-rays and
X-ray irradiating means capable of switching the energy spectrum of X-rays, a filter for separating the spectrum of X-rays radiated from the X-ray irradiating means into a plurality of energy bands,
The subject is irradiated with X-rays of a plurality of energy bands separated by the filter, and X-ray detection means for detecting the X-ray transmission intensity of the subject for each energy band; and X detected by the X-ray detection means. And a calculation means for calculating quantitatively the substance contained in the subject by using the line transmission intensity.

The X-ray irradiating means of the X-ray quantification device of the present invention comprises an X-ray tube for irradiating X-rays and a switching device for switching the tube voltage of the X-ray tube to switch the X-ray energy spectrum. The filter is composed of a K absorption edge filter, and the X-ray detecting means is composed of a CdTe semiconductor X-ray detector.

Further, in the X-ray quantification method of the present invention, the spectrum of the X-rays emitted from the X-ray irradiating means is separated into a plurality of energy bands by a filter, and the spectrum of the X-rays emitted from the X-ray irradiating device. By changing the energy bands separated by the filter to generate X-rays of three or more energy bands, measure the intensity of each energy band transmitted through the subject, and use the measured intensity. The calculation is performed to quantify a plurality of substances in the subject.

[0051]

With the above structure, the X-rays emitted from the X-ray tube are separated into a plurality of energy bands by the filter, and the X-ray spectrum emitted from the X-ray tube is switched to obtain three or more energy bands. It is possible to directly irradiate the subject with X, and X in each energy band
The X-ray detector detects the X-ray transmission intensity, and the detection intensity is calculated to quantify multiple substances in the subject. Therefore, the transmission of each energy band after passing through the K absorption edge filter is performed. The number of photons is large enough, and X
The number of times the tube voltage is switched to change the spectrum of X-rays emitted from the X-ray tube can be reduced, and three or more energy bands can be directly irradiated to the subject in a short time, affecting the movement of the subject such as the human body. The accurate quantification is performed without being performed.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows X in one embodiment of the present invention.
It is a block diagram of a linear quantification device. In FIG. 1, the X-ray irradiation device comprises an X-ray tube 11 and a tube voltage switching device 12, the X-ray tube 11 irradiates X-rays, and the tube voltage switching device 12 is an X-ray tube 11
The tube voltage is switched in order to change the spectrum of the X-ray generated from the. The K absorption edge filter 13 separates the spectrum of the X-ray emitted from the X-ray tube 11 into two energy bands. The CdTe semiconductor X-ray detector 14 measures the X-ray intensity transmitted through the subject 15 in each energy band. The arithmetic unit 17 to which the X-ray detector 14 is connected via the control unit 16 is connected to the display unit 18, and the X-ray detector
X-ray detector is calculated by using transmission information from 14
The X-ray transmission intensity detected in 14 is calculated to quantitatively calculate the substance contained in the object 15, and the calculation result is displayed.
Show on 18. Further, the control device 16 is a tube voltage switching device 1
2. Connected to the X-ray detector 14 and the moving device 19, switching the tube voltage and controlling the X-ray detector 14 and the moving device 19. The support 20 includes an X-ray tube 11, a K absorption edge filter 13 and an X-ray detector.
The moving device 19 supports 14 and moves them in synchronization.

Here, gadolinium was used as the K absorption edge filter 13. Gadolinium has a K absorption edge at 50.2 keV. FIG. 2 shows a spectrum after the fan beam X-rays 21 emitted from the X-ray tube 11 are transmitted through the K absorption edge filter 13 with the X-ray tube voltage set to 80 kV. In FIG. 2, 50
It is separated into two energy bands L1 and H1 at the boundary of keV. The effective energy of L1 is 45 keV and the effective energy of H1 is 65 keV.

Further, the tube voltage switching device 12 allows the X-ray tube
When the tube voltage of 11 is changed from 80 kV to 120 kV, the X-ray spectrum transmitted through the same K absorption edge filter 13 becomes as shown in FIG. In FIG. 3, as in the case of FIG. 2, it is separated into two energy bands L2 and H2 at the boundary of 50 keV. The effective energy of L2 is 45 keV and the effective energy of H2 is 85 keV.

In any of the above energy bands,
The thickness of the K absorption edge filter 13 is equal to the number of photons when obtaining two energy bands. Therefore, the tube voltage
By switching between 80 kV and 120 kV, it is possible to irradiate the subject 15 with X-rays having three energy bands of effective energy of 45 kV, 65 keV, and 85 keV.

