JP4724250B2 - X-ray CT system - Google Patents

Description

The present invention relates to an X-ray CT apparatus provided with a so-called multi-slice X-ray detector having a plurality of X-ray detector rows in the body axis direction of a subject, and in particular, an X-ray for multi-slice. The present invention relates to an X-ray CT apparatus capable of displaying an irradiation range (X-ray width) of an X-ray to be irradiated corresponding to a detector.

Conventionally, in an X-ray CT apparatus, when a tomographic image of a subject is imaged, an imaging position is previously determined using a projector. For example, as shown in FIG. 5, the projector includes an upper side (projector 102) and a left and right side (projectors 103, 10) of the gantry 101 of the gantry rotating unit 100.
4), which is displayed by irradiating the subject placed on the bed 105 with an optical marker such as a laser beam.

FIG. 6 shows an optical marker M that is irradiated to the subject from the projector 103 provided on the left side of the gantry 101 when photographing the head of the subject. As can be seen from FIG. 6, in the case of head imaging, the optical marker M from the projector 103 provided on the left side of the gantry 101 is generally a line connecting the right buttocks of the subject and the right ear hole. Irradiated according to the line. Note that the light marker from the projector 104 provided on the right side of the gantry 101 is also aligned with the OM line, which is a line connecting the left buttocks of the subject and the left ear hole, similarly to the light marker M from the projector 103. Is irradiated. On the other hand, the optical marker from the projector 102 provided on the upper side of the gantry 101 is a line that bisects the subject from the nose of the subject along the body axis direction in order to see left-right symmetry. Irradiate along the midline.

The operator adjusts the imaging position by driving the bed 105 up and down and sliding so that the light markers irradiated from the projectors 102 to 104 are aligned with the lines. Then, after the adjustment of the imaging position, the process shifts to capturing a tomographic image of the subject.

At the time of imaging, as shown in FIG. 7, the X-ray tube 110 and the X-ray detector 111 are rotationally driven while maintaining the mutually opposing positional relationship, and the X-ray tube 110 is intermittently or continuously. Driven to emit X-rays. The X-ray detector 111 is formed by arranging a plurality of X-ray detection elements in a line in a direction perpendicular to the body axis direction of the subject, and is formed by exposing the subject to X-rays. The obtained X-ray images are captured by the plurality of X-ray detection elements, projection data which is an electric signal corresponding to the X-ray dose is formed, and supplied to a data collection unit (DAS).

The data collection unit collects projection data from the X-ray detector 111 and supplies it to the image reconstruction unit. Based on the projection data, the image reconstruction unit forms a reconstructed image of a desired part of the subject using an image reconstruction technique such as a back projection method, and this is formed on a monitor device, an image storage device, or the like. Supply. Thus, a tomographic image of a desired part of the subject can be displayed on the monitor device or stored in the storage device.

Here, in the X-ray CT apparatus, as described above, a single slice X-ray detector 111 formed by arranging a plurality of X-ray detection elements in a line in a direction orthogonal to the body axis direction of the subject. In general, it is common to take tomographic images one by one. However, in recent years, as shown in FIG. 8, a plurality of X-ray detection elements 115 are orthogonal to the body axis direction of the subject. An X-ray CT apparatus provided with a multi-slice X-ray detector 117 having a plurality of rows of X-ray detector rows 116 formed in a row in the direction of the body along the body axis direction of the subject. Are known. FIG. 8 shows a dual slice X-ray detector in which two X-ray detector rows 116 are provided in the body axis direction of the subject.

In the X-ray CT apparatus provided with the multi-slice X-ray detector 117, an X-ray image formed by one X-ray exposure is converted into each X-ray detector row of the X-ray detector 117. Capture at 116. Thereby, the projection data in the direction orthogonal to the body axis direction of the subject and the projection data in the body axis direction of the subject can be collected at one time by one-time X-ray exposure, and the projection data can be collected in three dimensions. Collection can be made possible.

