JPH095441A - Radiodiagnosis and radiodiagnostic device - Google Patents

Abstract

PURPOSE: To provide a radiodiagnostic device and a radiodiagnosis measuring the position information concurrently with the collection of the inspection infor mation on a subject, positioning an X-ray tomographic image and a SPECT image, and capable of accurately and anatomically dentifying in which portion of tissues or an organ RI is concentrated or lacking. CONSTITUTION: The moving means 43 of a bed device 4 relatively moves a γ-camera device 2, an X-ray CT device 3, and a bed top plate section 41 mounting a subject so that the interest region of the subject is contained in the effective visual field of the γ-camera device 2 or in the effective field of the X-ray CT device 3. A position measuring means 44 measures the relative position between the γ-camera device 2 or the X-ray CT device 3 and the bed top plate section 41 to obtain the position information. A data processor 5 positions or composites the image of the γ-camera device 2 and the image of the X-ray CT device 3, based on the position information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation diagnostic method and a radiation diagnostic apparatus, and more particularly to an X-ray CT apparatus and a single photon emission computed tomography (hereinafter abbreviated as SPECT) apparatus. TECHNICAL FIELD The present invention relates to a radiation diagnostic method and a radiation diagnostic apparatus capable of performing accurate diagnosis in a short time in cooperation with each other.

[0002]

2. Description of the Related Art Generally, clinical diagnosis includes morphological diagnosis and functional diagnosis. What is important in clinical diagnosis is whether or not the tissue or organ is functioning normally due to disease. With the exception of congenital abnormalities and trauma, in many diseases, anatomical morphological changes in tissues occur as functional abnormalities progress. The X-ray diagnostic apparatus and the X-ray CT apparatus are devices for this morphological diagnosis, and therefore, it is difficult to detect a functional abnormality before the morphological change at an early stage.

An X-ray diagnostic apparatus and an X-ray CT apparatus irradiate X-rays from outside the body to directly image the difference in X-ray transmittance due to tissues or organs on a film or tomographic image from the value measured by a detector. Is to be reconstructed.

On the other hand, the radioisotope (hereinafter abbreviated as RI) or a labeled compound thereof is utilized by utilizing the property of being selectively taken up by a specific tissue or organ in the living body.
There is a method of measuring γ-rays emitted from the outside of the body and imaging the dose distribution of RI to make a diagnosis, which is called a nuclear medicine diagnosis method.

In the nuclear medicine diagnostic method, the principle itself that a labeling substance is accumulated in a specific tissue or organ is associated with the physiological function of a tissue or organ and the biochemical substance metabolism function. Not only diagnosis, but also functional diagnosis of lesions at an early stage is possible, which is a major feature that other diagnostic methods do not have.

In this nuclear medicine diagnostic method, a scintigram for obtaining a two-dimensional distribution image using a scintillation scanner or a gamma camera device and information obtained by rotating the gamma camera around the subject are reconstructed. There is a SPECT that obtains a tomographic image of the RI concentration distribution.

Conventionally, in order to obtain an accurate tomographic image by SPECT, it is necessary to perform attenuation correction (also referred to as absorption correction) using the attenuation coefficient distribution in the tomographic plane from the point of γ-ray generation to the incidence on the gamma camera. For this purpose, a transmission CT (hereinafter TC) using RI as an external radiation source is used.
The attenuating distribution is obtained by (T is omitted).

[0008]

However, when it is necessary to make a diagnosis by associating the form and the function with each other, the conventional X-ray CT apparatus and gamma camera apparatus are independent diagnostic apparatuses, and the subject is imaged separately. Therefore, there is a problem that the posture of the subject is changed or the same slice position cannot be imaged in each diagnostic device.

Further, the TCT data collection and the SPECT data collection have a problem that the subject suffers a great deal of pain because the subject is forced to have a fixed posture for a long time.

Further, the TCT using RI has a problem that the resolution is low and good attenuation correction cannot be performed.

Further, since it takes a long time to collect the inspection data, there is a problem that the inspection throughput is low.

In view of the above problems, an object of the present invention is to collect examination information while keeping the posture of the subject constant, and at the same time measure the position of the subject, and to collect the X-ray tomography by the X-ray CT apparatus. SP collected by image and gamma camera device
It is an object of the present invention to provide a radiation diagnostic method and a radiation diagnostic apparatus capable of accurately anatomically identifying in which region of a tissue or an organ the RI is concentrated or missing by aligning it with an ECT image or the like. .

