JP4453322B2 - Tomography equipment - Google Patents

Description

  The present invention relates to a tomography apparatus used in the medical field, industrial fields such as non-destructive inspection, RI (Radio isotope) inspection, and optical inspection.

Conventionally, this type of apparatus includes an X-ray tube at one end and a C-type arm that supports an image intensifier (hereinafter abbreviated as “I.I” as appropriate) at the other end. body axis, namely that the C-arm rotates in Ri Jikushu scanning central axis, X-rays tube and I. I integrally scans around the subject to obtain a tomographic image of the subject (for example, see Patent Document 1).
JP 2001-45374 A (page 3, FIG. 1)

However, in the case of Patent Document 1 described above, there are the following problems. This will be described with reference to FIG. Here, reference numeral 101 in FIG. 15 denotes a C-arm, 102 denotes an X-ray tube, 103 denotes an image intensifier (II), and M denotes a subject. C shaped arm 101 when rotating in Ri Jikushu the body axis of the subject M (y-axis in FIG. 15), is sent to rotate within the length of the C-arm 101. Thus, the X-ray tube 102 and the I.D. The operation of I103 is limited, it can not be one revolution Ri Jikushu the scanning center axis continuously C-arm 101 (body axis). Therefore, in order to obtain a tomographic image of the entire subject M, the X-ray tube 102 and the I.D. The I103, is rotated to Ri Jikushu the sectional axis (z-axis in FIG. 15). Here, the tomographic axis refers to another axis that is not parallel to the scanning center axis and that passes through the region of interest of the subject M. Note that the X-ray tube 102 and the I.V. X-ray tube 102 and I.I. so that the center of the X-ray beam connecting I103 is inclined at a predetermined angle α (hereinafter, this angle α is referred to as “lamino angle”). I103 is supported. Usually, the scanning center axis and the tomographic axis are set so as to be substantially orthogonal to each other.

X-ray tube 102 and I.V. The C-shaped arm 101 supporting the I103 needs a length to be sent and becomes heavier by that amount. In practice, therefore, the X-ray tube 102 and the I.I. To directly I103 not rotated Ri Jikushu the sectional axis. In practice, the X-ray tube 102 and the I.D. The C-arm 101 which supports the I103 is rotated to Ri Jikushu arm axis (x-axis in FIG. 15), X-ray tube 102 and I. The I103 is rotated to Ri Jikushu the body axis of the subject M (scanning center axis), X-ray tube 102 and I. And indirectly rotated Ri Jikushu the sectional axis of I103. Here, the arm axis refers to an axis that is substantially perpendicular to the scanning center axis and substantially perpendicular to the tomographic axis.

(I)
Since the two axes (scanning center axis and arm axis) are rotated in this way, the X-ray tube 102 and the I.D. When the I103 rotated Ri fault Jikushu (for example, about 6 seconds) it takes time. Conversely, X-ray tube 102 and I.D. C-arm 101, X-ray tube 102 to rotate the Ri Jikushu of directly sectional axis of I103, and I. When configuring I103 respectively, it becomes possible to rotate the Ri Jikushu of C-arm 101 each sectional axis. Body axis of the C-arm 101 patient M in the case of rotating the Ri Jikushu of (scanning center axis), a possibility that the C-arm 101 and the object M so rotate around the subject M is conflict small, when rotating the Ri Jikushu of C-arm 101 each sectional axis is, there is a possibility that the C-arm 101 collides with the end portion of the body axis direction, such as the head and legs of the patient M, It cannot be safely rotated and scanned.

(II)
Further, since the two axes (scanning center axis and arm axis) are rotated in this way, the X-ray tube 102 and the I.D. I103 The Rotation in Ri fault Jikushu resolution of the tomographic axis direction, there is another axis (e.g., the scanning center axis) problem becomes worse as compared with the resolution of the direction of. This is because it corresponds only to the main scanning in the present invention, and the spatial resolution becomes inferior in the tomographic axis direction, resulting in anisotropic spatial resolution. Further, due to the structure of the C-arm, high-speed scanning is impossible.

  On the other hand, the conventional X-ray CT apparatus has evolved so that continuous spiral scanning of about 0.5 seconds / rotation can be performed, but it is still insufficient for imaging fast-moving organs such as the heart, ECG synchronization data is collected from a number of angular directions during a number of rotations on the same slice plane, and a static reconstructed image of the heart is obtained by synthesis. Also, isotropic spatial resolution is not possible due to the limitations of simple helical scanning.

  The present invention has been made in view of the above circumstances, and (I) a tomography apparatus capable of rotating and scanning an irradiation source and a detection means safely and at high speed is (II) high-speed scanning. In addition, an object is to provide a tomography apparatus capable of improving the resolution in the tomographic axis direction and acquiring a three-dimensional tomographic image with isotropic spatial resolution.

As a result of earnest research to solve the above problem (I), the inventor has obtained the following knowledge.
That is, the inventor has paid attention to the field of X-ray CT (Computed Tomography). In recent years, in the field of CT, the concept of 4DCT (4-dimensional CT) has been popularized. This is an attempt to grasp not only the three-dimensional structure collection of the subject but also its temporal change, and specifically, an attempt to capture a moving image tomographic image of the heart. In the tomography apparatus, a moving image tomographic image of the heart can be taken by shortening the scanning time for one rotation.

Usually, in the case of an X-ray CT apparatus, it is required to increase the speed of a rotating frame, which is a gantry composed of an X-ray tube and a detector, but the rotation radius of the X-ray tube and the detector can be essentially reduced. Since this is not possible, the scanning time for one rotation in the gantry is about 0.5 seconds, which cannot be shortened further. On the other hand, in the case of tomography apparatus, tomographic Jikushu Rino rotation radius of a detection means as illumination source and the image intensifier, such as X-ray tube (I.I) is X in the gantry of the CT Smaller than the radius of rotation of the tube and detector.

In the case of X-ray CT apparatus, as shown in the side view of FIG. 16 (a), the X-ray tube detector is rotated Ri Jikushu the sectional axis 202 of the subject M within the gantry 201 The In such a case, the body axis of the subject M is parallel to the tomographic axis 202, and the lamino angle, which is the angle between the tomographic axis 202 and the X-ray beam center connecting the X-ray tube and the detector, is 90 °. Become. Therefore, the present inventor obtained an idea from the X-ray CT, changed the lamino angle to an angle other than 90 ° as shown in the plan view of FIG. by rotating the tomographic Jikushu Rinisorezore integrally radiation source and detector, such as a line pipe, tomographic Jikushu Rino rotation radius of the radiation source and the detection means is reduced, since only a small need torque, integrated I thought that it would be possible to rotate at high speed. The present invention based on such knowledge has the following configuration.

That is, the invention according to claim 1 integrates the irradiation source for irradiating the subject with electromagnetic waves, the detection means for detecting the electromagnetic waves transmitted through the subject, and the irradiation source and detection means. A tomography apparatus for acquiring a three-dimensional tomographic image from a group of projection data detected at each position of the detection means scanned by the scanning means, wherein the region of interest of the subject An irradiation source and a detection unit are disposed so that an irradiation axis connecting the irradiation source and the detection unit is inclined at a predetermined angle with respect to a tomographic axis passing through the scanning axis, and the scanning unit is an irradiation surrounding the irradiation source. A detector case surrounding the source case and the detection means; and a rotating means for integrally rotating the casings around the tomographic axis passing through the casings , the irradiation source and the detection means Surround these It is characterized in being rotated while maintaining its position relative to the housing.

According to the invention described in Operation and Effect according to claim 1, the radiation source on the radiation source housing surrounding the radiation source, the detection means on detection means housing surrounding the detector, Ri fault Jikushu a by rotating integrally respectively, it is possible to rotate the radiation source and detecting means Ri fault Jikushu on each housing, it is possible to safely rotate scanned radiation source and detector. Further, the radiation source on the radiation source housing surrounding the radiation source, the detection means on detection means housing surrounding the detector, is rotated in the tomographic Jikushu Rinisorezore integrally fault as in the prior art without rotating the radiation source and detector in axis other than the axis, it can be rotated to Ri directly tomographic Jikushu can be scanned rotating the radiation source and detector fast. As a result, the irradiation source and detection means can be rotated and scanned safely and at high speed.

Note that rotates the radiation source and the detection means of each enclosure Ri fault Jikushu, the radiation source and detecting means by rotating the Ri each housing tomographic Jikushu may be rotated Ri fault Jikushu and, a radiation source and detecting means in the housing in a state of fixing the housing may be rotated to Ri fault Jikushu.

An irradiation source casing and a detection means casing are connected to a rotating shaft connected to the rotating means, and the rotating shaft is disposed on one end side of each casing. Of the present invention). With this configuration, the radiation source and detector means on the housings can be rotated integrally with Ri fault Jikushu. In addition, the rotation axis is not disposed in the vicinity of the subject, but is disposed on one end side of each case that does not affect the subject, so that it is detected with the irradiation source case connected by the rotation axis. The means housing is configured in a so-called “U-shape” to provide a feeling of opening of the subject.