JP-A-11-206751

In the X-ray CT apparatus provided with the multi-slice X-ray detector 117, the projection data is provided along the body axis direction of the subject in order to enable the three-dimensional acquisition of the projection data. It is necessary that each X-ray detector row 116 captures an X-ray image. For this reason, as shown in FIG. 8, the X-rays exposed to the subject from the X-ray tube 110 inevitably have a width H along the body axis direction of the subject (the column direction of the X-ray detector row 116). Width).

However, since the projectors provided in the conventional X-ray CT apparatus (the projectors 102 to 104) were provided on the assumption that an X-ray detector for single slice was provided as an X-ray detector, The imaging position (slice position) is displayed on the subject with dots or lines. For this reason, when such a projector is provided in an X-ray CT apparatus provided with a multi-slice X-ray detector 117, exposure of X-rays having a width along the body axis direction of the subject is performed. The slice range that is the range cannot be accurately displayed, and it is difficult to accurately position the photographing position.

The present invention has been made in view of the above-described problems. Even when three-dimensional acquisition of projection data is performed using a multi-slice X-ray detector, an X-ray exposure range is provided to an operator. Can be displayed accurately, the imaging position can be accurately positioned, and the trouble of newly inputting the scan plan after setting the X-ray exposure range can be omitted. An object of the present invention is to provide an X-ray CT apparatus capable of improving the operability and convenience of the X-ray CT apparatus.

The X-ray CT apparatus according to the present invention includes an X-ray detector array in which a plurality of X-ray detection elements are arranged in a line in a direction orthogonal to the body axis direction of the subject, and the body axis direction of the subject. X-ray detection means provided for a plurality of rows in the X-ray detector, and an exposure range of the X-rays exposed toward the X-ray detection means along the body axis direction of the subject on the subject Range display means, imaging condition setting means for automatically setting imaging conditions based on the slice thickness corresponding to the X-ray exposure range set by the exposure range display means, and setting by the imaging condition setting means Image pickup control means for controlling image pickup based on the set image pickup conditions.

In such an X-ray CT apparatus, the exposure range display means indicates on the subject the X-ray exposure range that is exposed corresponding to the X-ray detection means. Accordingly, even when three-dimensional collection of projection data is performed, the X-ray exposure range can be accurately displayed to the operator, and the imaging position can be accurately positioned.

Since the X-ray CT apparatus according to the present invention can indicate on the subject the X-ray exposure range to be exposed corresponding to the X-ray detection means, the multi-slice X-ray detector is used. 3 of projection data
Even when performing dimensional acquisition, the X-ray exposure range can be accurately displayed to the operator, the imaging position can be accurately positioned, and the X-ray exposure range can be controlled. It is possible to save the trouble of newly inputting the scan plan after setting, and it is possible to improve the operability and convenience of the X-ray CT apparatus.

It is a block diagram of the light projection system provided in the X-ray CT apparatus of the 1st Embodiment of this invention. It is a figure which shows a mode that the optical marker is irradiated with respect to the subject from the light projector provided in the X-ray CT apparatus of the said 1st Embodiment. It is a block diagram of the light projection system provided in the X-ray CT apparatus of the 2nd Embodiment of this invention. It is a block diagram of the X-ray CT apparatus of the 3rd Embodiment of this invention. It is a perspective view which shows the external appearance of the conventional X-ray CT apparatus. It is a figure which shows the optical marker irradiated with respect to the subject from the light projector provided in the conventional X-ray CT apparatus. It is a block diagram of the principal part of the conventional X-ray CT apparatus. It is a perspective view of the X-ray detector for multi slices.

[First Embodiment]
[Configuration of the projector]
The X-ray CT apparatus according to the first embodiment of the present invention is a multi-slice X-ray having a plurality of X-ray detector rows along the body axis direction of the subject as shown in FIG. It is an X-ray CT apparatus provided with a detector, and is characterized by the provision of a projector 1 that indicates the X-ray exposure range as shown in FIG.

