JPH01299533A - Positioning device for ct unit - Google Patents

Abstract

PURPOSE:To enable a reference member to be always displayed with a tomogram by forming the reference member, serving as the reference of a position, into a concentric circular multi-layer structure consisting of two or more materials mutually different in CT value. CONSTITUTION:A positioning device 7 is constituted of a half ring-shaped fixed part 8 in a detected body head part H, supporting members 9, 10 supporting reference member holding parts 11, 11 mounted in the vicinity of both release end parts of the fixed part 8 and embedding a reference member in the inside and a movable supporting part 18 of laser sources 12, 12 mounted to the other end of the supporting member 9. The reference member holding part 11 is provided with a molded member 12 generating no artifact and reference members 13 to 15 embedded in the member 12 and formed into a concentric circular multi-layer structure consisting of two or more materials with a mutually different CT value. Thus because the reference member is formed into the multi-layer structure consisting of two or more materials with a mutually different CT value, even when a light-shade value and a light-shade width corresponding to the CT value, desired to be displayed, are changed, any of the layers is displayed with a tomogram.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention is directed to
The present invention relates to a positioning device for a CT device used during tomography in a CT device.

(Prior Art) Conventionally, in order to obtain a tomographic image at an arbitrary position of a subject using an X-ray CT device, an MRT device, etc., the tomographic image is usually reconstructed from projection data of the subject. C is used to obtain projection data accurately and easily.
This is a positioning device for T device.

Such a conventional positioning device for a CT apparatus will be explained with reference to FIGS. 4(a) and 5(b) and FIG. 5.

The conventional positioning device 1 for a CT apparatus shown in FIG. 4
and a reference member (described later) which is fixed at a position opposite to this fixing member 4 and arranged to serve as a reference for the tomographic position when taking a tomographic image at an arbitrary position of the head H. Two reference member holding parts 2.2 are provided.

The positioning device 1 for a CT device having such a configuration is attached to one end of the top plate 5, and the positioning device 1 for the CT device is attached to one end of the top plate 5, and the positioning device 1 for a gantry such as an X-ray CT device or an MRI device is attached to the top plate 5 whose sliding is controlled. A person is made to appear inside the photographing hole 6. In this way, by controlling the sliding position of the top plate 5, a tomographic image at an arbitrary position of the head H fixed to the device 1 is obtained and displayed on a display section (not shown). There is.

Furthermore, head fixing screw members 3a to 3d are attached to the fixing member 4 at predetermined positions. These head fixing screw members 3a to 3d are attached to positions where two head fixing screw members, for example 3a and 3d, face each other across the center of a ring-shaped fixing member 4, and these two The head H located between the two head fixing screw members 3a and 3d is fixed. This arrangement relationship is the same for the remaining head fixing screw members 3b and 3c.

By the way, the reference member holding parts 2, 2 have a synthetic resin molded member 2a and a reference member 2b made of rod-shaped aluminum embedded in the molded member 2a, as shown in detail in FIG. It consists of 2d to 2d. Further, when the reference members 2b to 2d are viewed from the direction of arrow A,
They are arranged in a rZJ shape.

When a tomographic plane of the head H is photographed using a conventional positioning device for a CT apparatus having such a configuration, a tomographic image as shown in FIG. 5 is obtained. The location of the illustrated tomographic plane is shown in Figure 4 (
b) The inside should be in the position indicated by B-8'.

In this case, the position or coordinates of the photographed tomographic plane is calculated by the control unit of the CT apparatus from the mutual arrangement of the reference members 2b to 2d embedded in the molded member 2a. On the other hand, as the tomographic plane position to be photographed moves in the direction of arrow C shown in FIG. 4(b), the reference member 2
The position of G on the tomographic image changes in the direction of the arrow in accordance with the position of the tomographic plane. That is, by changing the position of the reference member 2C in the tomographic image displayed on the graphic display section, the position of the tomographic plane can be specified on the display section as well.

(Problems to be Solved by the Invention) However, the above-described conventional positioning device for a CT apparatus has the following drawbacks.

Since the reference members 2b to 2d were made only of aluminum, for example, a portion with a CT value different from the CT value of the reference member on a display section (not shown) may be displayed as "
The shading value for “Brain” is 8! When displaying the tomographic image by setting the light/dark width, the tomographic image will be outside the range of the set gray value and density width.

