JPS6075036A - Multicolor x-ray ct 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 The present invention relates to a tomography apparatus for inspecting objects such as products using a computer tomography scanner.

[Technical background of the invention]

It is important to be able to inspect internal defects such as cavities and cracks in objects such as engine blocks, ceramic plates, or wood, as well as internal composition and structure, in order to maintain quality and check for defective products.

Among these, conventional methods for detecting internal defects include displaying and observing an X-ray fluoroscopic image on a TV monitor using an X-ray television system, or detecting flaws using ultrasonic waves. Although it is possible to understand the general appearance of internal defects, it is not possible to understand the composition or structure;
When logs have internal defects, it is important to accurately determine their distribution in preparation, but it has been difficult to accurately determine the distribution of internal defects in long objects.

Therefore, it is conceivable to use an X-ray computer tomography scanner (hereinafter referred to as X-ray CT) as a device that can accurately measure internal defects, composition, structure, etc.

In other words, X-ray CT consists of, for example, an X-ray source that emits fan-beam X-rays that spread in a flat fan shape, and an X-ray source that is placed opposite to this X-ray source through a subject to be measured. Using a detector with a plurality of X-ray detection elements arranged in the direction in which X-rays spread, the X-ray source and detector are sequentially rotated in the same direction centering on the subject over a range of 180 degrees to 3600 degrees, for example, in 1 degree increments. After collecting X-ray absorption data from multiple directions on the tomographic plane of the subject, a computer etc. performs image reconstruction processing to reconstruct the image of the tomographic plane. 20 depending on the composition for each position on the surface.
Since images can be reconstructed with gradation levels as high as 00, it is possible to know the state of each position on the tomographic plane in detail.

The above is said to be the 3rd generation, and it also uses an X-ray tube that generates a pencil-shaped X-ray beam.
A single detector is placed opposite the X-ray tube, and these detectors are scanned in parallel in a straight line through the subject (this is called traparse). 180 degrees to 360 degrees while repeating the operation of rotating the body by a predetermined angle around the subject (this is called rotation) and performing the trapper again.

The so-called first generation system collects X-ray absorption data of a cross-section of the object while changing the direction over a period of time. , detecting elements of about 8 channels are installed in parallel to control the spread width of this fan beam, and a traverse and rotation are repeated using a final detector, which is more advanced than the first generation. There are many methods, such as the 21st L generation, which has improved collection efficiency overnight.

By the way, the X-rays generated from the X-ray generating tube have a considerable energy range. For this purpose, inspection equipment using an X-ray generating tube, especially X-ray CTt; A phenomenon in which the X-ray spectrum of sieve energy increases relative to that of low energy)
There was a difference of %7+, and an error occurred in the +ij image formation.

The above beam... - as a method of correcting donning, it is performed during LOG conversion of the signal from the detector as preprocessing,
There are also known methods in which correction is performed as post-processing after regeneration, such as Japanese Patent Publication No. 33339/1983.

For example, in the case of an inspection target with a relatively uniform degree of beam hardening, such as the human body, the above correction works effectively, but when CT is used for industrial purposes, the target is a complex consisting of various materials. In particular, in the case of an object in which the degree of beam heart ninening differs greatly from part to part, correction is not necessary in principle with the above method.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and although the problem of beam hardening can basically be solved by using a single-energy radiation source (radioisotope, 7"), the present invention Multicolor
The present invention provides a line CT device.

[Summary of the invention]

That is, in order to achieve the above object, the present invention provides an X-ray generation means and its support means, an inspection object support means, an X-ray detection means and its support means, the X-ray generation means, the inspection object, and the X-ray detection. a scanning means for emitting X-rays from said X-ray generating means along a plurality of substantially straight paths on one or more substantially planes containing said object; means for deriving energy-specific signals indicating attenuation in each of a plurality of energy regions of X-rays; reconstruction means for reconstructing one or more cross-sectional images based on the energy-specific signals; and display means for displaying the above-mentioned inspection object as a composite cross-sectional image.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained without reference to the drawings. This apparatus shown in the embodiment is a second generation CT apparatus.

