JPH07303631A - Ct scanner - Google Patents

Abstract

PURPOSE:To provide a CT scanner that solves low resolution problems such as a space resolving power by a zooming reconstruction to obtain a high resolution tomography for the target area. CONSTITUTION:An examined body 6 is mounted on a XY stage 5 and is rotated by a rotation table 4, the stage traverses the fan-shape radiation generated from a radiation source 1 by a traverse mechanism 3, a radiation from the radiation source 1 which has been transmitted through the examined body 6 is detected by a detector 2. The transparent data of the examined body which has been detected by the detector 2 is collected by a data collection device 21, and a tomography of the examined body is reconstructed by an imaging device 22 and displayed on a CRT display 23. A target area ROI is set on any position of the tomography of the examined body displayed, the examined body 6 is moved so that the approx. center of the target area ROI becomes the center of scanning, and the area to be scanned is scanned in high resolution to obtain a high resolution tomography for the target area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention scans a subject while irradiating the subject with radiation, and creates a cross-sectional image based on projection data from many directions of the radiation transmitted through one cross section of the subject. The present invention relates to a CT scanner which is a computer tomography apparatus.

[0002]

17 and 18 are diagrams showing the structures of conventional traverse / rotation (T / R) type and rotate / rotate (R / R) type CT scanners, respectively. In FIG. 17, 401 is an X-ray tube,
402 is a detector, 403 is a T / R table, 404 is a mechanical controller, 405 is CNSL, 4011 is an X-ray controller, 4021 is a data acquisition device (DAS), 4
Reference numeral 022 is an imaging device, and 4023 is a CRT display. Further, in FIG. 18, 411 is an X-ray tube, 412
Is a detector, 413 is an R table, 414 is a mechanical controller, 415 is a CNSL, 4111 is an X-ray controller, 4121 is a data acquisition device (DAS), 4122 is an imaging device, and 4123 is a CRT display.

In the conventional CT scanner shown in FIGS. 17 and 18, projection data is obtained from the entire circumferential direction of the cross section of the subject to be obtained, and image reconstruction operations are performed by the imaging devices 4022 and 4122 to obtain the cross section. I'm getting a statue. Then, a part of the cross-sectional image obtained in this way is used as a region of interest (ROI: Re
gion Of Interest), and zooming reconstruction (enlargement reconstruction) including interpolation of projection data can be performed to obtain an enlarged cross-sectional image.

[0004]

As in the conventional CT scanner described above, the accuracy of projection data obtained by CT scanning is determined only by performing zooming reconstruction in order to obtain a finer sectional image of the region of interest. Therefore, there is a limit to the enlargement due to zooming, which is insufficient, and there is a problem that a highly accurate cross-sectional image cannot be obtained.

The present invention has been made in view of the above,
It is an object of the present invention to provide a CT scanner capable of solving a lack of definition such as spatial resolution due to zooming reconstruction and obtaining a highly accurate sectional image of a region of interest.

[0006]

In order to achieve the above object, a CT scanner of the present invention scans a subject while irradiating the subject with radiation, and a plurality of directions of radiation transmitted through one cross section of the subject. A CT scanner that creates a cross-sectional image based on projection data from, and a region-of-interest setting unit that sets a region of interest at an arbitrary position on the cross-sectional image of the subject,
A moving unit that moves the subject so that the center of the region of interest is aligned with the scan center, and a scan range limiting unit that limits the scan to a scan range necessary and sufficient to collect projection data of the region of interest. Then, the center of the region of interest is moved by the moving unit so as to match the scan center, and the scan range limited by the scan range limiting unit is finely scanned to obtain a high-quality cross-sectional image of the region of interest. That is the summary.

Further, the CT scanner of the present invention irradiates a subject with radiation generating means for generating radiation in a fan shape and fan-shaped radiation generated by the radiation generating means, and the radiation transmitted through the subject. Detecting means for detecting
Traverse means for linearly moving the fan-shaped radiation generated from the radiation generating means so that the subject traverses in the direction along the fan surface, rotating means for being traversed linearly by the traverse means, and on the rotating means. A moving means for moving the subject in an arbitrary direction, a region of interest setting means for setting a region of interest at an arbitrary position on a sectional image of the subject, and a substantially center of the region of interest set by the region of interest setting means And a movement control means for controlling the movement means so as to align with the scanning center, and obtain a high-quality cross-sectional image of a desired region of interest of the subject.