  The detection means in the present invention may be, for example, an image intensifier (II), a gate line that takes in transmitted electromagnetic waves by switching ON / OFF, and a gate line that is orthogonal to the gate line. Further, it may be a flat panel detector (hereinafter abbreviated as “FPD” as appropriate) provided with a plurality of readout lines that are read out as projection data. When the detection means is a flat panel detector (FPD), for example, the flat panel detector is arranged so that each readout line is along the projection axis obtained by projecting the tomographic axis onto the detection surface of the FPD. (Invention of Claim 3) There is a form.

  In such a case, by simultaneously turning on a plurality of gate lines, electromagnetic waves at respective positions corresponding to the gate lines are simultaneously captured as charges, and the captured charges are converted into projection data via the readout line. It is preferable that low-pass filtering is performed by simultaneously turning on a plurality of gate lines for the read projection data and the read projection data (the invention according to claim 4).

  In such a case, since the low-pass filtering is performed on the read projection data by simultaneously turning on a plurality of gate lines, the false image of the tomographic image can be reduced by the low-pass filtering.

Further, as the time required for one rotation of the radiation source and detecting means for rotating integrally with Ri fault Jikushu by rotating means it is less than 0.1 seconds, constituting the scanning means (claim 5) Thus, for example, a temporal change of the tomographic image can be grasped like a moving image tomographic image of the heart. For example, the sectional axis, by reducing the lamino angle is an angle between the illumination axis connecting the radiation source and detector, it is small torque required for high-speed rotation, the irradiation which rotates integrally with Ri fault Jikushu The time required for one rotation of the source / detection means can be shortened.

An example of the irradiation source is an X-ray tube that emits X-rays. The rate of conversion from thermoelectrons emitted from the cathode constituting the X-ray tube to X-rays at the anode constituting the X-ray tube is small, and the rest is converted to heat, so that damage caused by the heat generated at the anode In order to prevent this, an X-ray tube is a rotating anode X-ray tube composed of a cathode that emits thermoelectrons, an anode that generates X-rays by accelerated thermoelectron collision from the cathode, and an anode rotating shaft that rotates the anode. There are many types. However, inertia caused by anode rotation by duplication of the rotation of the tomographic Jikushu Riniyoru radiation source and detecting means, subjected to any excessive force to the anode rotating shaft, which may bear the X-ray tube according. Therefore, the X-ray tube is configured and arranged so that the anode rotation axis is parallel to the tomographic axis (the invention according to claim 6), thereby reducing the force applied to the anode rotation axis, thereby reducing the X-ray. The burden on the pipe can be reduced.

In addition to the rotary anode X-ray tube type described above, the X-ray tube type includes a cathode that emits thermoelectrons, an anode that generates X-rays by accelerated thermoelectron collision of the cathode, and a support that supports the cathode. There is a type of rotating cathode X-ray tube configured. In this case, the anode with constituting fixed parallel Jikushu Rinien annular sectional axis, the support portion configured to Jikushu Rinien annular parallel to the sectional axis, the cathode together with the support part, the X-ray tube arranged to rotate Ri parallel Jikushu the sectional axis at (claim 7), fault Jikushu Riniyoru from inertia accompanying the rotation of the support and the cathode to rotate The burden on the X-ray tube can be reduced by reducing the force applied to the cathode together with the support portion due to the overlapping of the rotation of the irradiation source / detection means.

On the other hand, as a result of diligent research to solve the problem (II), the inventor has obtained the following knowledge.
In the case of X-ray CT apparatus, as shown in the side view of FIG. 16 (a), the X-ray tube detector are rotated Ri Jikushu the sectional axis 202 of the subject M within the gantry 201. In such a case, the body axis of the subject M is parallel to the tomographic axis 202, and the lamino angle, which is the angle between the tomographic axis 202 and the X-ray beam center connecting the X-ray tube and the detector, is 90 °. Become. Therefore, the present inventor obtained an idea from the X-ray CT, changed the lamino angle to an angle other than 90 °, as shown in the plan view of FIG. and by reducing the rotation radius of the detecting means, by rotating integrally with Ri fault Jikushu, and conceived that it is possible to realize the main scanning of the high-speed rotation, such as, for example, 0.1 sec / rotation. Further, it has been conceived that a reconstructed image with isotropic spatial resolution can be obtained by applying a sub-scan to the subject to rotate the main scanning structure integrally. The present invention based on such knowledge has the following configuration.

In other words, the invention according to claim 8 is a combination of an irradiation source that irradiates a subject with electromagnetic waves, a detection unit that detects the electromagnetic waves transmitted through the subject, and the irradiation source and detection unit. A tomography apparatus comprising: a scanning unit that scans; and an image processing unit that acquires a three-dimensional tomographic image from a group of projection data detected at each position of the detection unit scanned by the scanning unit, An irradiation source and a detection unit are arranged so that an irradiation axis connecting the irradiation source and the detection unit is inclined at a predetermined angle with respect to a tomographic axis passing through a region of interest of the subject. Main scanning rotation means for integrally rotating the casing around the tomographic axis passing through the irradiation source casing surrounding the irradiation source and the detecting means casing surrounding the detecting means, and substantially orthogonal to the tomographic axis Run that is one of the axes Subordinate scanning rotation means for integrally rotating the irradiation source and the detection means relative to the subject around the central axis, and the irradiation source and the detection means maintain a position relative to the casing surrounding them. It is characterized by being rotated as it is.

According to the invention described in Operation and Effect according to claim 8, since a main scanning rotating means for rotating integrally radiation source and detecting means Ri fault Jikushu, other than the sectional axis as in the conventional axial in without rotating the radiation source and detector can be rotated to Ri directly tomographic Jikushu. As a result, high-speed main scanning can be realized. Further, Ri is one scanning center Jikushu axis substantially perpendicular to the sectional axis, is provided with the secondary scanning rotating means for rotating integrally relatively radiation source and detector to the subject, sub By adding main scanning to scanning, a three-dimensional tomographic image with isotropic spatial resolution can be acquired.

The scanning means comprises a housing for detecting means surrounding the housing and detection means for the radiation source which surrounds the radiation source, the main scanning rotating means, the radiation source and the detection means of each enclosure Ri the tomographic Jikushu The scanning means may include a scanning casing surrounding the irradiation source and the detection means, and the secondary scanning rotating means may be an irradiation source of the scanning casing. and it may be rotated integrally with the detection means to Ri scan center Jikushu (claim 10). Note that rotates the radiation source and the detection means of each enclosure Ri fault Jikushu, the radiation source and detecting means by rotating the Ri each housing tomographic Jikushu may be rotated Ri fault Jikushu and, a radiation source and detecting means in the housing in a state of fixing the housing may be rotated to Ri fault Jikushu.

  In the present invention, it is preferable that the sub-scanning rotation means includes a scanning housing support member that holds the scanning housing, and the holding portion between the scanning housing support member and the scanning housing includes By providing the feeding mechanism, the feeding mechanism rotates the scanning housing (the invention according to claim 11). Further preferably, the scanning housing support member has an arc-shaped portion, and the feed mechanism rotates the scanning housing along an inner peripheral surface of the arc-shaped portion. As a result, the sub-scanning rotating means has a simple configuration, and the floor occupation area of the tomography apparatus can be reduced.

Further, since lamino angle to be described later is often set at usually 45 ° or less, when the radiation source and detector means are inclined at lamino angle is arranged with respect to the sectional axis, fault Jikushu Rinoomo rotation of the scanning becomes faster than the rotation in the scanning center Jikushu Rino従scanning (claim 12).

Further, to a sectional axis, the lamino angle is an angle between the illumination axis connecting the radiation source and detecting means when the alpha, and the rotation range in the scanning center Jikushu Rino従scan, at least [pi-2.alpha more thing (claim 13), the rotation range of the scanning center Jikushu Rino従scanning, without setting in 2 [pi (1 rotation), since joining the rotation of the main scanning, within the limits set Thus, a three-dimensional tomographic image with isotropic spatial resolution can be acquired.

  Further, the direction of the scanning center axis in the secondary scanning and the direction of the tomographic axis in the main scanning are not particularly limited. In a normal tomography apparatus, the horizontal axis or vertical axis direction is set as in the inventions of claims 14 to 17.

  For example, the scanning central axis in the secondary scanning may be a horizontal axis, the tomographic axis in the primary scanning may be on the vertical plane (the invention according to claim 14), and the scanning central axis in the secondary scanning is the vertical axis. Thus, the tomographic axis in the main scanning may be in a horizontal plane (the invention according to claim 15).