The light projector 1 includes a light generator 2 that forms one light marker, and a light marker having a width L that indicates an X-ray exposure range based on one light marker from the light generator 2. And a width forming optical system 3 for forming the. The width forming optical system 3 collimates a width forming lens 4 for giving a light width to one light marker from the light generator 2 and a light marker having a width formed by the width forming lens 4 to form a subject. And by changing the distance between the width forming lens 4 and the parallel lens 5, the width L of the optical marker is set to a width corresponding to the X-ray exposure range. It is supposed to be.

Such a projector 1 is provided on the upper side of the gantry (position of the projector 102) and the left and right sides (positions of the projectors 103 and 104) of the gantry rotating part as described with reference to FIG. The X-ray exposure range is displayed on the subject prior to imaging by the light markers.

In FIG. 1, the projector 1 is configured in such a manner that the light generator 2 and the width forming optical system 3 are separately provided. This is because the width forming optical system 3 is provided in the light generator 2. The projector 1 may be configured to be housed and integrated with each other.

[Configuration of projector drive system]
Next, the X-ray CT apparatus of the first embodiment includes an operation panel 6 provided in the gantry rotating unit.
And a lens driving unit 7 that variably controls the distance (distance) between the width forming lens 4 and the parallel lens 5 of the width forming optical system 3 according to the operation of the operation panel 6. X to do
The exposure range of the line is variable.

The operation panel 6 includes a first operation key 6a for moving the lenses 4 and 5 in the direction of narrowing the X-ray exposure range, and the lenses 4 and 5 in a direction of expanding the X-ray exposure range. And a second operation key 6b for moving the. The X-ray exposure range is variably controlled according to the number of times (or time) that any one of the operation keys 6a and 6b is turned on.

On the operation panel 6, when the X-ray exposure range is variably adjusted by operating the operation keys 6a and 6b, the corresponding slice thickness is displayed.

A dial key may be provided in place of the operation keys 6a and 6b, and the movement range of the lenses 4 and 5 may be controlled according to the operation of the dial key to vary the X-ray exposure range. In addition, the movement control of each lens 4 and 5 according to the number of times (or time) when any one of the operation keys 6a and 6b is turned on has been described as an example, but this corresponds to the slice thickness. A plurality of slice thickness selection keys may be provided, and the X-ray exposure range may be varied by controlling the movement of the lenses 4 and 5 according to the slice thickness of the slice thickness selection key operated by the operator.

[Operation of the X-ray CT apparatus of the first embodiment]
Next, the operation of the X-ray CT apparatus according to the first embodiment having the projector 1 having such a configuration will be described.

[Determining shooting range]
The X-ray CT apparatus according to the first embodiment has the multi-slice X-ray detector as described above, and this projector 1 is used before taking a desired tomographic image. The imaging range corresponding to the multi-slice X-ray detector is determined.

When determining the imaging range, the operator turns on one of the operation keys 6a and 6b on the operation panel provided on the gantry rotating unit side according to the desired X-ray exposure range. The lens driving unit 7 variably controls the distance between the width forming lens 4 and the parallel lens 5 according to the number of operations of the operation keys 6a and 6b. Specifically, when the first operation key 6a is operated by the operator, the lens driving unit 7 narrows the X-ray exposure range in accordance with the number of operations of the first operation key 6a. The movement between the lenses 4 and 5 is controlled to adjust the distance between the lenses 4 and 5. In addition, when the operator operates the second operation key 6b, the lens driving unit 7 expands the X-ray exposure range in accordance with the number of operations of the second operation key 6b. , 5 is controlled to adjust the distance between the lenses 4, 5.

The light marker of one light formed by the light generator 2 has its light width expanded according to the distance between the width forming lens 4 and the parallel lens 5, converted into parallel light by the parallel lens 5, and light having a width L. It is projected onto the subject as a marker.