Further, the CT scanner of the present invention scans the subject by a method of traverse / rotation to obtain projection data from a number of directions, and creates a sectional image of the subject by a T / R type CT scanner. The moving means for moving the rotating means in the direction perpendicular to the traverse direction and the rotating means for each traverse operation perform a rotation operation for the fan angle of the radiation, when the data collection start point and end point in the traverse direction are It is a gist to have a traverse control means capable of controlling collection conditions including points for each angle of the rotation operation, and enabling a scan for obtaining a high-quality cross-sectional image of a desired region of interest of a subject.

The CT scanner of the present invention is a traverse / rotation type CT scanner, and includes a region of interest setting means for setting a region of interest at an arbitrary position on a cross-sectional image of a subject, and a center of the region of interest is scanned. It has a traverse control means for performing a traverse by changing the data collection condition including the data collection start point and the end point for each traverse / rotation operation so as to match the center, and to obtain a high-quality cross-sectional image of the desired region of interest of the subject. The main point is to obtain.

The CT scanner of the present invention is a rotate / rotate type CT scanner which rotates a subject or radiation generating means and radiation detecting means to perform scanning to obtain projection data and create a sectional image. A region of interest setting means for setting a region of interest at an arbitrary position on the cross-sectional image of the subject, and a movement for moving the point of the subject corresponding to the center of the region of interest so as to match the rotation center which is the scan center. Means and distance changing means for changing the distance between the radiation generating means and the rotation center within a range where the region of interest of the subject does not protrude from the radiation beam, and obtains a high-quality cross-sectional image of the desired region of interest of the subject. That is the summary.

Further, in the CT scanner of the present invention, a cross section of one surface is formed by a radiation source that rotates around the subject in one surface and a ring-shaped multi-channel detector that does not rotate about the center of rotation. A fourth-generation CT scanner for creating an image, comprising: a region-of-interest designating unit for designating a region of interest on a cross-sectional image; and a moving unit for moving a point of the subject corresponding to the center of the region of interest around a rotation center. The gist is to obtain a high-quality cross-sectional image of the designated region of interest.

The CT scanner of the present invention comprises a radiation source for generating fan-shaped radiation, a one-dimensional detector for detecting the fan-shaped radiation transmitted through the subject, and a radiation detector between the radiation source and the detector. Positioning means for positioning the sample,
Obtaining transmission data of the subject by traversing / rotating around the subject along the fan surface of the fan-shaped radiation integrally with the radiation source and the detector,
A traverse / rotation type CT scanner for obtaining a cross-sectional image of a subject, a designating unit for designating a region of interest on a cross section of the subject, and a center position of the region of interest of the subject being the center of the traverse / rotation. Thus, the gist is to have a moving unit that moves the radiation source and the detector, and obtain a high-quality cross-sectional image of the designated region of interest.

Further, in the above-mentioned CT scanner of the present invention, the moving means is brought into contact and moved only when the subject is not performing a scanning operation, the center of the region of interest is aligned with the scan center, and the subject is scanned during scanning. The gist is to have a means to isolate from the specimen.

[0014]

In the CT scanner of the present invention, the region of interest is set at an arbitrary position on the cross-sectional image of the subject, the subject is moved so that the center of the region of interest is aligned with the scan center, and the scanning range limiting means is provided. By finely scanning the scan range limited by, a high-quality sectional image of the region of interest is obtained.

Further, in the CT scanner of the present invention, the object is moved in any direction on the rotating means which is traversed linearly by the traverse means, and the region of interest is set at any position on the cross-sectional image of the object. The movement is controlled so that the center of the region of interest is set to the scan center, and a high-quality cross-sectional image of the desired region of interest of the subject is obtained.

Further, in the CT scanner of the present invention, when the rotating means performs the rotation operation for the fan angle of the radiation for each traverse operation, the collection condition including the data collection start point and the end point in the traverse direction is set as the rotation operation. Control for each angle,
It enables a scan for obtaining a high-quality cross-sectional image of a desired region of interest of a subject.

In the CT scanner of the present invention, a region of interest is set at an arbitrary position on the cross-sectional image of the subject, and data collection including a data collection start point and an end point is performed so that the center of the region of interest is aligned with the scan center. Traverse is performed by changing the condition for each traverse / rotation operation, and a high-quality cross-sectional image of a desired region of interest of the subject is obtained.

