JPH05161633A - Radiation diagnostic device - Google Patents

Abstract

PURPOSE:To provide the radiation diagnostic device which can obtain an image containing information expressing the difference of the existent amounts of materials composing a patient. CONSTITUTION:This device is provided with a means to obtain plural images obtained by radiating radioactive rays having the plural kinds of energy to a patient and an average absorption coefficient corresponding to the plural materials composing the patient P and the plural kinds of energy, and an arithmetic part 10 to calculate the existent amounts of the plural materials for each picture element based on the plural images and the average absorption coefficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation diagnostic apparatus which obtains a new image based on a plurality of radiation images obtained by photographing with radiations of a plurality of types of energy and is used for diagnosis based on the images.

[0002]

2. Description of the Related Art Usually, a radiation diagnostic apparatus obtains an X-ray transmission image according to a transmission amount of radiation, for example, X-rays transmitted through a subject, in other words, an X-ray absorption amount, and provides the image for diagnosis. However, the drawback of this X-ray transmission image is that even if the tissue component on the first transmission path of X-rays and the tissue component on the second transmission path are actually different, If the X-ray absorption amounts of are equal, they are displayed as if they were the same tissue, and if a specific tissue of interest, such as a blood vessel, and another tissue, such as bone, are on the same path, That is, it is hidden by bones and not displayed.

Further, in recent years, a so-called energy subtraction method has been devised, which is a method of erasing and displaying only a tissue that hinders diagnosis of a specific tissue of interest, for example, only bone or soft tissue. This energy subtraction method has the property that the X-ray absorption coefficient of a substance depends on the energy of X-rays, and that the energy dependence of the X-ray absorption coefficient of a substance depends on the difference in the atomic number of the substance. It is what you use. Here, the X-ray absorption coefficient is an absorptance per unit thickness (X-ray transmission path length) of a substance, and thus the same substance is the same regardless of the difference in thickness. The energy subtraction method will be described below.

In the energy subtraction method, first, X
An energy spectrum of a band in which a relatively low energy X-ray obtained by applying a relatively low kilovolt tube voltage to a X-ray tube is applied to a subject, and the X-ray transmitted through the subject has a relatively low average energy. An X-ray transmission image having a distribution (hereinafter referred to as "low energy image") is obtained. here,
For the sake of convenience, it is assumed that the transmission image area of the subject is a lung field including bones and blood vessels. Next, a tube voltage higher than the tube voltage at the time of obtaining the low energy image is applied to the X-ray tube, and the X-ray transmission image (hereinafter referred to as “X-ray transmission image” having an energy spectrum distribution of a band in which the X-ray has a relatively high average energy High energy image "
Called)).

The low energy image is subtracted from the obtained high energy image to obtain an image of the difference between the two images. However, before subtraction, each of the high energy image and the low energy image is multiplied by an appropriate weighting coefficient so that the tissue to be erased is offset by the subtraction. This weighting factor is set according to the energy dependence of the X-ray absorption coefficient of the tissue to be erased, and by variously changing it, for example, "the image in which only bone is erased" or "the image in which only soft tissue is erased" It is possible to obtain

However, the diagnosis by the "image in which the desired tissue is erased" obtained by this energy subtraction method has the following problems. That is, if the tissue that has been erased to aid in the discovery of the lesion, which is the original purpose of diagnosis, is composed of the same substance that makes up the lesion, the tissue that is erased by the lesion It will be erased with. For example, the image obtained by the energy subtraction method is the "image in which only the bones are deleted",
When the transmission image area is a lung field and the lesion to be diagnosed is a tissue containing calcium, the lesion is erased together with the bone, and as a result, accurate diagnosis is hindered.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a radiation diagnostic apparatus capable of obtaining an image containing information indicating the difference in the abundance of substances constituting a subject.

[0008]

A radiation diagnostic apparatus according to the present invention is adapted to a plurality of images obtained by irradiating a subject with radiation having a plurality of types of energy and a plurality of substances constituting the subject. And means for obtaining an average absorption coefficient corresponding to the plurality of types of energy, and means for calculating the abundance of the plurality of substances for each pixel based on the plurality of images and the average absorption coefficient. Characterize.