Another object of the present invention is to obtain an attenuation coefficient distribution image of high resolution in a shorter time than TCT using RI, realize more accurate attenuation correction, and quantify the RI distribution. It is to provide a radiation diagnostic method and a radiation diagnostic apparatus capable of performing the same.

Another object of the present invention is to provide a radiation diagnostic method and a radiation diagnostic apparatus capable of shortening the restraining time of a subject and reducing the pain.

Further, another object of the present invention is to provide a radiation diagnostic method and a radiation diagnostic apparatus which shorten the examination time and improve the examination throughput.

[0016]

To achieve the above object, the present invention has the following constitution. That is, the radiation diagnostic method according to claim 1 includes a step of collecting an X-ray tomographic image and a nuclear medicine image without changing the posture of the subject along with position information, and an X-ray tomographic image of the same position of the subject. And a step of performing morphological measurement and functional measurement from a nuclear medicine image.

The radiation diagnosis method according to claim 2 is
The step of obtaining the correspondence between the attenuation coefficient of γ-rays and the CT value using a known standard sample in advance, and the attenuation coefficient distribution image of the subject with respect to the energy of γ-rays emitted from the radiopharmaceutical are shown as X-ray tomographic images and It is characterized by including a step of calculating based on the correspondence relationship and a step of performing attenuation correction in reconstruction of the single photon emission CT using the attenuation coefficient distribution image.

Further, the radiation diagnostic method according to claim 3 is
The step of obtaining the correspondence between the attenuation coefficient of γ-rays and the CT value using a known standard sample in advance, and the attenuation coefficient distribution image of the subject with respect to the energy of γ-rays emitted from the radiopharmaceutical are shown as X-ray tomographic images and From the gamma camera device, a step of calculating based on the correspondence relationship, a step of calculating depth information of the region of interest of the subject from the X-ray tomographic image, and a step of calculating the attenuation coefficient distribution image and the depth information of the region of interest. A step of performing attenuation correction for obtaining a specific activity from the obtained two-dimensional distribution image.

The radiation diagnostic apparatus according to claim 4 is
A couch device having a tabletop on which a subject is placed, and a gamma camera device for detecting a γ-ray emitted from a radiopharmaceutical administered to the subject to obtain a two-dimensional distribution image or a three-dimensional distribution image of the radiopharmaceutical And an X-ray CT apparatus for taking an X-ray tomographic image of the subject, and a gamma camera apparatus and / or X-ray so that the region of interest of the subject is included in the effective field of view of the gamma camera apparatus or the X-ray CT apparatus. Moving means for relatively moving the CT device and the top plate portion; and position measuring means for measuring relative position between the gamma camera device and the top plate portion and relative position between the X-ray CT device and the top plate portion to obtain position information. A data processing device for aligning or synthesizing the image obtained by the gamma camera device and the image obtained by the X-ray CT device based on the position information obtained by the position measuring means and displaying the image. Characterized by .

Further, the radiation diagnostic apparatus according to claim 5 is
A gamma camera device that obtains a two-dimensional distribution image or a three-dimensional distribution image of a radiopharmaceutical by detecting γ-rays emitted from the radiopharmaceutical administered to the subject, and an X-ray CT that captures an X-ray tomographic image of the subject An apparatus, a time phase measuring means for measuring time phase of periodic body movement of a subject to obtain time phase information, and an X-ray CT apparatus performing time phase synchronous CT scan based on the time phase information. The gamma camera device is made to collect the time-phase synchronous distribution image, and the X-ray tomographic image obtained by the time-phase synchronous CT scan and the time-phase synchronous distribution image obtained by the gamma camera device are time-phased and displayed or information. And a data processing device for processing.

[0021]

According to the radiation diagnosis method of the first aspect, the morphological measurement and the functional measurement in which the posture and the slice position coincide with each other are performed from the X-ray tomographic image and the nuclear medicine image of the same position of the subject collected in the same posture. You can

The radiation diagnostic method according to claim 2 uses a standard sample (also called a phantom) which is known in advance to perform CT.
The correspondence between the value and the attenuation coefficient of γ-ray is obtained, and the X-ray tomographic image of the subject is converted into the attenuation coefficient distribution image of the subject according to this correspondence. At the time of this conversion, the CT value that does not exist in the standard sample is interpolated by an appropriate interpolation method. Then, the attenuation correction in the reconstruction of the single photon emission CT is performed using this attenuation coefficient distribution image. Thereby, since the attenuation distribution image obtained by converting the X-ray tomographic image having a higher resolution than the attenuation distribution image by the TCT using RI as the external source is used for the attenuation correction, it is possible to perform the attenuation correction with higher accuracy. At the same time, it is not necessary to collect the attenuation distribution image by TCT, and the inspection time can be greatly reduced.

