JP2012217631A - Medical image processing apparatus and medical image diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical image processing apparatus and a medical image diagnostic apparatus which delete personal information from a moving image file containing a medical image and the personal information, not depending on handwork.SOLUTION: The moving image file for diagnosis is generated by combining image signals 1 and 2 obtained by imaging the inside of a subject by an imaging part 10 with the personal information specifying the subject. A recording part 30 includes a personal information extracting means for extracting the personal information from the moving image file and a personal image deleting means for erasing the extracted personal information or substituting nonspecific information for the personal information, and generates and records the moving image file wherefrom the personal information is erased.

Description

  The present invention relates to a medical image processing apparatus and a medical image diagnostic apparatus, and more particularly to a technique for protecting personal information by erasing personal information on a moving image.

  An image recorded by a medical image diagnostic apparatus is often used not only for diagnosis but also for education, conference presentation, and the like. Among medical image diagnostic apparatuses, in particular, an X-ray image diagnostic apparatus normally records an X-ray image without processing, and thus subject information is recorded while being displayed on the image. In the case of diagnosis, the subject information contained in the image is useful for preventing the subject from being mistaken, but when it is disclosed to an unspecified number of people, such as at a conference presentation, the subject information is protected from the viewpoint of personal information protection. It is necessary to delete the sample information. Therefore, under the present circumstances, the subject information is erased by human manual work, and this work takes an enormous amount of time.

  In order to solve these problems, for example, in Patent Document 1, a video signal that includes personal identification information of a subject only at the beginning of a moving image and does not include personal information of the subject until the end of the moving image is output for recording. A medical image processor device is disclosed.

JP 2007-54097 A

  In the medical image processor apparatus of Patent Document 1, this function must be mounted on the apparatus side. In the case of a video signal obtained by an apparatus that does not have the function, such as an old medical image diagnostic apparatus, character information is also deleted. Had to be done manually. Erasing personal information by hand requires a great deal of effort and special knowledge about time and video editing. Moreover, since the size and position of characters may change in the middle of a moving image, there is a problem that all moving images cannot be processed uniformly.

  The present invention has been made in view of the above problems, and provides a medical image processing apparatus and a medical image diagnostic apparatus that delete personal information from a moving image file including medical images and personal information without using manual operations. With the goal.

  In order to solve the above problems, a medical image processing apparatus according to the present invention includes a video signal obtained by imaging a subject using a medical image capturing device and personal information that identifies the subject, Personal information extracting means for extracting personal information; and personal information deleting means for deleting the extracted personal information or replacing the personal information with non-specific information.

  Further, a medical image diagnostic apparatus according to the present invention includes the medical image processing apparatus and an imaging unit that images a video signal obtained by imaging a subject. The medical image processing apparatus is obtained by the imaging unit. The moving image file created using the video signal is read, and the personal information included in the moving image file is extracted and the extracted personal information is deleted or replaced.

  As described above, according to the present invention, by automatically performing the process from recognition to deletion of personal information for each frame, it is possible to save enormous labor and time, and no special knowledge is required, and the effect of preventing omission of deletion. There is.

A block diagram showing an outline of an X-ray diagnostic imaging apparatus 1 according to the present embodiment The schematic diagram which shows an example of the screen display example which displayed the synthetic | combination video signal on the monitor 40 The schematic diagram which shows an example of the screen display example which displayed the synthetic | combination video signal on the monitor 40 The schematic diagram which shows an example of the example of a screen display which displayed the synthetic video signal on the monitor 40 The block diagram which shows the structure of the recording part 30 which concerns on 1st embodiment. The block diagram which shows the structure of the recording part 30 which concerns on 1st embodiment. The block diagram which shows the structure of the recording part 30 which concerns on 2nd embodiment. The block diagram which shows the structure of the recording part 30 which concerns on 3rd embodiment. The block diagram which shows the structure of the recording part 30 which concerns on 4th embodiment.

  Hereinafter, an embodiment of the present invention will be described by taking an X-ray image diagnostic apparatus as an example. However, in addition to the X-ray image diagnostic apparatus, the present invention is an MRI apparatus, for example, as long as it has a function for generating a moving image. The present invention can be applied to all medical image diagnostic apparatuses such as PET apparatuses, ultrasonic diagnostic apparatuses, and endoscope apparatuses. In addition, the present invention does not use these medical image diagnostic apparatuses alone, but also in an integrated medical image diagnostic apparatus that provides composite diagnostic information using video signals from two or more medical image diagnostic apparatuses. Can be applied. In the following example, a description will be given using a fluoroscopic image (moving image) obtained using an X-ray image diagnostic apparatus as a medical image. However, when the medical image is a still image, one frame of the moving image is used. The present invention can be applied by performing the processing to be performed on a still image.