[0009]

According to the present invention, a plurality of images obtained by irradiating a subject with radiation of a plurality of types of energy and an average of a plurality of substances constituting the subject and a plurality of types of energy The abundances of the plurality of substances can be obtained for each of the pixels based on the absorption coefficient, and as a result, an image including information indicating the abundances of the substances constituting the subject can be obtained.

[0010]

Embodiments will be described below with reference to the drawings. Here, the radiation used in the radiation diagnostic apparatus according to the present invention will be described below as X-rays. FIG. 1 is a block diagram showing the configuration of an X-ray diagnostic apparatus according to the first embodiment of the present invention.

The X-ray diagnostic apparatus according to the first embodiment is an X-ray apparatus for obtaining X-ray transmission image data, a correction unit for correcting the X-ray transmission image data obtained by the X-ray apparatus, and the correction unit. A storage unit for storing the X-ray transmission image data, a μ calculation unit 12 for performing a predetermined calculation process on the X-ray transmission image data stored in the storage unit to calculate an average absorption coefficient μ, and the average absorption coefficient thereof. The abundance of a plurality of substances that make up the subject P based on the μ storage unit 13 that stores μ, the X-ray transmission image data stored in the storage device, and the average absorption coefficient μ stored in the μ storage unit 13. An arithmetic unit 14 for obtaining (thickness) for each pixel,
Chromaticity information is given to each pixel according to the abundance of multiple substances,
An RGB frame memory 15 that outputs the chromaticity information according to the scanning system of the monitor (CRT) 17, a digital / analog (D / A) conversion unit 16 that performs digital / analog conversion of the output of the RGB frame memory 15, and a color. A monitor (CRT) 17 for displaying an image (hereinafter referred to as “abundance image”) according to the degree information, a CPU 18 for controlling the entire system, and various information, particularly calculation of the average absorption coefficient μ in the μ storage unit 13. And a keyboard 19 for inputting thickness information for each substance required for the.

The X-ray apparatus includes an X-ray tube 1 for irradiating the subject P with X-rays, an X-ray controller 3 for applying a tube voltage to the X-ray tube 1 to control the exposed X-rays, and the subject. An image intensifier 2 which is provided to face the X-ray tube 1 with P interposed therebetween and converts a transmitted X-ray image of the subject P into an optical image, and an optical image from the image intensifier 2 is converted into an electric signal. A TV camera 4 for obtaining X-ray transmission image data, an analog / digital (A / D) converter 5 for analog / digital converting the X-ray transmission image data obtained by the TV camera 4, and the X-ray transmission image data temporarily. Buffer memory 6 for temporarily storing the data. Here, the X-ray tube 1 irradiates X-rays having energy corresponding to the tube voltage applied from the X-ray controller 3. The X-ray controller 3 also receives a tube voltage control signal from the CPU 18 and controls the tube voltage applied to the X-ray tube 1.

The correction unit comprises a scattered radiation correction unit 7 and a beam hardening correction unit 8. The processing content of this correction unit is a known technique, and therefore will be briefly described. The scattered radiation correction unit 7 inputs the X-ray transmission image data from the X-ray apparatus, removes the error component due to the scattered radiation generated during the transmission of the subject P contained in the X-ray transmission image data, and uses the scattered radiation. X-ray transmission image data having no error component is obtained. The beam hardening correction unit 8 removes the soft X-ray component from the X-ray transmission image data to obtain X-ray transmission image data of only the hard X-ray component. This correction unit may be omitted from the apparatus of this embodiment as needed.