Therefore, the reference member is not displayed together with the tomographic image of the "brain". In such a case, the operator can alternately change the gradation value and gradation width corresponding to the CT value of the reference member and the gradation value and gradation width corresponding to the CT value of the part from which a tomographic image is to be obtained on the display. It must be observed while being displayed.

Such problems cannot be solved even if the reference material is changed to a material with a different CT value, and if left as it is, it will impose an excessive burden on the operator and will lead to
When making a diagnosis based on tomographic images, problems such as a significant decrease in reliability remain unsolved.

Therefore, in order to solve the above-mentioned problems, the present invention aims to provide a positioning device for a CT apparatus in which a reference member can always be displayed together with a tomographic image.

[Structure of the invention] (Means for solving the problem) The structure of the present invention for achieving the above object is based on the above-mentioned C.
The reference member provided in the positioning device for the T device has a multilayer structure made of two or more materials having mutually different CT values, so that the reference member is always displayed together with the tomographic image. In this case, it is preferable that the reference member is made of two or more materials having mutually different CT values and formed into concentric circles.

(for production) The present invention having the above configuration will be explained in detail.

Since the reference member has a multi-layered structure consisting of two or more materials with different CT values, even if the shading value and shading width corresponding to the CT value to be displayed are changed, either one of the reference members layers are displayed together with the tomographic image.

(Example) The present invention will be explained below with reference to the drawings.

FIGS. 2(a) to (C) are explanatory diagrams showing the configuration and operation of a positioning device for a CT apparatus as an example, and FIG. 1 is based on the standards shown in FIGS. 2(a) to (C). It is a detailed explanatory view of a member holding part. In addition, in this embodiment, the above-mentioned FIG. 4(a).

Components equivalent to those explained in (b) are given the same reference numerals and their explanation will be omitted.

In FIGS. 2(a> to (C)), the CT'W1 shadow positioning method is provided at one end of the top plate (not shown) similar to the one described above, and the head of the subject placed on this top plate. A half-ring-shaped fixing part 8 that fixes part H, and support members 9 and 10 that are attached near both open ends of this fixing part 8 and support reference member holding parts 11°11 in which a reference member is embedded. and a movable support part 18 which movably supports the laser sources 12, 12 which are attached to the other end of the support member 9 and which irradiate the head H with laser. The middle portions 3a to 3d are the aforementioned head fixing screw members.

FIG. 1 <a> is an enlarged explanatory view of the reference member holding portion 11.11. The reference member holding parts 11.degree. 11 are mounted substantially vertically on the support members 9.degree. 10, with the head H fixed to the fixing section 8 sandwiched therebetween.

In the figure, the reference member holding part 11 is a molded member 12 made of, for example, acrylic resin, which does not cause artifacts.
A reference member 13 is embedded in the molded member 12 and has a multilayer structure made of two or more materials having different CT values.
15 to 15.

The reference members 13 to 15 are arranged in a rZJ shape when viewed from the six directions shown by the arrows in FIG. The cross-sectional appearance of the parts 1 to 15 is as shown in FIG. 1(b).

The reference member 13 (14, 15) shown in FIG. 2B has a circular cross section and has a multilayer structure in which three materials 13a to 13G having different CT values are formed in concentric circles.

In this embodiment, the outer layer 13a is made of aluminum having a CT value similar to CTTa 205 to 1000 of bone,
The CT value of the soft tissue for the middle layer 13b is 28 to 60.
The inner layer 13 is made of a material having a CT value similar to that of the inner layer 13.
C is a material having a CT value approximately equal to that of fat (-100).

Such a reference member is not limited to one in which the cross-sectional shape is circular, but may also be square or star-shaped, consisting of layers 16a to 16c made of materials with different CT values as shown in FIG. 1(C). The reference member 16 may have a polygonal shape, or the layers 17a to 17c made of materials having different CT values may have a multilayer structure other than concentric circles as shown in FIG. In other words, when displaying a tomographic image on a display unit, etc., no matter how the gradation value and convergence width are set in accordance with the part to be displayed, a CT is such that the reference member is always displayed together with the tomographic image. The reference member may be constructed by combining materials having different values.

By the way, the movable support part 18 to which the laser source 12 shown in FIG. A movable part 18C supported by the movable part 18C,
This movable portion 18G also moves along the arrow R1 with the axis 18b as the center.
, R2. In addition, the same figure (a
) and 20.21 indicate the position when the movable part 18G is rotated to a horizontal state.

Furthermore, the movable part 18G has a laser source support arm 18d attached to the open end side so that the laser source 12 can be rotated within the arrow Ra (shown in FIG. The other end is supported so that it can move within a certain distance of the arrow R3 at the center. In the figure, 18' is the position where the movable support part 18 is moved in the direction of arrow Z, that is, the sliding direction of the top plate, 18'' is the position where the movable part 18G is moved upward in the figure (in the direction of arrow Y), and 19 is the position The positions where the laser source support arm 18d is moved in the direction of arrow X (rightward in the figure) are shown.

In the above explanation, a case has been described in which a tomographic image of the head of the subject is obtained, but other parts, such as the legs, may be obtained.

Of course, the same can be applied to body parts and the like.

The operation and effects of the positioning device for a CT apparatus configured as described above will be explained with reference to FIGS. 3(a) and 3(b).

First, as shown in FIG. 2(b), the head H of the subject is fixed by the head fixing screw members 3a to 3d provided on the fixing part 8. Further, the movable portion 18C and the like are adjusted appropriately to make settings so that photographing can be performed.

Then, move the top plate in the direction of inserting it into the copying hole 6 of the gantry explained in FIG. 4, and move the fixed head H.
Start photographing the tomogram. In this case, the position of each tomographic plane can be determined by calculating the position between the cross-sectional image of the reference member 14 and the cross-sectional image of the reference member 13 and the cross-sectional image of the reference member 15, so that the relative position of the tomographic plane can be determined. become.

A tomographic image reconstructed based on the projection data thus obtained is displayed on a display unit 22 provided in the CT apparatus shown in FIG. 3(a).

At this time, the gradation values and gradation widths are set so that, for example, "fat" tissue is displayed in the center as the subject tissue to be displayed on the display unit 22. Then, on the display unit 22, as shown in FIG. It is displayed together with the cross-sectional image of H.

Next, in order to display a tomographic plane centered on the "bone" of the head H, change the gradation value and II light width of the display section and display the cross-sectional image again. Along with the central cross-sectional image, outer layers 13a to 15a having CT values similar to those of "bone" among the layers constituting the reference members 13 to 15 are displayed as shown in FIG. It becomes like this.

With the positioning device for CT apparatus configured as described above, the reference member can always be displayed together with the tomographic image, so the operator can display the gradation value, gradation width, and cross-sectional image corresponding to the CT value of the reference member. It is possible to omit the conventionally necessary complicated work of observing the gradation values and gradation widths corresponding to the CT value of the region to be obtained while alternating and displaying them on the display unit. Therefore, the burden placed on the operator can be significantly reduced, and the reliability can also be improved when diagnosis is roughly based on cross-sectional images.

It should be noted that the present invention is not limited to the above embodiment,
Various modifications can be made within the scope of the gist. For example, although the reference members 13 to 15 are shown arranged so as to have a substantially rZJ shape, the reference members 13 to 15 are not limited to this as long as they are arranged so that the cross-sectional position can be specified.

In addition to X-ray CT equipment, the present invention also applies to MHI equipment.

It can also be applied to an ultrasonic device, etc., and the same effects as described above can be obtained in this case as well.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a positioning device for a CT apparatus in which a reference member can always be displayed together with a tomographic image.

[Brief explanation of the drawing]

1(a) is an enlarged detailed explanatory view of the reference member holding portion shown in FIG. 2, and FIG. 1(b) to (d) are sectional views of the reference member shown in FIG. (a) thru|or (C) are a side view, a front view, a top view, and FIG. 3 (a) which show the structure and operation|movement of the positioning device for CT apparatuses as one Example of this invention, respectively. (b) is an explanatory diagram showing a display example of a tomographic image and a reference member displayed on the display unit, and FIG. (b) is a perspective view showing details of the reference member holding part shown in (a), and FIG.
FIG. 6 is an explanatory diagram showing a display example when a tomographic image is obtained using the positioning device for a CT apparatus shown in a). 11... Reference member holding part, 13 to 15... Reference member. Agent Patent Attorney Masayoshi Misawa Figure 2 Figure 3 Figure 5 ~ ■

Claims (2)

[Claims] (1) In a positioning device for a CT apparatus that is equipped with a reference member that serves as a reference for each tomographic plane position when obtaining a tomographic image on an arbitrary tomographic plane of a subject, the reference member is made of two or more materials with mutually different CT values. A positioning device for a CT device, characterized by having a multilayer structure consisting of. (2) The reference member according to claim 1, wherein the reference member has a multilayer structure in which two or more materials having different CT values are concentrically formed.
Positioning device for T device.