FIG. 2 shows that the light marker whose width is adjusted from the projector 1 provided on the upper side of the gantry of the gantry rotating unit (position of the projector 102 shown in FIG. 5) to the chest of the subject (in the case of chest imaging). It shows the light being projected. As can be seen from FIG. 2, when the multi-slice X-ray detector 10 positioned on the back side of the subject has, for example, four rows of X-ray detector rows 11, the width L of the optical marker Is adjusted by variably controlling the distance between the lenses 4 and 5 so as to correspond to the X-ray detector array 11 and is projected onto the subject.

The operator can change the distance between the lenses 4 and 5 by operating the operation keys 6a and 6b of the operation panel 6 while visually checking the width of the light marker projected on the subject. While adjusting the exposure range of X-rays. In the X-ray CT apparatus, since the operation keys 6a and 6b for adjusting the X-ray exposure range are provided on the gantry rotating unit side, the X-ray exposure range is being checked closely. Can be adjusted.

FIG. 2 shows an optical marker projected on the subject from the projector 1 provided on the upper side of the gantry of the gantry rotating unit, but is provided on the left and right side of the gantry. The same light marker is also projected from each projector, and the X-ray exposure ranges on the left and right surfaces of the subject are indicated.

In the example of FIG. 2, the X-ray exposure range indicated by the optical marker is 1 of the X-ray detector.
The number of X-ray detector rows 11 matches the number of X-ray detector rows 11, but this is an example. For example, desired X-ray detector rows of four rows of X-ray detector rows 11 are arranged. When imaging is performed using only the X-ray detector, the distance between the lenses 4 and 5 is adjusted according to the width of the two X-ray detector rows.

[Shooting operation]
Next, when the shooting position is determined by the projector 1 in this way, shooting is started. When taking an image, the X-ray tube and the multi-slice X-ray detector rotate around the subject by rotating the inner circumference of the gantry while maintaining the opposing positional relationship, and may be continuous or intermittent. X-rays are exposed. The exposure range of the X-rays exposed to the subject is the range set by the projector 1 as described above. Then, an X-ray image formed by exposing the subject to X-rays is captured by a multi-slice X-ray flat detector. At this time, since X-rays having a width along the body axis direction of the subject are exposed to the subject, an X-ray image corresponding to the width of the X-ray is X
Each X-ray detector row of the line detector is taken in at once. Each X-ray detector row forms projection data that is an electrical signal corresponding to the acquired X-ray image.

This projection data is collected by the data collection unit and supplied to the image reconstruction unit. The image reconstruction unit forms a reconstructed image of a desired part of the subject using an image reconstruction technique such as a back projection method based on the projection data from the data collection unit, Supply to storage device. Thus, a tomographic image of a desired part of the subject can be displayed on the monitor device or stored in the storage device.

[Effect of the X-ray CT apparatus of the first embodiment]
As is clear from the above description, the X-ray CT apparatus of the first embodiment uses the projector 1 to set an X-ray exposure range corresponding to an X-ray detector having a plurality of X-ray detector arrays. It can be displayed on the subject. For this reason, even when three-dimensional collection of projection data is performed, the X-ray exposure range can be accurately shown to the operator, and the imaging position can be accurately positioned.

[Second Embodiment]
Next, an X-ray CT apparatus according to the second embodiment of the present invention will be described. The X-ray CT apparatus of the first embodiment described above is a projector that changes the light width of one light marker from the light generator 2 by variably controlling the distance between the width forming lens 4 and the parallel lens 5. However, the X-ray CT apparatus according to the second embodiment is provided with two projectors each forming an optical marker, and each optical marker can be changed by varying the distance between the projectors. The distance is varied to indicate the width of the X-ray exposure range. The first embodiment and the second embodiment described above are different only in this point. Therefore, only the difference will be described below, and redundant description will be omitted.