The storage device includes an I storage unit 9 and an I ′ storage unit 10.
And an I ″ storage unit 11. The I storage unit 9 detects the X-ray exposure dose from the X-ray tube 1 without passing through the subject P (hereinafter, this “X-ray data” is referred to as “X-ray image”) I To store the I ′ storage unit 10
Stores an X-ray image I ′ obtained by the X-ray passing through the subject P,
I ″ storage unit 11 is an X-ray image I ″ obtained by transmitting X-rays through each of the three phantoms FA, FB, FC of the substances A, B, C.
Memorize However, the X-ray image I and the X-ray image I ′ stored in each part of the storage device are obtained in plural types, for example, three types for each X-ray of three types of energy,
Similarly, X-ray images I ″ are obtained and stored for each of the three phantoms FA, FB, FC in the same manner for each of a plurality of types of energy, for example, for each X-ray of three types of energy. Here, an X-ray image I obtained by X-rays of these three types of energy
Are referred to as X-ray image I1, X-ray image I2, and X-ray image I3, respectively. Similarly, the X-ray image I ′ is also an X-ray image I1 ′, an X-ray image I2 ′, and an X-ray image I3 ′, and the X-ray image I ″ is also a phantom FA, F.
X-ray image I1A ", I2A", I3A ", X-ray image I1 for each of B and FC
B ", I2B", I3B ", X-ray image I1C", I2C ", I3C"
And Here, it is assumed that the existing amounts (thicknesses) tA ″, tB ″, and tC ″ of the three phantoms FA, FB, and FC are simulated objects that are known in advance. Here, Phantom FA,
The composition substances of FB and FC are three kinds of substance A (lesion tissue), substance B (bone), and substance C (soft tissue). Here, the information of the thicknesses tA ″, tB ″, tC ″ is input from the keyboard 19 as described above. See also Phantom F
Can be selected according to the lesion tissue to be diagnosed, for example, cancer tissue, and the type can be prepared according to the number of tissues to be diagnosed. The CPU 18 controls the write / read timing of each of the I storage unit 9, the I ′ storage unit 10, and the I ″ storage unit 11.

The μ calculation unit 12 includes an I storage unit 9 and an I ″ storage unit 1.
1 to X-ray images I1, I2, I3 and X-ray images I1A '', I2
A ", I3A", I1B ", I2B", I3B ", I1C", I2
Input C ", I3C", and also the thickness 19 of each of the three phantoms FA, FB, FC from the keyboard 19 tA ", tB".
, TC ″ are input, predetermined arithmetic processing is performed based on these data, and X of three types of energy of substances A, B, and C
Calculate the average absorption coefficient μ for each line. Here, the average absorption coefficient μ for substance A is μ1 for each X-ray of three types of energy.
Referred to as A, μ2A, and μ3A. Similarly for substance B, μ1B, μ2B, μ3B, and for substance C, μ1c, μ2c, μ3c, respectively. Each average absorption coefficient μ is calculated for each substance and for each X-ray. For example, the average absorption coefficient μ1A for the X-ray of the first energy of the substance A is obtained from the X-ray image I1, the X-ray image I1A ″ and the thickness tA ″ based on the equation (2) shown in the joint. Other average absorption coefficients μ are similarly obtained based on the equation (2). However, "ln" is a natural logarithm. I ″ = Iexp {−μt ″} (1) The formula (1) is modified to obtain the formula (2). μ = (lnI−lnI ″) / t ″ (2) μ The storage unit 13 stores the average absorption coefficient μ obtained by the μ calculation unit 12.
1A, μ2A, μ3A, μ1B, μ2B, μ3B, μ1c, μ2c, μ3c
Memorize

The operation unit 14 receives the X-ray image I1 from the I storage unit 9,
The X-ray image I2 and the X-ray image I3 are input, the X-ray image I1 ', the X-ray image I2', and the X-ray image I3 'are input from the I'storage unit 10, and the average absorption coefficient μ1A, μ2A, μ3A, μ1B, μ2
B, μ3B, μ1c, μ2c, μ3c are input, and the abundance of each of the substances A, B, and C constituting the subject P, that is, the thickness t
A ', tB', and tC 'are calculated for each pixel by a predetermined calculation process, and are independently output for each of the thicknesses tA', tB ', and tC'. This predetermined arithmetic processing is performed using equation (6).
The formula (6) is obtained by modifying the formula (3), the formula (4), and the formula (5). The formula (3), the formula (4), and the formula (5) are the formula (1).
Is a formula similar to.