In the radiation diagnosis method according to the third aspect, the correspondence between the attenuation coefficient of γ-rays and the CT value is obtained in advance using a known standard sample, and is stored in the form of a correspondence table, for example. Then, the X-ray tomographic image of the subject is collected, and the CT value is converted into a predetermined pixel unit of the X-ray tomographic image in the correspondence table, so that the attenuation coefficient of the subject with respect to the energy of the γ-rays emitted from the radiopharmaceutical. Obtain the distribution image, X
The depth information of the region of interest of the subject is calculated from the line tomographic image.
Then, by using the attenuation coefficient distribution image and the depth information of the region of interest, the attenuation correction of the two-dimensional distribution image (planar image) obtained from the gamma camera device is performed, so that the three-dimensional distribution image is not collected and radioactive The exact specific activity (Bq / ml) of a drug can be determined in a short time.

According to a fourth aspect of the radiation diagnostic apparatus, the object placed on the bed top is X-rayed without changing its posture.
The X-ray tomographic image of the same posture of the subject and the two-dimensional distribution image or three-dimensional distribution image of the radiopharmaceutical can be placed in the effective field of view of the X-ray CT apparatus or the gamma camera apparatus. Can be obtained.

Further, the relative position between the gamma camera device, the X-ray CT device and the top plate portion is measured by the position measuring means,
By using this position information, the image obtained by the gamma camera device and the image obtained by the X-ray CT device are aligned or combined to superimpose the morphological information and the functional information on the same tomographic plane. It is possible to observe the image and to use one image to correct the other image.

The radiation diagnostic apparatus according to claim 5 can obtain an X-ray tomographic image and a time-phase synchronous distribution image synchronized with the time phase of periodic body movements of the subject, and It is possible to observe the morphological information and the functional information in each time phase in one cycle in an overlapping manner and to use one image to correct the other image.

[0027]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a front view showing the configuration of the mechanical portion of the first embodiment of the radiation diagnostic apparatus according to the present invention. In the figure, the radiation diagnostic apparatus 1 is configured to include a SPECT apparatus 2 as a gamma camera apparatus, an X-ray CT apparatus 3, a bed apparatus 4, and a data processing apparatus 5. SPECT device 2
The X-ray CT apparatus 3 and the X-ray CT apparatus 3 are arranged such that their effective visual field centers (rotation centers) are aligned with the common effective visual field center line 6.

The SPECT device 2 is a gamma camera 2 which is two γ-ray detectors facing each other with the effective visual field center line 6 interposed therebetween.
1a and 21b, radial movement support portions 22a and 22b that support the gamma cameras 21a and 21b so as to be movable in the radial direction of rotation, and a detector rotation support portion 23 that supports the radial movement support portions 22a and 22b. , Detector rotation support 2
Rotation mechanism part 2 for rotating 3 around the effective visual field center line 6
4 and a gamma camera mechanism controller (25) not shown
And a γ-ray data acquisition unit (26) (not shown). The SPECT device 2 can collect a two-dimensional distribution image and a three-dimensional distribution image of the radiopharmaceutical taken in the subject.

The X-ray CT apparatus 3 includes an X-ray generating tube 31 and
X-ray detector 32, tube / detector rotation support 33, rotation mechanism 34 that rotates tube / detector rotation support 33 around effective visual field centerline 6, and CT mechanism controller not shown (35) is also provided with a CT data acquisition unit (36) and a CT image reconstruction unit (37) which are also not shown. The X-ray CT apparatus 3 can perform data acquisition in cooperation with the bed apparatus 4 described below, for example, by the helical scan method disclosed in Japanese Patent Publication No. 60332/1990.