In the latter case (claim 15), secondary scanning rotating means, wherein the irradiation source and the detecting means may be rotated integrally (claim 16 to Ri vertical Jikushu relative to the ceiling surface invention), and secondary scanning rotation means, the invention described above in may rotate the object (claim 17 to Ri vertical to the floor surface Jikushu).

Further, as the time required for one rotation of the radiation source and detecting means for rotating integrally with Ri fault Jikushu does not exceed 0.1 seconds by the main scanning rotation means, the scanning means (according to claim 18 Invention), it is possible to grasp the temporal change of the tomographic image, such as a moving image tomographic image of the heart. For example, the sectional axis, by reducing the lamino angle is an angle between the illumination axis connecting the radiation source and detector, the time required for one rotation of the radiation source and detecting means for rotating integrally with Ri fault Jikushu It can be shortened.

Further, as the time required for half rotation of the radiation source and detecting means for rotating integrally with Ri scanning center Jikushu by secondary scanning rotation means is below 5 seconds, constituting said scanning means (claim 19 Therefore, when the subject is a patient, for example, the time during which the patient can hold his / her breath or the time during which no body movement occurs is 5 seconds or less. while does not occur, the radiation source and detecting means may be half rotation integrally with Ri scanning center Jikushu. Therefore, a tomographic image with little deviation can be acquired.

The invention described in claims 13, 18, and 19 will be described more specifically with reference to FIG. FIG. 17 is an explanatory diagram for explaining the collection of a three-dimensional tomographic image with isotropic resolution of a heart part. FIG. 17A is a collection data distribution diagram in Fourier space, and FIG. It is a data collection timing chart. For the sake of simplicity, the lamino angle α is 15 °. As shown in FIG. 17 (b), a slow sub-scan is superimposed on the main scan of 0.1 second (0.1 second / rotation), and the time required for one rotation of the irradiation source / detection means is over 150 ° to Ri scan center Jikushu (= 180 ° -2 × 15 ° ), is performed between 5 seconds time necessary for the half rotation of the radiation source and detecting means (10 sec / rotation).

  Preferably, the tomography apparatus further includes a measuring unit that detects a periodic movement of the heart of the subject, and an electromagnetic wave synchronized with a certain timing among the periodic movements detected by the measuring unit. And an irradiation source control means for controlling the irradiation source so as to irradiate the subject (the invention according to claim 20).

  When the imaging part is moving, it is difficult to reconstruct a good three-dimensional tomographic image because the projection data of the imaging part in the same state cannot be collected. Therefore, by providing a detection means for detecting the motion of the heart, projection data having the same imaging region can be efficiently collected without waste.

  For the acquisition of 3D tomographic images without cardiac motion artifacts, the acquisition is performed in synchronization with an electrocardiogram (ECG) waveform, as shown in FIG. 17 (b). The Fourier space distribution of the data obtained by one rotation of the main scan is in the range of 30 ° (= 2 × α) as shown in the hatched (hatched) portion in FIG. That is, it can be seen from FIG. 17 that in order to collect data necessary for obtaining a three-dimensional tomographic image with isotropic spatial resolution, it is sufficient to perform six main scanning acquisitions every 30 ° of the secondary scanning. .

  More specifically, as shown in the timing chart of FIG. 17B, the transmitted X-ray image of the subject during one rotation period of main scanning that is continuously rotating at a high speed from the α wave of ECG from a predetermined delay time. Collection is performed and this is performed a total of 6 times in synchronism with the ECG every 30 °. Actually, the main scan does not rotate only for the time (0.1 second) of the black portion in FIG. 17B but continues to rotate for 5 seconds of the sub-scan. The electromagnetic wave (in this case, X-rays) is irradiated from the irradiation source only for the black portion (0.1 second).

As is apparent from the above description, according to the present invention, the irradiation source is arranged on the irradiation source casing surrounding the irradiation source, the detection means is arranged on the detection means casing surrounding the detection means, and the common fault axis is used. by moving integrally with Ri circumferential safely radiation source and detector, and can be rotated high-speed scanning. Accordingly, it is possible to obtain a moving image tomographic image of a region of interest having a motion such as the heart.
Further, according to the present invention, a main scanning rotational means for rotating integrally radiation source and detecting means Ri fault Jikushu, secondary scanning rotation which rotates integrally relatively radiation source and detector relative to the object In addition to high-speed scanning, the resolution in the tomographic axis direction can be improved and a three-dimensional tomographic image with isotropic spatial resolution can be acquired. Furthermore, by collecting data in synchronization with a biological signal, a three-dimensional tomographic image with isotropic spatial resolution can be obtained for a region of interest such as the heart.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The first embodiment solves the problem (I).
FIG. 1 is a perspective view showing a schematic configuration of a tomography apparatus according to the present embodiment. FIG. 2 is an X-ray tube frame and a flat panel detector (hereinafter referred to as “FPD”) of the tomography apparatus according to the present embodiment. 3 is a magnified view of the X-ray tube in the X-ray tube frame, and FIG. 4 is a flat panel detector (FPD) of the tomography apparatus according to the present embodiment. FIG. 5 is a diagram showing the relationship between the gate lines and data lines constituting the flat panel detector (FPD) and the tomographic axis, and the flat panel detector (FPD) of FIG. It is the perspective view seen from the top.

As shown in FIG. 1, the apparatus according to the present embodiment includes a top plate 1 on which a subject M is placed, a base 2, and a scanning frame 3. The top plate 1 is configured to be movable up and down and movable along the body axis direction of the subject M (y-axis in FIGS. 1 and 2) as shown in FIG. The base 2 is fixed to the floor surface. Scan frame 3 is fixed except for rotation Jikushu Rino body axis of the subject M mounted on the base 2, FIG. 1, is configured to form "U" as shown in FIG. 2 ing. By being configured in a “U” shape, a sense of openness to a patient (subject) that cannot be obtained with a normal X-ray CT apparatus is obtained. In this embodiment, the body axis of the subject M is the scanning center axis A and also the horizontal axis. The scanning frame 3 corresponds to the scanning means in this invention.

The side surface of the base 2, as shown in FIG. 1, the rotary table 4 is arranged to rotate Ri circumferential scan center axis (body axis), and the rotary table 4 and the scan frame 3, the support member 5 are connected. Further, as shown in FIG. 2, the scanning frame 3 incorporates an X-ray tube frame 6 and a flat panel detector (FPD) frame 7, and the X-ray tube frame 6 includes an X-ray tube 8 and an FPD. The frame 7 is configured to surround the flat panel detector (FPD) 9.

With this configuration, the scan frame 3, Ri Jikushu the body axis of the subject M, or scan center Jikushu rotates in is, further X-ray tube frame 6 on the scanning frame 3, FPD frame 7 above The X-ray tube 8 and the FPD 9 rotate around the tomographic axis. The X-ray tube frame 6 is used as an irradiation source housing in the present invention, the FPD frame 7 is used as a detection means housing in the present invention, and the X-ray tube 8 is used as an irradiation source in the present invention. (FPD) 9 corresponds to the detection means in the present invention.

A specific configuration of each of the frames 3, 6 and 7 will be described with reference to FIG. In the scanning frame 3, in addition to the X-ray tube frame 6 and the FPD frame 7, a rotation drive motor 10, a rotation drive shaft 11, and gears and bearings 6a and 7a are incorporated. The rotary drive motor 10 and the rotary drive shaft 11 are connected to each other through a gear, and the rotary drive shaft 11 and the X-ray tube frame 6 are connected to the gear or the tomographic axis B (z in FIGS. 1 and 2). the shaft) via a bearing 6a configured in parallel Jikushu Rinien cyclic, a rotary drive shaft 11 and the FPD frame 7, a gear and are configured parallel Jikushu Rinien annular sectional axis B The bearings 7a are connected to each other. The bearing 6 a is joined to the surface of the X-ray tube frame 6, and the bearing 7 a is joined to the surface of the FPD frame 7. That is, the X-ray tube frame 6 and the FPD frame 7 are connected to the rotary drive shaft 11 connected to the rotary drive motor 10. In this embodiment, the tomographic axis B is a vertical plane as shown in FIGS. 1 and 2 and passes through the region of interest of the subject M. The tomographic axis B is orthogonal to the scanning center axis A.

Also, X-rays emitted from the X-ray tube 8, as shown in FIG. 2, FIG. 3, open the predetermined angle component, a so-called "cone-beam" shape, Ri tomographic Jikushu the X-ray tube 8 and FPD9 The X-ray tube 8 and the FPD 9 are set so that the X-ray beam center R always passes through the substantially central position P of the region of interest of the subject M even if the X-ray tube 8 is rotated. Further, the X-ray tube 8 and the FPD 9 are arranged so that the beam center R is inclined with respect to the tomographic axis B by the lamino angle α. In this embodiment, the lamino angle α is about 20 °. The beam center R corresponds to the irradiation axis in the present invention.

