JP2000293528A - Image reading apparatus, image reading method, and recording medium storing image reading program - Google Patents

Abstract

(57) [Summary] [Problem] To sequentially display images by prefetching a plurality of images collectively in a frame memory, it is necessary to wait for prefetch and increase the capacity of the frame memory. . SOLUTION: A plurality of medical images required for image interpretation and the display order thereof are set as an image group, a corresponding group is selected from an image storage unit (S21), and the first medical image data of the group is searched and retrieved. The readout and gradation conversion are performed and stored in the frame memory (S22 to S25), and the medical image data stored in the frame memory is displayed as an image (S2).
6) In parallel with this image display, if there is medical image data to be displayed next (S27), the next medical image data is retrieved / read / gradation converted / stored in the frame memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and method, and more particularly to a medical image reading apparatus and a medical image reading apparatus for efficiently reading medical images such as a chest radiograph and a stomach radiograph in the medical field. About the method.

[0002]

2. Description of the Related Art In medical practice, various medical images are used for diagnosis. For example, there are a chest X-ray image, a stomach X-ray image, an ultrasound image, an endoscope image, a CT image, an MRI image, and the like. The most commonly used of these medical images are various X-ray images. An X-ray image is usually observed by holding an X-ray film over a light box called a Schaukasten.

As described above, the digitization of medical images, which is conventionally performed on a film basis and electronically performs display, storage management, and the like of medical images, has recently started to attract attention. In this method, medical images recorded on film are converted into digital data, stored and managed as digital data in various storage media (semiconductor memory, magneto-optical memory, etc.), read out as necessary, and displayed on a CRT monitor. It's about observing. By storing and managing images by digitizing the images, image storage / management, movement, and the like can be made much more efficient than in the past.

When digitizing a medical image and displaying it on a CRT monitor, it is necessary to pay close attention to prevent a decrease in diagnostic accuracy. To obtain a digital image equivalent to a plain chest X-ray film, the number of pixels must be 4000 ×
It is said that 4000 or more and 12 bits or more of gradation are required. In order to realize at least image quality enough to withstand diagnosis, the number of pixels is required to be 2000 × 2000. As described above, a medical image converted into digital data is characterized in that the data amount is enormous.

FIG. 5 shows a general configuration of a medical image reading apparatus. 1, reference numeral 1 denotes an image storage unit, 2 denotes an image processing unit, 3 denotes a frame memory, 4 denotes a control unit, 5 denotes an image display unit, 6 denotes a digital / analog conversion circuit, and 7 denotes a CR.
Each T monitor is shown.

The image storage unit 1 is a database in which a plurality of digital medical images are stored. The image data read from the image storage unit 1 is subjected to gradation conversion in the image processing unit 2 and then temporarily stored in the frame memory 3. The image data stored in the frame memory is sequentially read out, converted into an analog signal by the digital / analog conversion circuit 6 of the image display unit 5, and then guided to the CRT monitor 7 to display the image. The control unit 4 receives a request from a doctor who diagnoses an image and controls the flow of data of the entire apparatus.

FIG. 6 shows a flow of a conventional operation example of the medical image reading apparatus. First, when a doctor makes a request for displaying a medical image to the device (S1), the image storage unit (database) 1 of the device searches for target image data (S2) and reads the target image (S3). The read image data is subjected to gradation conversion in a form suitable for image display by the image processing unit 2 (S4), and is written to the frame memory (S5). The image data stored in the frame memory is sequentially read out and subjected to digital / analog conversion.
It is displayed on the RT monitor (S6). The doctor makes a diagnosis by looking at the medical image displayed on the CRT monitor 7. After diagnosing the displayed image, the doctor inputs a request for displaying the next image to the apparatus (S7).

The conventional medical image reading apparatus has a problem that it takes a long time from issuing an image display request to actually displaying an image on a CRT monitor because the data amount of the medical image is enormous. there were. As the number of medical images stored in the image storage unit increases, the time required for image search increases.

Next, the processing time in the image processing section increases in proportion to the amount of image data. When the amount of image data increases, it takes time to write data to the frame memory.

As described above, in the conventional medical image reading apparatus,
Since the amount of image data to be handled becomes enormous, there is a problem that the time required for displaying an image becomes long.

In order to alleviate such a problem relating to the image display time, an implementation of a pre-fetch function for reading out an image in advance has been proposed.