The couch device 4 includes a couch top 41 on which a subject (not shown) is placed, a couch up-and-down moving mechanism 42 for fixing the base of the couch top 41 to the floor, and vertically moving the couch top 41.
The bed top plate 41 is used for the slice direction effective visual field 13 of the X-ray CT apparatus 3 and the slice direction effective visual field 12 of the SPECT apparatus 2.
In addition, a top moving mechanism 43 that can move horizontally and a top position detecting unit 44 that detects a top moving position are provided. The couchtop position detecting unit 44 converts the linear movement distance of the couchtop into a rotation angle of the pinion by, for example, a rack fixed to the couchtop 41 and a pinion provided on the couch base, and the pinion axis is arranged. A method may be used in which a pulse is generated according to the moving distance by a provided rotary encoder and is counted by a counter.

A workstation equipped with a color image display device is used as the data processing device 5, and image display and image processing can be performed together with control of the entire system of the radiation diagnostic apparatus 1.

Next, referring to FIG. 2, an example of an inspection procedure according to this embodiment will be shown. In the inspection procedure, the head of the subject is illustrated as the region of interest, but the region of interest is not limited to this.

First, RI, which is a radiopharmaceutical that is selectively taken up by a tissue or an organ in a region of interest of a subject, or a labeled compound thereof is administered. As the RI or its labeled compound, one having an appropriate physiological activity may be selected depending on the desired test content. Then, the bed top and bottom plate 41 is moved by the bed up-and-down moving mechanism 42 so that the subject can easily get on the bed.
Is lowered, and the subject lies on the bed top 41. Then, the bed top 41 is raised, and the elevation is stopped at a height at which the body axis center of the subject and the effective visual field center line 6 coincide with each other. This position is the initial position 71 of the subject. Next, the bed top 41 on which the subject is placed is horizontally moved to the left, and the positions of the subject are sequentially changed from the initial position 71 to the CT imaging position 7.
2, passing through the intermediate position 73 to the SPECT device,
The SPECT photographing position 74 is reached.

When the bed top plate 41 on which the subject is placed passes through the effective field of view 13 in the CT slice direction, the X-ray CT apparatus 3
Collects continuous X-ray projection data called a helical scan. The moving speed of the bed top at this time is
The speed is controlled so as to synchronize with the rotation speed of the rotation mechanism unit 34 so that a desired slice pitch of the X-ray tomographic image is realized.

The bed top 41 on which the subject is placed is a SPEC
When it reaches the T imaging position 74, it stops and the SPECT apparatus 2 collects SPECT projection data. SPEC
When the collection of the T projection data is completed, the bed top plate 41 is moved rightward to the initial position, and the position of the subject is also set to the initial position 7.
Return to 1.

Next, the data flow in this embodiment will be described with reference to FIG. Regarding each component related to the data flow in FIG. 3, the same component as the component shown in the configuration diagram of FIG. 1 is assigned the same reference numeral.

In FIG. 3, first, the couch top 41, on which the subject lies on its back, rises, and the initial position 71 of the subject is at a height at which the body axis center of the subject and the effective visual field center line 6 coincide.
Stop at (Fig. 2). Next, the CT mechanism control unit 35 issues a movement instruction signal 101 for moving the tabletop to the left to the tabletop moving mechanism 43, and the bed tabletop 41 on which the subject is placed.
Moves in the direction of the X-ray CT apparatus 3 and enters the range of the CT slice direction effective visual field 13. When the subject enters the CT slice direction effective visual field 13, the data processing device 5 instructs the CT image reconstruction unit 37 via the control signal line 106 to start projection data acquisition and start CT image reconstruction. To do. At this time, the position information 102 of the bed top 41 is detected by the top position detection unit 44 and the CT data together with the projection data 103 and 104 collected by the CT data collection unit 36.
The continuous CT images are reconstructed by the image reconstructing unit 37 and are sent to the data processing device 5 together with the tomographic position information 105.

Next, the subject moves to the SPECT apparatus of FIG.
Position information from the top position detecting unit 44,
When the data processing device 5 determines 2, 105 and the region of interest of the subject is completely within the SPECT slice direction effective visual field 12, the top moving mechanism 43 stops the movement of the top. Then, the position of the CT continuous image of the subject and the relative position information 1 of the SPECT images continuously collected from now on
02 and 105 are stored by the data processing device 5 as supplementary information of a series of CT images and SPECT images.