With this configuration, it is possible to rotate the Ri tomographic Jikushu each frame 6, tomographic X-ray tube 8 and FPD9 on each frame 6 by respective frames 6 and 7 are rotated Jikushu Rinisorezore can be rotated integrally. The rotation drive motor 10 corresponds to the rotation means in the present invention, and the rotation drive shaft 11 corresponds to the rotation shaft in the present invention.

Incidentally, these frames 6, 7 when rotated in Ri Jikushu the sectional axis B, and because the cable connected to the X-ray tube 8 and FPD9 to prevent the tangling by rotation thereof, the present embodiment apparatus A slip ring mechanism is adopted.

  A specific configuration of the X-ray tube 8 will be described with reference to FIG. In the present embodiment, the X-ray tube 8 employs a rotary anode X-ray tube type shown in FIG. That is, the X-ray tube 8 includes a cathode (filament) 12 that emits thermoelectrons, an anode 13 that generates X-rays by accelerated collision of thermoelectrons emitted from the cathode 12, and an anode rotation shaft 14 that rotates the anode 13. Consists of Actually, the rate at which the thermoelectrons emitted from the cathode 12 are converted into X-rays at the anode 13 is small, and the remainder is converted into heat. Therefore, in order to prevent damage caused by the heat generated at the anode 13, the anode rotation The shaft 14 rotates the anode 13.

Depending overlap of inertia caused by anode rotation the rotation of the tomographic Jikushu Riniyoru X-ray tube 8 · FPD9, subjected to any excessive force to the holding portion of the anode rotating shaft 14, may bear the X-ray tube 8 is applied is there. Therefore, the X-ray tube 8 is configured and arranged so that the anode rotation shaft 14 is parallel to the tomographic axis B, so that the force applied to the anode rotation shaft 14 is reduced and the load on the X-ray tube 8 is reduced. Can be reduced.

  In the present embodiment, cone beam-shaped X-rays are generated from the anode 13 of the X-ray tube 8 in the direction as shown in FIGS. 2 and 3, so that the anode rotation axis 14 is parallel to the tomographic axis B. In relation to this, the cathode (filament) 12 is disposed at a position as shown in FIG. 3, and an X-ray emission window 8a is disposed at a position as shown in FIG.

  The X-rays generated from the anode 13 are irradiated onto the subject M in a cone beam shape as shown in FIGS. 2 and 3, and are transmitted into the subject M and incident on the FPD 9 as shown in FIG. The The beam center R is incident on both ends of the FPD 9 at both ends of the beam opened by a predetermined angle at the center of the FPD 9.

A specific configuration of the flat panel detector (FPD) 9 will be described with reference to FIG. The FPD 9 is a radiation-sensitive detector that generates carriers by the incidence of radiation such as X-rays. The FPD 9 has a vertical / horizontal two-dimensional matrix arrangement in which a large number of detection elements DU (for example, 1024 × 1024) are formed. The detection element DU includes a charge storage capacitor Ca that accumulates carriers generated by the incidence of X-rays irradiated and transmitted to the subject M, an application electrode 15 that applies a high bias voltage _VA , radiation, and the like. The carrier collecting electrode 16 is disposed opposite to the application electrode 15 with a sensitive semiconductor film (not shown) interposed therebetween. In addition, the detection elements DU are separately formed for each carrier collection electrode 16, and the application electrode 15 is formed over the entire surface as a common electrode of all the detection elements DU.

  In addition to this, the FPD 9 is connected to a thin film transistor (TFT) Tr that is a switching element for taking off charges that are normally OFF (blocked) for taking out the charges accumulated in the capacitor Ca, and a source of the thin film transistor Tr. A data line (bit line) 17 and a gate line 18 connected to the gate of the thin film transistor Tr are provided. The data line 17 is connected to the multiplexer 20 via the charge-voltage conversion group 19, and the gate line 18 is connected to the gate driver 21. The data line 17 corresponds to the read line in the present invention, and the gate line 18 corresponds to the gate line in the present invention.

In the present embodiment, as shown in FIG. 5, the FPD 9 is disposed along the projection axis 9 </ b> B obtained by projecting the tomographic axis B onto the detection surface 9 a of the FPD 9 so that each data line 17 is along the projection axis 9 </ b> B. Incidentally, by disposing the thus FPD9, even when the FPD9 rotated Ri fault Jikushu, each data line 17, along always a projection axis 9B obtained by projecting the sectional axis B on the detection surface 9a of the FPD9 .

  In addition, the gate driver 21 applies a voltage to turn on the thin film transistor Tr to each gate line 18 so that the plurality of gate lines 18 are simultaneously turned on. In this way, the X-rays of the detection elements DU corresponding to the gate lines 18 are simultaneously captured as carriers, and the captured carriers are read out as projection data via the data lines 17, respectively.

  Specifically, the carriers generated by the incidence of the X-rays irradiated and transmitted to the subject M are accumulated in the capacitor Ca. Since the plurality of gate lines 18 are simultaneously ON, the carriers accumulated in the capacitor Ca in each detection element DU are simultaneously read out to each data line 17 via the thin film transistor Tr. Carriers become voltage data by the charge-voltage conversion group 19 and are collected as projection data by the multiplexer 20.

  A three-dimensional tomographic image is acquired by performing various image processing based on the projection data collected in this way. Moreover, since the low-pass filtering is performed on the read projection data by simultaneously turning on the plurality of gate lines 18, false images of the tomographic image can be reduced by the low-pass filtering.

According to the tomography apparatus according to the present embodiment described above, the X-ray tube 8 on the X-ray tube frame 6 surrounding the X-ray tube 8, a FPD9 on FPD frame 7 surrounding the FPD9, the sectional axis B Jikushu Rinisorezore is rotated integrally, can be rotated to Ri tomographic Jikushu the X-ray tube 8 and FPD9 on each frame 6, to be safely rotated scanning the X-ray tube 8 and FPD9 it can. Further, the X-ray tube 8 on the X-ray tube frame 6 surrounding the X-ray tube 8, a FPD9 on FPD frame 7 surrounding the FPD9, is rotated in the tomographic Jikushu Rinisorezore integrally fault as in the prior art without rotating the X-ray tube 8 and FPD9 the axis other than the axis B, can be rotated to Ri directly tomographic Jikushu safely X-ray tube 8 and FPD9, and be rotated scanning speed it can.

In the present embodiment, the X-ray tube frame 6 and the FPD frame 7 are connected to the rotary drive shaft 11 connected to the rotary drive motor 10, respectively. it is possible to rotate the linear tube 8 and FPD9 tomographic Jikushu Rinisorezore integrally. The rotational drive shaft 11 is not disposed in the vicinity of the subject M, but is disposed on one end side of each of the frames 6 and 7 that does not affect the subject M, and thus the rotational drive shaft 11. The frames 6 and 7 connected to each other are configured in a “U” shape, and a feeling of opening of the subject M is obtained.

Note that, as the time required for one revolution of the X-ray tube 8 and FPD9 that rotates integrally with Ri fault Jikushu by the rotation motor 10 is equal to or less than 0.1 second, by forming the scan frame 3, such as the heart As in the moving image tomographic image, it is possible to grasp the temporal change of the tomographic image. For example, the sectional axis B, by reducing the lamino angle α is an angle formed between the beam center R of X-rays connecting the X-ray tube 3 and FPD9, X-ray tube 8 rotates integrally with Ri fault Jikushu and The time required for one rotation of the FPD 9 can be shortened.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In the present embodiment described above, radiation represented by X-rays or the like is detected and a tomographic image is acquired from the radiation. However, other than radiation, there is no particular limitation as long as it is an electromagnetic wave. For example, light may be detected and a tomographic image may be acquired from the light. In this case, the flat panel detector (FPD) is a photosensitive detector in which carriers are generated by the incidence of light, and is composed of a photosensitive semiconductor film.

(2) In the embodiment described above, by rotating the Ri X-ray tube frame 6, FPD frame 7 each tomographic Jikushu has rotated X-ray tube 8, FPD9 to Ri fault Jikushu, later modified example (7) as described, even in a state of fixing the X-ray tube frame 6 or box-shaped X-ray tube 8 (see FIG. 6), and the like cathode fixed housing rotated Ri fault Jikushu Also good.

  (3) In the present embodiment described above, the detection means in the present invention is a flat panel detector (FPD), but is not particularly limited as long as it is a means for detecting electromagnetic waves. For example, the detection means may be an image intensifier (I.I). Further, the detection surface of the detection means in the present invention represented by the FPD 9 shown in FIG. 2 does not necessarily need to be orthogonal to the X-ray beam center R, and may be orthogonal to the tomographic axis B.