[Configuration of Second Embodiment]
As shown in FIG. 3, the X-ray CT apparatus of the second embodiment includes a first projector 21 that forms a first optical marker M1, and a second projector 22 that forms a second optical marker M2. And a projector drive mechanism 23 for controlling the movement of the projectors 21 and 22 along the body axis direction of the subject in response to the operation of the operation keys 6a and 6b of the operation panel 6.

[Operation of Second Embodiment]
In such an X-ray CT apparatus, when the operation keys 6a and 6b of the operation panel 6 provided on the gantry rotating unit side are operated by an operator before imaging, the projector drive mechanism 23 causes the operation keys to be operated. Corresponding to the operations 6a and 6b, the projectors 21 and 22 are controlled to move along the body axis direction of the subject.

As shown by a solid line in FIG. 3, the first light marker 21 that indicates one end of the X-ray exposure range (width) is irradiated from the first projector 21 to the subject. The subject is irradiated with a second optical marker M2 indicating the other end of the X-ray exposure range (width). Therefore, the distance L between the light markers M1 and M2 is changed by controlling the movement of the projectors 21 and 22 along the body axis direction of the subject in response to the operation of the operation keys 6a and 6b. The X-ray exposure range is changed.

As described above, since the operation keys 6a and 6b are provided on the gantry rotating part side, the operator can perform X-ray exposure while actually checking the distance between the optical markers M1 and M2 with the eyes. Make adjustments. Then, imaging is started after the adjustment of the X-ray exposure range.

[Effect of the second embodiment]
As is clear from the above description, the X-ray CT apparatus according to the second embodiment includes the first and second X-ray CT apparatuses.
By controlling the movement of the projectors 21 and 22, the distance L between the first and second optical markers M1 and M2 is varied to display the X-ray exposure range. Thereby, the same effect as the first embodiment described above can be obtained.

[Third Embodiment]
Next, an X-ray CT apparatus according to a third embodiment of the present invention will be described. The X-ray CT apparatus of the third embodiment has an X-ray exposure range (adjusted by the projector 1 or the projectors 21 and 22 provided in the X-ray CT apparatus of any of the above-described embodiments ( A scan plan is automatically formed based on the slice thickness, and this is reflected in imaging. In addition,
Each of the above-described embodiments and the third embodiment are different only in this point. Therefore, only the difference will be described below, and redundant description will be omitted.

[Configuration of Third Embodiment]
As shown in FIG. 4, the X-ray CT apparatus according to the third embodiment includes an X-ray tube 36 that rotates the outer periphery of a subject while maintaining the opposing positional relationship, and an X-ray detector for multi-slice. 10 is a gantry rotating unit 35 that captures an X-ray image, and a console 30 that automatically forms a scan plan based on the set X-ray exposure range and controls the imaging based on the scan plan.
And have.

The gantry rotating unit 35 drives the projector 1 (or the projectors 21 and 22) in accordance with the operation of the operation panel 6 together with the operation panel 6 to display the X-ray exposure range (slice thickness) on the subject. And a slice thickness reading unit 31 for reading the set slice thickness based on the X-ray exposure range adjusted by the operation of the operation panel 6.

The light projection width control unit 29 becomes the lens driving unit 7 when a projector that can change the distance between the lenses 4 and 5 shown in FIG.
When a projector that can change the distance between the projectors 21 and 22 is provided, the projector driving mechanism 23 is provided.

Further, by providing the light projection width control unit 29 on the gantry rotating unit 35 side, the length of the cable connecting the light projection width control unit 29 and the projector 1 (or the projectors 21 and 22) can be shortened. Measures against EMC noise are achieved by suppressing generation of unnecessary radiation noise and the like.

The console 30 includes a scan plan forming unit 32 that forms a corresponding scan plan based on the slice thickness read by the slice thickness reading unit 31 provided on the gantry rotating unit 35 side, and a scan plan forming unit 32. A scan plan storage unit 33 that stores the formed scan plan, and an imaging control unit 34 that performs imaging control of the gantry rotating unit 35 based on the scan plan stored in the scan plan storage unit 33 are provided.