Then, the data processing device performs SPECT.
A collection start signal 110 is sent to the gamma camera mechanism control unit 25 and the gamma camera collection unit 26. As a result, the rotation control signal 111 is sent from the gamma camera mechanism control unit 25 to the rotation mechanism unit 24, and the SPECT image projection data 112 and 113 obtained from the gamma cameras 21a and 21b are collected by the gamma camera collection unit 26, and SPECT. It is sent to the data processor 5 for image reconstruction (114).

FIG. 4 shows an external view (a) of a phantom for creating a conversion table of a CT value and an attenuation coefficient for γ rays of a specific energy (for example, ^99m Tc), and a conversion table obtained from this phantom. It is shown as a graph (b). This phantom has a container with an overall diameter L of 20 to 30 cm and a thickness of 10 cm, and a substance P2 having an equivalent attenuation coefficient from a lung to a bone having a diameter of 3 cm.
~ P8 are arranged, and the other part is filled with water P1.

An X-ray CT image of this phantom is taken, and a conversion relationship or conversion table between the CT value and the attenuation coefficient is created. A graph showing this conversion relationship is shown in FIG.
In the case of (b), an intermediate CT value is linearly interpolated, for example.

Next, an example of processing the CT image and the SPECT image will be described. FIG. 5A shows the positional relationship of slice images obtained from the subject by the continuous CT images. Slice positions S1 to S5 are the CT of the heart and the myocardial SPECT.
It is an example of a combination of.

FIG. 5B shows X at slice position S3.
FIG. 4B is a line CT image, in which CT values for each pixel of tissues such as lung fields, spines, and muscles are converted into S values using a conversion relationship as shown in FIG.
The attenuation coefficient of the energy of γ-rays detected by PECT is converted to obtain an attenuation coefficient distribution image.

Next, the slice position S shown in FIG.
The 3rd SPECT image (myocardial image) is attenuation-corrected using the attenuation coefficient distribution image. The attenuation-corrected SPECT image is converted into the specific activity (Bq / ml) of the radioisotope labeled with the radiopharmaceutical of interest. This image can also be displayed as shown in FIG. 5D by superimposing it on the CT image at the same position.

Next, an example of processing the CT image and the scintigram (planar) image will be described with reference to FIGS. FIG.
A CT image crossing the kidney at the slice position S14 in (a) is shown in FIG. 6 (a). From this CT image, the depth d1 from the body surface to the kidney in the counting direction of the planar image and the depth d2 (length in the depth direction) of the kidney itself can be measured.
FIG. 6B is a scintigram image of the kidney taken from the back surface of the subject. The count value of the kidney in the scintigram image of FIG. 6 (b) is attenuation-corrected from the depth obtained from the CT image and the attenuation coefficient value on the path L counted in the scintigram image by the gamma camera to obtain the specific activity. Converted.

Next, referring to FIGS. 7 and 8, the time phase of the periodic body movement of the subject is measured, and the X-ray C along with the time phase information is measured.
An example of collecting the T data and the radiation distribution image will be described. Periodic body movements include body movements caused by the heartbeat and breathing.The former is known as heartbeat synchronization using an electrocardiograph or phonocardiograph, and the latter is known as respiratory synchronization using a respiratory volume sensor that measures chest circumference. Has been. First, in this embodiment, as shown in FIG. 7, the sensor 9-1 of the respiratory rate sensor device 9 is attached to the subject 7, and the respiratory rate sensor device 9 and the data processing device 5 are connected. Other configurations are the same as those in FIG.

Next, while the subject 7 is breathing, a helical CT scan is performed by passing the bed top plate on which the subject is placed at a low speed through the effective field of view in the CT slice direction, and X-ray projection data is obtained together with respiratory volume information. Collect (Figure 8). Then, the projection data is reconstructed to create a slice image.
Then, for example, B1, B2, ..., Bn,
Breathing volume is divided into several sections, and images having almost the same breathing volume belonging to the same section, for example, B1 are collected and interpolated to construct a three-dimensional X-ray CT image corresponding to the breathing volume B1. Do this for each respiratory volume category. In this way, a three-dimensional X-ray CT image for each respiratory volume B1, B2, ..., Bn is constructed.

Similar to the X-ray CT, the respiration rate is measured when the SPECT image is acquired. Then, the projection data of the gamma camera having the substantially equal respiratory rate B1 is collected to reconstruct the SPECT image of the respiratory rate B1. Similarly, respiratory volume B
, Bn, the projection data of the gamma camera is collected and reconstructed for each respiratory amount to form a three-dimensional SPECT image for each respiratory amount B1, B2, ..., Bn.