Further, in the CT scanner of the present invention, the region of interest is set at an arbitrary position on the cross-sectional image of the subject, and the point of the subject corresponding to the center of the region of interest is aligned with the center of rotation which is the scan center. Thus, the distance between the radiation generating means and the rotation center is changed within a range in which the region of interest of the subject does not protrude from the radiation beam, and a high-quality cross-sectional image of the desired region of interest of the subject is obtained.

Further, in the CT scanner of the present invention, a cross-sectional image of one surface is obtained by a radiation source that rotates around the subject in one surface and a ring-shaped multi-channel detector that does not rotate about the center of rotation. In the fourth-generation CT scanner to be created, a region of interest is designated on the cross-sectional image, the point of the subject corresponding to the center of the region of interest is moved to the center of rotation, and a high-quality cross-sectional image of the designated region of interest is obtained. obtain.

In the CT scanner of the present invention, the radiation source and the detector are integrally traversed / rotated around the subject along the fan-shaped surface of the fan-shaped radiation to obtain the transmission data of the subject to obtain the transmission data of the subject. In a traverse / rotation type CT scanner that obtains a cross-sectional image of
Designate a region of interest on the cross section of the subject, move the radiation source and detector so that the center of the region of interest of the subject is the center of traverse / rotation, and obtain a high-quality cross-sectional image of the designated region of interest. obtain.

Further, in the CT scanner of the present invention, in the above, the moving means is contacted and moved only when the scanning operation of the subject is not performed, the center of the region of interest is aligned with the scan center, and the subject is moved from the subject during scanning. To be isolated.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. 1 (a) and 1 (b) respectively show the first embodiment of the present invention.
6A and 6B are a plan view and a side view showing the configuration of the CT scanner according to the embodiment of the present invention. The CT scanner shown in the figure is of a T / R type, and is an XY on which a radiation source 1, a detector 2, a data acquisition device (DAS) 21, an imaging device 22, a CRT display 23, and a subject 6 are placed. It has a stage 5, a rotation table 4, a traverse mechanism 3, a mechanical controller 7, and an ROI designation device 8. Note that FIG.
(C) shows an example of the structure of the subject 6.

The radiation source 1 generates radiation having a fan angle α, and this radiation passes through a subject 6 placed on an XY stage 5 and a detector 2 provided facing the radiation source 1. Detected by. The XY stage 5 is provided on the rotation table 4, and the subject 6 placed on the XY stage 5 can be set at an arbitrary position with respect to the center of the rotation table 4, that is, the scan center. The traverse mechanism 3 linearly moves across the rotation table 4 with respect to the fan angle α, and during this period, data is collected by the detector 2 and the data collecting device 21, but the scan area is ROI.
When the scan narrows, this traverse distance is correspondingly shorter.

The scan area has a region of interest ROI prepared by the CT scanner as an ROI scan in addition to the normal scan area, and the data collection start point and end point when performing data acquisition by traversing are Pre-programmed.

In the CT scanner thus constructed,
The subject 6 is placed on the XY stage 5, rotated by the rotation table 4, and traversed by the traverse mechanism 3 so as to traverse fan-shaped radiation generated from the radiation source 1. Then, in this case, the detector 2 detects the radiation from the radiation source 1 that has passed through the subject 6, and the transmission data of the subject detected by the detector 2 is used as the data collection device 21.
The cross-sectional image of the subject is reconstructed by the imaging device 22 and displayed on the CRT display 23.

In this way, the cross-sectional image of the subject 6 obtained by the CT scanner of FIG. 1 is 2 in FIG.
22 is shown positioned with respect to the scan center, but a portion on the tomogram of the subject to be particularly magnified and observed in detail, that is, a region requiring a higher-definition cross-sectional image is a region of interest ROI 223. As R
It is designated by the OI designation device 8. This region of interest ROI 223
Its center is shown at 2231. The center 2231 of the region of interest ROI is aligned with the scan center 42 as shown in FIG. This alignment is performed by controlling the movement of the XY stage 5 by the mechanical controller 7.

Then, the region of interest ROI centered in this way is rescanned (ROI scan) with respect to a predetermined scan area as a scan region to collect projection data with a desired definition. You can By reconstructing this projection data, a highly accurate sectional image of the region of interest ROI can be obtained as shown in FIG.
It can be obtained as shown in (c).