  FIG. 1 is a block diagram showing an outline of an X-ray image diagnostic apparatus 1 according to the present embodiment. The X-ray image diagnostic apparatus 1 according to the present embodiment mainly includes an imaging unit 10 that acquires an X-ray fluoroscopic image, an image processing unit 20 that processes an image captured by the imaging unit 10 and generates a video signal. A recording unit 30 that receives the perspective image 201 (video signal 1) generated by the image processing unit 20 and generates a moving image file. The image processing unit 20 and the recording unit 30 are provided with the imaging unit 10. It is located in an operation room different from the inspection room.

  The imaging unit 10 includes an X-ray source 11 that irradiates X-rays, an X-ray detector 12 that detects X-rays emitted from the X-ray source 11 and transmitted through the subject (here, a patient), and the subject. The bed apparatus 13 provided with a mechanism for moving in accordance with X-ray imaging or changing the angle so that good imaging can be performed, X-ray irradiation from the X-ray source 11, and X-rays synchronized therewith A control device 14 that reads out an image signal from the detector 12 and controls the movement of the bed apparatus 13 and a switch 15 for instructing start and end of imaging are provided. By operating the switch 15, continuous X-ray irradiation and transmission X are performed under preset fluoroscopic conditions (X-ray tube voltage, tube current, exposure amount (mAs), and exposure time (msec). The fluoroscopic imaging for performing line detection is started or ended, and the switch 15 also serves as a recording start switch in the recording unit 30.

  The X-ray diagnostic imaging apparatus 1 includes a monitor 40 (with a speaker) that also displays a created moving image file and also serves as an operation user interface (GUI) for the operator, and an input device including a mouse 41 and a keyboard. Yes. Although the figure shows a state where the monitor 40 and the input device are connected to the recording unit 30, the image processing unit 20 and the recording unit 30 can be incorporated in the same workstation. The input / output device provided in the workstation is the monitor 40 or the input device. When the image processing unit 20 and the recording unit 30 are constructed on separate computers, each may include a monitor 40 and an input device.

  The image processing unit 20 performs signal processing such as filter processing and noise reduction processing on the electrical signal (image signal) corresponding to the intensity of the X-ray detected by the X-ray detector 12 as necessary, and A video signal including a vertical synchronizing signal is generated every time.

  The recording unit 30 receives the video signal from the image processing unit 20 and creates a moving image file for display on a display device (monitor or the like) or recording on a recording medium. In addition to the fluoroscopic image 201 (video signal 1), an external camera image 501 (video signal 2) captured by a medical image imaging apparatus different from the X-ray image diagnostic apparatus 1 is read from the external camera image data recording apparatus 50. The recording unit 30 receives information for identifying a patient (hereinafter referred to as “personal information”) from an input device such as a mouse 41, an RIS (abbreviation of Radiography Information System), or an electronic medical record system. Then, the recording unit 30 generates, displays, and records a signal (hereinafter referred to as “synthesized video signal 1”) obtained by combining the video signal 1, the video signal 2, and the personal information.

  Next, the synthesized video signal 1 generated by the recording unit 30 will be described with reference to FIGS. 2, 3, and 4 are schematic diagrams illustrating an example of a screen display example in which the composite video signal is displayed on the monitor 40.

  In the screen of FIG. 2, the perspective image 201 is displayed on the right half of the screen. In the lower left part of the screen, the external camera image 501 is displayed by being fitted in a screen smaller than the perspective image 201 (hereinafter referred to as “small screen”). Further, “ID: 1234”, “Name: Hitachi Taro”, “Gender: Male”, and “Address: Tokyo ...” are displayed as personal information 212 of the patient in the upper left part of the screen. The patient's name “Hitachi Taro” is displayed in the upper left corner of the small screen in which the external camera image 501 is fitted, and the patient ID “1234” is displayed in the lower right corner of the small screen.