In this way, a CT image and a SPECT image in which the influence of the deformation of the organ or tissue due to the respiratory motion is removed are obtained. Then, using this, each respiratory volume B1, B2, ...,
Accurate attenuation correction for Bn can be performed.

Next, another embodiment will be described in which the effect of respiratory motion is eliminated by using a respiratory volume sensor. As in FIG.
A respiratory rate sensor is attached to the subject, and a predetermined respiratory rate Bf
At that time, the subject is instructed to hold his breath. For this, the signal from the respiratory rate sensor may be displayed in a form that the operator can easily recognize, and the operator may call the subject with a microphone, or the signal from the respiratory rate sensor and the set value may be compared by a comparator. Alternatively, the subject may be instructed by the sound generator or the display device by the comparison result signal. Then, a helical CT scan of the respiratory volume Bf is performed to collect data and reconstruct a CT image.

Next, while the subject is breathing, measurement of the respiratory volume and collection of SPECT projection data are performed in parallel. Then, from the projection data, only the projection data when the respiratory volume is close to the respiratory volume Bf is collected to reconstruct the SPECT image. In this way, an X-ray CT image and a SPECT image for a certain respiration rate of the respiration rate Bf are obtained. The subsequent processing is the same as that of the above-described embodiment.

Next, the subject on the bed is fixed and the SPEC
An embodiment will be described in which the T apparatus and the X-ray CT apparatus are moved relative to the subject to perform relative movement. FIG.
The bed 4-1 is a double-sided fixed bed, and this bed 4-1 is used.
On the other hand, the SPECT apparatus 2-1 and the X-ray CT apparatus 3-1
It is a front view which shows the structure which was made movable. In this configuration, the rail 10 is laid on the floor surface of the examination room, and the SPECT apparatus 2-1 and the X-ray CT apparatus 3-1 move on the rails 10 within the movable range shown in the drawing, respectively, and are not shown as drive units. To provide. Further, in order to detect the amount of movement with respect to the bed 4-1, the SPECT apparatus 2-1 and the X-ray CT apparatus 3-1 are each provided with a position detecting means (not shown).

FIG. 10 shows an SPE for a fixed bed.
It is a top view which shows the structure of the modification which made the CT apparatus and the X-ray CT apparatus movable. In FIG. 10, the SPECT apparatus 2-2 and the X-ray CT apparatus 3-2 are movable on the rail 10 with respect to the bed apparatus 4-2, respectively. An orthogonal X-ray CT device separation rail 10-1 and an X-ray CT dedicated bed device 4-3 are added. Further, the bed top plate 41 of the bed device 4-2.
-1 is detachably fixed to the bed base using, for example, a fixing screw 46.

Thus, when the radiation diagnostic method of the present invention is not performed, the X-ray CT apparatus 3-2 is placed on the X-ray CT apparatus separating rail 10-1 and the X-ray CT apparatus single-use position 3-3.
Can be moved to and separated from the SPECT apparatus 2-2. Then, the X-ray CT apparatus 3-2 can be used alone in combination with the X-ray CT dedicated bed apparatus 4-3 having a tabletop moving function, and when the SPECT apparatus 2-2 is used alone, the X-rays are simultaneously used. It is not necessary to move the CT device, and the operating efficiency of the inspection equipment can be improved. In addition,
It is apparent that the objects of the present invention can be achieved even if the arrangements of the SPECT apparatus and the X-ray CT apparatus are interchanged with each other in the configurations of the above respective embodiments.

[0055]

As described above, according to the present invention, the position information is measured at the same time as the inspection information about the subject is collected, and the X-ray tomographic image collected by the X-ray CT apparatus and the gamma camera apparatus are collected. The obtained SPECT image can be aligned based on the positional information, and the morphological diagnosis and the functional diagnosis can be accurately integrated for the accurate diagnosis.

Further, according to the present invention, there is an effect that a high-resolution attenuation coefficient distribution image can be obtained in a short time and more accurate SPECT attenuation correction can be performed.

Further, according to the present invention, there is an effect that the restraint time of the subject is shortened and the pain is reduced.

Further, according to the present invention, there is an effect that the inspection time can be shortened and the inspection throughput can be improved.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a radiation diagnostic apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing movement of a subject with respect to a SPECT apparatus and an X-ray CT apparatus according to an embodiment.

