JP2002158848A - Medical picture processing method and medical picture processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical picture processing method for changing a blacking processing area even if picture data before and after a blacking processing are not to be preserved, and outputting a visible picture which is blacking- processed to an output device. SOLUTION: Picture data recorded by radiation photographing and read by a picture reader is received, processed and preserved. Area information showing an area whose picture data is designated is preserved. Picture data with which the designated area is painted out based on area information is transmitted to the output device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a medical image processing method and apparatus for performing data processing on image data obtained from a recording sheet on which a radiation image is recorded and displaying the processed data.

[0002]

2. Description of the Related Art Conventionally, when a radiation is irradiated, a part of the radiation energy is accumulated, and thereafter, when an excitation light such as a visible light is irradiated, the stimulable phosphor emits a stimulating light according to the accumulated energy. The presence of (accumulative phosphor) is known. Radiation imaging using this substance has already been put to practical use in the medical field and the like. That is, when a radiation image of a subject such as a human body is captured and recorded on a sheet coated with a stimulable phosphor, and the stimulable phosphor sheet is scanned with excitation light such as laser light, stimulable emission light is generated. By reading this light photoelectrically, image data can be obtained. After appropriately processing this image data, the radiation image can be displayed as a visible image by outputting it to a display such as a CRT or printing it on a film using a laser printer or the like.

[0003] Such a radiographic image recording and reproducing system is compared with radiographic images using conventional silver halide photography.
Images can be recorded over a very large radiation exposure area. Further, the amount of stimulated emission is proportional to the exposure amount of the irradiated radiation in a wide range. Therefore, even when the exposure amount of radiation fluctuates due to the imaging conditions, when reading the stimulable phosphor sheet, by reading the emitted light under the optimal reading conditions, converting the emitted light into an electric signal, and appropriately processing it. It is possible to obtain a visible image suitable for observation.

Further, in this system, the stimulable phosphor sheet after reading the image data is irradiated with uniform light by a fluorescent lamp or the like to erase the data, so that the stimulable phosphor sheet is erased. Since the sheets can be used repeatedly, it can be said that the system is suitable for recent global resource issues and environmental issues. Furthermore, since the image record is stored as data, the image is not deteriorated,
It is possible to store a large amount of data for a long time.

FIG. 8 shows an example of a radiation image reading apparatus and a radiation image processing apparatus using a stimulable phosphor sheet.
The stimulable phosphor sheet 21 on which the radiation image is recorded is set at a predetermined position of the reading device. The stimulable phosphor sheet 21 is moved by a sheet conveying means 2 driven by a motor 22.
By 3, it is conveyed in the arrow Y direction. On the other hand, the beam 25 oscillated from the laser light source 24 is reflected and deflected by the rotating polygon mirror 26 driven by the motor 20 and rotated at high speed in the direction of the arrow, and passes through the converging lens 27. Thereafter, the beam 25 is incident on the stimulable phosphor sheet 21 by changing the optical path by the mirror 28, and scans in the direction of the arrow X. By this scanning, the excitation light 25 is irradiated on the stimulable phosphor sheet 21, and the irradiated light emits a stimulable emission light 29 in an amount corresponding to the radiation image information stored and recorded.
The stimulated emission light 29 is guided by a light guide 30 and is photoelectrically detected by a photomultiplier (photomultiplier tube) 31. The analog signal output from the photomultiplier 31 is amplified by the amplifier 32 and digitized by the A / D converter 33. This digital signal is transmitted to the image processing device 40 as image data.

In the above reading process,
In some cases, data is read ahead. That is, the stimulable phosphor sheet 21 is scanned in advance with a low-level light beam, an outline of an image recorded on the sheet is read (pre-read), and image data obtained by the pre-read is analyzed. After that, it scans by irradiating with a beam of a higher level than the beam illuminated in the pre-reading, and according to the dose of the irradiated radiation, etc.
Some systems perform an operation of reading data (optimal reading) under optimum reading conditions.

The image processing device 40 includes an input unit 41 including a keyboard and a mouse for inputting commands and information, and a floppy (registered trademark) disk or M
A drive unit 42 for driving O and the like, a display unit 43 such as a CRT for displaying a visible image based on image data, a central processing unit (CPU), an internal memory, a hard disk as a recording medium and an image reading device. And a main unit 44 in which an interface or the like for transmitting and receiving the signals is provided.

