JPH02280079A - Multi-layer tomography image display method - Google Patents

Abstract

PURPOSE:To obtain a tomography image being excellent in observation and shadow- reading by extracting only a notice part from a multi-layer tomography image, and subsequently synthesizing the notice part and displaying it as one composite tomography image. CONSTITUTION:From a sheet 12 in which a tomography image is recorded, a look- ahead reading part 32 deflects a laser light 38 by one dimension through an optical system by allowing it to pass through a specific filter 40 and irradiates the sheet 12 with the light and moves in the C direction. The sheet 12 executes a stimulated luminous light emission of the quantity being proportional to X-ray energy which is accumulated and recorded, and a conductive sheet 46 executes photodetecting by a detector 48 and sends image information to a control circuit 52 of a reading part 34 for regular reading. The reading part 34 allows a laser light to pass through a filter 58 and adjusts the diameter by a beam expander 60, irradiates the sheet 12 and feeds it in the C direction. Subsequently, the stimulated luminous light emission is detected by a detector 70, amplified, and thereafter brought to A/D conversion 74 and stored in a memory 78 through a processing circuit 76. Next, by using a keyboard 84 and a track ball 88, a coordinate to be segmented is designated and a desired tomography image is read out to a CRT 86 through an image synthesizing circuit 80.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for displaying a multilayer tomographic image.
The present invention relates to a method of extracting a partial region of interest from a plurality of pieces of image information regarding the same subject obtained by a multilayer tomographic image capturing apparatus and displaying the extracted partial region as a composite image.

[Background of the Invention] Recently, the applicant has developed an image information processing system that uses a stimulable phosphor to obtain a multilayer tomographic image of a subject.
Patent applications related to this (for example, Japanese Patent Application Laid-Open No. 58-66
No. 933) has been made.

Here, a stimulable phosphor is a material that, when irradiated with radiation (X-rays, α-rays, γ-rays, electron beams, ultraviolet rays, etc.), stores a portion of this radiant energy and later emits excitation light such as visible light. A phosphor that, when irradiated, emits stimulated light with an intensity corresponding to the energy accumulated in accordance with the irradiation energy intensity of the irradiated radiation.

That is, the above-mentioned image information processing system utilizes this stimulable phosphor, and collects multilayer tomographic image information of a human body, etc., using a large number of sheets (hereinafter referred to as stimulable) each having a layer made of stimulable phosphor. phosphor sheet or simply sheet)
After each sheet is recorded, each sheet is scanned with excitation light such as a laser beam to generate stimulated luminescence light, the resulting stimulated luminescence light is read photoelectrically to obtain an image signal, and a predetermined image signal is added to the image signal. The image is processed and output as a visible image to a recording material such as a photographic light-sensitive material or a CRT of a display device.

In addition, in this system, the subject is placed between the X-ray source and the laminated stimulable phosphor sheet, and during X-ray irradiation, the X-ray source and the sheet are aligned with the straight line rule (X The focal point of the source, one point on the tomographic plane, and one point on the sheet form a straight line) and the geometric side (the distance between the focal point and the tomographic plane and the ratio between the tomographic plane and the sheet are constant) are satisfied. By moving the sheets relative to each other in this manner, a multilayer tomographic image is obtained by imaging only a desired tomographic plane on each sheet.

By the way, when observing a large number of tomographic images obtained in such a system on film or CRT, there is a problem that it is difficult to observe them. In other words, when a film containing a tomographic image is attached to a camera and observed, a doctor or the like must extract a necessary part from a wide range of images and make a diagnosis.

Furthermore, when a tomographic image is displayed on a CRT screen, the screen must be switched, which makes it even more difficult to imagine the tomographic image and significantly reduces work efficiency.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned disadvantages. It is an object of the present invention to provide a multilayer tomographic image display method that can obtain a tomographic image that is excellent in observation and interpretation by extracting partial regions of interest from an image and composing them.

[Means for Achieving the Object] In order to achieve the above-mentioned object, the present invention provides a method for displaying a multilayer tomographic image, which extracts a desired portion of interest from each tomographic image of the multilayer tomographic image, and then extracts a desired portion of interest from each tomographic image of the multilayer tomographic image. , the above-mentioned portions of interest are combined and displayed as one composite tomographic image.