The ROI scan is designated on the tomogram 221 shown in FIG. The cursor appears on the screen of the CRT display 23, and the ROI 22
Specify 3. Then, the center 22 of the region of interest ROI
31 is recognized, and the operation of the XY stage 5 is performed as shown in FIG.
The center 2231 of the region of interest ROI is aligned with the table center 42 as shown in FIG. In addition, this accuracy is the region of interest R
An accuracy of about 1/10 of OI is sufficient. ROI of interest
When the setting of I is completed, the traverse range corresponding to the scan area of the ROI scan that is determined in advance is set to R.
Perform OI scan. Since the scan is performed in a range narrower than the first scan area, the capability of the CT scanner is applied to the narrow range. That is, since data with a finer pitch can be collected, a CT scan with improved spatial resolution and SN ratio becomes possible. The scan area of the ROI scan is not a predetermined area, and it is also possible to scan in an arbitrary size by setting the scan condition in the range of the cursor designated by the ROI.

Next, the operation will be described with reference to the flow chart shown in FIG. First, a sample, which is the subject 6, is placed on the XY stage 5 (step 110), and the traverse mechanism 3 traverses the subject, whereby the radiation from the radiation source 1 that has passed through the subject 6 is detected by the detector 2
Detected by the data collection device 2
A CT scan is performed by collecting in step 1 (step 120). Then, the cross-sectional image of the subject is reconstructed from the transmission data of the subject collected by the data collection device 21 (step 130). A cross-sectional image of the subject thus reconstructed is shown in FIG.

Next, a region of interest ROI is set for the cross-sectional image of the subject thus obtained (step 14).
0). By setting this region of interest ROI, 2 in FIG.
A region of interest ROI is set as indicated by 23. Then, the center 22 of the set region of interest ROI 223
The XY stage 5 is moved to align 31 with the scan center 42, and the data acquisition traverse area and the data acquisition pitch are set for this ROI scan.
The image reconstruction conditions are set, and the ROI scan is set accordingly (step 150). Then, an ROI scan (CT scan) is performed under the set conditions (step 160), a cross-sectional image of the region of interest ROI is reconstructed (step 170), and CRT is performed as shown in FIG. 2C.
A cross-sectional image of the region of interest ROI is displayed on the display 23.

The ROI designating device 8 designates the region of interest ROI, which is the CRT display 23.
When the region of interest ROI is designated on the cross-sectional image of the subject displayed above, the coordinates on the XY stage 5 are calculated from the reduced scale, and the mechanical controller 7 is moved to the XY stage 5.
This is done by specifying the moving distance of.

FIG. 4A shows a traverse range when a normal CT scan is performed, and FIG. 4B shows a traverse range with respect to a region of interest ROI when an ROI scan is performed.

In the above embodiment, the region of interest ROI can be designated on the cross-sectional image of the subject, and the region of interest R
By scanning the OI, it is possible to obtain a high-definition sectional image that cannot be obtained by conventional zooming. Further, the XY stage 5 allows the subject to be set in an arbitrary region of interest ROI by remote control. Further, since the region of interest ROI is designated on the cross-sectional image of the subject, the position of the region of interest ROI can be set accurately.

FIGS. 5A and 5B are a plan view and a side view, respectively, showing the configuration of the CT scanner according to the second embodiment of the present invention. The CT scanner shown in the figure is an X-ray tube 5 that generates an X-ray fan beam 511 having a fan angle α.
1, detector 52, data acquisition device 521, imaging device 5
22, CRT display 523, rotation table 54 on which subject 506 is placed, Y stage 55, traverse mechanism 53, mechanical controller 524, C
It has a PU 525 and a linear encoder 531.

In the CT scanner of this embodiment, the Y stage 55, which can move the rotation table 54 by one axis only in the Y direction perpendicular to the traverse direction, has a traverse mechanism 53.
It is provided above. Then, as shown in FIG. 6, with respect to the region of interest ROI 523 designated on the first tomogram 521, positioning is performed by the Y stage 55 only in the Y direction.
The center 5231 of the region of interest ROI 523 is always positioned so as to coincide with the traverse direction of the scan center. That is, the fan angle α is rotated for each traverse, and at that time, the Y stage 55 is moved by the shift amount of the scan center in the Y direction, so that the ROI center is always aligned with the scan center in the traverse direction.