  The small screen including the external camera image 501 and the fluoroscopic image 201 are appropriately moved and displayed in the screen during the fluoroscopic examination. For example, in FIG. 3, the perspective image 201 is displayed on the left half of the screen, and the small screen is displayed on the right half of the screen. In FIG. 4, the small screen is displayed at the center of the screen, and as a result, is superimposed on a part of the fluoroscopic image 201. As a result, the position of the personal information included in the screen is not constant and changes as the screen layout changes.

<First embodiment>
In the first embodiment, a diagnostic moving image file including personal information is generated and stored at the time of fluoroscopy, and the personal information is deleted from the moving image file at another opportunity. Hereinafter, based on FIG. 5, FIG. 6, 1st embodiment of this invention is described. 5 and 6 are block diagrams showing the configuration of the recording unit 30 according to the first embodiment.

  As shown in FIGS. 5 and 6, the recording unit 30 according to the present embodiment mainly includes a video signal synthesis unit 31, an image reception control unit 32, a storage processing unit 33, a reading unit 34, and an image processing control unit 35. Is done. The image reception control unit 32 includes a reception processing unit 321 that receives the composite video signal 1 and an image reception memory 322 that temporarily stores the composite video signal 1. The storage processing unit 33 includes a recording device 332 that records a moving image file in a fixed manner, and a storage processing unit 331 that performs a writing process on the recording device 332. The reading unit 34 performs a reading process of the moving image file recorded in the recording device 332, and also performs a so-called reproduction process of outputting the read moving image file to the monitor. The image processing control unit 35 performs processing for deleting personal information from a moving image file, performs character recognition processing on each frame constituting the moving image file, and determines a character size and position. 351, and a character erasure processing unit 352 that makes the recognized character unreadable by, for example, painting the recognized character black or applying a mosaic process.

  The video signal synthesis unit 31, the image reception control unit 32, the storage processing unit 33, the reading unit 34, and the image processing control unit 35 are composed of hardware such as a calculation / control device (eg, CPU, MPU), memory, hard disk, and the above functions. It is configured by cooperating with a program for realizing the above.

  Next, a process at the time of generating / recording a moving image file will be described with reference to FIG.

  Based on the electrical signal obtained by the imaging unit 10 (X-ray detector 12), the image processing unit 20 generates a fluoroscopic image 201 (video signal 1) and transmits it to the video signal synthesis unit 31 in the recording unit 30. The video signal synthesis unit 31 also receives the external camera image 501 (video signal 2) and personal information.

  The video signal synthesis unit 31 fits the perspective image 201, the external camera image 501, and the personal information into each frame according to predetermined layout information, and generates a synthesized video signal 1. The generated composite video signal 1 is transmitted to the reception processing unit 321.

  The reception processing unit 321 outputs the composite video signal 1 to the monitor 40 and the image reception memory 322. As a result, a moving image based on the composite video signal 1 is displayed on the monitor 40 in real time during the operation. This moving image includes personal information. On the other hand, the image reception memory 322 temporarily stores the composite video signal 1. The storage processing unit 331 stores the temporarily recorded composite video signal 1 as the moving image file 1 in the recording device 332.

  Next, a process for deleting personal information from the moving image file 1 will be described with reference to FIG. This process is performed in order to process the video file 1 that has been inspected into a file suitable for non-diagnostic applications such as academic presentations.

  The reading unit 34 reads the moving image file 1 recorded in the recording device 332, and the character recognizing unit 351 performs character recognition in the moving image file 1 to determine the size and position of the character. In this embodiment, it is only necessary to recognize a character, and it is not necessary to recognize the character or the meaning (attribute) of text information.

  The character erasure processing unit 352 performs a process of erasing the recognized character. For example, the pixels constituting the recognized character are replaced with the same color as the background color, or mosaic processing and masking processing (filling the character portion) are performed so that the character cannot be recognized. The saving processing unit 331 saves the moving image file that has been subjected to the character erasing process as the moving image file 2 in the recording device 332. A series of operations from reading the moving image file 1 to saving the moving image file 2 is performed frame by frame.

  According to the present embodiment, character information on an image can be automatically deleted from a moving image file including personal information generated for diagnosis.