[0008] The image data input to the image processing apparatus is analyzed here and processed under optimal reading conditions and image processing conditions. Conventionally, various methods have been proposed to analyze and process this data. For example, as disclosed in Japanese Patent Application Publication (JP-A) No. 60-156055, there is a method of creating a histogram of image data. By obtaining the histogram of the image data, the maximum value, the minimum value of the image data, the value of the image data at the point where the frequency is maximum, and the like are obtained, and from these values, the radiation image recorded on the stimulable phosphor sheet is obtained. Characteristics can be grasped. Therefore, by obtaining the reading conditions and the image processing conditions based on this histogram,
A visible image suitable for observation can be output.

By the way, in taking a radiographic image, radiographing is performed using an irradiation field diaphragm that limits the radiation irradiation area so that the radiation is irradiated only to a necessary part of the subject and a part of the sheet. There are many. This is to prevent irradiation of a part unnecessary for observation of a subject with radiation, or when irradiating a part unnecessary for observation with radiation, scattered radiation enters the part required for observation from that part, and image quality performance is deteriorated. This is to prevent

The image data photographed as described above and processed under appropriate reading conditions and image processing conditions is output as a visible image and provided for observation. That is, it is output as a luminance distribution to a CRT or output as a density distribution to a film using a laser printer or the like. At this time, the radiation-irradiated field area, that is, the area to which almost no radiation was irradiated at the time of imaging becomes a high-luminance area on a CRT, a low-density area on a film, and a high-luminance area in any case. . When such an image is used for diagnosis or the like, it is very difficult to observe the image because the light that enters the eye through the region is strongly felt.

In order to eliminate this difficulty in observing, CR
In some cases, observation was performed with a shielding plate or the like arranged in front of T or the film. However, since the shape and size of the radiation field differ from image to image, using this method requires that the position of the shielding plate be adjusted each time observation is performed. Since it is difficult to cover, the suitability for observing a visible image has been reduced.

In order to solve such a problem, Japanese Patent Laid-Open Publication No. Hei 3-98174 discloses a radiation image processing method for assigning data values corresponding to low luminance or high density to image data corresponding to an area outside a radiation irradiation field. And equipment. This is a process in which the radiation-irradiated field is subjected to a process of apparently blacking it out, and is called “blackening process”. That is, the radiation outside the radiation irradiation field of the visible image reproduced based on the image reproduction image data representing the radiation image has low luminance when displayed on a CRT or the like, and has high density when printed on a film or the like. A data value is assigned to image data corresponding to an area outside the irradiation field. According to this method, it is possible to obtain a visible image suitable for observation without using a shielding plate or the like that covers a part of the front surface of the visible image and without intense light entering the eyes from a region outside the radiation irradiation field. .

According to the above method, first, image data is read from the stimulable phosphor sheet, and the outline of the radiation irradiation area is recognized. Alternatively, a contour line is designated by the user. Next, for the inside of the radiation field, the image is processed so as to have excellent observation suitability, and for the outside of the radiation field, a data value corresponding to low luminance is assigned. In this manner, a visible image blackened is obtained for an area where irradiation of radiation is restricted during imaging. FIG. 9 shows a blackened image displayed on the CRT. On the CRT, the brightness of the hatched portion in FIG. 9 is displayed low.

[0014]

However, according to the above-mentioned method, since the image data is processed by directly modifying the image data, once the blackening process is performed, the image data cannot be restored. . That is, even when the user specifies the area, it is impossible to start over. There is also a method of storing the image data before the blackening process in order to enable the redoing, but an extra memory area for storing is required.

As another method, if an area outside the irradiation field is attached to the image data as area information, the image data itself is not changed, and the data amount can be suppressed. However, if the device that has received this data does not have means for filling the corresponding area, an image that has been subjected to blackening processing cannot be displayed.

In view of the above, the present invention is capable of re-performing the blackening process without storing both the image data before and after the blackening process, and an output device having no filling means. It is an object of the present invention to provide a medical image processing method and apparatus capable of outputting a visible image subjected to blackening processing.

[0017]

In order to solve the above-mentioned problems, a medical image processing method according to the present invention receives, processes, and stores image data recorded by radiography and read by an image reading device. A step of storing area information representing an area specified for the image data; and, based on the area information, performing a filling process on the specified area in the image data. Transmitting to the output device.

In the above-mentioned medical image processing method, it is determined whether or not the output device has a means for performing a filling process based on the area information. The method may further include transmitting the data and the area information to the output device.

Further, the medical image processing apparatus according to the present invention
First means for receiving and processing image data recorded by radiography and read by the image reading device, and second means for storing image data and area information representing an area designated for the image data; And a third means for performing a filling process on a designated region in the image data based on the region information, and transmitting the image data on which the filling process has been performed to an output device.