[0017]

[Equation 1]

The RGB frame memory 15 is an R (red) frame memory 15R and a G (green) frame memory 15G.
And a B (blue) frame memory 15B. R
The (red) frame memory 15R gives and stores redness information according to the thickness tA of each pixel of the substance A that composes the subject P input from the calculation unit 14. The G (green) frame memory 15G provides and stores greenness information according to the thickness tB of each pixel of the substance B forming the subject P input from the calculation unit 14. The B (blue) frame memory 15B gives and stores blueness information in accordance with the thickness tC of each pixel of the substance C constituting the subject P input from the calculation unit 14. Then, the chromaticity information stored in each of the R (red) frame memory 15R, the G (green) frame memory 15G, and the B (blue) frame memory 15B is simultaneously output for each pixel at the same display position. However, this output timing is CRT17
It is assumed to comply with the scanning method of.

Digital / analog (D / A) converter 1
6 is provided corresponding to the R (red) frame memory 15R, and is provided corresponding to the D / A converter 16R for analog-converting the output from the R (red) frame memory 15R and the G (green) frame memory 15G. G (green) frame memory 1
D / A converter 16G that converts the output from 5G to analog
And a D / A converter 16B provided corresponding to the B (blue) frame memory 15B for analog-converting the output from the B (blue) frame memory 15B. CRT17
Displays chromaticity information converted into an analog signal from the D / A converter 16 and displays an abundance image.

Next, the operation of the X-ray diagnostic apparatus according to the first embodiment constructed as described above will be described with reference to FIG. Here, there are two types of substances (healthy tissues) that compose the imaged site of the subject P, and one type of lesion tissue that is the diagnosis target, that is, three types of substances whose abundance is desired to be known in total,
It is assumed that the X-rays used for imaging are three types of X-rays having different energies, and the phantoms F to be prepared are three types. If there are N types of substances whose presence amounts are to be known, that is, N types of composition substances of the subject P at the imaging site, N types of X-rays are used and N types of phantoms F are also used.

FIG. 2 is a function for calculating the abundance (thickness) of each of the substances A, B, and C in the subject P based on the average absorption coefficient μ for each of the substances A, B, and C and for each X-ray energy. It is a figure explaining. However, it is assumed that the reference numerals used in FIG. 2 are the same as the reference numerals used in the description of the configuration described above.

First, an image taken without placing the subject P and the phantom F between the X-ray tube 1 and the image intensifier 2, that is, X-ray images I1 and I corresponding to only the exposure X-ray dose.
2 and I3 are respectively the first X-ray, the second X-ray, and the third X-ray.
Get for each line. The X-ray images I1, I2, I3 are A /
The D converter 5 converts it into a digital signal, and the scattered radiation correction unit 7
And, after being corrected by the beam hardening correction unit 8, it is stored in the I storage unit 9.

Next, 3 depending on the purpose of diagnosis and the site to be diagnosed.
Phantoms FA, FB, FC of various kinds, here, because it is a diagnosis of cancer tissue in the lung field, phantom FA consisting of pseudo-cancer substance A and phantom FB consisting of pseudo-bone substance B and pseudo-soft tissue substance For each phantom FC composed of C and the X-ray images I1, I2
, The same as the three types of X-rays used to capture I3 3
X-ray images I1A ", I2A", and I3 are taken for each type of X-ray.
A ", I1B", I2B ", I3B", I1C ", I2C", I3
Get C ''. Here, the abundance (thickness) tA ″, tB ″, t of each substance A, B, C in each phantom FA, FB, FC
C ″ is known in advance, and the thicknesses tA ″, tB ″, tC ″ are input from the keyboard 19 and stored in the memory in the μ calculation unit 12. These X-ray images I1A ", I2A",
I3A ", I1B", I2B ", I3B", I1C ", I2C", I
Similarly, 3C ″ is converted into a digital signal by the A / D converter 5, and the scattered radiation correction unit 7 and the beam hardening correction unit 8 are also provided.
It is stored in the I ″ storage unit 11 after being corrected by.