FIG. 7 shows an operation flow of the apparatus when the pre-etch function is used. When a doctor interprets a medical image, the display image, display order, and the like are often known in advance. When a doctor issues a display request for an image group to be displayed using this (S11), the image storage unit 1 searches a plurality of target images in the display order (S12), and reads out the target image group at once (S11).
13). The read image data is sequentially subjected to gradation conversion (S14) and stored in the frame memory (S1).
5). At this point, all the medical images that the doctor wants to display are stored in the frame memory. next,
Since the image data to be displayed has already been stored in the frame memory, when the doctor issues an image display request, each image stored in the frame memory is read and displayed (S16, S17). If there is a next image group, the process returns to the selection of the group (S18).

[0013] This makes it possible to display images in groups at a high speed without going through image search and gradation conversion processing.

[0014]

A conventional medical image reading apparatus having a pre-etching function can display a medical image at a high speed. However, there is a problem in that it takes time from when a doctor issues a request to view an image to when a plurality of medical images are read into the frame memory. Once the image is stored in the frame memory, the subsequent image display can be performed at high speed, but there is a problem that the doctor has to wait for the image display until the pre-etch is completed. Further, when the number of images that a doctor wants to view at a time increases, there is a problem that the memory capacity of the frame memory must be increased accordingly.

Such a problem is caused by searching for a plurality of images.
It is expected that other image reading devices that store the image in the gradation conversion / frame memory, switch the image, and display the image on the monitor will be available.

An object of the present invention is to provide an image reading apparatus, an image reading method, and a recording medium which stores an image reading program, which can display a plurality of images such as medical images at high speed.

[0017]

According to the present invention, in order to solve the above-mentioned problems, images are grouped, an image in the group is searched, and the first image is read out.
The following image data is searched, read out, gradation converted, and stored in the frame memory while the image is displayed in the frame memory, and the following configuration, method and recording medium are used. Features.

(Invention of Apparatus) An image storage unit for storing a large number of digital image data, an image processing unit for reading out image data stored in the image storage unit and performing gradation conversion, A frame memory for storing the output image data, an image display unit for displaying the image data stored in the frame memory, and an image reading device including a device control unit for controlling the entire device.
The frame memory is configured to be able to store a plurality of grouped image data, the device control unit sets a display order of the plurality of image data stored in the image storage unit, and sets the display order according to the display order. Means for reading out image data from the image storage unit and sending it to the image processing unit, and storing the image data output from the image processing unit in the frame memory; and storing the image data requested to be displayed in the frame memory. If so, the image data is read out from the frame memory to perform image display control, and the next image data to be displayed is searched and read out from the image storage unit, and is read into the frame memory via the image processing unit. If the corresponding image data is not stored in the frame memory, the image data is read from the image storage unit. Characterized by comprising a means for performing image display control via the image processing unit and the frame memory by.

Further, the image storage unit is connected via a network and includes a cache memory for temporarily storing image data transferred via the network.

Further, the frame memory is characterized in that the number of image data that can be stored is 10 or more.

Further, the image processing section performs gradation conversion so that the ratio between the luminance of the film image and the luminance of the image displayed on the image display section becomes constant.

(Invention of Method) A large number of digital image data are stored in an image storage unit, and the stored image data is subjected to gradation conversion and stored in a frame memory. An image interpretation method for displaying an image on a display unit, wherein a plurality of images required for image interpretation and a display order thereof are set as an image group, and a corresponding group is selected from the image storage unit in an image display request, The first image data of the group is searched, read, and gradation-converted and stored in the frame memory, and the image data stored in the frame memory is image-displayed on the image display unit, and in parallel with the image display. If there is image data to be displayed next, the next image is retrieved and read from the image storage unit and stored in the gradation conversion / frame memory. And it features.

Also, a large number of digital image data are stored in an image storage unit via a network, the stored image data is fetched via the network, and the fetched image data is subjected to gradation conversion. An image interpretation method for storing image data in a frame memory and displaying image data of the frame memory on an image display unit, wherein a plurality of images necessary for image interpretation and a display order thereof are set as an image group, and the network A corresponding group is selected from the image storage unit in response to an image display request via the network, image data of the group retrieved and read from the image storage unit is stored in a cache memory via the network, and the cache memory is Search, read, and tone conversion of the image data stored in the frame memory and store it in the frame memory. Displaying the image data stored in the image memory on the image display unit, and in parallel with the image display, when there is image data to be displayed next, retrieve and read the next image from the cache memory, It is characterized in that it is stored in a gradation conversion / frame memory.

(Invention of recording medium) A part or all of the method or the apparatus is described in a computer program so that it can be executed, and the method or apparatus is recorded on a computer-readable recording medium.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a processing flow of a medical image interpretation apparatus showing an embodiment of the present invention. The device configuration in this embodiment is the same as that in FIG. 5, but the data control method in the control unit 4 is different from the conventional one.