  (4) In the present embodiment described above, the FPD 9 is arranged so that the data line 17 corresponding to the readout line in the present invention is along the projection axis 9B obtained by projecting the tomographic axis B onto the detection surface 9a of the FPD 9. However, the present invention is not limited to this form as long as low-pass filtering is not performed. For example, the FPD 9 may be disposed so that the gate line 18 extends along the projection axis 9B (that is, the data line 17 is orthogonal to the projection axis 9B), or the data line 17 obliquely crosses the projection axis 9B. An FPD 9 may be provided. Similarly, if low-pass filtering is not performed, it is not necessary to simultaneously turn on a plurality of gate lines 18 corresponding to the gate lines in the present invention.

(5) In the above-described embodiment, the X-ray tube frame 6 and the FPD frame 7 are connected to the rotation drive shaft 11 corresponding to the rotation shaft in the present invention, which is connected to the rotation drive motor 10 corresponding to the rotation means in the present invention. It had been constructed by connecting, a configuration for rotating X-ray tube frame 6, FPD frame 7 independently so that both frames to rotate integrally with Ri fault Jikushu, synchronously controls each rotation of May be.

  More specifically, a description will be given with reference to FIG. FIG. 7 is a right side view of the X-tube frame and flat panel detector (FPD) frame of the tomography apparatus according to this modification.

  The scanning frame 3 includes a calculation device 43, and separate rotation drive motors 10A and 10B, rotation position sensors 41A and 41B, and rotation control units 45A and 45B for the X-ray tube and the FPD, respectively.

  The rotational position sensors 41 </ b> A and 41 </ b> B are installed on the sides of the X-ray tube frame 6 and the FPD frame 7. Then, the rotational positions of the X-ray tube 8 and the FPD 9 are detected, and the rotational position signal of each frame is sent to the arithmetic unit 43. For example, each of the rotational position sensors 41A and 41B is an optical sensor in which a light emitting unit 46A and 46B and a light receiving unit 47A and 47B are paired. The light passing through the optical slits 48A and 48B is detected, and rotational position signals of the frames 6 and 7 are obtained.

  The computing device 43 computes the phase difference between the rotational positions of the X-ray tube 8 and the FPD 9 based on the rotational position signals. And a rotation control signal is sent to rotation control part 45A, 45B so that a phase difference may be set to zero. The rotation control units 45A and 45B control the rotation motors 10A and 10B based on the rotation control signal. The rotary motors 10A and 10B rotate the X-ray tube frame 6 and the FPD frame 7 through gears, bearings, and the like, respectively, based on the rotation control signal. By performing such feedback control, synchronous operation can be performed.

  However, even if feedback control is performed, it is inevitable that a phase difference of a certain rotational position occurs. In this case, high resolution of the reconstructed image is realized by performing back projection at the time of image reconstruction reflecting the phase difference between the rotational positions of the X-ray tube 8 and FPD 9 obtained by the arithmetic unit. This is due to the following reason. During the synchronous operation, the detection surface 9a of the FPD 9 is always at a position facing the X-ray tube 8 as shown in FIG. 7, and X-rays are detected at such a predetermined detection position. On the other hand, when a phase difference occurs between the X-ray tube 8 and the FPD 9, the detection surface 9a detects X-rays at a position that is shifted from the predetermined detection position by the phase difference. In this case, even if the detection surface 9a is deviated from the predetermined detection position, a good tomographic image cannot be acquired if the X-ray is detected at the predetermined detection position.

  Thus, even if the X-ray tube frame 6 and the FPD frame 7 are configured to rotate independently, a good tomographic image can be obtained by performing feedback control and correcting the phase difference.

  Further, with such a configuration, the rotary drive shaft 11 connected to the X-ray tube frame 6 and the FPD frame 7 can be omitted. Therefore, the scanning frame 3 can be formed in an arc shape like a C-arm, or can be separated into a scanning frame incorporating the X-ray tube frame 6 and a scanning frame incorporating the FPD frame 7. Therefore, the scanning frame 3 can secure a wider space around the subject M.

  In the present invention, the irradiation source and the detection means are integrally scanned by rotating the X-ray tube frame 6 and the FPD frame 7 shown in the above-described modified example independently and synchronously. Scanning is also included.

  (6) In the present embodiment described above, the irradiation source in this invention is the X-ray tube 8 that irradiates X-rays, but is not particularly limited as long as it is a means for irradiating electromagnetic waves. For example, the irradiation source may be a means for irradiating light.

  (7) In the above-described embodiment, the X-ray tube 8 is a rotary anode X-ray tube type, and reduces the force applied to the anode rotating shaft 14 and reduces the load on the X-ray tube 8. As shown in FIG. 3, the X-ray tube 8 is configured so that the anode rotation shaft 14 is parallel to the tomographic axis B, but the type of the X-ray tube is not limited to this embodiment.

For example, the rotary cathode X-ray tube type shown in FIG. 6 may be used. That is, the X-ray tube 8 shown in FIG. 6 includes a cathode (filament) 51 that emits thermoelectrons, an anode 52 that generates X-rays from the thermoelectrons emitted from the cathode 51, and a support portion 53 that supports the cathode 51. Composed. Actually, the rate at which the thermoelectrons emitted from the cathode 51 are converted to X-rays by the anode 52 is small, and the remainder is converted to heat. Therefore, in order to prevent damage caused by the heat generated at the anode 52, the anode 52 together with and configure fixed parallel Jikushu Rinien annular sectional axis, the supporting portion 53 configured to Jikushu Rinien annular parallel to the sectional axis, a cathode 51 together with the supporting portion 53, the fault Jikushu An X-ray tube 8 is disposed so as to rotate in a straight line.

With this configuration, while the cathode 51 emits thermal electrons with the support portion 53, the heat electrons rotate in Ri fault Jikushu, anode 52 configured to fix the fault Jikushu Rinien annular receives Is local, so that the heat generated in the anode 52 can be prevented from being damaged. Incidentally, since it is configured in a ring shape about the sectional center, due to the overlap of the rotation of the tomographic Jikushu Riniyoru X-ray tube 8 · FPD9 from inertia accompanying the rotation of the support portion 53 and the cathode 51 rotates, the supporting portion 53 At the same time, the force applied to the cathode 51 can be reduced, and the burden on the X-ray tube 8 can be reduced.

Since rotate in Ri fault Jikushu while the cathode 51 is irradiated with X-rays in this modification, it is not necessary to rotate the X-ray tube 8 to Ri fault Jikushu as in this embodiment, the scanning frame 3 ( (See FIG. 1). Therefore, the X-ray tube frame 6 (see FIG. 2) surrounding the X-ray tube 8 is not particularly necessary, and the X-ray tube 8 is configured as a casing instead of the X-ray tube frame 6. Therefore, in this modification, the cathode 51 in the X-ray tube 8 corresponds to the irradiation source in the present invention, and the X-ray tube 8 corresponds to the irradiation source casing in the present invention. This way can be seen from, while fixing the X-ray tube 8 (radiation source housing), so that rotating the cathode 51 to the Ri fault Jikushu in fixed housing.

  Further, the X-ray tube is not limited to the X-ray tube shown in FIG. 3 or the X-ray tube shown in FIG. For example, an electron beam control X-ray tube may be used.

Example 2 solves the problem (II).
In addition, about the same structure as Example 1, detailed description is abbreviate | omitted by attaching | subjecting a same sign.
FIG. 1 is a perspective view showing a schematic configuration of a tomography apparatus according to the present embodiment. FIG. 2 is an X-ray tube frame and a flat panel detector (hereinafter referred to as “FPD”) of the tomography apparatus according to the present embodiment. FIG. 4 is a right side view of the frame.

Here, in Example 2, tomographic Jikushu Rino rotation "main scanning" the scanning of the X-ray tube 8 · FPD9 by the scanning of the X-ray tube 8 · FPD9 by scanning center Jikushu Rino rotation "secondary scanning" And define them respectively. Thus, rotary drive motor 10 for rotating the X-ray tube 8 · FPD9 to Ri fault Jikushu is the main scanning rotation means, the rotary table 4 for rotating the X-ray tube 8 · FPD9 to Ri scanning center Jikushu is secondary scanning Each corresponds to a rotating means. Further, the scanning frame 3 having the rotary table 4 and the rotary drive motor 10 corresponds to the scanning means in this invention.

According to the tomography apparatus according to this embodiment is provided with the rotary drive motor 10 for rotating integrally X-ray tube 8 and FPD9 to Ri Jikushu the sectional axis B, other than the sectional axis B as in the conventional without rotating the X-ray tube 8 and FPD9 the axis, it can be rotated Ri directly tomographic Jikushu. As a result, high-speed main scanning can be realized. Furthermore, the Ri Jikushu which is one scan center axis A of the axis perpendicular to the sectional axis B, and comprises a rotary table 4 to rotate together relatively X-ray tube 6 and FPD9 to the subject M Therefore, by adding the main scanning by the rotation drive motor 10 to the sub scanning by the rotary table 4, a three-dimensional tomographic image with isotropic spatial resolution can be acquired in the reconstruction after acquisition.

