JPH01107743A - Radiation image diagnostic equipment - Google Patents

Abstract

PURPOSE:To enable comparison of a radiation image under observation with a standard image without preparing hard copies, by refreshing and displaying side by side the radiation image based on a radiation image signal obtained by a retrieval means and a read means, and the standard image based on a standard image signal obtained by the retrieval means. CONSTITUTION:A radiation image signal S1 carrying radiation image information is obtained from a storage medium by a read means 1, subjected to an image processing by an image processing means 2 and sent to a display means 3. A piece of information S2 concerning the type of a subject corresponding to the radiation image signal S1 is input to a retrieval means 5 by an input means 4. A standard image signal S3 corresponding to the radiation image signal S1 is obtained from a large number of standard image signals stored in a storage means 6. The standard image signal S3 is sent to the image processing means to be subjected to an appropriate image processing if necessary. A standard image signal S3' is sent to a display means 3, which refreshes and displays the radiation image and the standard image side by side.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a radiation image diagnostic apparatus that reproduces and displays a radiographic image of a subject on a display means.

(Prior art) A radiographic image signal carrying radiation image information of the subject is obtained by irradiating a subject with radiation such as X-rays, and various algorithms related to image processing are applied to this image signal. It has been conventionally practiced to reproduce and display the radiation image of the subject on a display means based on the above-mentioned radiation image.

The applicant also believes that when a stimulable phosphor is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), part of this radiation energy is accumulated in the phosphor, and then becomes visible. Taking advantage of the fact that when irradiated with excitation light such as light, the phosphor exhibits stimulated luminescence according to the accumulated energy, radiation image information of the human body is partially recorded on the sheet-shaped stimulable phosphor, and then , this stimulable phosphor sheet is scanned with excitation light such as a laser beam to generate stimulated luminescence light, this stimulated luminescence light is read photoelectrically to obtain an image signal, and this image signal is subjected to image processing. , a radiation image information recording and reproducing apparatus has already been proposed which outputs a radiation image of a subject as a visible image to a recording material such as a photographic light-sensitive material or a display means such as a CRT based on the image signal subjected to image processing. (Unexamined Japanese Patent Publication No. 55-12
No. 429, No. 56-11395, etc.).

Normally, in such a radiation image diagnostic apparatus, when a radiation image is reproduced and displayed on a display means such as a CRT display, it is displayed only one screen at a time, so when comparing with other radiation images, at least one radiation image is displayed. I prepared hard copies of these and observed them side by side.

(Problems to be Solved by the Invention) In order to prepare hard copies for comparative observation as described above, it is necessary to have a reproduction means capable of obtaining hard copies. When hard copies are not required in daily work, a problem arises in that equipment costs are high if a reproduction means for obtaining hard copies is provided just for this comparative observation. Furthermore, even if a reproduction means for obtaining a hard copy is provided, it is not enough to take the trouble of making a hard copy and compare it, but there may be cases where one would like to make some comparative observations.

Furthermore, even if hard copies of radiographic images are prepared and stored in advance for comparative observation, there is a problem in that they may become difficult to view due to scratches or dirt. One of the most frequent types of comparative observation is the comparison between the radiographic image currently being observed and a standard image representing the standard state of this radiographic image.

Here, the standard state refers to, for example, the state before pressurization or the standard deformation state when examining the internal deformation state of a specific machine part due to pressure application using radiographic images, or the state before pressure is applied or the standard deformation state of a specific part of the human body. When a lesion is examined by radiographic images, the standard way the disease appears in the radiographic image, or the multiple standard deformation states and lesion states at each deformation stage and each progression stage of the above deformities and diseases, etc. say.

In this specification, each group classified by, for example, parts of a machine, parts of the human body, disease name, etc. is referred to as a "type", and each change state of a plurality of marks within the same type, e.g. The multiple standard deformation stages of mechanical parts, each progressive stage of a disease, etc. are called "stages".

In view of the above-mentioned circumstances, the present invention provides a radiation image diagnostic apparatus that can compare a radiation image currently being observed with a standard image representing the standard state of this radiation image without preparing a hard copy. The purpose is to provide

(Means for Solving the Problems) Among the present invention, a radiation image diagnostic apparatus according to a first aspect of the present invention obtains a radiation image signal carrying radiation image information of a subject from a recording medium on which this radiation image information is recorded. a reading means, a type inputting means for inputting the type of the subject, a storage means for storing a standard image signal obtained from a standard image indicating a standard state of the radiographic image, and a means for performing image processing on the radiographic image signal obtained by the reading means. image processing means to perform the image processing, a search means for determining one or more standard image signals corresponding to the radiation image signal stored in the storage means, and a reading means, based on the type inputted from the type input means. a radiographic image based on the obtained radiographic image signal, a search means,
The standard image based on the standard image signal obtained by
It is characterized by comprising display means for reproducing and displaying the images side by side so that they can be viewed at the same time.