A doctor who performs medical image interpretation often determines in advance the images necessary for image interpretation and the order of observation. The images necessary for a general patient diagnosis are several images such as an image taken from the front and side of a simple chest X-ray image, a CT image, and the like. The images are displayed and interpreted in the above order. In general, about 10 stomach images are displayed per patient in the order of imaging. As described above, when a doctor interprets a medical image, it is common to display and observe a plurality of images in a predetermined order.

Therefore, in the present embodiment, a plurality of images necessary for image interpretation and their display order are grasped in advance. When the doctor makes a medical image display request to the device, the device selects the medical image group (S21), and searches the image storage unit 1 for the first image from among a plurality of images required for interpretation (S22). ), The first image is read from the image storage unit (S23), and is stored in the frame memory via gradation conversion (S24) (S25). The medical image data stored in the frame memory is displayed on the image display unit (S26). The doctor performs image interpretation while viewing the displayed image.

During the interpretation, if there is an image to be displayed next (S27), the image is read out and displayed (S26).
At the same time, the next image is searched in the image storage unit (S
22) Then, the next image is read out, gradation converted, and stored in the frame memory (S23 to S25). Further, if there is an image group to be displayed next (S28), the apparatus selects the next medical image group (S21).

Therefore, in this embodiment, the image data to be displayed next is read from the image storage unit while the doctor is performing image interpretation, and is stored in the frame memory after gradation conversion. When the doctor performs image interpretation based on the first image and issues a next image display request, the image data is already stored in the frame memory, so that the image can be displayed instantaneously. The doctor performs image reading again while viewing the image.

As described above, in the present embodiment, the image data to be displayed next is read out from the image storage unit and stored in the frame memory while the doctor performs image interpretation.

FIG. 2 shows a comparison of the operation status of the apparatus and the operation status of the doctor according to the conventional example and the present embodiment in chronological order. Part (a) of the figure shows the operation of the apparatus and the operation of the doctor in the conventional example, respectively. First, when a doctor issues an image display request, the apparatus stores an image, performs an image search in the unit, then performs gradation conversion, and stores and stores the image in the frame memory.
After reading, an image is displayed on the CRT monitor. When the image is displayed, the doctor interprets the image while viewing the image. When the interpretation is completed and the next image display request is made to the apparatus, the apparatus performs image search, gradation conversion, frame memory storage, and image display again.

In this conventional example, the doctor waits for the image display to be performed after issuing the image display request.
The reading of the next image is performed only after the image is displayed.

As described above, in the conventional method, the doctor has a waiting time while the apparatus is operating, and it can be understood that the apparatus is in a halt state while the doctor is performing the reading operation.

Next, part (b) shows the case of a conventional example having a pre-etch function. When a doctor issues an image display request, the apparatus retrieves all medical images necessary for image interpretation and writes them to a frame memory through gradation conversion processing. Thereafter, an image is displayed, and the doctor interprets the displayed image. When the doctor issues the next image display request to the apparatus, the image can be displayed at high speed because it is already stored in the frame memory.

In the conventional example having the pre-etching function as described above, although the image display can be performed at a high speed, the pre-etching takes a long time, during which the doctor must wait.

Part (c) shows the case of the present embodiment. In the present embodiment, when a doctor issues an image display request, only one image is read from the image storage unit, and the image is displayed through gradation conversion processing and frame memory storage. The doctor performs image interpretation on the basis of the displayed image. During this time, the apparatus reads out the next image from the image storage unit, stores the image in the frame memory through a gradation conversion process, and stores the image in the frame memory. When the doctor finishes reading the first image and issues a next image display request, the next image is stored in the frame memory at that time, so that the display is performed at high speed, and the doctor can wait for the next image without waiting. Image interpretation can be performed. The rest is the repetition. Since the apparatus is preparing for the next image display while the doctor is performing image interpretation, it is possible for the doctor to sequentially perform image display and perform image interpretation without waiting time.

As described above, according to the present embodiment, the image can be displayed at high speed by the apparatus preparing for the next image display while the doctor is performing image interpretation. Furthermore, since it is configured to pre-etch only the next image,
The capacity of the frame memory does not become enormous. Also,
There is an advantage that the doctor does not need to wait for a long time for pre-etching before starting interpretation, unlike the conventional pre-etching function.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
FIG. 2 is a device configuration diagram showing the embodiment. In FIG.
Is an image storage unit (database) installed in a remote place, 9
Are the network interfaces on the image storage unit side;
Is the network interface of the image reading device, 1
Reference numeral 1 denotes a cache memory for temporarily storing image data transferred via a network.