In the case of the apparatus of the present embodiment, an X-ray tube frame 6 surrounding the X-ray tube 8 and an FPD frame 7 surrounding the FPD 9 are provided, and the rotary drive motor 10 includes the X-ray tube 8 and the FPD frame 7 on each frame 6, 7. It is rotated to a fault Jikushu Rinisorezore integrally FPD9. Further, in the case of the present embodiment apparatus comprises a scanning frame 3 surrounding the X-ray tube 8 and FPD9, rotary table 4, the X-ray tube 8 and FPD9 integrally with Ri scanning center Jikushu on scan frame 3 It is rotating. More specifically, as shown in FIG. 1, by rotating the Ri each scan frame 3 scan center Jikushu rotates the X-ray tube frame 6 and FPD frame 7 in Ri scanning center Jikushu, X-ray by rotating the Ri fault Jikushu each per tube frame 6 and FPD frame 7, and X-ray tube 8 of the X-ray tube frame 6, and the FPD9 in FPD frame 7 is rotated fault Jikushu Rinisorezore .

Further, in this embodiment apparatus, and lamino angle 20 °, which are set to 45 ° or less, is rotated in the main scanning of Ri fault Jikushu, the rotation in the scanning center Jikushu Rino従scanning Will also be faster.

Further, when the lamino angle is alpha, the rotation range in the scanning center Jikushu Rino従scanning, by at least [pi-2.alpha above, the rotation range in the scanning center Jikushu Rino従scanning, 2 [pi (1 Even if it is not set to (Rotation), rotation of main scanning is also applied, so that a three-dimensional tomographic image can be acquired within the set range.

  In the present embodiment, the scanning center axis A in the secondary scanning is a horizontal axis, and the tomographic axis B in the main scanning is a vertical plane.

Further, for example, by reducing the lamino angle alpha, it is possible to shorten the time required for one rotation of the X-ray tube 8 · FPD9 that rotates integrally with Ri fault Jikushu. Thus, for example, the time required for one revolution of the X-ray tube 8 · FPD9 that rotates integrally with Ri fault Jikushu it can be set to be less than 0.1 seconds, for example, as the heart of a moving tomographic image The time change of the tomographic image can be grasped.

Further, for example, by shortening the distance between the X-ray tube 8 · FPD9, it is possible to shorten the time required for one rotation of the X-ray tube 8 · FPD9 that rotates integrally with Ri scanning center Jikushu. Thereby, for example, the scan center Jikushu Ri time required for half the rotation of the X-ray tube 8 · FPD9 that rotates integrally with it can be set to be less than 5 seconds, for example, when the patient M is patient Since the time when the patient can hold his / her breath and the time when no body movement occurs is 5 seconds or less, the X-ray tube 8 / FPD 9 scans while holding his / her breath or when there is no body movement. it can be half rotation integrally with Ri center Jikushu. Therefore, a tomographic image with little deviation can be acquired.

  In the case of the present embodiment, as shown in FIG. 2, the scanning frame 3 is formed in a “U” shape, so that the subject feels a blockage like a gantry in an X-ray CT apparatus. There is also an effect that it is possible to receive a picture without any problems.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In the present embodiment described above, radiation represented by X-rays or the like is detected and a tomographic image is acquired from the radiation. However, other than radiation, there is no particular limitation as long as it is an electromagnetic wave. For example, light may be detected and a tomographic image may be acquired from the light. In this case, the flat panel detector (FPD) is a photosensitive detector in which carriers are generated by the incidence of light.

  (2) In the present embodiment described above, the detection means in this invention is a flat panel detector (FPD), but is not particularly limited as long as it is a means for detecting electromagnetic waves. For example, the detection means may be an image intensifier (I.I).

  (3) In the above-described embodiment, the irradiation source in the present invention is the X-ray tube 8 that irradiates X-rays, but is not particularly limited as long as it is a means for irradiating electromagnetic waves. For example, the irradiation source may be a means for irradiating light.

(4) In the embodiment described above, the scan frame 3, Ri Jikushu the body axis of the subject M, or scan center Jikushu rotates in is, further X-ray tube frame 6, FPD frame on scan frame 3 X-ray tube 8 and FPD9 on 7, so that rotating the Ri fault Jikushu, each frame 3, 6, 7 has been consists of housing, the X-ray tube which corresponds to the radiation source in this invention 8, and the FPD9 which corresponds to the detecting device in this invention, is rotated integrally with Ri fault Jikushu, as long as the structure is rotated relative integrally with the scanning center Jikushu Rinihi analyte M, It is not limited to the case.

For example, by the present embodiment for rotating the scan frame 3 to Ri scanning center Jikushu, X-ray tube frame 6 in the scan frame 3, FPD frame 7, further X-ray tube 8 and within each frame 6,7 FPD9 is rotated Ri scan center Jikushu but the X-ray tube frame 6, FPD frame 7 without enclosed by scan frame 3 includes independently relative to the scanning center Jikushu Rinihi analyte M it may be fixed to the patient M only rotated Ri scan center Jikushu, X-rays tube frame 6, FPD frame 7 when rotating integrally with.

Similarly, the X-ray tube frame 6, FPD frame 7 without enclosed by scan frame 3, provided independently, when rotating relatively together with respect to the scanning center Jikushu Rinihi analyte M it may be configured to rotate Ri scan center Jikushu conjunction X-ray tube frame 6, FPD frame 7. Of course, this time may rotate Ri subject M may scan center Jikushu.

Further, in this embodiment, the X-ray tube 8 and FPD9 of each frame 6,7 is rotated in the tomographic Jikushu Rinisorezore integrally, integrated in the X-ray tube 8 and FPD9 is Ri directly tomographic Jikushu rotated but, as long as the structure can rotate integrally with Ri directly tomographic Jikushu need not be configured in the frame 6, 7, such as a housing.

(5) In the embodiment described above, to thereby tomographic Jikushu Rinisorezore rotating FPD9 in X-ray tube 8, FPD frame 7 of the X-ray tube frame 6, Ri each tomographic Jikushu each frame 6,7 Although went rotated, may be an X-ray tube 8, FPD9 in each frame 6,7 is rotated Ri fault Jikushu while fixing the frame 6,7.

  (6) In this embodiment described above, the scanning center axis A is the horizontal axis, the tomographic axis B is on the vertical plane, and the scanning center axis A is orthogonal to the tomographic axis B. The substantially orthogonal state may be used.

Further, the direction of the scanning center axis A in the sub-scanning and the direction of the tomographic axis B in the main scanning are not limited to the directions as in the present embodiment (see FIG. 1). For example, as shown in FIGS. 8 and 9, the scanning center axis A in the secondary scanning may be a vertical axis, and the tomographic axis B in the main scanning may be a horizontal axis. Figure 8 is a perspective view showing a schematic configuration of a tomographic imaging apparatus according to a modification, irradiation source Ri vertical Jikushu relative to the ceiling surface (X-ray tube 8) and detection means (FPD9) integrally in case of rotating, FIG. 9 is a perspective view showing a schematic configuration of a tomographic imaging apparatus according to a further modified embodiment is the case of rotating the vertical Jikushu Rinihi patient M to the floor surface . In the case of FIGS. 8 and 9, the subject M is in a standing posture, and there is no need for a top plate as shown in FIG. 1, but the subject M is placed on the rotary table 4 as shown in FIG. When placed and rotated, a support bar may be erected so that the subject M (patient) is held by the support bar.

In the case of Figure 8, the base 2 is fixed to the ceiling surface, by rotating the rotary table 4 disposed on the lower surface of the base 2 to Ri Jikushu a vertical axis (scan central axis A) , through the supporting member 5, the scan frame 3 is rotated Ri scan center Jikushu relative to the ceiling plane, X-rays tube frame 6 in the scan frame 3, FPD frame 7, further within each frame 6,7 X-ray tube 8 and FPD9 is rotated Ri scan center Jikushu against the ceiling surface. On the other hand, by rotating the Jikushu Rinisorezore integral of each frame 6,7 on the horizontal axis X-ray tube 8 and FPD9 in (sectional axis B), X-ray tube 8 and FPD9 is integral with Ri fault Jikushu Rotate.

In is fixed to the base 2 floor surface, to rotate the rotary table 4 disposed on an upper surface of the base 2 to Ri Jikushu a vertical axis (scan central axis A) in the case of FIG. 9, the by supporting the patient M to the rotary table 4, the scan frame 3 while fixing and rotates Ri scan center Jikushu to the subject M floor surface. That is, the rotation relatively, X-ray tube frame 6 in the scan frame 3, FPD frame 7, even more X-ray tube 8 and FPD9 in each frame 6,7 Ri scanning center Jikushu to the subject M Will do. On the other hand, by rotating the Jikushu Rinisorezore integral of each frame 6,7 on the horizontal axis X-ray tube 8 and FPD9 in (sectional axis B), X-ray tube 8 and FPD9 is integral with Ri fault Jikushu Rotate. In the case of FIG. 9, in order to fix the scanning frame 3, the support member 5 is disposed on the upper surface of the base 2 at a fixed location other than the rotary table 4.