FIG. 1 is a diagram showing the configuration of this apparatus, and 1 in the figure is an X-ray tube. The X-ray tube 1 emits a relatively narrow 7 am beam, and the X-ray tube 1 and the detector array 3 are fixed opposite to the scanning frame 22. The scanning frame 22 is connected to a scanning mechanism 4 fixed to the rotating frame 9, which is movably supported by guide rails 25, 2B fixed parallel to each other on the rotating frame 9. The rotating frame 9 is rotatably supported by the fixed frame 26 and connected to a Geneva mechanism 29 fixed to the fixed frame 26. The rotating frame 9 has an opening 24 near the center of rotation, and the inspection object 2 is separated from the rotating frame 9 and supported by a support stand 27 in the opening 24 . The position of the movement of the scanning frame 22 is detected by a photocell ql fixed to the rotating frame 9 and a gratecule 30 fixed to the scanning frame 22. The scanning frame 22 and the portions fixed thereto, such as the X-ray tube 1, are configured so as not to touch the inspection object 2 during movement.

The X-ray tube J has a collimator 23 and an M-shaped X-ray beam 1.
0 into a substantially plane parallel to the plane defined by the parallel guide rails 25, 28,
The detector row 3 has a collimator 23 and the X-ray beam 10
is configured to receive. The Geneva mechanism 29, the scanning mechanism 4, and the photocell 3 are connected to a control circuit 5, and the control circuit 5 is connected to a CPU (central processing unit) 7. The detector array 3 is connected to a signal processing circuit 6 to create a cross-sectional image of the inspection object 2.
The signal processing circuit 6 is connected to the display 8. The signal processing circuit 6 and display 8 are connected to the CPU 7. It will be appreciated that the above connections are electrical connections and not physical fixations.

The signal processing circuit 6 of FIG. 1 is shown in detail in FIG. The detector row 3 is connected to the preprocessor 11, and the 61J processor 11 has three signal memory sets 12-1, 12-2, 12-3,
connected to the three signal memory sets 12-1.12-
2.12-3 is connected to a reconstruction circuit 13 having a known configuration for creating a cross-sectional image of the inspection object 2;
3 is a set of three image memories 14-1, J4-2.1
4-3, and three image memory sets 14-1.
14-2 and 14-3 are connected to the display 8 through the compound device 15. Signal memory 12-1.12-2.12-3
They have the same structure, and the image memory 14-1゜14
-2.14-3 also have the same structure.

The detector array 3 and preprocessor 11 shown in FIG. 2 are shown in more detail in FIG. Detector row 3 includes scintillator 16 and PMT
(Photo-electrical conversion element) 17 and amplifier 18, the detector unit includes a plurality of detector units, eight units in this embodiment. Since the portion of the preprocessor connected to each unit has a common structure to each unit, only two units are shown in the figure, and the following explanation will be made only for the first unit. The first detector unit amplifier f1s-z is connected to a pulse height analyzer 19-1, and the pulse height analyzer 19 is connected to three A/D converters 2O-Ik,
Connected to 2O-IB and 2O-IC, respectively. 3 A/D converters 2O-Ik, 2O-In, 2O-IC
are three arithmetic units 21-11.2l-IB, 2l, respectively.
- Connected to the IC.

In the computing unit 21-1, 2l-IB and 2l-1c are each liquefied in the signal memory 12-1.12-2.12-3. The units are also summarized in a schematic manner, and many connection lines are symbolized by one, but those skilled in the art will understand that the details are unnecessary for explaining the present invention.

Next, the operation of this device having the above configuration will be explained. In this apparatus, the scanning mechanism 4 performs unit scanning in which the scanning frame makes one reciprocation or half a reciprocation. During the unit scan, an X-ray beam 10 is emitted from the xi tube 1, and Xli that passes or does not pass through the inspection object 2 is detected by a detector, a detection array 3. When the unit scan is completed, the general mechanism 29I
J-It-jl The sector of the X-ray beam 10 in the rotation 7 +/- beam 9 is subjected to a step rotation 11 of an active angle, 6° in this example, and then the other unit scan described above is performed. . l ur: The process is repeated with the neck of the rotating frame 9 rotating approximately half a turn or Its l'+J 1
Complete one scan. During the scanning, the scanning direction of the unit scanning is changed by 6 degrees, and the scanning direction is changed by <b75. During the above scanning, the scanning mechanism 4, the general mechanism 29, and the X-ray tube 1 are Q-controlled by the CPU 7 through the control circuit 5. During the scanning, the photocell 31 generates a position signal indicating the position of the X-ray, and the X-ray detection signal discriminated by the position signal is sequentially transmitted to the signal processing circuit 6. The detection signal processed by the signal processing circuit 6 to represent the cross section of the inspection object 2 is displayed on the display 8 as a cross-sectional image. The above <g processing and display are controlled by CPtJ7.