The average absorption coefficient μ1A, μ2A, μ3A for each of the three types of substance A, the average absorption coefficient μ1B, μ2B, μ3B for each of the three types of substance B, and the three types of substance C The average absorption coefficients μ1c, μ2c, μ3c for each X-ray are input from the I storage unit 9 and the I ″ storage unit 11 as X-ray image I1, X-ray image I2,
X-ray image I3 and X-ray image I1 '', X-ray image I2 '', X-ray image I
3 ″ and the thicknesses tA, tB, and tC of the phantoms FA, FB, and FC of the substances A, B, and C, which are input from the keyboard 19 and stored in advance, according to the equation (2),
The average absorption coefficient μ1 calculated by the μ calculator 12 is obtained.
A, μ2A, μ3A, μ1B, μ2B, μ3B, μ1c, μ2c, μ3c
Is stored in the μ storage unit 13.

Next, as shown in FIG. 2, the X-ray images I1 ', I2', I3 'of the lung field of the subject P are converted into the X-ray images I1, I2, I2,
I3 is photographed using the same three types of X-rays used for photographing, similarly converted to a digital signal by the A / D converter 5, and the scattered ray correction unit 7 and beam hardening are performed. After being corrected by the correction unit 8, the data is stored in the I ′ storage unit 10.

The abundances (thicknesses) tA ', tB', tC 'of the substances A, B, C for each pixel in the lung field of the subject P are calculated by the calculation unit 14 in the I storage unit 9 and the I'storage unit. X-ray image I1, X-ray image I2, X-ray image I3 and X-ray image I1 ', X-ray image I2', X-ray image I3 'inputted from 10 and average absorption coefficient μ1A inputted from the μ storage unit 13, μ2A, μ3A, μ1B, μ2B, μ3B, μ1c, μ
2c and μ3c are used to obtain the arithmetic processing shown in equation (6).

The thickness tA 'for each pixel obtained by the calculation unit 14
tB 'and tC' are given as R (red) chromaticity, G (green) chromaticity, and B (blue) chromaticity corresponding to the RGB frame memory 15, and are stored as color abundance images.

The color abundance image is output from the RGB frame memory 15 in the order according to the scanning system of the CRT 17, converted into an analog signal by the D / A converter 16, and then displayed on the CRT 17.

As described above, according to the X-ray diagnostic apparatus of the present embodiment, the average absorption coefficient corresponding to a plurality of types of energy X-rays of a plurality of substances forming the subject and the X-rays for each of a plurality of types of energy X-rays. The abundances of the plurality of substances can be obtained for each of the pixels based on the absorption amount, and as a result, an image can be obtained according to the abundances of the substances constituting the subject. For example, substances A, B, and C are soft tissue (red), cancer tissue (green),
By observing the color abundance image obtained by the apparatus of this embodiment as a bone (blue), it can be diagnosed that there is a suspicion of cancer in a site colored in green.

Next, a second embodiment will be described. Figure 3
FIG. 4 is a block diagram showing a configuration of a main part according to the second embodiment of the present invention, and FIG. 4 is a diagram showing an example of a profile image obtained in this embodiment. However, the structure other than the main part of the present embodiment is the same as the structure of the first embodiment shown in FIG. 1, so the description of the other constituent parts except the main part will be omitted. In FIG. 3, the same parts as those in FIG. 1 are designated by the same reference numerals.

In this embodiment, the thickness t obtained by the calculation unit 14 is
A ', tB', and tC 'are displayed as a profile. As shown in FIG. 3, the main part according to the present embodiment is a profile position specifying section 2 for specifying a position for displaying a profile.
0 and the thicknesses tA ', tB', and
The profile calculators 21, 22, 23 for calculating the respective profiles of tC '.

The profile position designation section 20 is a CRT 17
A desired profile position is input on the displayed X-ray transmission image using an input device (not shown) such as a light pen, and the profile position information is supplied to the profile calculators 21, 22, 23.

The profile A calculator 21, the profile B calculator 22, and the profile C calculator 23 are
It is provided corresponding to each thickness tA ', tB', tC 'of each pixel obtained in 4, and is supplied from the profile position designating section 20 among the thicknesses tA', tB ', tC'. From the thickness tA ', tB', tC 'depending on the profile position
Profile data PA, PB, PC for each of B and C are calculated, and the profile data PA, PB, PC are converted to RGB.
Output to the frame memory 15.

The RGB frame memory 15 has R (red) chromaticity and G for each of the profile data PA, PB and PC.
The (green) chromaticity and the B (blue) chromaticity are given according to the values, and FIG.
The color profile image as shown in FIG.