In this embodiment, a multi-channel CdTe semiconductor X-ray detector 14 which operates by the photon counting method is used as the X-ray detector. FIG. 4 is a multi-channel type C in FIG.
3 is a block diagram showing the configuration of one channel of the dTe semiconductor X-ray detector 14. FIG. In FIG. 4, the fan beam X
A CdTe detector 22, which converts the X-ray photons on line 21 into electrical signal pulses, is connected to an amplifier 23 and outputs a pulse height pulse proportional to the input X-ray photon energy. The pulse wave height discriminators 24 and 25 connected to the amplifier 23 are each composed of a comparator and output a pulse when a pulse having a wave height value larger than the comparison voltage is input. This pulse wave height discriminator
A counter 26 to which 24 is connected and a pulse wave height discriminator 25
The counter 27 to which is connected is a pulse wave height discriminator 24, 25.
Count the number of pulses from each.

With the above structure, first, the X-ray photons of the fan-beam X-ray 21 that has passed through the subject 15 are detected by the CdTe detector.
22 When further input to the amplifier 23, a pulse having a wave height proportional to the energy of the X-ray photon is output from the amplifier 23. Then, among the output pulses from the amplifier 23, the number of pulses having a peak value higher than the comparison voltage set in each of the pulse height discriminators 24 and 25 is counted by the counters 26 and 27, respectively.

Here, in order to measure the transmission intensity of the X-ray having the energy band shown in FIGS. 2 and 3 to the object 15, the comparison voltage of one pulse height discriminator 24 is determined by the noise component and the X-ray. Set the voltage that becomes the boundary of the signal pulse and set the comparison voltage of the other pulse height discriminator 25 to 50 ke.
The voltage is set to the pulse wave height corresponding to V. Counter 26
Then, the total number of X-ray photons absorbed in the CdTe detector 22 is counted as the number of pulses. In counter 27, 50
X-ray photons with energies above keV are counted as the number of pulses. Therefore, by switching the tube voltage of the X-ray tube 11 by the tube voltage switching device 12 to switch the X-ray energy spectrum, the X-ray photons of the effective energies H1 and H2 are measured by the counter 27, respectively, and the effective energies L1 and L2 are measured. X-ray photons are obtained by subtracting the value counted by the counter 27 from the value counted by the counter 25. As described above, the X-ray transmission intensities of the three energy bands can be counted as the number of photons. The multi-channel CdTe semiconductor X-ray detector 14 of this embodiment is
It consists of 64 channels, and the above measurements are performed simultaneously on 64 channels.

Next, using this apparatus, body components in the human body were analyzed. As shown in the cross-sectional view of the human body in FIG.
28 was composed of 29 bones, 30 fats, and 31 muscles, and the distribution of each amount was measured.

That is, the X-ray tube 11,
While the K absorption edge filter 13 and the X-ray detector 14 were synchronously moved in the line direction of the arrow R in FIG. 1, the number of X-ray photons after passing through the human body 28 as the subject 15 was measured over 75 lines. With the tube voltage switching device 12, the tube voltage of the X-ray tube 11 is
Each line was switched to 80 kV and 120 kV, and the intensities after the X-rays in the three energy bands transmitted through the human body 28 were measured by the X-ray detector 14 to obtain two-dimensional transmission information. These are controlled by the control device 16.

According to the value measured by this method, (Equation 23)
From (Equation 25), the attenuation coefficients μ _A , μ _B , and μ _C are associated with the attenuation coefficients of the bone 29, fat 30, and muscle 31 to calculate the bone in each part of the human body 28 shown in FIG. We were able to determine the amount of 29, fat 30, muscle 31. Since the number of X-ray photons irradiated to the human body 28 as the subject 15 is sufficiently large, high measurement accuracy can be obtained.

Therefore, the X-ray tube 11, the tube voltage switching device 12 of the X-ray tube 11, the K absorption edge filter 13 and the CdTe.
The semiconductor X-ray detector 14 is synchronously moved to obtain two-dimensional transmission information. The fan beam X-ray 21 emitted from the X-ray tube 11 is separated into two energy bands by the K absorption edge filter 13. Also, by switching the tube voltage for each line, X-rays of different spectra can be emitted from the X-ray tube 11 and separated by the K absorption edge filter 13 to obtain at least one different energy band. The transmission amount of X-rays in these three or more energy bands is Cd.
The Te semiconductor X-ray detector 14 is used for the measurement, and the calculated amount of transmitted light is used for the calculation by the calculation device 17 to obtain 3
One or more substances can be quantified. This makes 3
Irradiate the subject 15 with X-rays of three or more energy bands in an extremely short time while maintaining a sufficient number of photons, and measure the transmitted intensity of each of the objects composed of three or more substances. The substance can be quantified with high accuracy without being affected by the movement of the subject 15.