In the medical image processing apparatus, it is determined whether or not the third means has a means for performing a filling process based on the area information, and if the output device has a means for performing a filling process. May transmit the image data and the area information to the output device.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The same components are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 is a diagram showing a configuration of a medical image display system including a medical image processing device according to one embodiment of the present invention. In this system, first, radiography is performed in the imaging unit 1. For imaging, a sheet coated with a stimulable phosphor is used as a recording sheet, and a radiation field stop is used to irradiate only the necessary part of the subject or part of the sheet as necessary. Is done.

Next, the reading section 2 reads the image data recorded on the recording sheet. Here, in a device in which the photographing unit and the reading unit are integrated,
The reading is performed following the photographing. When the photographing unit and the reading unit are independent devices, after recording, the recording sheet is taken out of the photographing device for each case to be protected and inserted into the reading device. Note that the medical image processing method according to the present invention can support both a method of performing prefetching and a method of not performing prefetching.

In the reading unit 2, the image information stored and recorded on the recording sheet is photoelectrically detected by a photomultiplier under optimum reading conditions, output as an analog signal, amplified, and then amplified. The digital signal is converted by a D converter and input to the image processing apparatus 10 as a digital signal.

The image processing apparatus 10 operates a central processing unit (CPU) and an internal memory for performing various processes including the information processing section 3 and a recording medium on which data and a program for performing the above processes and the like are recorded. It includes an interface for transmitting and receiving signals between the possible storage unit 6 and external devices such as a reading unit and an output device. A hard disk corresponds to the recording medium, and when a floppy disk, a magnet optical (MO), a CD-ROM, or the like is used as an auxiliary recording medium, these also apply.
The image processing apparatus 10 includes a display unit 4 such as a CRT for displaying a visible image based on image data, various commands and information, and an input unit such as a keyboard and a mouse for inputting various commands and information. 5 is connected. Further, an output device 7 such as a printer for outputting processed image data is connected to the image processing device 10.

Next, a medical image processing method according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a flowchart showing the medical image processing method according to the present invention. The image data input to the image processing apparatus 10 as described above is first received by the information processing unit 3, subjected to image processing under optimal processing conditions, and stored in the storage unit 6 (step S1). . Further, the image data is displayed as a visible image on the display unit 4 connected to the main body (step S2).

Here, the arrangement of the photographing record photographed on one recording sheet may be a case where one screen is recorded as a whole, or as shown in FIGS. 3A and 3B. Alternatively, various patterns are conceivable, such as a case where two screens are arranged vertically and a case where four screens are arranged as shown in FIG. The image processing method according to the present invention can deal with any of the above patterns.

FIG. 4 is an example of an image displayed on the display unit 4 before blackening processing. FIG. 4 shows one screen among one or a plurality of screens variously arranged on one recording sheet as shown in FIG. In FIG. 4, subject 1
1 and the shaded area indicate the inside of the irradiation field, and the area outside the shaded area indicates the area outside the irradiation field. At this stage,
An image captured using a radiation diaphragm has high brightness outside the radiation field, and is not suitable for observation for diagnosis.

Next, the user designates an area outside the irradiation field, that is, an area where blackening is desired (step S3).
The user inputs an area to be specified while viewing the image displayed on the display unit 4 using the input unit 5 connected to a main body such as a mouse or a keyboard. In FIG. 4, a bold line indicates an area designated by the user. The area specified by the user is stored in the storage unit 6 as area information separately from the image data (step S4). The storage format may be bitmap format overlay data or point coordinate information defining an area. FIG.
An example in which only the area information is displayed is shown, and the area 12 is an area to be blackened.

When the user instructs to display the image subjected to the blackening processing, the original image data and the area information are superimposed on the display unit 5 (FIG. 4), or the pseudo blackening processing is performed. The applied image (FIG. 6) is displayed (step S5). In FIG. 6, a region 13 indicates a blackened region. The user looks at the displayed screen and can change the designated area if necessary. Further, since the area information can be set for each user, another user can specify another area and create the area information for the same image data.

The user looks at the display unit 4, and if a desired blackened image has been obtained, instructs to output the image. When outputting, the image data is actually subjected to blackening processing based on the area information (step S6). By transmitting this to the output device 7 (step S7), an image in which the area outside the radiation irradiation field is painted black can be obtained. That is, data is output such that the luminance distribution of the area becomes low when displaying on a CRT, and the density distribution becomes high when printing on a film by a laser printer or the like. The visible image thus obtained has been subjected to a desired blackening process by the user, so that strong light from a high-brightness portion around the subject can be observed without entering the eyes, and medical diagnosis It becomes a visible image suitable for observation for example.