Next, the operation of the signal processing circuit 6 will be described in detail with reference to FIG. The detector is a proportional number tube, a semiconductor detector tube, a scintillator, etc., which can measure the incident X-ray energy according to energy.In this embodiment, a scintillator, such as CaF or BaF2'i, is used.

The detection signal obtained by the detector array 3 including the scintillator is passed through the preprocessor 1 and is divided into appropriate X-rays as shown in FIG. ν2. A signal memory 12- is separated and corresponds to each energy region represented by ν.
1. , 12-2. 12-3.

The signal stored in the signal memo IJ-72-1 is converted into a cross-sectional image signal by the reconstruction circuit 13 and sent to the image memo IJ-14-
1, and then stored in signal memory 12-2, 12-.
Similarly, the signals stored in ``J-z4-2. Stored in J4i. Image memory 14-1.14 to 2.14-3
The signals stored in the crosslinker 15 are sent to B (blue) respectively.
, G (green).

The R (red) color is associated and composited, and the composite color video (as g) is sent to the display 8, and the display 8Q displays the cross-sectional image of the object to be inspected in color.

The functions of the detector array 3 and the preprocessor 1) will be described in more detail with reference to FIG. The operation of the above 46 alarm units is as follows. When a certain X-ray photon enters the scintillator 16-1, the scintillator l
6-1 generates light in the visible range with an intensity proportional to the energy of the photon. The above light is detected by PMT 77-7, and the detection signal is amplified by Ang 18-1.
A pulse-like signal whose pulse height is substantially proportional to the energy of the photon is sent to the pulse height analyzer 19-1. Wave height analyzer 1
9-1 is A/1) converter 2O-1k, 2O-IB, 2O which distributes the signal according to the comparison value determined corresponding to the above-mentioned X-ray energy region and has the aspect of a counter.
- Send to either IC. Signals from X-ray photons incident on the scintillator 16-1 during the predetermined integration time are stacked in A/D converters 2o-zA, 2o-zB, and 2o-1c K for each of the above energy regions, and Arithmetic unit 2l-IA as a digital signal indicating the number of incident photons at the end.

Sent to 2l-IPr and 2l-IC. Arithmetic unit 21-1
1゜The above signals sent to 2l-IB and 2l-IC are LO
Each signal memory 12- is subjected to G conversion and correction calculation.
1.12-2.12-3. All the above detector units have the above action.

In FIG. 1 showing this embodiment, the physical arrangement of each unit 5, 6° 7.8 is not shown. For example, in this actual M1 example, the pulse height analyzer 9 and A/D converter 20, which are part of the No. 48 processing circuit 6, are fixed to the scanning frame 22, and the other 7S1 (minutes are not fixed to the scanning frame 22). .

The energy of the X-rays generated in the X-ray tube is shown in Figure 4: Energy distribution of intensity I. It has (ν). On the other hand, the mass absorption coefficient of each element in the substance constituting the inspection object 2 changes depending on the energy of the X-ray, as illustrated in FIG. Therefore, as shown in the X-ray intensity (, 1, shi) after passing through the inspection object 2 through one path indicated by 1 (ν) in Fig. 4, the attenuation of ζ varies depending on the energy. Although the details are omitted, this causes the problem of so-called beam hardening, which causes errors in tl imaging in CT, especially image inhomogeneity.

The present invention will now be described in detail by way of example. In this embodiment, the X-ray 10 is ν1 in FIG. ν,.

It is detected separately for each of the three energy regions represented by ν3, and a cross-sectional image of the inspection target is reconstructed for each region.

As shown in Figure 4, each of the above energy regions is a narrower region than the energy spread of the X-rays generated from the problems are alleviated. By modifying this embodiment and setting the energy region more precisely, this problem can be fundamentally solved.

The second effect of this embodiment relates to the element distribution in the inspection object 2. In this example, the X-ray energy ν
1. ν2. B to the cross-sectional images corresponding to ν, respectively.
Make a color 〇 screw composite image by matching the colors of (W), G (green), and R (red).