Further, among the present invention, the radiographic image diagnostic apparatus of the second invention includes a reading means for obtaining a radiographic image signal carrying radiographic image information from a recording medium in which radiographic image information of the subject is recorded, and inputting the type of the subject. storage means for storing a large number of standard image signals obtained from standard images representing several standard states of radiographic images for each of a large number of types, and the type of radiographic image signals obtained by the reading means. 1 corresponding to the above-mentioned stage of the radiation image signal stored in the storage means based on the type inputted from the type input means and the automatically identified stage. A search means for obtaining one or more standard image signals, and a radiographic image based on the radiographic image signal obtained by the reading means and a standard image based on the standard image signal obtained by the search means can be observed simultaneously. The invention is characterized by comprising display means for reproducing and displaying the images side by side.

(Function) Of the present invention, the radiation image diagnostic apparatus of the first invention corresponds to the radiation image in question from the standard image signal stored in the storage means, based on the type input from the type input means. Since the apparatus includes a search means for finding one or more standard image signals, it is possible to find a standard image signal of the same type as the radiation image signal. In addition, since the display means of this device reproduces and displays the radiographic image based on the radiographic image signal and the standard image based on the standard image signal side by side so that they can be observed at the same time, it is possible to display the radiographic image based on the radiographic image signal and the standard image based on the standard image signal. Compare the radiographic image you are observing in question with a standard image that shows the standard state of this radiographic image, and find out how much this radiographic image differs from the standard image, or how much this radiographic image differs from the standard image. You can know what stage you are in.

Of the present invention, the second radiation image diagnostic apparatus is provided in a case where the storage means stores a large number of standard image signals obtained from standard images representing several levels of standard states for each of a large number of types. , automatically identifies the stage for each type of radiation image signal currently in question, and creates a standard stored in the storage means based on the type input from the type manual means and the automatically identified stage. It has a search means for finding one or more mark image signals corresponding to the radiographic image signal currently in question from the image signal, and the display means is configured to display the radiographic image and the standard as in the first invention. Since the images are reproduced and displayed side by side so that they can be observed at the same time, there is no need to prepare a hard copy. A standard image representing the same stage, or two standard images representing the two stages when this radiographic image is in the middle of two stages, etc., is compared to find out the peculiarities that this radiographic image has that are not found in the standard image. Differences from the standard image, such as points, can be recognized.

As described above, this second invention has the function of automatically recognizing the stage of each type of radiographic image signal, so compared to the first invention which does not have this function. , when there are many stages for each type and standard image signals exist for each of these many stages, in the first invention, by comparing the radiation image with the many standard images obtained by the search means, The observer needs to judge in which stage the radiation image is located, which is complicated, but in the second invention, a standard image signal that approximates the radiation image signal is required, so the above-mentioned complexity can be avoided. The time required for diagnosis can be shortened.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1A is a block diagram of an embodiment of a radiation image diagnostic apparatus according to a first aspect of the present invention.

For example, by the reading means 1 as shown in the example described later,
A radiation image signal S1 carrying radiation image information of a subject is obtained from a recording medium on which radiation image information of the subject is recorded. This obtained radiation image signal sl is the radiation image signal that we are currently trying to observe. The radiation image signal s1 is input to the image processing means 2, and the image processing means 2 performs appropriate image processing according to the radiation image signal, and the image processed radiation image signal Sl' is obtained.
is sent to the display means 3.

The type manual means 4 outputs information S regarding the type of the subject to be interpreted corresponding to the radiation image signal s1 obtained by the reading means 1.
2 is input, and information S2 regarding the input type is input to the search means 5. Here, the information S2 regarding the type (as mentioned above, refers to information for specifying the group to which the subject belongs, such as the body part to be photographed and the name of the disease when used for diagnosing a disease in the human body, for example. Also, the storage means 6 Based on many years of experience, for example, radiographic images showing the standard appearance of various diseases in radiographic images,
A radiographic image signal corresponding to a typical radiographic image for each progressive stage of a specific disease is selected from among a large number of radiographic image signals obtained from the reading means 1, for example, and stored as a standard image signal. ing. Furthermore, this storage means 6
The standard image signal stored in the reading means 1 shown in this figure
The information is not limited to those obtained by the above method, but may be obtained from other reading means and stored in the storage means 6 via a magnetic disk, magnetic tape, etc., for example. Also,
It is preferable to select from among a large number of radiographic image signals as described above, but if a ready-made standard image is available, it is also possible to obtain a ready-made standard image and read this image with a digitizer or the like to obtain a standard image signal.