The present embodiment is an embodiment in a case where the image storage unit (database) 8 is located at a remote place and is connected to an image reading apparatus via a network. this is,
There is a database in the hospital, image reading device and LAN
This corresponds to the case where the image reading device is connected to the image reading device via a network between hospitals or the like, or when there is a database in a remote place outside the hospital.

FIG. 4 shows a processing flow of this embodiment. First, when a doctor issues an image display request, a target image group is selected and searched for and read out in a remote image storage unit (database) 8 (S31, S3).
2), sequentially transferred and stored in the cache memory 11 of the image reading apparatus via the network (S33, S3)
4).

The control section 4 of the image interpretation apparatus searches the cache memory for the image to be displayed first among the target images (S35), reads out the image if any (S36), and performs the gradation conversion process (S37). And storage in the frame memory (S3
The image is read out and displayed through 8) (S39). The doctor interprets the displayed image. In the meantime, if there is an image to be displayed next (S40), the medical image reading apparatus searches the cache for the next image (S35). Store. Other processes are the same as those in the first embodiment (S41).

When the medical image reading apparatus and the database 8 are connected to a network, the time required to transfer the medical image via the network is the longest. for that reason,
In the present embodiment, the image transfer via the network is performed continuously at the same time as the image display request of the doctor is generated, so that the cache is performed locally as if it were an image storage unit. With such a configuration, high-speed image switching and display can be performed without being conscious of the image transfer time even during image reading via a network.

(Third Embodiment) In the medical image reading apparatus according to the second embodiment, the image storage unit is connected to the reading apparatus via a network. In this case, in order for a doctor to display a medical image and perform image interpretation, an image interpretation time of usually 10 to 15 seconds per image is required. Also,
The data amount of a normally transferred medical image is 6 to 8 megabytes per image. In order to transfer images over a network while a doctor is reading images, it is necessary to transfer 6 to 8 megabytes of data within about 10 seconds. To do so, if the network speed is 6 megabits per second or more, Need to be.

Therefore, in the present embodiment, it is preferable that the network speed is 6 Mbit / s or more. By setting the network speed to 6 megabits per second or more, medical images can be transferred within 10 seconds, and the waiting time for doctors due to the network transfer time can be avoided.

(Fourth Embodiment) The number of medical images read by a doctor at a time is about 10 at most. Therefore, in the present embodiment, when the frame memory has a capacity to store 10 or more pieces of medical image data, and when it is desired to store the image data exceeding the capacity, the most of the image data stored in the frame memory is used. It is configured to overwrite old data.

According to the present embodiment, when a doctor looks at a medical image and then reviews several images,
The probability that image data remains in the frame memory increases, and it is sufficient to directly display the image stored in the frame memory without searching the image storage unit or performing the gradation conversion process. Will be realized. By setting the capacity of the frame memory to 10 or more medical images, it is possible to cope with almost all cases where a doctor interprets a plurality of medical images.

(Fifth Embodiment) A medical image used by a doctor for image interpretation must be comparable to a conventional film-based medical image. In order to satisfy this, the number of pixels of the display image needs to be 2000 × 2000 pixels or more, and the gradation of each pixel needs to be 8 bits or more.

Therefore, in the present embodiment, the image display performance of the medical image reading apparatus is set to 2000 × 2000 pixels or more (4
And the gradation of each pixel is 8 bits or more. As a result, it is possible to perform an image diagnosis comparable to the conventional image interpretation using a film image.

(Sixth Embodiment) For the past 100 years, a method of displaying a film by illuminating the film on a light box has been used for interpretation of a radiographic image. Therefore, there is a great deal of accumulated diagnostic know-how in film image interpretation technology. In image diagnosis in which a medical image is displayed on a CRT to make a diagnosis, it is desirable to display an image equivalent to a film image. This makes it possible to apply the image reading technique using a film image as it is to CRT image reading. In order to make the film image and the CRT image look equivalent, the ratio between the luminance of the film image and the luminance of the image displayed on the image display unit may be kept constant.

The present embodiment is characterized in that a gradation conversion method for making the ratio between the luminance of the film image and the luminance of the image displayed on the image display unit constant is applied. This makes it possible to make the CRT image look the same as a film image.

In the above embodiment, FIG.
4 and a part or all of the apparatus shown in FIGS. 3 and 5 are described in a computer program so that they can be executed, and the computer program can be executed by a computer-readable recording medium, for example, FD ( floppy disk)
Alternatively, the program can be recorded on an MO, a ROM, a memory card, a CD, a DVD, a removable disk, or the like, provided, and distributed.