Above ν7. ν21 ν, 50 KeV~l 50 K
It is taken between eV and υ. Referring to Figure 6, in this energy range, except for elements with much larger atomic weights such as lead, heavy elements have a large absolute value of the mass absorption coefficient slope, and light elements have a small value. Recognize.

In other words, it can be seen that the smaller the energy (ν,), the heavier elements are emphasized in the corresponding cross-sectional image Qt).

In cross-section A9 above, the parts with a large amount of absorption are displayed brightly, and therefore the differences in the elemental composition of each part are displayed in different colors. In particular, the parts with a large proportion of heavy elements appear reddish. Parts with a large ratio of ``bluishness'' are displayed.

First, the general effects of implementing the present invention will be described. The projection data (projection data) proportional to the amount of absorption at each energy ν is expressed as f
When ν(θ1 + Sj) and the cross-sectional image at each energy ν are Dl/(Xl(+yt)), fν at each ν
Combine them and re-arrange/stretch the cross-sectional image from the combined projection data, and create a cross-sectional image at each ν■)
By combining v and creating a combined cross-sectional image, differences in elemental composition in the specimen can be highlighted and displayed. The combination of the above is f if it is a linear combination.
It can be seen that , can be replaced by the same linear combination of . It is shown below.

With reference to FIG. 5, consider the attenuation of X-rays along a path passing through an object. Considering the X-ray beam as a wave beam,
The detector output V is yo=/lt(ν)io (ν)
dν ・−(1)W = J”R(ν)I(ν)dν =fR(ν)IO(ν)exp(/Σμm(ν)・ρm
(t)・dt)dν=fR(ν)Io(ν)exp(
/Σμm(ν)・Pm(t)・ρ(t)−dtldν=
fR(ν)IO(ν)-xp(-/μν(1)(t
) dtl dν −, (2) In the above formula, C: X-ray energy (or frequency) (77,: Detector output to(ν) when there is no object: X-ray intensity R when there is no object
ν): Detector response E(ν) = X-ray intensity μm (ν) Mass absorption coefficient of heavy element m t: Length along the communication path ρm (1): Density of element m in the object ρ(t): Object Density Pm(t) : Weight ratio of element m in the object μν(t)22
μm(ν) Pm(t) =−(3) The above integral is ν.

If the energy region is integrated in the energy region represented by , and the energy region detector output is vSagi, then if the energy region is small enough, F, n = R (vn) to (vn) ex
p(Cy,7t)・4t)dt)・Δνn−(4) Output when there is no trench object is I. Vn= R(vn)Io(vn)・ΔI/1・
(5) becomes.

Detection signal S′ν. is callbratlon log
Converted projection data f, n(θ+,
Sj).

Expressing the re-transformation operation (land transformation) using the operator R, it is Dvn(X)-μvn(X)(,)-...(8), and proJectlon (7° Ronoexion)
Five from fvn. It was shown that a statue of the same person was made.

fν. Let g be the linear combination of . Let αn be a constant that does not depend on θ, g:Σαn Ilfνn' (9). If the reconstructed image obtained by performing operation R on g is D (x), then due to the linearity of R, D (x) = R (Σα□・fν piece = ΣαnR (fν.

)=Σα.・DI/n(X)n n...Ql In other words, a composite image created by linearly combining reconstructed images created separately in each energy region is obtained by applying the same linear combination to the gronoection data in each energy region. It was shown that the result was equivalent to the reconstructed image created from the combined data.

It is easy to see that if the above combination is nonlinear, the two generally do not match.

An example of the above linear combination will be described with reference to FIG. From FIG. 6, it can be said that in the energy range of X-rays generally used for CT, typically 100 KeV, the mass absorption coefficient of heavy elements is generally large and that of light elements is small. Utilizing this, it is possible to increase the contrast of heavy element distribution and lower the contrast of light element distribution in a composite image, or vice versa.

ν1. Let ν be taken as shown in FIG. Each ν,.

The average mass absorption ratio of heavy elements at ν2 is μm, (ν,
)/μh(ν,), and the ratio for light elements is μt(ν,)/
Let μt(ν,). Image D l/fi (x
) is roughly made up of the sum of heavy and light elements, D p, (x ) - μl/, (X)"ρ(X') =
(J,μm(ν,)pm(x))su(,)μh(ν
+)P)1(x)”ρ(X)+μt(ν+)Pzcc)
”/'(X)...Q])Dy2(xXmoμh(ν2)P
h(X)”ρ(,) 10μt(νt)Pz(X)”ρ(,
) −... Becomes α-bu. However, Ph and Pt are the weight ratios of heavy elements and light elements, respectively.