Further, since the data collection start point is shifted in the traverse direction due to rotation, the data collection start point is shifted by R.
The CPU 525 which constitutes the OI designating apparatus performs the calculation and controls the data collection by designating L1 and L2 as shown in FIG. That is, the distance L corresponding to the region of interest ROI from the encoder reference points Z1 and Z2 during traverse
By making 1 and L2 variable according to the size of the region of interest ROI, a free scan area can be set.

In this embodiment, in addition to the effect of the first embodiment, only the Y stage 55 is required instead of the XY stage 5 shown in FIG. 1, so that the mechanical rigidity on the table may be small, and The scanner becomes smaller and lighter.

FIG. 8 shows C according to the third embodiment of the present invention.
It is a figure which shows roughly the structure of the principal part of T scanner. In the figure, 61 is an X-ray tube, 62 is a detector, 64 is a rotation table, 65 is a region of interest ROI, 651 is a center of the region of interest ROI, and 66 is a sample (subject).

The CT scanner of this embodiment is the one in which the XY stage 5 and the Y stage 55 are removed and only the rotation table 64 is provided in the embodiment shown in FIGS. In such a CT scanner, the region of interest ROI
When 65 is designated, the center 651 of the region of interest ROI
Is calculated in the X and Y directions, and the data collection is performed while changing the data collection start point and the data collection area (range). Since the scan center changes for each traverse, the image reconstruction is set accordingly. The reason that the data acquisition region (traverse direction) changes is that the ROI sensor changes in the Y direction, and thus the distance that the region of interest ROI crosses the fan angle changes.
In the second embodiment described above, since the Y direction is aligned, the data collection range is constant and does not deviate.

FIG. 9 is a flow chart showing the operation of the embodiment shown in FIG. After performing the traverse and collecting the data, the rotation operation of the rotation table 64 is performed to correct the data collection starting point and the collection range of the traverse.

In addition to the effect of the first embodiment, the present embodiment does not require the XY stage, the mechanical rigidity is increased, and only the rotation table 64 is required, so that the size and weight are reduced.

The second and third embodiments shown in FIGS. 5 and 8 are both of the T / R type, but the same applies to the R / R type in which the X-ray tube and the detector are integrated. The effect of can be obtained.

FIG. 10 is a view schematically showing the arrangement of the main parts of a CT scanner according to the fourth embodiment of the present invention. In the figure, 71 is an X-ray tube, 72 is a detector, 73 is a rotation table, 74 is an FCD stage, and 75 is X.
The Y stage, 76 is the subject, and 731 is the center of rotation.

The CT scanner shown in FIG. 10 is of the R / R type, and as shown in FIG. 10B, the center 771 of the region of interest ROI 77 designated on the first tomogram 761 is recognized and the The sample 76 is moved to the rotation center 731 by the XY stage on the rotation table 73. The FCD direction is positioned by moving the rotation table by the FCD stage 74 to a position within the fan angle that matches the designated ROI radius.
Match the CD). After that, perform ROI scan,
A cross-sectional image of the region of interest ROI is obtained. The same effect can be obtained even when the X-ray tube and the detector are relatively integrated and moved in the FCD direction.

Further, in the case of a type in which the scanner composed of the X-ray tube and the detector rotates integrally, by providing means for moving the scanner in each of the X and Y directions, the region of interest ROI
The center and scan center can be matched.

FIG. 11 shows a system in which the set of the X-ray tube and the detector 72 rotates. FIG. 12 is a flow chart showing the operation of the CT scanner shown in FIG. In the present embodiment, ROI scanning is possible with the R / R method. In addition, a so-called fourth generation C in which the X-ray source rotates around the subject and data is collected (scanned) by the detector fan.
Similar to the R / R method, the T scanner can also specify the ROI, control the ROI, and scan the ROI.

13 and 14 are views showing the fifth embodiment of the present invention. In FIGS. 13 and 14, 81 is X
Reference numeral 82 is a detector, 83 is a detector, 83 is a traverse mechanism, 84 is a rotation table, 85 is a sample positioning means for positioning a sample which is an object, 89 is an object,
That is, the sample, 86 is the first tomogram, 87 is the region of interest ROI, 871 is the center of the region of interest ROI, 88
Is a scan center.