[0052]

As described above, according to the present invention, in the medical image reading apparatus and method for displaying a medical image, the next image is read into the frame memory while the doctor is reading the image. Image display can be performed at high speed. As a result, high-speed image display is possible from the viewpoint of a doctor who interprets the image.

In the present invention, if the display order of a plurality of image data is determined in advance and each image data is enormous and takes a long time to process, the present invention can be applied to other image interpretation apparatuses and systems. Can be applied.

[Brief description of the drawings]

FIG. 1 is a processing flow showing an embodiment of the present invention.

FIG. 2 is a diagram showing a process of operating an image reading apparatus and operating a doctor in a conventional example and an embodiment.

FIG. 3 is a configuration diagram showing another embodiment of the present invention.

FIG. 4 is a processing flow showing another embodiment of the present invention.

FIG. 5 is a configuration diagram of a medical image interpretation apparatus.

FIG. 6 is a conventional medical image interpretation processing flow.

FIG. 7 is another conventional medical image interpretation processing flow.

[Description of Signs] 1 ... Image storage unit 2 ... Image processing unit 3 ... Frame memory 4 ... Control unit 5 ... Image display unit 6 ... Digital-to-analog conversion circuit 7 ... CRT monitor 8 ... Image storage unit installed in a remote place 9 Network interface on image storage unit 10 Network interface on image reading device 11 Cache memory

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 15/403 380A 15/42 JX F term (Reference) 5B075 KK03 ND06 PQ02 UU29 5C082 AA04 BA20 BA35 BB01 BB15 BB26 BB29 CA11 CB01 DA87 MM02

Claims (7)

[Claims] An image storage unit for storing a large number of digital image data, an image processing unit for reading out image data stored in the image storage unit and performing gradation conversion, and an image output from the image processing unit An image reading apparatus comprising: a frame memory for storing image data; an image display unit for displaying the image data stored in the frame memory; and a device control unit for controlling the entire device. The apparatus control unit sets a display order of the plurality of image data stored in the image storage unit, and sets an image from the image storage unit according to the display order. Read data and send it to the image processing unit,
Means for accumulating the image data output from the image processing unit in the frame memory; and, when the image data requested to be displayed is stored in the frame memory, reading the image data from the frame memory to read the image data. Along with performing display control, image data to be displayed next is retrieved and read from the image storage unit, stored in the frame memory via the image processing unit,
Means for reading image data from the image storage unit and performing image display control via the image processing unit and the frame memory when the corresponding image data is not stored in the frame memory. Characteristic image interpretation device. 2. The image processing apparatus according to claim 1, wherein the image storage unit is connected via a network and includes a cache memory for temporarily storing image data transferred via the network. Image interpretation device. 3. The image interpretation apparatus according to claim 1, wherein the frame memory has a capacity of storing at least 10 pieces of image data. 4. The image processing apparatus according to claim 1, wherein the image processing unit performs a gradation conversion so that a ratio between the luminance of the film image and the luminance of the image displayed on the image display unit is constant. The image interpretation device according to claim 1. 5. A large number of digital image data are stored in an image storage unit, and the stored image data is subjected to gradation conversion and stored in a frame memory, and the image data in the frame memory is stored in an image display unit. An image interpretation method for displaying an image, wherein a plurality of images required for image interpretation and a display order thereof are set as an image group, a corresponding group is selected from the image storage unit in an image display request, and The first image data is searched / read / graded and stored in the frame memory, the image data stored in the frame memory is displayed on the image display unit, and in parallel with the image display, If there is image data to be displayed, the next image data is retrieved and read from the image storage unit and stored in the gradation conversion / frame memory. Image interpretation method to be. 6. A large number of digital image data are stored in an image storage unit via a network, the stored image data is captured via the network, and the captured image data is subjected to gradation conversion. An image reading method of storing image data in a frame memory and displaying image data of the frame memory on an image display unit, wherein a plurality of images required for image reading and a display order thereof are set as an image group, and the network A corresponding group is selected from the image storage unit in response to an image display request via the network, image data of the group retrieved and read from the image storage unit is stored in a cache memory via the network, and the cache memory is Search / read / gradation conversion of the image data stored in the frame memory and store it in the frame memory; Displaying the image data stored in the image memory on the image display unit.In parallel with the image display, if there is image data to be displayed next, the next image is retrieved and read from the cache memory, An image interpretation method characterized in that gradation conversion and storage in a frame memory are performed in advance. 7. An image interpretation program, characterized in that part or all of the method or apparatus is described in a computer program so that the method or apparatus can be executed, and the method or apparatus is recorded on a computer-readable recording medium. Recording medium.