  In addition to the above-described modifications, if the scanning center axis A is one of the axes substantially orthogonal to the tomographic axis B, of course, the scanning center axis A and the tomographic axis B are not limited to a vertical plane or a horizontal plane, and are oblique directions. It may be.

In (7-1) The present embodiment described earlier, the turntable 4 disposed fixedly installed base 2 is, via the supporting member 5, has to rotate the scan frame 3 to Ri scanning center Jikushu However, as long as the scanning frame 3 is rotated, the configuration is not limited thereto.

For example, a scanning frame, a tomography apparatus comprising a support member for holding this, the junction between the scan frame support member gear for rotating the scan frame to Ri scan center Jikushu (secondary scanning rotation) May be provided.

  More specifically, it demonstrates with reference to Fig.10 (a)-FIG.10 (c), and FIG. FIG. 10A to FIG. 10C are schematic views of a tomography apparatus according to this modification, and show the position of the scanning frame 3 at different points in time. The scanning frame 3 has a C-shaped arm shape. The support member 5a that holds the scanning frame 3 is fixed to the floor surface. Moreover, it has an arc-shaped portion, and the scanning frame 3 is held on the inner peripheral surface of the arc-shaped portion, and is rotated in a sub-scanning manner.

  FIG. 11 is a vertical sectional view of the joint portion 30 between the scanning frame 3 and the support member 5a. On the inner peripheral surface of the arc-shaped portion of the support member 5a, a guide groove 5b for holding the scanning frame 3 and rotating it in a secondary scan, and a secondary scanning rotation bearing 33 are formed. On the other hand, the scanning frame 3 is provided with a sub scanning rotation motor 31, a sub scanning rotation shaft 32, and a gear. The secondary scanning rotation motor 31 and the secondary scanning rotation shaft 32 are connected via a gear, and the secondary scanning rotation shaft 32 and the secondary scanning rotation bearing 33 are also connected via a gear. This is the configuration of the transmission device described above. By this transmission device, the scanning frame 3 and the support member 5a are connected, and the scanning frame 3 can be rotated in a sub-scanning manner along the guide groove 5b.

  The support member 5a described above corresponds to the scanning housing support member in the present invention, and the transmission device described above corresponds to the feed mechanism in the present invention.

  Here, since the guide groove 5b is formed so as to rotate the scanning frame 3 by about 180 °, the scanning frame 3 is reciprocated as shown in FIGS. 10 (a), 10 (b) and 10 (c). By doing so, the secondary scanning is rotated. Furthermore, a bearing 34 is disposed at a portion where the scanning frame 3 contacts the guide groove 5b of the support member 5a. This is because the scanning frame 3 is smoothly rotated.

  With such a configuration, the base 2 and the rotary table 4 described above are omitted, and the floor occupation area of the entire tomographic apparatus is reduced.

  Further, at the position of the scanning frame shown in FIG. 10C, which is the home position for performing the IVR procedure or the like, the upper part is opened, so that there is a feeling of opening for the subject M who is a patient.

  In this modification, the sub-scanning rotation motor 31 and the like of the transmission are built in the scanning frame 3, but may be built in the support member 5a. In this modification, the guide groove 5b is formed so as to rotate the scanning frame 3 by about 180 °. However, if a three-dimensional tomographic image with isotropic spatial resolution can be acquired in consideration of the rotation of the main scanning and the like. The range in which the guide groove is formed is not limited to this.

  (7-2) Further, in this modified example, the support member 5a has an arc-shaped portion, but if the scanning frame 3 is rotated in a sub-scanning manner, the support member 5a needs to be a support member having an arc-shaped portion. There is no.

  More specifically, this will be described with reference to FIGS. 12 (a) to 12 (c) and FIG. FIG. 12A to FIG. 12C are schematic views of a tomography apparatus according to this modification, and show the position of the scanning frame 3 at different points in time. Also in this modification, the scanning frame 3 has a C-arm shape. The support member 5c that holds the scanning frame is fixed to the floor surface.

  FIG. 13 is a schematic vertical sectional view of a tomography layer apparatus according to this modification. The scanning frame 3 is provided with a scanning belt 35 according to the arc-shaped outer peripheral portion. Further, the support member 5 c includes a roller 36 that sends the sub-scanning belt 35, and a driving device (not shown) that rolls the roller 36. Then, the scanning frame 3 is rotated about 180 ° and reciprocated as shown in FIGS. 12A to 12C by the transmission device including the sub scanning belt 35, the roller 36, and the driving device. Can do.

  Here, the above-described support member 5c corresponds to the scanning housing support member in the present invention, and the above-described transmission device including the sub-scanning belt 35, the roller 36, and the drive device corresponds to the feed mechanism in the present invention. .

  With such a configuration, the floor occupation area of the entire tomography apparatus can be reduced, and the support member 5c that holds the scanning frame 3 can be made more compact.

  In addition, at the position of the scanning frame shown in FIG. 12B, which is the home position for performing the IVR procedure or the like, the upper part is open, so that the subject M who is a patient has a feeling of opening.

  (8) In the present embodiment described above, X-rays may be generated at a constant timing based on the periodic movement of the subject's heart.

  More specifically, description will be made with reference to FIGS. 14, 17A, and 17B. FIG. 14 is a block diagram of a tomography apparatus according to this modification. An X-ray tube 8 that irradiates X-rays is disposed above the subject M. Further, the FPD 9 that detects this X-ray is disposed below the subject M. Then, the X-ray is irradiated onto the subject M in a cone beam shape, transmitted through the subject M, and incident on the FPD 9.

  Furthermore, an electrocardiograph 61 for measuring the heartbeat of the subject (not shown) is attached to the subject M. The electrocardiograph 61 is electrically connected to an X-ray generation control device 63 that performs X-ray irradiation control on the X-ray tube 8.

  Here, the electrocardiograph 61 described above corresponds to a measuring means for detecting a biological signal in the present invention, and the X-ray generation control device 63 corresponds to an irradiation source control means in the present invention.

  In such a configuration, the tomography apparatus operates as follows. As shown in FIG. 17B, the heart movement of the subject M is detected as an electrocardiogram (ECG) waveform by the electrocardiograph 61. This electrocardiogram (ECG) waveform is input to the X-ray generation control device 63. When detecting that the heart is in a predetermined state based on the electrocardiogram (ECG) waveform, the X-ray generation control device 63 performs control to irradiate the X-ray tube 8 with X-rays in synchronization with this timing. . Here, the predetermined state is, for example, a systole or a diastole, and is arbitrarily determined depending on which state of the three-dimensional tomographic image is acquired. The X-ray generation control device 63 causes the X-ray tube 8 to irradiate the subject M with X-rays after the elapse of the delay time t. X-rays transmitted through the subject M are detected by the FPD 9 and collected as projection data. Thereby, it is possible to collect only projection data in the same state of the heart.

  Here, the relationship between main scanning and collection of projection data will be described in more detail. For the acquisition of 3D tomographic images without cardiac motion artifacts, the acquisition is performed in synchronization with an electrocardiogram (ECG) waveform, as shown in FIG. 17 (b). The Fourier space distribution of the data obtained by one rotation of the main scan is in the range of 30 ° (= 2 × α) as shown in the hatched (hatched) portion in FIG. That is, in order to collect data necessary for obtaining a three-dimensional tomographic image with isotropic spatial resolution, it is sufficient to perform six main scanning acquisitions every 30 ° of the secondary scanning. ) And FIG. 17B.

  More specifically, as shown in the timing chart of FIG. 17 (b), the transmitted X-ray of the subject during one main scanning rotation period continuously rotating at a predetermined delay time from the ECG α wave. Image acquisition is performed, and this is performed a total of 6 times in synchronism with the ECG every 30 °. Actually, the main scan does not rotate only for the time (0.1 second) of the black portion in FIG. 17B but continues to rotate for 5 seconds of the sub-scan. The electromagnetic wave (in this case, X-rays) is irradiated from the irradiation source only for the black portion (0.1 second).