Information S regarding the type is sent to the search means 5 from the type input means 4.
2 is sent, the retrieval means 5 reads out the radiographic image signal currently in question from among a large number of standard image signals stored in the storage means 6 by the retrieving means 5 based on the information S2 regarding the type. One or more standard image signals S3 corresponding to S1 are determined.

The one or more standard image signals S3 obtained in this way are sent to the image processing means 2 and subjected to appropriate image processing if necessary. A signal 83' is sent to the display means 3. The display means 3 reproduces and displays the radiation image and the standard image side by side so that they can be observed simultaneously, in a manner described later, based on the sent radiation image signal S' and standard image signal 83'.

FIG. 1B is a block diagram of an embodiment of a radiation image diagnostic apparatus according to a second aspect of the present invention.

s<5 i The same parts as in Fig. A are given the same numbers, and the explanation is omitted.

The radiation image signal sl obtained by the reading means 1 is input to the image processing means 2 and subjected to appropriate image processing, and then
It is sent to the display means 3 and also to the search means 5'. The search means 5' uses information S2 regarding the type input from the type input means 4 and the input radiation image signal S1.
Based on this, the stage for each type of radiation image signal S1 is automatically identified, for example, by a method as described below.

Thereafter, based on the type of radiation image signal S and the automatically identified stage, one standard image signal corresponding to the stage of this radiation image signal S1 is selected from among the large number of standard image signals stored in the storage means 6. Alternatively, a plurality of standard image signals S3 are obtained. One standard image signal S3 is, for example, a standard image signal 83 at the same stage as the radiation image signal S1.
etc., and the plurality of standard image signals S3 refers to, for example, the standard image signal 83 of the two stages when the radiation image signal S1 is in the middle of the two stages.

The one or more standard image signals S3 obtained in this way are sent to the image processing means 2 as in the first invention.
The radiation image and the standard image are transmitted to the display means 3 via the display means 3, where the radiographic image and the standard image are reproduced and displayed side by side so that they can be observed at the same time.

Next, a method for automatically identifying the stage for each type of radiation image signal S□ in the search means 5' will be explained.

As the automatic identification method (2), any known method may be used, but here, radiological images of pneumoconiosis are treated as one type, and an example of a method for automatically identifying stages within this type is used. is briefly explained below.

Pneumoconiosis is a disease in which dust particles are inhaled and deposited in the lungs, causing symptoms such as shortness of breath and asthma, and affected areas are seen as spots on radiographic images of the lung field. A plurality of standard stages are defined depending on the number of spots, etc.

A method for automatically identifying the stages of radiological images of pneumoconiosis is a method using a co-occurrence matrix (IEEETI?AN
SACTIONS SYSTEMS, MAN, AND
CYBERNETIC3゜SMC-4, pages 40-49,
(1974), a method using the average density change of the extracted region (IEEE TRANSACTIONSON
COMPUTER8, C-25, pages 95-97, 1
976), a method based on the linear prediction method (Medical Electronics and Bioengineering, Vol. 20, No. 5, September 1980), etc.
Here, a method using a co-occurrence matrix will be explained.

First, the co-occurrence matrix 1) (i, j, a, d) for all image data in the lung field.
・Calculate (1). , where 1 and j each represent the density level and take values from 0 to 7 (
The entire concentration range is classified into eight levels. ) a represents the direction (angle) of the pixel whose density level is j as seen from the pixel whose density level is 1, and is 0", 45°, 90°, 135°
The pixels in the direction are adopted.

d represents the distance from a pixel whose density level is i to a pixel whose density level is j, and pixels at distances of 1, 3, and 7°11 are employed.

Next, the co-occurrence matrix p (
i, j, a, d), the following five feature quantities T1 (
a, d) to T5(a, d).

...(5) ...(6) Tl (a, d) obtained in this way ~ T5 (a,
d), then the following mean Mk (a), range Rh (d), variance Vk (d) (k-1
y2. −・・−・−, 5).

Rh (d) = max Th (a, d) −ffl
in Tk(a, d) −(8) where −1, 2,・
..., 5, and 0@ again.

a-1 for each direction of 45@, 90°, and 135°,
The numerical values of 2°3.4 correspond to each other.

For a total of 60 equations (7) to (9), or some characteristic quantities determined from these, numerical values are calculated according to the above calculation formula, and each stage is determined in advance based on a large number of pneumoconiosis images. Compared to the numerical values of the feature quantities classified in
It is identified to which stage the pneumoconiosis image in question belongs. When classifying into four stages, Tatoeha, Ra
The following feature values are used: (3, M5 (1), R5 (7), Va (3), Rich (3), V5 (3), and Mountain (3).