[Embodiments] Next, preferred embodiments of the multilayer tomographic image display method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory diagram of a multilayer tomographic imaging apparatus using X-rays. In the same figure, the X-ray source 10 and the
A cassette 14 containing laminates of 1 to 12n is placed opposite to each other with a subject (human body) 1B having an imaging area 16 in between.

When photographing, the X-ray source 10 is moved in the direction of arrow A and the subject 18 is irradiated with X-rays, while the cassette 14 is moved in the direction of arrow B. The X-rays emitted from the X-ray source 10 pass through the uppermost region 20a of the imaging region 16 of the human body 18 to the uppermost region 12a of the cassette 14.
continues to be irradiated. As a result, the imaging area 16 of the human body 18
A tomographic image of the uppermost layer region 20a is formed on the uppermost sheet 12a of the cassette 14. Similarly, tomographic images of each region 20b to 2On of the human body 18 are stored in the cassette 1.
It is formed on the sheets 12b to 12n housed in the 4.

Incidentally, the cassette I4 contains - sheets of stimulable phosphor, and by changing the cassette one by one and photographing n times, a tomographic image of each region 20a to 2On of the human body 18 is recorded. Alternatively, the sheets 12a to 12n may be obtained.

Next, the tomographic images of the imaging area 16 accumulated and recorded on the sheets 12a to 12n as described above are read by the reading/output device 30 shown in FIG.

Here, the reading/output device 30 includes a pre-reading reading section 32 for grasping in advance the recorded information of the tomographic images stored and recorded in the seas N2a to 12n, and a readout section 32 for pre-reading the recorded information of the tomographic images stored and recorded in the seas N2a to 12n, and 12n to 12n are provided.

In the pre-reading reading section 32, the laser beam 38 emitted from the laser light source 36 passes through a filter 40 that cuts the wavelength range of stimulated luminescence light emitted from the sheets 12a to 12n by excitation of the laser beam 38, and then passes through a galvanometer mirror. The light is one-dimensionally deflected by a light deflector 42 such as - through a plane reflecting mirror 44 and irradiated onto the seas N2a to 1271. In this case, the sheets 12a to 12n are moved in the direction of arrow C to perform sub-scanning, and as a result, the laser beam 38 is irradiated over the entire surface of the sheets 12a to 12n.

When the laser beam 38 is irradiated in this way, the sheet 1
2a to 12n emit stimulated luminescent light in an amount proportional to the stored and recorded X-ray energy, and this luminescent light enters the light-guiding sheet 46 for pre-reading.

The light incident on the light guiding sheet 46 exits from the exit surface and is received by the photodetector 48. The stimulated luminescent light detected by the photodetector 48 is converted into an electrical signal, which is further amplified by the amplifier 50.

The image information output from the amplifier 50 is sent to the reading section 34 for main reading.
The sheets N2a to 12n that have been manually input to the control circuit 52 and have finished pre-reading are transferred to the main reading reading section 34.

Next, in the reading unit 34 for main reading, the laser beam 56 emitted from the laser light source 54 passes through a filter 58 that cuts the wavelength range of stimulated luminescence light emitted from the seas N2a to 12n by excitation of the laser beam 56. After that, the diameter of the beam is strictly adjusted by a beam expander 60, and it is one-dimensionally deflected by an optical deflector 62 such as a galvano mirror via a plane reflecting mirror 64, and is irradiated onto the beams 12a to 12n. be done. Note that a lens 66 is disposed between the optical deflector 62 and the plane reflecting mirror 64, and the sheet 12a
The laser beam 56 is set to always have a uniform beam diameter even when the laser beam 56 scans over 12n.

Therefore, the sheets N2a to 12n are moved in the direction of arrow C to perform sub-scanning, and as a result, the laser beam 56 is irradiated over the entire surface of the sheets N2a to 12n. When the LED light 56 is irradiated in this manner, the sheets 12a to 12T1 emit stimulated luminescence light in an amount proportional to the stored and recorded X-ray energy, and this luminescent light is directed to the main reading light guiding sheet 68. incident. The stimulated luminescent light guided through the main reading light guiding sheet 68 while repeating total reflection is emitted from its exit surface and detected by the photodetector 70.