The CT scanner of the present embodiment controls the positioning of the subject by designating the region of interest ROI, and regardless of the scanning method such as the T / R method and the R / R method, the CT scanner is displayed on the first tomogram. By designating the region of interest ROI 87, the position of the center 871 of the region of interest ROI on the rotation table 84 can be recognized. The sample positioning means 85 is capable of positioning the object with respect to the coordinates on the rotation table so as to move the center of the region of interest ROI to the scan center 88 on the rotation table 84. It should be noted that this embodiment has a pawl for holding the subject 89.

In this embodiment, the CT scanner-side X and Y moving stage and the ROI scan condition control means are unnecessary, and since there is no moving stage for the subject or the rotation table, the rigidity of the mechanism is increased and It can be made smaller and lighter.

FIG. 15 is a diagram showing the structure of a CT scanner according to the sixth embodiment of the present invention. In FIG.
91 is a radiation source, 92 is a detector, 93 is a traverse mount, 94 is a rotation mount, 95 is a Y stage, 9
6 is an X stage, 97 is a mount, 951 is a Y stage rail, and 961 is an X stage rail.

The CT scanner of the embodiment shown in FIG. 15 is a ROI scan type CT scanner in which the radiation source 91 and the detector 92 integrally perform T / R operation.
The traverse pedestal 93 is provided on the rotation pedestal 94, and CT scanning is possible with the subject fixed. Then, the X and Y stages 96 and 95
By making the scan center variable, the scan center can be aligned with the ROI center. R
OI scanning is possible by controlling the traverse distance and the data acquisition pitch.

FIG. 16 is a diagram showing the structure of a CT scanner according to the seventh embodiment of the present invention. The CT scanner shown in the figure uses an X-ray tube 101 that rotates around the subject in one plane and a ring-shaped multi-channel detector 102 that does not rotate about the center of rotation to obtain a cross-sectional image of one plane. This is a fourth-generation CT scanner to be created, and has a region of interest designating means for designating a region of interest ROI on a cross-sectional image, and a moving means for moving a point of the subject corresponding to the center of the region of interest ROI to the center of rotation. , To obtain a high-quality cross-sectional image of the designated region of interest ROI.

[0053]

As described above, according to the present invention,
The region of interest ROI can be accurately specified on the cross-sectional image of the subject, and by scanning the region of interest ROI, it is possible to obtain a high-definition cross-sectional image that cannot be obtained by conventional zooming reconstruction. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a CT scanner according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing ROI scanning in the CT scanner shown in FIG.

FIG. 3 is a flowchart showing the operation of the CT scanner shown in FIG.

4 is a diagram showing a traverse range when performing a normal CT scan and a traverse range regarding a region of interest ROI when performing a ROI scan in the CT scanner shown in FIG.

FIG. 5 is a diagram showing a configuration of a CT scanner according to a second embodiment of the present invention.

6 is an explanatory diagram showing ROI scanning in the CT scanner shown in FIG.

7 is an explanatory diagram showing a data collection start point in the CT scanner shown in FIG.

FIG. 8 is a diagram schematically showing a configuration of a main part of a CT scanner according to a third embodiment of the present invention.

9 is a flowchart showing the operation of the CT scanner shown in FIG.

FIG. 10 is a diagram schematically showing a configuration of a main part of a CT scanner according to a fourth embodiment of the present invention.

FIG. 11 is a diagram showing a system in which a set of an X-ray tube and a detector rotates.

12 is a flowchart showing the operation of the CT scanner shown in FIG.

FIG. 13 is a diagram showing a configuration of a CT scanner according to a fifth embodiment of the present invention.

14 is a diagram showing an ROI scan in the CT scanner shown in FIG.

FIG. 15 is a diagram showing a configuration of a CT scanner according to a sixth embodiment of the present invention.

FIG. 16 is a diagram showing a configuration of a CT scanner according to a seventh embodiment of the present invention.

FIG. 17: Conventional traverse / rotation (T /
It is a figure which shows the structure of the R) system CT scanner.

FIG. 18 is a diagram showing a configuration of a conventional rotate / rotate (R / R) type CT scanner.