By performing the above calculations in the search means 5', the stage of the radiological image of pneumoconiosis is automatically identified, and then the standard image signal corresponding to this stage is read out from the storage means 6 and sent to the display means 3. The standard image is reproduced and displayed on the display means 3 together with the radiological image of pneumoconiosis.

By replaying and displaying the standard images corresponding to the stages in this way together with the radiological images, it is possible to see whether there are symptoms specific to this pneumoconiosis patient that are not present in the standard images, and whether the symptoms are milder or more severe even if they are within the same stage compared to the standard images. etc., or when the radiographic image is in the middle of two stages, it is possible to compare and find out which of the two standard images of each stage it is closer to.

FIG. 2 is a perspective view showing an example of a reading means and a type input means.

The reading means 1 shown in this example uses the stimulable phosphor sheet described above.

A stimulable phosphor sheet 11 on which radiation image information of a subject is stored and recorded is conveyed (sub-scanned) in the direction of arrow Y by a sheet conveying means 13 such as an endless belt driven by a motor 12. On the other hand, the excitation light 15 emitted from the laser light source 14 rotates at high speed in the direction of the arrow.
is reflected and deflected by a focusing lens 17 such as an fθ lens.
After passing through, the optical path is changed by a mirror 18, and the light enters the sheet 11, and is main-scanned in the direction of arrow X, which is substantially perpendicular to the direction of sub-scanning (direction of arrow Y). From the part of the sheet 11 irradiated with this excitation light 15, stimulated luminescence light 19 is emitted in an amount corresponding to the radiographic image information stored and recorded.
This stimulated luminescence light 19 is collected by a condenser 20, and a photomultiplier (photomultiplier tube) serves as a photodetector.
21 photoelectrically detected. The light collector 20 is made by molding a light guiding material such as an acrylic plate, and the linear incident end surface 20a is formed by a stimulable phosphor sheet l.
The light-receiving surface of the photomultiplier 21 is coupled to an annular output end surface 20b extending along the main scanning line on the photomultiplier 21. The stimulated luminescent light 19 that has entered the light condenser 20 from the incident end surface 20a travels through the interior of the light condenser 20 by repeating total reflection, and then travels through the light condensing body 20 through the exit end surface 20b.
The photomultiplier 21 detects the amount of stimulated luminescent light 19 that is emitted from the photomultiplier 21 and is received by the photomultiplier 21 and carries the radiation image information.

The analog signal S output from the photomultiplier 21 is amplified by an amplifier 22 and digitized by an A/D converter 23 at a predetermined recording scale factor. The signal digitized in this manner is input to the image processing means 2 as the diagnostic radiation image signal Sl, as described above.

Note that the reading means 1 is not limited to a device that uses a stimulable phosphor sheet as in this example; for example, it scans a conventional X-ray photographic film on which an X-ray image is recorded.
It may be a device that reads an image signal carrying this X-ray image information. Furthermore, in recent years, diagnostic equipment such as CT and US has been widely used, and the present invention may be a device that reads image signals from a film on which images output from these equipment are recorded.

Around the time when the radiation image information is read from the stimulable phosphor sheet 11 in FIG. is input. Information S2 regarding this type is sent to the search means 5 as described above.

Figures 3A-3C are diagrams showing each side of the display means. Here, for simplicity, when representing an image, symbols S1' and S3' representing image signals are also used.

FIG. 3A shows a radiation image 81' based on a radiation image signal Sl' and a standard image signal 8 displayed on one CRT display.
This is an example in which a standard image 83' based on 3' is displayed side by side. If there are a plurality of standard images 83' to be displayed, each image may be made smaller and the plurality of standard images 83' may be displayed simultaneously along with the radiation image 81' on one CRT display. , if each image becomes too small, the radiation image S t-/ may be always displayed, and a plurality of standard images 83' may be displayed one by one in sequence. When displaying this sequentially,
Among the plurality of standard images 83', if the standard image 53' corresponding to the endmost stage when arranged in the order of stages is displayed, and then the standard images 83' of adjacent stages are sequentially displayed, the radiation image It is easy to see which standard image 83'81' is approximated to.

FIG. 3B shows an example in which a radiation image 81' is displayed on one of two CRT displays and a standard image 83' is displayed on the other. When there are multiple standard images 83', the multiple images may be displayed on one CRT display as shown in FIG. 3A, and as described above, the standard images 83'
may be displayed sequentially one by one.