[Operation of Third Embodiment]
When the operator operates the operation panel 6 before imaging, the X-ray CT apparatus of the third embodiment having such a configuration is the same as that of the first embodiment or the second embodiment described above. X
Like the line CT apparatus, the projection width control unit 29 responds to the operation of the operation panel 6 to each lens 4.
, 5 or the distance between the projectors 21 and 22 is variably controlled to vary the X-ray exposure range.

The slice thickness reading unit 31 operates the operation panel 6 (light marker width = X-ray exposure range).
And the data indicating the slice thickness is supplied to the scan plan forming unit 32 of the console 30. Based on the data indicating the slice thickness, the scan plan forming unit 32 forms the condition of the slice image of the scan plan so as to obtain an optimum imaging condition according to the slice thickness of the multi-slice X-ray detector 10. This is stored and controlled in the scan plan storage unit 33.

When the start of shooting is designated by the operator, the shooting control unit 34 reads out the scan plan stored in the shooting scan plan storage unit 33 and controls shooting of the gantry rotating unit 35 based on this scan plan. Thus, a scan plan can be automatically formed based on the X-ray exposure range (slice thickness) adjusted by operating the operation panel 6, and this can be reflected in imaging.

[Effect of the third embodiment]
As is apparent from the above description, the X-ray CT apparatus of the third embodiment, when an X-ray exposure range (slice thickness) is set by an operator, A scan plan can be automatically formed according to the shooting range and reflected in shooting. For this reason, the trouble of newly inputting a scan plan after setting the X-ray exposure range can be omitted, and the operability and convenience of the X-ray CT apparatus can be improved.

[Other application examples of the present invention]
Finally, each of the above-described embodiments is an example of the present invention. For this reason, the display form of the exposure range by each projector 1 and 21 and 22 demonstrated in 1st Embodiment and 2nd Embodiment is only an example of the exposure range display means.

Therefore, for example, a plurality of optical units having different refractive indexes may be prepared, and these may be replaced automatically or manually according to the slice thickness to display the exposure range.

Further, a slit is provided between the projector 1 (or the projectors 21 and 22) and the subject, and the light marker from the projector 1 is obliquely illuminated by a predetermined amount so that the width of the light marker is set to a width corresponding to a desired slice thickness. The specimen may be projected.

Of course, even in the other embodiments, various modifications can be made according to, for example, the design as long as they do not depart from the technical idea according to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Light projector, 2 ... Light generator, 3 ... Width formation optical system, 4 ... Width formation lens, 5 ... Parallel lens, 6
DESCRIPTION OF SYMBOLS ... Operation panel, 7 ... Lens drive part, 10 ... Multi-slice X-ray detector, 11 ... X-ray detector row | line | column, 21 ... 1st projector, 22 ... 2nd projector, 23 ... Projector drive mechanism, 29 ... Projection width control unit, 30. Console, 31. Slice thickness reading unit, 32. Scan plan forming unit, 33. Scan plan storage unit, 34 ... Imaging control unit, 35.

Claims (2)

X-ray detection means provided with a plurality of X-ray detector rows arranged in a row in a direction perpendicular to the body axis direction of the subject for a plurality of rows in the body axis direction of the subject When,
An exposure range display means for indicating an exposure range of the X-rays emitted toward the X-ray detection means along the body axis direction of the subject on the subject;
Imaging condition setting means for automatically setting imaging conditions based on the slice thickness corresponding to the X-ray exposure range set by the exposure range display means;
Imaging control means for controlling imaging based on the imaging conditions set by the imaging condition setting means;
An X-ray CT apparatus comprising: The imaging condition setting means reads the slice thickness reading data indicating the slice thickness
Based on the data indicating the slice thickness and the optimum imaging conditions according to the slice thickness,
So as to, X-rays diagnostic apparatus according to claim 1, characterized in that have a scan plan forming unit for forming a scan plan.

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