[Explanation of symbols]

 1 Radiation Source 2 Detector 3 Traverse Mechanism 4 Rotation Table 5 XY Stage 6 Subject 7 Mechanical Controller 8 ROI Designator 21 Data Acquisition Device 22 Imaging Device 23 CRT Display

Claims (8)

[Claims] 1. A CT for scanning a subject while irradiating the subject with radiation and creating a cross-sectional image based on projection data from a number of directions of the radiation transmitted through one cross section of the subject.
A scanner, a region of interest setting means for setting a region of interest at an arbitrary position on a cross-sectional image of the subject, moving means for moving the subject so as to align substantially the center of the region of interest with the scan center, Scan range limiting means for limiting the scan to a scan range necessary and sufficient for collecting projection data of the region of interest, and moving the center of the region of interest to the scan center by the moving means, and performing the scan A CT scanner characterized in that a high-quality cross-sectional image of the region of interest is obtained by finely scanning the scan range limited by the range limiting means. 2. Radiation generating means for generating radiation in a fan shape, and detection means for irradiating the subject with fan-like radiation generated from the radiation generating means and detecting the radiation that has passed through the subject. Traverse means for linearly moving the fan-shaped radiation generated from the radiation generating means so that the subject traverses in the direction along the fan surface, rotating means for being traversed linearly by the traverse means, and on the rotating means. A moving means for moving the subject in an arbitrary direction, a region of interest setting means for setting a region of interest at an arbitrary position on a sectional image of the subject, and a substantially center of the region of interest set by the region of interest setting means And a movement control means for controlling the movement means so as to align the scanning center with the scanning center, and a high-quality cross-sectional image of a desired region of interest of the subject is obtained. Canna. 3. A T / R type CT scanner for scanning a subject by a method of traverse / rotation to obtain projection data from a number of directions to create a cross-sectional image of the subject, the CT scanner being in the traverse direction. When moving means for moving the rotating means in a direction orthogonal to the rotating means and rotating means for each traverse operation perform a rotating operation for a fan angle of radiation,
It has a traverse control means capable of controlling acquisition conditions including a data acquisition start point and an end point in the traverse direction for each angle of the rotation operation, and enables a scan to obtain a high-quality cross-sectional image of a desired region of interest of the subject. A CT scanner characterized by the following. 4. A traverse / rotation type CT
A scanner, which is a region of interest setting means for setting a region of interest at an arbitrary position on a cross-sectional image of a subject, and data collection including a data collection start point and an end point for aligning the center of the region of interest with the scan center A CT scanner having traverse control means for performing traverse by changing conditions for each traverse / rotation operation, and obtaining a high-quality cross-sectional image of a desired region of interest of a subject. 5. A rotate / rotate type C for rotating a subject or radiation generating means and radiation detecting means for scanning to obtain projection data and create a sectional image.
A T scanner, which is a region of interest setting means for setting a region of interest at an arbitrary position on a cross-sectional image of a subject, and a point of the subject corresponding to the center of the region of interest is aligned with the center of rotation which is the scan center. And a distance changing means for changing the distance between the radiation generating means and the rotation center within a range in which the region of interest of the subject does not protrude from the radiation beam, and has a high quality of the desired region of interest of the subject. A CT scanner characterized by obtaining a sectional image. 6. A fourth generation in which a cross-sectional image of one surface is created by a radiation source that rotates around the subject in one surface and a ring-shaped multi-channel detector that does not rotate about a rotation center. The CT scanner of claim 1, which has region-of-interest designating means for designating a region of interest on the cross-sectional image and moving means for displacing a point of the subject corresponding to the center of the region of interest around the center of rotation. A CT scanner characterized by obtaining a high-quality sectional image of a region. 7. A radiation source for generating fan-shaped radiation,
A one-dimensional detector that detects the fan-shaped radiation that has passed through the subject, a positioning unit that positions the subject between the radiation source and the detector, and the radiation source and the detector integrally What is claimed is: 1. A traverse / rotation CT scanner that obtains cross-sectional images of a subject by obtaining transmission data of the subject by traversing / rotating around the subject along a fan surface of fan-shaped radiation. Specifying means for specifying the region of interest on the cross section,
A moving means for moving the radiation source and the detector so that the center position of the region of interest of the subject is the center of the traverse / rotation, and obtaining a high-quality cross-sectional image of the designated region of interest. Characteristic CT scanner. 8. The moving means has means for contacting and moving the object only when the scan operation of the object is not performed, aligning the center of the region of interest with the scan center, and separating the object from the object during scanning. Claim 1
The CT scanner according to 2, 5, or 6.