FIG. 3C shows an example in which three CRT displays are arranged side by side for display. If there is only one standard image 83', it is sufficient to use only two CRT displays instead of one CRT display. Standard drawing fg! When there are multiple s3′,
The number of standard images 83 (two in this example) that this display means can simultaneously display together with the radiographic image kSs'
' is displayed simultaneously with the radiation image 81'. As the mark image 83' to be displayed at the same time, it is preferable to select an image that is as close as possible to the radiation image St'.

Furthermore, if there are standard images 83' that cannot be displayed simultaneously, they may be displayed sequentially as described above.

In addition, although all of FIGS. 3A to 3C use CRT display devices as display means, the number of CRT display devices constituting the display means is not limited to 1 to 3, and the number can be changed as necessary. can be determined. The display means is not limited to a CRT display device either.

(Effects of the Invention) As explained in detail above, the radiographic image diagnostic apparatus according to the first aspect of the present invention stores data in the storage means based on the type of radiographic image signal inputted from the type input means. It has a search means for finding one or more standard image signals corresponding to the radiographic image signal from among the stored standard image signals, and the display means is capable of observing the radiographic image and the standard image at the same time. Since it is for side-by-side playback and display, /
It is possible to easily compare the image currently being observed as a problem and the standard image corresponding to this image without taking the %-tocoby.

Furthermore, a second aspect of the present invention is to automatically identify the stage for each type of radiation image signal, and to identify the type of radiation image signal input from the type input means and the automatically identified stage. The above-mentioned first method has a search means for finding a standard image signal corresponding to the stage of the radiation image signal based on the above, and the display means reproduces and displays the radiation image and the standard image side by side. Similar to the invention, it is possible to easily compare the image currently being observed with the standard image corresponding to this image without having to make a hard copy. Further, in the case where there are many stages within each type and standard image signals exist for each of these many stages, in this second invention, the standard image signal that is similar to the radiation image signal is automatically recognized. This eliminates the need for the observer to select a standard image signal similar to the radiographic image signal from among many standard image signals within the same type as the radiographic image signal, reducing the time required for diagnosis. can.

[Brief explanation of the drawing]

Figure mlA is a block diagram showing an embodiment of the radiation image diagnostic apparatus according to the first aspect of the present invention, and Figure 1B is a block diagram showing an example of the radiation image diagnostic apparatus according to the second aspect of the present invention. , FIG. 2 is a perspective view showing an example of the reading means and type inputting means, and FIGS. 3A to 3C are views showing each side of the display means. 1...Reading means 2...Image processing means 3...
・Display means 4... Type input means 5.5'...
・Search means 6...Storage means 11...Stormable phosphor sheet 14...Laser light source 15...Excitation light 1
9... Stimulated luminescent light 20... Focusing light body 21
... Photo multiplier 24 ... Keyboard Figure 1A Old figure

Claims (4)

[Claims] (1) A reading means for obtaining a radiographic image signal carrying radiographic image information from a recording medium on which radiographic image information of a subject is recorded, a type inputting means for inputting the type of the subject;
a storage means for storing a standard image signal obtained from a standard image indicating a standard state of a radiation image; an image processing means for performing image processing on the radiation image signal obtained by the reading means; searching means for searching one or more standard image signals corresponding to the radiation image signal stored in the storage means, based on the type of the radiation image signal;
and display means for reproducing and displaying a radiographic image based on the radiographic image signal obtained by the reading means and a standard image based on the standard image signal obtained by the searching means so that they can be viewed at the same time. A radiation imaging diagnostic apparatus characterized by: (2) The standard image signal stored in the storage means is
2. The radiation image diagnostic apparatus according to claim 1, characterized in that the apparatus includes a plurality of standard image signals representing each stage of pneumoconiosis. (3) a reading means for obtaining a radiographic image signal carrying radiographic image information from a recording medium on which radiographic image information of the subject is recorded; a type inputting means for inputting the type of the subject;
Storage means for storing a large number of standard image signals obtained from standard images representing standard states of several stages of radiographic images for each of a large number of types; one signal corresponding to the stage of the radiation image signal that is automatically identified and stored in the storage means based on the type input from the type input means and the automatically identified stage; or a search means for obtaining a plurality of standard image signals; and a radiographic image based on the radiographic image signal obtained by the reading means and a standard image based on the standard image signal obtained by the search means. A radiation image diagnostic apparatus characterized by comprising a display means for displaying the images side by side for observation. (4) The standard image signal stored in the storage means is
4. The radiation image diagnostic apparatus according to claim 3, characterized in that the apparatus includes a plurality of standard image signals representing each stage of pneumoconiosis.