FIG. 3 is a block diagram illustrating the flow of data and control signals according to the embodiment.

4A is a shape explanatory diagram of a phantom for which an attenuation coefficient is obtained from a CT value, and FIG. 4B is a graph showing a correspondence relationship between the CT value and the attenuation coefficient.

FIG. 5 is a diagram illustrating composition of an X-ray CT image and a SPECT myocardial image.

FIG. 6 is a diagram illustrating a method of performing attenuation correction of a scintigram image (planar image) using information obtained from a CT image.

FIG. 7 is a system configuration diagram for synthesizing an X-ray CT image and a SPECT image from which the influence of body movement is removed by using a respiratory volume sensor device.

FIG. 8 is a diagram for explaining the respiratory volume and the timing of X-ray CT image acquisition.

FIG. 9: SPECT apparatus and X-ray CT with the bed apparatus fixed
It is a system block diagram (front view) which shows another Example which made the apparatus movable.

FIG. 10: SPECT apparatus and X-ray C with the bed apparatus fixed
It is a system block diagram (plan view) which shows the modification of the other Example which made the T apparatus movable.

[Explanation of symbols]

1 Radiation diagnostic equipment 2 SPECT equipment 3 X
X-ray CT device 4 Bed device 5 Data processing device
6 Effective visual field center 7 Subject 8 Moving range of the top 9 Respiratory volume sensor device 41 Bed top 4
3 Top moving mechanism 44 Top position detector

Claims (5)

[Claims] 1. A step of collecting an X-ray tomographic image and a nuclear medicine image without changing the posture of the subject along with position information, and a morphological measurement from the X-ray tomographic image and the nuclear medicine image of the same position of the subject. A radiation diagnostic method comprising: a step of performing functional measurement. 2. A step of obtaining a correspondence relationship between a γ-ray attenuation coefficient and a CT value using a known standard sample in advance, and an X-ray attenuation coefficient distribution image of an object with respect to γ-ray energy emitted from a radiopharmaceutical. A radiation diagnostic method comprising: a step of calculating based on a line tomographic image and the correspondence; a step of performing attenuation correction in reconstruction of a single photon emission CT using an attenuation coefficient distribution image. 3. A step of obtaining a correspondence relationship between a γ-ray attenuation coefficient and a CT value using a standard sample known in advance, and an X-ray attenuation coefficient distribution image of a subject with respect to γ-ray energy emitted from a radiopharmaceutical. A step of calculating the depth information of the region of interest of the subject from the X-ray tomographic image, and a step of calculating the depth information of the region of interest from the X-ray tomographic image using the attenuation coefficient distribution image and the depth information of the region of interest And a step of performing attenuation correction for obtaining a specific activity from a two-dimensional distribution image obtained from the gamma camera device, and a radiation diagnostic method. 4. A bed apparatus having a top plate on which a subject is placed, and a two-dimensional or three-dimensional distribution image of the radiopharmaceutical by detecting γ-rays emitted from the radiopharmaceutical administered to the subject. A gamma camera device for obtaining an X-ray tomographic image of a subject, and a gamma camera device such that the region of interest of the subject is included in the effective field of view of the gamma camera device or the X-ray CT device. And / or moving means for relatively moving the X-ray CT apparatus and the top plate section, and measuring the relative position between the gamma camera apparatus and the top plate section and the relative position between the X-ray CT apparatus and the top board section to obtain position information. And a data processing device for aligning or synthesizing the image obtained by the gamma camera device and the image obtained by the X-ray CT device based on the position information obtained by the position measuring device. Equipped with Radiodiagnostic and wherein the. 5. A gamma camera device for detecting a γ-ray emitted from a radiopharmaceutical administered to a subject to obtain a two-dimensional distribution image or a three-dimensional distribution image of the radiopharmaceutical, and an X-ray tomographic image of the subject. An X-ray CT apparatus for imaging, a time phase measuring means for measuring time phase of periodic body movement of the subject to obtain time phase information, and a time phase synchronous CT for the X-ray CT apparatus based on the time phase information. The gamma camera device is made to perform scanning, and the gamma camera device is made to collect time-phase synchronous distribution images, and the X-ray tomographic image obtained by the time-phase synchronous CT scan and the time-phase synchronous distribution image obtained by the gamma camera device are time-phased. And a data processing device that displays or processes information, and a radiation diagnostic device.