As a first example, the coupling is Dv2(X)Xμh(ν+)/Ah(νz)−1% (
X) ・(If L3 is taken, the re-formed image D (x) is 1)(x)z(μt(ν2)×μh(ν1)/μゎ(ν
,)−μt(νr)) Pt(';)ρ)...α
The distribution of heavy elements becomes Pz(x)ρ(,), and the contrast disappears, and the distribution of light elements Pz(x)ρ(,)
is obtained as a reconstructed image.

When the combination as the second example is taken, the reconstructed image D(x) becomes...(11) and, contrary to Example 1, the distribution of heavy elements Ph(x)・ρ(X)
is obtained as a reconstructed image.

The combination in the first and second embodiments is performed using the glodivision data f as described above.

and fl can be replaced with the same combination.

These will be referred to as third and fourth embodiments, respectively.

In general, by supplying coupling parameters from the CPU 7 to the signal processing circuit 6, it is possible to create a device that can select various couplings with one device.

FIG. 7 is shown as a fifth example. As shown in FIG. 7, ν8. Consider the energy region represented by ν. Combined with cross-sectional image, I) v, (x) D
I, x (x) or DI/, (x)/DV,
(X) to create a composite cross-sectional image. or pro je
A cross-sectional image is created by applying the coupling ry(θ)rp(θ) to ction. This cross-sectional image or composite cross-sectional image is sensitive to the presence of lead in the specimen and shows the distribution of lead. More precisely, the above bonds should be chosen as follows.

Above ν3. The cross-sectional image at ν, Dv, is considered to be the distribution of 1te1- on the right side. Here, select a certain constant k. k is usually around 1, which is a slightly smaller number than 1. However, in the above equation, addition is performed excluding lead, and pm(x)ρ(,) is the average P in this test specimen.
m(X)ρ(,). Then, -kD is Dv, -kDν, and (μPb(ν+) − is μPb(ν
2) ) ・Ppb (x)ρ(,)...(a) The contrast of the elements outside the ship's gear almost disappears, and the lead mass distribution ρpb (X), that is, Ppb(x)ρ(,)
is obtained as a reconstructed image.

Although the fifth example above describes lead, it will be easily understood that the material is not limited to lead in general.

If the method shown above is developed, it will be possible to analyze the distribution of substances with a specific composition of elements in a test object, its proportion and weight, quantitative structural analysis, selection, sorting, etc. of the test object. It can be applied.

It will be appreciated that the method described above can be used not only for CT but also for X-ray fluoroscopic images. However, the t"5 effect in a CT image of a strawberry is that a reconstructed image is obtained that is proportional to or quantitatively related to the amount of the substance present, in the fifth example above, the lead density ρPb(X), Furthermore, it is possible to obtain it as an absolute value, and therefore it can be used not only for pattern recognition but also for measurement purposes.

Other examples are given below.

(Example 6) As shown in FIG. 8, a modification of Example O has a plurality of reconstruction circuits 13 and the signals stored in a plurality of signal memories 12 are processed in parallel.
Those with 6.

(Example 7) As shown in FIG. 9, in an example that includes Example 32 and Example 4, the above 0 logic is a set of data f, n(θ) (Note 1 of item g) -J, ? -1°12-2. ...
A set of energy-specific signals stored in 2 is combined in a combiner 37, converted into a cross-sectional image signal in a reconstruction circuit 13, stored in a composite image memory 36, and displayed on a display 8. In addition, the A' parameter of the bond or the selection signal of the bond is sent to the CPU 7.
A device that can be easily supplied and can be connected in various ways with one device.

(Example 8) In Example 7, 97 and 38 are appropriately programmed general-purpose computers.

(Example 9) In the above example, 12-1.12'-2゜1
2-3. ...or 14-1.14-2.14-3
A device that stores signals temporarily stored in ゜... onto a floppy disk or magnetic disk.

In other words, it becomes possible to once store the energy-specific signal or cross-sectional image in a permanent storage medium and then attempt to reconstruct it by changing the combination method as many times as desired.