In this example, gadolinium was used as the K absorption edge, but the invention is not limited to this, and a material having a K absorption edge that gives an energy band suitable for the substance to be measured. Can be used. For example, even if gadolinium and erbium are combined, they can be separated into two energy bands at the boundary of 50 keV. Moreover, when energy separation is performed at 40 keV, cerium or the like can be used.

The X-ray tube voltage is also 80 kV and 12 in this embodiment.
It is not limited to 0 kV, and it can be selected together with the K absorption edge so that an energy band suitable for the substance to be measured can be obtained.

Further, the X-ray detector 14 is a multi-channel type C
Not limited to the dTe semiconductor, a silicon X-ray detector, a mercury iodide detector, a scintillation detector such as sodium iodide, or the like can be used.

Further, the switching of the tube voltage of the X-ray tube 11 is not limited to the method of this embodiment. That is, instead of switching for each line, the measurement area may be scanned with the same tube voltage, and then the tube voltage may be switched and scanned again. Alternatively, only the specific region of interest may be scanned with different tube voltages.

Furthermore, in the present embodiment, the analysis of body components in the human body 28 has been described, but the present invention is not limited to this, and it is also applicable to industrial nondestructive inspection such as inspection of printed boards and mounting boards and analysis of metal components. Can be used.

[0068]

As described above, according to the present invention, the X-ray spectrum radiated from the X-ray tube is switched, the effective energy of the energy band after energy separation by the filter is changed, and three or more energy bands are generated. By generating and irradiating the subject with the transmitted X-ray dose, the number of X-ray photons sufficient to obtain sufficient quantitative accuracy is maintained, and the movement of the subject such as the human body is not affected for a short time. Can easily quantify three or more substances.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an X-ray quantification device according to an embodiment of the present invention.

2 is an X-ray spectrum diagram after passing through a K absorption edge filter 13 with the tube voltage of the X-ray tube 11 in FIG. 1 set to 80 kV.

FIG. 3 shows the X-ray tube 11 of FIG. 1 with a tube voltage of 120 kV and K
X-ray spectrum diagram after passing through absorption edge filter 13

4 is a block diagram showing the configuration of one channel of the multi-channel type CdTe semiconductor X-ray detector 14 in FIG.

FIG. 5 is a transverse sectional view of a human body as a subject.

FIG. 6 is a sectional view of an object including two substances to be measured.

FIG. 7 is an X-ray spectrum diagram of a conventional X-ray quantification device.

FIG. 8 is a sectional view of an object including three substances to be measured.

[Explanation of symbols]

 11 X-ray tube 12 Tube voltage switching device 13 K absorption edge filter 14 Multi-channel type CdTe semiconductor X-ray detector 15 Object 16 Control device 17 Computing device 21 Fan beam X-ray 22 CdTe detector 24, 25 Pulse wave height discriminator 26 ， 27 Counter 28 Human body 29 Bone 30 Muscle 31 Fat

Claims (3)

[Claims] 1. An X-ray irradiating means capable of irradiating an X-ray and switching the energy spectrum of the X-ray, said X-ray irradiating means.
A filter for separating the spectrum of the X-rays emitted from the radiation irradiating means into a plurality of energy bands, and the X-rays of the plurality of energy bands separated by the filter are irradiated onto the subject, and the X-rays of the subject are separated for each energy band. X comprising an X-ray detection means for detecting the X-ray transmission intensity and an operation means for performing a quantitative calculation of a substance contained in the subject by performing an operation using the X-ray transmission intensity detected by the X-ray detection means. X-ray quantitation device. 2. The X-ray irradiating means comprises an X-ray tube for irradiating X-rays and a switching device for switching the tube voltage of the X-ray tube to switch the X-ray energy spectrum, and the filter is a K absorption edge filter. The X-ray detection means is CdT
The X-ray quantification device according to claim 1, which is composed of an e-semiconductor X-ray detector. 3. The X-ray spectrum emitted from the X-ray irradiation means is separated into a plurality of energy bands by a filter, and the spectrum of the X-ray emitted from the X-ray irradiation means is switched to be separated by the filter. The X-rays of three or more energy bands are generated by changing the energy bands to be measured, the intensity of each energy band transmitted through the subject is measured, and the measured intensity is used to calculate the intensity of the energy in the subject. An X-ray quantification method for quantifying a plurality of substances.