This color profile image is read from the RGB frame memory 15 to the CRT 17 in the same manner as in the first embodiment.
Output in the order according to the scanning method of the D / A converter 16
After being converted into an analog signal by, it is displayed on the CRT 17.

As described above, according to the X-ray diagnostic apparatus of the present embodiment, in the case of the first embodiment, the difference in chromaticity and hue,
That is, since the difference in composition was visually recognized, an error may occur in the recognition, but according to the color profile image obtained in this example, the difference in composition at the designated position is quantitatively recognized. can do.

Next, a third embodiment will be described. Figure 5
FIG. 9 is a block diagram showing a configuration of a main part according to a third embodiment of the present invention. However, the structure other than the main part of the present embodiment is the same as the structure of the first embodiment shown in FIG. 1, so the description of the other constituent parts except the main part will be omitted.
5, the same parts as those in FIG. 1 are designated by the same reference numerals as those in FIG.

In this embodiment, the thickness t obtained by the arithmetic unit 14 is
Based on A ', tB', tC ', the total (volume) of the existing amount of each substance A, B, C in the designated area is calculated and displayed. As shown in FIG. 5, the main part according to the present embodiment is a region where the volume of each substance A, B, C is desired to be obtained, that is, a region of interest designating section 25 for designating a region of interest, and each substance A in the region of interest. , B, and C, and a summation unit 26 in the region of interest.

The ROI designating unit 25 designates a desired ROI on the displayed X-ray transmission image of the CRT 17 by using an input device (not shown) such as a light pen, and sums the information of the ROI within the ROI. It is supplied to the unit 26.

The in-region-of-interest summation unit 26 calculates the thickness of the pixel included in the region of interest supplied from the region-of-interest specifying unit 25 among the thicknesses tA ', tB', and tC 'of each pixel obtained by the calculation unit 14. T
A ', tB', tC 'are selected, and in the region of interest, the spread of the pixels corresponding to the substances A, B, C in the region of interest and the thickness tA', tB ', tC' of each pixel in the region of interest are selected. Obtain the volumes VA, VB, and VC of each substance A, B, and C. The volumes VA, VB, and VC of the substances A, B, and C obtained by the summation unit 26 in the region of interest are displayed on the CRT 17 as numerical values. Furthermore, in the volumes VA, VB, and VC, the substances A, B, and
The mass of each substance A, B, C in the region of interest may be obtained by multiplying the density of C. Further, the mass of each substance may be obtained instead of the volume by using the mass absorption coefficient instead of the average absorption coefficient μ.

As described above, according to the X-ray diagnostic apparatus of the present embodiment, in the case of the first embodiment, the difference in chromaticity and hue,
That is, since the difference in composition was visually recognized, there was a possibility that an error may occur in the recognition, but according to the volume display or the mass display obtained in this example, each substance A,
The abundance of B and C can be quantitatively recognized. For example, when diagnosing mammoline calcification, the abundance of calcified calcium can be recognized by volume or mass.

The present invention is not limited to the above embodiments, but can be variously modified and implemented without departing from the gist of the present invention. For example, in the above embodiment, the tube voltage was changed to obtain X-rays of three kinds of energy, but several kinds of filters are inserted between the X-ray tube and the subject or between the subject and the image intensifier. X by inserting
The linear energy may be changed.

Further, in the above-mentioned embodiment, when there are N kinds of substances which are contained in the object and the amount of which is to be known, X-rays of N kinds of energy are irradiated to obtain N kinds of images corresponding to the X-rays. Although it was obtained, X-rays of energies of more than the number of kinds of substances for which it is desired to know the abundance constituting the analyte, for example, N
It is also possible to irradiate X-rays of +1 type of energy to obtain N + 1 types of images, and obtain a more accurate abundance from the images by using the least squares method.

The assignment of chromaticity in the color abundance image obtained by the apparatus of the first embodiment depends on the absolute amount (abundance) of each substance obtained by the arithmetic unit of this apparatus. This allocation may be performed according to the abundance ratio of each substance instead of the absolute amount (abundance amount) of each substance.