Next, a medical image processing method according to a second embodiment of the present invention will be described. FIG. 7 is a flowchart illustrating the medical image processing method according to the present embodiment. The apparatus for outputting data processed by the medical image processing apparatus according to the present invention includes a unit that performs blackening processing on image data based on region information, corresponding to the medical image processing apparatus according to the present invention. There are output devices, while other output devices do not have such a means as conventional output devices. The medical image processing method according to the present invention is adapted to be compatible with any of the above output devices. That is, in the medical image processing method according to the present embodiment, in addition to the medical image processing method according to the first embodiment of the present invention, the output device performs blackening processing on the radiation irradiation field in the area information. It is determined whether or not the output device has the means, and if the output device has such means,
A step of transmitting the image data and the area information to the output device is added.

In FIG. 7, first, after receiving the image data from the reading unit, the image data is processed and stored under the optimum processing conditions (step S11), and the image before the blackening process is displayed on the display unit. (Step S12). Next, while viewing the displayed image, the user specifies an area to be blackened from the input unit (step S13). The designated area is stored in the storage unit as area information separately from the image data (step S14). At this time, the save format is
Bitmap format overlay data may be used,
Point coordinate information that defines an area may be used. The user can also superimpose the original image data and the area information on the display unit (step S15), and re-designate the area based on the result.

When outputting a visible image, it is first determined whether or not the output device has blackening processing means (step S16). That is, when the image data and the area information are separately transmitted, it is determined whether or not the output device has a unit for filling and displaying or printing the specified area. If the output device has such means, the image data and the area information are separately output and transmitted (step S17). On the other hand, if the output device does not have such means, the image data is blackened based on the area information to create blackened image data (step S18) and output. (Step S1
9). By receiving the data, even an output device having no blackening processing means can display or print the visible image that has been blackened.

[0034]

According to the present invention, since the blackening processing can be performed in a pseudo manner without directly modifying the image data, both the pre-processing and post-processing images are necessary for re-performing the blackening processing. There is no need to save data. In addition, the pseudo blackening process can be redone, and then the actual blackening process is performed to display or print the visible image subjected to the blackening process even on an output device having no blackening processing means. can do.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a medical image display system including a medical image processing device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a medical image processing method according to the first embodiment of the present invention.

FIG. 3 is a diagram showing an example of an arrangement pattern of a screen displayed in the medical image processing method according to the present invention.

FIG. 4 is a diagram showing an original image displayed in the medical image processing method according to the present invention.

FIG. 5 is a diagram showing a designated area displayed in the medical image processing method according to the present invention.

FIG. 6 is a diagram showing a blackened image displayed in the medical image processing method according to the present invention.

FIG. 7 is a flowchart illustrating a medical image processing method according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating an example of a conventional radiation image reading device and a conventional radiation image processing device.

FIG. 9 is a perspective view showing a blackened image displayed on the display unit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging unit 2 reading unit 3 information processing unit 3 4, 43 display unit 5, 41 input unit 6 storage unit 7 output device 10 image processing device 11 subject 12 blackened area 20, 22 motor 21 stimulable phosphor sheet 23 sheet Conveying means 24 Laser light source 25 Beam (excitation light) 26 Rotating polygon mirror 27 Convergent lens 28 Mirror 29 Stimulated emission light 30 Light guide 31 Photomultiplier (photomultiplier tube) 32 Amplifier 33 A / D converter 40 Image processing device 42 drive unit 44 body unit

Claims (4)

[Claims] A step of receiving, processing, and storing image data recorded by radiography and read by an image reading apparatus; a step of storing area information representing an area designated for the image data; A medical image processing method, comprising: performing a filling process on the designated region in the image data based on region information; and transmitting the image data that has been subjected to the filling process to an output device. 2. A method for determining whether the output device has a means for performing a filling process based on the area information. If the output device includes a means for performing a filling process, the image data and the area are determined. 2. The medical image processing method according to claim 1, further comprising a step of transmitting the information to the output device. 3. A first means for receiving and processing image data recorded by radiography and read by an image reading device, wherein the image data and area information representing an area designated for the image data are stored. A second unit for storing, and a third unit that performs a filling process on the designated region in the image data based on the region information, and transmits the image data that has been subjected to the filling process to an output device.
Medical image processing apparatus comprising: 4. The image processing apparatus according to claim 1, wherein the third unit determines whether or not there is a unit that performs a filling process based on the area information. 4. The medical image processing apparatus according to claim 3, wherein the data and the area information are transmitted to an output device.