(Example 10) A single device that can be used in consideration of how to divide the energy regions. This is done by using the CPU 7 to switch the wave height analyzer 19 shown in FIG.

(Example 11) As shown in FIG. 10, there is an overlap in the above energy range.

(Example 12) As shown in Fig. 11, if the energy region is scattered over a wide energy range and the range cannot be covered by single energy operation of the X-ray tube, the A device that collects data by changing the river multiple times.

(Example 13) The energy area is divided into bag layer-0 in which the area is set so that the average S/N ratio in each area is approximately equal. (Example 14) In the above 10th example, one screen is B.

G and R are displayed in units of minutes.

('t+015) Applying the method of Example 5 to elements with fM number, the quality 61 distribution of valley elements with less than 1J is shown.
This is a device that creates an image with a 50% difference by matching and compositing the faded colors.

(Kai 16) Example 7 The combination is additive. Simply create the same Ii weight as before, but with the beam bar 1° ning supplement L.
It has been completely completed for about 1 time. This is an effective way to increase the S/N ratio even if energy information is reduced. It should be noted that the addition is performed after the conversion to 70 ronoexion r-unit. That is, in conventional OCT, this is the same as addition at the output stage of the detector.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing the structure of a signal processing circuit, Fig. 3 is a diagram showing the structure of a preprocessor, and Fig. 4 shows intensity and Figure 5 is a diagram showing the relationship between the X-ray path and the object, and Figures 6 and 7 are diagrams showing the relationship between the P (quantity absorption coefficient and X-ray energy). 8 and 9 are block diagrams showing other configuration examples of the signal processing circuit, and FIGS. 10 and 11 are diagrams showing the relationship between X-ray intensity and X-ray energy. 1. X-ray tube, 2...Test object, 3...Detector row, 4
...Scanning mechanism, 5.Control circuit, 6.Signal processing circuit, 7.CPU, 8.Display device, 9.Rotating frame, 22.Scanning frame, 23.Collimator . Application Fee J4 ■ 1 Patent Attorney Takehiko Suzue Figure 2 Figure 4 x 4 Shield Energy V -v Kazuo Wakasugi, Commissioner of the Patent Office, Incident Display Q'! i Application No. 182-94 No. 2, Name of the invention Multi-cut X-ray cT device 3, Relationship with the Nagisa incident without correction Patent applicant (30'7) Tokyo Shibaura Electric (1 (; Shikisha 4) , Agent No. 17, 26-51J, Toramon, Minato-ku, Tokyo
Mori Building 5, Voluntary Tin Procedural Amendment 1995 1. ) l-rs '4', 1st Director of the Agency, Mr. Kazuo Wakasugi], Indication of Case Patent Application No. 182794/1982 2, Title of Invention Multicolor X-ray C Mounting h 3, iT? Relationship with the Nagisa incident that makes i-correct Patent 1421. ij #person (307) Toishi Shiba music 2b, Ki Stock Society Neko 4, Agent (i, Specification subject to amendment 1 Drawing 7 Contents of sleeve closure (1) Specification Peng, page 10, 5h (2) "was done"
"It's 1-yen," he stopped. (2) "Supported" written on page 1 (), line 8 of the specification is changed to "1-Supported." (3) “X-ray publication” stated on page 13, line 14 of the specification
is corrected to "X-ray 11." (4) ``Collimator 23'' listed on page 11, f4'J, line 3 of the specification is referred to as ``collimator 32''. (5) “Detector,” described on page 13, line 14 of the specification.
"Detector row" is revised to "Detector row". (6) Seiya No. 13 Tei No. 16 b [=1 in ``
The shape of the moon is reduced to 1 square of the moon. (7) “Through CP” stated on page 14, line 4 of the specification
tJ 7 Delete J. (8) ``Detection'' LL J described in ``Subyoui'', page 14, 153] is referred to as ``detector''. (9) "1-Reconstructed image" stated on page 13, line 14 of the specification is referred to as "reconstructed image." ttul Mei MIII 20th page 7th line +'-8
C, 1- = JR(ν)IO(ν)eXp(-,/
'μν(tJsu(tld t l dν...-+21J
"-]'R(thin IO(ν)exp (f/',
(t)・ρ(t)d t l d ν −, −, (21
J Correct. uLj Statement box 2 (I Q e517;i''l=
r'n [ratio J Y I weight ratio] and N,
l NET. (I2) Statement box 2 (l r:+18th
・(3' J 'a: □ m "μ, (t) 52 μm (thin Pm(tl ・-t3'
Correct it with J. 0: Ta From page 21, line 9, line II to page 21, line 17 of the specification etc. If the town structure and calculation (Radon transformation) are expressed by the originator I2, equation (6) can be expressed as follows. However, χ is +yB and 2 is -Qi, and S. is expressed by U. Here, 1%n('')=μ,g(s・ρ(χ)...(8) is the 4j-1 eclipse image.''04) Details @23rd shell No. 12r-J 05) Expression 1.9i listed in He on page 25 of the specification store is 1-
Σ(μ ν+) −kzzm(I2))Pm(z+ρ(
χ）−□−(191Jmsu116. 1-
Ru. As an example of formula (6), let n be a material containing n elements.
I [at the energy of δ1 4゛-(I1) I! 11-Sui)
Falcon. The combination is f・er. The monohedron 1), , (χ) at each energy is; i=
1.2. ..., expressed as n. This is a set of simultaneous forces 4) with vn unknowns and n force equations - it's a matter of hastily compiling this into each element m. ” α7) In the 14th line of page 26 of the specification, ``to develop the technique'' has been amended to ``by the technique.'' 0) The details are also listed in the 4th line of page 28 (-, 38J
Delete. tl! l) Particular heat, page 30, item 81-] to item 9 of the same page
1-intent J-t(1
``'X-ray intensity'' is corrected. tall 111141 ia visit txt1114 No. 31
81 another &Ik)j4'BsuiiJ stop oru.