The stimulated luminescence light detected by the photodetector 70 is converted into an electrical signal, amplified by the amplifier 72 to an electrical signal of an appropriate level, and then input to the A/D converter 74 . The A/D converter 74 converts the electrical signal into a digital signal,
The signal processing circuit 76 is manually operated. The signal processing circuit 76 performs signal processing to obtain an X-ray image with the same density and contrast of the I+fr layer images of each tomographic plane and excellent suitability for observation and interpretation, and inputs the image into the memory 78 . In this way, the images 12a' to 12rl are sequentially read, and the tomographic image information of each tomographic plane is held in the memory 78.

After the reading of the sheets 12a to 12n is completed, the tomographic image information of each tomographic plane held in the memory 78 is either as it is or is synthesized by the image synthesizing circuit 80, and is transmitted to an output device for outputting as a visible image. .

Therefore, next, a case in which image compositing processing is performed will be described. A desired tomographic image is read out from the memory 78 by an instruction from the keyboard 84 by the observer, and the necessary image is displayed on the CRT 86 screen via the image synthesis circuit 80. The viewer uses the keyboard 84, trackball 88, etc. to specify the coordinates for cutting out a noteworthy part of the image and cuts it out.

FIG. 3 shows multilayer tomographic images 90a to 90n obtained from each sheet 12a to 12n. In this case, the observer can, for example, view the shaded area 9 from each of the multilayer tomographic images 90a to 9On.
Part 9 of interest excluding 2a to 92n and 94a to 94n
Cut out 6a to 96n.

Parts of interest 96a to 96 of this cut out multilayer tomographic image
n is sequentially determined where on the screen to be placed in the image synthesis circuit 80, and sequentially stored in a predetermined area of the memory 82 to synthesize one image.

Then, as shown in FIG. 4, the composite image 98 is displayed on the CRTa2. The composite image 98 obtained by collecting and combining the attention parts 96a to 96n of the multilayer tomographic image in this way is not only displayed on the CRTa2, but also printed in hard copy by a separate laser printer or the like, according to instructions from the observer's keyboard 84. It is also possible to output as .

[Effects of the Invention] As described above, according to the present invention, the parts of interest from a plurality of multilayer tomographic images are extracted and combined and output as a single aggregate image, so it is extremely easy to observe the parts of interest. Become something. Furthermore, when this composite image is displayed on a display means such as a CRT, there is no need to switch the screen, so operability is improved.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
For example, the present invention is not limited to a system that obtains multilayer tomographic images using a stimulable phosphor sheet, but also a system that performs multilayer tomography using an image intensifier (II), or a system that performs multilayer tomography using an ordinary X-ray film. It is possible to make various improvements and changes in design without departing from the gist of the present invention, such as being applicable to a system that records tomographic images, reads the recorded film with a film digitizer, etc., and displays the image, etc. Of course.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a multilayer tomographic imaging device for carrying out the method of the present invention, and FIG. 2 is a diagram showing how the device shown in FIG. 1 reads and outputs an image from a stimulable phosphor sheet on which a tomographic image has been recorded. A schematic diagram of a reading/output device, Figure 3 is an explanatory diagram of an image obtained from a stimulable phosphor sheet, and Figure 4 is an explanatory diagram of an image obtained by combining the parts of interest of the images in Figure 3. . 18...Subject (human body) 10...X-ray source 14...
Cassette 16...imaging areas 12a-12
n...Stormable phosphor sheet 30...Image output device
32... Read ahead reading section 36.54... Rade light source 80... Image synthesis circuit 86... CRT

Claims (1)

[Claims] (1) A method for displaying a multilayer tomographic image, in which a desired portion of interest is extracted from each tomographic image of the multilayer tomographic image, and then the respective portions of interest are combined and displayed as one composite tomographic image. A multilayer tomographic image display method characterized by: