JPH03971Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is a computerized tomography device (hereinafter referred to as CT).
The present invention relates to a phantom device for testing the measurement accuracy of a device (referred to as a device), and in particular to a phantom for testing contrast.

(b) Prior Art Conventionally, this type of test phantom was constructed by fixing a round rod made of plastic material with a certain radiation absorption rate to a fixed plate, and placing this in a water tank. However, it is impossible to make minute changes in low contrast with plastic round rods, and in conventional aquariums, air bubbles remain inside the tank, resulting in poor measurement accuracy, and the type of plastic material (radiation absorption rate) The drawback was that there were limitations and it was not possible to conduct extensive testing.

(c) Purpose In view of the above points, the present invention is a test phantom for CT equipment that is capable of performing measurements with low contrast (for example, CT value 1/100) and eliminates the adverse effects of air bubbles on measurement results. The purpose is to provide equipment.

(D) Structure The phantom device of the present invention is composed of a sealable water tank, an air bubble collection chamber communicating with the water tank, and a test phantom that can be housed and taken out within the water tank. It consists of a plurality of measurement liquid storage containers supported by this substrate.

(e) Examples The illustrated embodiment will be described in detail below.

In Figure 1, 1 is an aquarium, which is made of a transparent plastic with high radiation transmittance, such as acrylic resin, and has a short cylindrical shape, and 2 is a lid that is attached to the aquarium by multiple screws (only one is replaced by 3). (shown) allows for easy attachment and detachment. Reference numeral 4 denotes an air bubble collecting case, which is formed integrally with or attached to the peripheral edge of the lid 2;
The inner chamber 4a of the water tank 1 communicates with the inner chamber 1a of the aquarium 1.
As will be clear from what will be described later, the communication path 4b
Inner chamber 1 is located at the highest position of inner chamber 1a of aquarium 1 when aquarium 1 is attached to the fixed stand of the CT device for measurement.
The air bubbles in the aquarium inner chamber 1a communicate with the communication path 4b.
The air bubbles can be moved through the air bubbles into the interior chamber 1a of the collection case.

5 is a screw cap that can be screwed on and removed from the water inlet/outlet 2a of the lid 2; 6 is a packing; 7 is a screw cap that can be screwed on and removed from the water inlet/outlet 4b of the air bubble collection case 4; 8 is a packing.

Reference numeral 9 denotes a fixture attached and fixed to the lid 2, and is fixed to the fixing base 10 of the CT device with screws 11 when the present phantom device is used.

Reference numeral 12 denotes a phantom that is removably installed in the water tank 1, and includes a substrate 13 and a plurality of (seven in the illustrated example) measuring solution storage containers 1 attached to the substrate 13.
It consists of 4. The board 13 has a plurality of mounting screws (one of which is shown as 15) on the inner surface of the bottom wall 1c of the aquarium 1.
It is removably fixed by.

The base 13 is made of a suitable synthetic resin, and the aquarium 1
It forms a disc with a diameter slightly smaller than the inner diameter of the disc.
Each measurement solution storage container 14 is made of a suitable synthetic resin with high radiation transmittance.
The threaded opening 14b on the opposite side is sealed with a screw cap 16 via a packing 15. Each container 14 contains a solution (for example, a copper sulfate solution) having a known and constant radiation transmittance.

FIG. 4 shows different embodiments of the measurement solution storage container. The container 20 has a cylindrical shape with one end sealed, an opening 20a at the other end aligned with a corresponding threaded opening 21 in the substrate 13, and an end surface 20b fixed to the substrate 13 with, for example, adhesive. 22 is a nut having an outer peripheral thread 22a and a center through hole 22b for pouring the solution;
After injecting the measurement solution almost completely into the container 20, insert the disc-shaped rubber packing 23 into the opening 21 to close the opening 20a of the container 20, then screw the nut 22 into the opening 21 of the base plate 13, and insert the syringe into the syringe. A measurement solution of the same type is put in, and the injection needle is passed through the central hole 22b of the nut 22 and pierced through the rubber packing 23 to inject and fill the container 20 with the solution.

A plurality of similar containers 20 are installed on the substrate 13 in FIG. 4.

Reference numeral 24 denotes a ventilation hole provided in the substrate 13 to allow the phantom 12 to be easily taken in and out of the aquarium 1.

In the above configuration, after each container 14 or 20 is filled with a solution having the same or different radiation transmittance, the phantom 12 is sealed with the lid 2 placed in the aquarium 1, and then the phantom 12 is inserted into the aquarium through the inlet/outlet 2a or 4b. 1 is filled with water and placed on a fixed stand 10 as shown in FIG. At this time, if you tilt the water tank slightly to the right, the air bubbles in the water tank 1 will float to the top of the collection case 4.
The air is collected as an air layer 25 above the inner chamber 4a.

The measurement direction is the direction indicated by the arrow R, and the measurement width is the direction of the container 14 in the direction of the axis O of the phantom device.
Since it is within the axial length of the inner chamber, the air layer 2
5 does not interfere with measurement.

By placing solutions of different concentrations or types in container 14, phantom measurements of different radiotransmittances can be made.

(f) Effects As described above, according to the present invention, a wide range of measurements is possible because the radiation transmittance can be freely selected by placing solutions of different concentrations or types in the measurement solution storage container. Since an air bubble collection chamber is attached to the water tank, air bubbles will not remain in the water tank and adversely affect measurement accuracy.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the present invention and an embodiment, Fig. 2 is an enlarged front view of the Phantom, Fig. 3 is a side view of the same, and Fig. 4 is a longitudinal sectional view of the present invention.
The figure is a longitudinal sectional view of another embodiment of the measurement solution storage container. 1...Aquarium, 2...Lid, 4...Bubble collection case, 12...Phantom, 13...Substrate, 14...
...Measurement solution storage container.

Claims (1)

[Scope of utility model registration request] It consists of a sealable water tank, a bubble collection chamber communicating with the water tank, and a removable test phantom housed within the water tank, the test phantom having a substrate and a plurality of measurements supported by the substrate. and a solution storage container.
Phantom device for CT device testing.