Claims (1)

[Scope of Claims] (1) An X-ray generation means and its support means, an inspection object support means, an X-ray detection means and its support means, the X-ray generation means, the inspection object and the X-ray detection means; X-rays emitted from the X-ray generating means along a plurality of substantially straight paths on one or more substantially planes including the object to be examined; means for deriving an energy-specific signal indicating a capital reduction for each of a plurality of energy regions of the line; 1 reconstruction means for reconstructing a number or a plurality of cross-sectional images based on the energy-specific signals; and a reconstruction means for reconstructing a plurality of cross-sectional images. a display means for displaying the image as a composite cross-sectional image showing the object to be inspected. (2) a coupling means for coupling the energy-specific signals together or a coupling means for coupling the cross-sectional images together;
The multi-color X-ray CT apparatus according to claim 1, which includes the combining process. (3) The multicolor X-ray CT apparatus according to claim 1 or 2, wherein the reconstruction process of the reconstruction means is a process that is substantially mathematically equivalent to Radon transformation. (4) The multicolor X-ray CT apparatus according to claim 2 or 3, wherein the combination is a linear combination. (5) Claim 2 in which the above combination includes a nonlinear combination.
3. The multicolor X-ray CT apparatus according to item 3. (6) The multicolor X-ray CT apparatus according to any one of claims 1 to 5, wherein the reconstruction means includes one circuit that processes the energy-specific signal or a plurality of combined energy-specific signals according to time. . (7) The multicolor X-ray CT apparatus according to any one of claims 1 to 6, wherein the reconstruction means includes a plurality of circuits that process the energy-specific signals or a plurality of combined energy-specific signals in parallel. (8) Claims 2 to 7, wherein the means for combining the cross-sectional images includes means for combining each cross-sectional image with a different color corresponding to each other, and the composite cross-sectional image is displayed in color. The multicolor X-ray CT device described. (9) The multicolor X-ray CT apparatus according to any one of claims 1 to 8, wherein the energy region is set such that the energy-specific signals have a signal-to-noise ratio approximately equal to - in the reporter region. . Claims 1 to 4 set the energy at which the discontinuity of the energy dependence curve of the mass absorption coefficient of a certain element occurs in two of the energy regions set forth in Qtj - as a practical boundary. The multicolor X-ray CT apparatus according to item 9. (11) Claims 1 to 10 include a step of changing the energy distribution of the X-rays generated from the X-ray generating means in the step of deriving energy-specific signals indicating 1 m attenuation. multi-color X-ray CT device. (The above combination can be switched to one of a plurality of different combinations.) +Claims 2 to 1
The multicolor X-ray CT device according to item 1. (2) A multicolor X-ray CT apparatus according to any one of claims 1 to 12, which is capable of switching the setting of the energy range.