It is the perspective view which showed schematic structure of the tomography apparatus concerning a present Example. It is a right view of the X-ray tube frame and flat panel type | mold detector (FPD) frame of the tomography apparatus which concerns on a present Example. It is an enlarged view of the X-ray tube in an X-ray tube frame. It is a block diagram of the flat panel type detector (FPD) of the tomography apparatus which concerns on a present Example. It is a figure which shows the relationship between the gate line and data line which comprise a flat panel type detector (FPD), and a fault axis | shaft, Comprising: It is the perspective view which looked at the flat panel type detector (FPD) of FIG. 2 from diagonally upward. . It is the schematic of the X-ray tube which concerns on a modification. It is a right side view of an X tube frame and a flat panel detector (FPD) frame of a tomography apparatus according to a modification. It is the perspective view which showed schematic structure of the tomography apparatus which concerns on a modification. It is the perspective view which showed schematic structure of the tomography apparatus which concerns on the further modification. (A), (b), (c) is the schematic of the tomography apparatus which concerns on a modification. FIG. 6 is a vertical sectional view of a joint portion between a scanning frame and a support member. (A), (b), (c) is the schematic of the tomography apparatus which concerns on a modification. It is a schematic vertical sectional view of a tomography apparatus according to a modification. It is a block diagram of the tomography apparatus which concerns on a modification. It is the schematic of the conventional tomography apparatus. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the apparatus regarding the knowledge which came to contemplate this invention, Comprising: (a) is a side view of X-ray CT apparatus, (b) is a front view of a tomography apparatus. It is explanatory drawing with which it uses for description of three-dimensional tomographic image collection of the isotropic resolution of a heart part, Comprising: (a) is a collection data distribution map in Fourier space, (b) is a data collection timing chart. is there.

DESCRIPTION OF SYMBOLS 3 ... Scanning frame 4 ... Rotary table 5a ... Support member 5c ... Support member 6 ... X-ray tube frame 7 ... Flat panel type detector (FPD) frame 8 ... X-ray tube 9 ... Flat panel type detector (FPD)
DESCRIPTION OF SYMBOLS 10 ... Rotation drive motor 11 ... Rotation drive shaft 17 ... Data line 18 ... Gate line 61 ... Electrocardiograph 63 ... X-ray generation control apparatus M ... Subject A ... Scanning center axis B ... Fault axis α ... Lamino angle R ... Beam center

Claims (20)

An irradiation source that irradiates the subject with electromagnetic waves; a detection unit that detects the electromagnetic waves transmitted through the subject; and a scanning unit that integrally scans the irradiation source and the detection unit. A tomography apparatus for acquiring a three-dimensional tomographic image from a group of projection data detected at each position of the detection means scanned by the step, wherein the irradiation source is applied to a tomographic axis passing through a region of interest of the subject The irradiation source and the detection unit are arranged so that the irradiation axis connecting the detection unit is inclined at a predetermined angle, and the scanning unit detects the irradiation source case surrounding the irradiation source and the detection unit. And means for rotating the casings integrally around the tomographic axis passing through the casings, and the irradiation source and the detecting means maintain positions relative to the surrounding casings. Rotate while standing Tomography apparatus characterized by being.   The tomography apparatus according to claim 1, wherein the irradiation source casing and the detection means casing are connected to a rotation shaft connected to the rotating means, and the rotation is provided at one end of each casing. A tomographic apparatus characterized in that an axis is provided.   3. The tomography apparatus according to claim 1, wherein the detection unit includes a gate line that takes in the transmitted electromagnetic waves by switching between ON and OFF, and is orthogonal to the gate line, and is used as the projection data. A flat panel detector having a plurality of readout lines each for reading, wherein the flat line is such that each readout line is along a projection axis obtained by projecting the tomographic axis onto a detection surface of the flat panel detector. A tomography apparatus comprising a panel type detector.   The tomography apparatus according to claim 3, wherein the electromagnetic waves at positions corresponding to the gate lines are simultaneously captured as charges by simultaneously turning on the plurality of gate lines, and the captured charges are A tomography apparatus, wherein low-pass filtering is performed by simultaneously turning on the plurality of gate lines with respect to the projection data read out and read out as the projection data via a readout line. A radiographic apparatus according to any one of claims 1 to 4, the time required for one rotation of the radiation source and detecting means for rotating integrally with Ri tomographic Jikushu by said rotating means below 0.1 seconds The tomographic apparatus is characterized by comprising the scanning means.   6. The tomography apparatus according to claim 1, wherein the irradiation source is an X-ray tube that irradiates X-rays, and the X-ray tube includes a cathode that emits thermoelectrons, and the cathode. A rotating anode X-ray tube composed of an anode that generates X-rays by accelerated thermoelectron collision from an anode and an anode rotating shaft that rotates the anode, wherein the anode rotating axis is parallel to the tomographic axis A tomography apparatus comprising an X-ray tube. 6. The tomography apparatus according to claim 1, wherein the irradiation source is an X-ray tube that irradiates X-rays, and the X-ray tube includes a cathode that emits thermoelectrons, and the cathode. anode for generating X-rays in accelerated heat electrons collision from a rotating anode X-ray tube consists of a support unit for supporting the cathode, the anode Jikushu Rinien annular parallel to the sectional axis together constitute fixed to said supporting portion configured to Jikushu Rinien annular parallel to the sectional axis, the cathode together with the support part, wherein to rotate Ri parallel Jikushu the sectional axis X A tomography apparatus comprising a tube. An irradiation source that irradiates the subject with electromagnetic waves, a detection unit that detects the electromagnetic waves transmitted through the subject, a scanning unit that integrally scans the irradiation source and the detection unit, and scanning by the scanning unit And a tomographic apparatus including an image processing unit that acquires a three-dimensional tomographic image from a group of projection data detected at each position of the detection means, wherein the tomographic axis passes through the region of interest of the subject. The irradiation source and the detection unit are arranged so that an irradiation axis connecting the irradiation source and the detection unit is inclined at a predetermined angle, and the scanning unit includes an irradiation source casing surrounding the irradiation source and the irradiation source A main scanning rotation means for integrally rotating the respective casings around the tomographic axis penetrating a detection means casing surrounding the detecting means; and a scanning central axis that is one of axes substantially orthogonal to the tomographic axis. , Against the subject And a sub-scanning rotating means for integrally rotating the irradiation source and the detection means, and the irradiation source and the detection means are rotated while maintaining a position with respect to a casing surrounding them. Shooting device. 9. The tomography apparatus according to claim 8, wherein the scanning unit includes an irradiation source case surrounding the irradiation source and a detection unit case surrounding the detection unit, and the main scanning rotation unit includes the housings. tomography apparatus characterized by rotating the radiation source and the detection means of the body to the tomographic Jikushu Rinisorezore integrally. 10. The tomography apparatus according to claim 8, wherein the scanning unit includes a scanning casing surrounding the irradiation source and the detecting unit, and the sub-scanning rotating unit is an irradiation source of the scanning casing. and tomography apparatus characterized by rotating integrally detecting means Ri said scanning center Jikushu.   The tomography apparatus according to claim 10, wherein the sub-scanning rotation unit includes a scanning housing support member that holds the scanning housing, and the scanning housing support member and the scanning housing. The tomography apparatus according to claim 1, wherein the holding unit includes a feeding mechanism, and the feeding mechanism rotates the scanning housing. A radiographic apparatus according to claims 8 to claim 11, rotating in the main scanning of the tomographic Jikushu Ri, characterized in that it is faster than the rotation of the secondary scanning about the scan center axis Tomography equipment.   13. The tomography apparatus according to claim 8, wherein the scanning is performed when a lamino angle, which is an angle formed between the tomographic axis and an irradiation axis connecting the irradiation source / detecting means, is α. A tomographic apparatus characterized in that a rotation range in secondary scanning around the central axis is at least π-2α or more.   14. The tomography apparatus according to claim 8, wherein a scanning center axis in the secondary scanning is a horizontal axis, and a tomographic axis in the main scanning is on a vertical plane. apparatus.   15. The tomography apparatus according to claim 8, wherein a scanning center axis in the secondary scanning is a vertical axis, and a tomographic axis in the main scanning is on a horizontal plane. . A radiographic apparatus according to claim 15, wherein the secondary scanning rotating means, tomography apparatus characterized by rotating integrally the radiation source and detecting means Ri vertical Jikushu against the ceiling surface. A radiographic apparatus according to claim 15, wherein the secondary scanning rotating means, tomography apparatus characterized by rotating said object to Ri vertical Jikushu to the floor surface. A radiographic apparatus according to claim 17 claim 8, the time required for one rotation of the radiation source and detecting means for rotating integrally with Ri tomographic Jikushu by the main scanning rotating means 0.1 seconds A tomography apparatus comprising the scanning means as described below. A radiographic apparatus according to claim 18 claim 8, the time required for half rotation of the radiation source and detecting means for rotating integrally with Ri scanning center Jikushu by said secondary scanning rotating means less than 5 seconds The tomography apparatus is characterized in that the scanning means is configured to be.   The tomography apparatus according to any one of claims 8 to 19, wherein the apparatus further includes a measurement unit that detects a biological signal from a subject, and a periodic movement detected by the measurement unit. A tomography apparatus comprising: an irradiation source control unit that controls the irradiation source so as to irradiate a subject with electromagnetic waves in synchronization with a fixed timing.

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