The color abundance image obtained by the apparatus of the first embodiment is obtained by directly correlating the abundance of each substance obtained by the arithmetic unit of this embodiment. You may make it display as a more legible image by filtering independently. This filtering process is, for example, a filtering process in which the abundance of a specific substance, usually lesion tissue, is weighted higher than the abundances of other substances to emphasize and display the diseased tissue, or a so-called edge that emphasizes the boundary portion of each substance. This is an emphasis process. Of course, other currently used filter processes may be used.

Although the color abundance image obtained by the apparatus of the first embodiment is displayed only as the color abundance image, it may of course be displayed together with the X-ray transmission image (grayscale image). In this case, it becomes easier to recognize the position of the diseased tissue in the subject. It is also possible to color only a specific substance, usually a diseased tissue, and not colorize other substances in the superimposed display. In this case, the position, range, and amount of the diseased tissue can be more easily discriminated.

Further, in the above embodiment, the average absorption coefficient for each X-ray of the energy of the three kinds of substances A, B and C was obtained by using three kinds of phantoms before photographing the subject. By previously obtaining the average absorption coefficient of various energies of each of the X-rays in the μ storage unit shown in FIG. 1 and storing them in a table, the average absorption coefficient is selected according to the composition material of the imaging site. Alternatively, the trouble of obtaining the average absorption coefficient may be eliminated. Furthermore, instead of selecting the average absorption coefficient according to the composition substance of the imaging site from among the average absorption coefficients of various substances, the average absorption coefficient of various substances is stored for each anatomical site, and a doctor or a technician By designating a desired anatomical site, the average absorption coefficient may be selected according to the required composition substance. For example, when a doctor designates a lung field, a set of substances registered for the lung field, that is, a set of rib, soft tissue (water), and average absorption coefficient of lung cancer is automatically searched. In this case, it is possible for the doctor to save the labor of searching for the required combination of the constituent substances and the average absorption coefficient thereof, and to improve the diagnostic efficiency.

Further, the first embodiment, the second embodiment,
By combining the third embodiment, the abundance image,
Color profile images, volumetric displays or mass displays may be implemented in one device.

[0049]

As described above, according to the present invention, the average absorption coefficient according to plural kinds of energy X-rays of a plurality of substances constituting an analyte and the X-ray absorption amount for each of plural kinds of energy X-rays. An X-ray diagnostic apparatus capable of obtaining the abundances of the plurality of substances for each pixel based on the above, and as a result, obtaining an image containing information indicating the difference in the abundances of the substances constituting the subject. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an X-ray diagnostic apparatus according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining a calculation operation of a thickness of a composition substance of a subject in a calculation unit shown in FIG.

FIG. 3 is a block diagram showing a configuration of a main part of an X-ray diagnostic apparatus according to a second embodiment of the present invention.

FIG. 4 is a diagram showing an example of a profile image obtained by the X-ray diagnostic apparatus according to the second embodiment shown in FIG.

FIG. 5 is a block diagram showing a configuration of a main part of an X-ray diagnostic apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

1 ... X-ray tube, 2 ... Image intensifier, 3 ... X
Line control unit, 4 ... TV camera, 5 ... Analog / digital converter, 6 ... Buffer memory, 7 ... Scattered line correction unit, 8 ...
Beam hardening correction unit, 9 ... I storage unit, 10 ... I '
Storage unit, 11 ... I '' storage unit, 12 ... μ calculation unit, 13 ... μ
Storage unit, 14 ... Calculation unit, 15 ... RGB frame memory,
16 ... Digital / analog converter, 17 ... CRT, 1
8 ... CPU, 19 ... Keyboard.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Mitsukoshi 1385 No. 1385 Shimoishigami, Otawara City, Tochigi Prefecture Toshiba Nasu Factory

Claims (1)

[Claims] 1. A plurality of images obtained by exposing a subject to radiation of a plurality of types of energy, and an average absorption coefficient according to a plurality of substances constituting the subject and corresponding to the plurality of types of energy. A radiation diagnostic apparatus comprising: a obtaining unit; and a unit that calculates the abundances of the plurality of substances for each pixel based on the plurality of images and the average absorption coefficient.