  In the above embodiment, the storage processing unit 33, the reading unit 34, and the image processing control unit 35 are provided in the recording unit 30, but are in a commercially available video playback device such as a video deck, a DVD player, and a BLUE-RAY player. An image processing control unit 35 may be added to the existing storage processing unit 33 and reading unit 34 to constitute an image processing apparatus according to the present invention. In this case, the same processing as in this embodiment can be performed by reading the moving image file 1 recorded on an external recording medium such as a DVD or receiving the moving image file 1 via a network.

<Second embodiment>
The second embodiment is an embodiment for generating and displaying a diagnostic moving image file including personal information in fluoroscopy, and simultaneously generating and storing a moving image file from which the personal information is deleted. Hereinafter, based on FIG. 7, 2nd embodiment is described. FIG. 7 is a block diagram illustrating a configuration of the recording unit 30 according to the second embodiment. In addition, about the structure similar to 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 7, in the second embodiment, the video signal synthesis unit 31 outputs the layout information used for synthesis of the video signal together with the synthesized video signal 1 to the reception processing unit 321. This layout information includes the position of the small screen in which the external camera image 501 is inserted in each frame.

  The reception processing unit 321 outputs the composite video signal 1 to the monitor 40. The composite video signal 1 displayed on the monitor 40 includes personal information and is used for diagnosis. Although not shown in FIG. 7, the composite video signal 1 displayed on the monitor 40 may also be stored in the recording device 332. Further, the reception processing unit 321 outputs the composite video signal 1 and the layout information to the image reception memory 322, and the image reception memory 322 temporarily stores them.

  The area specifying unit 353 refers to each frame of the composite video signal 1 and the layout information corresponding to the frame, and specifies an area for performing character recognition processing for each frame. This area is desirably specified in order to prevent deterioration in diagnostic ability due to erroneous deletion of the subject areas of the fluoroscopic image 201 and the external camera image 501. Therefore, for example, an area composed of n × m pixels (n and m are natural numbers) located at the four corners in the small screen in which the external camera image 501 in each frame is inserted is designated as an extraction target area for character recognition. Since the position of the small screen on the entire screen in each frame can be calculated from the layout information, the coordinates of the n × m pixels are obtained on the basis of the calculated position, thereby obtaining the absolute size of the small screen in each frame. Specify the area by calculating the coordinates. Further, the area designating unit 35 designates a non-display area between the perspective image 201 and the small screen 501 in each frame as an extraction target area. In general, text information indicating personal information is often arranged at the four corners of the entire frame. Therefore, predetermined areas located at the four corners of the non-display area may be designated as the extraction target area.

  The character recognition unit 351 performs character recognition processing on the extraction target area designated for each frame, and the character erasure processing unit 352 performs recognized character erasure processing. By these processes, a composite video signal 2 in which personal information is deleted from the composite video signal 1 is generated. The storage processing unit 331 stores the composite video signal 2 as the moving image file 2 in the recording device 332. As another embodiment, instead of being permanently stored in the recording device 332, it may be configured to display on a monitor.

  According to the present embodiment, it is possible to display and store the composite video signal 1 including personal information during fluoroscopy, and to simultaneously generate and store the composite video signal 2 that does not include personal information. In addition, by performing area recognition and character recognition / erasure processing, it is possible to increase the processing speed while preventing deterioration in diagnostic ability.

<Third embodiment>
The third embodiment is an embodiment in which a difference processing unit 354 is added to the image processing control unit 35 of the second embodiment. In the second embodiment, the area is specified for each frame. In the third embodiment, the difference between successive frames is calculated, and if the difference value is less than the threshold, the same area as the previous one is recognized. This is characterized in that if the difference value is equal to or greater than the threshold value, the target area is set again.

  Hereinafter, a third embodiment will be described with reference to FIG. FIG. 8 is a block diagram illustrating a configuration of the recording unit 30 according to the third embodiment. In addition, about the structure similar to 1st, 2nd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The difference processing unit 354 calculates a difference between successive frames temporarily stored in the image reception memory 322, compares the difference value with a threshold value, and outputs the result to the region specifying unit 353. When the difference value is equal to or greater than the threshold value, for example, when the previous frame is FIG. 2 and the consecutive frames are FIG. 3 or FIG. 4, the region designating unit 353 performs redesignation of the target region. If the difference value is less than the threshold value, for example, if the previous frame is the screen of the layout in FIG. 2 and the subsequent frames are also screens of the same layout, the area specifying unit 353 specifies the previous frame. Specify the same area as the extracted area for character recognition. After that, as in the second embodiment, character erasure processing is performed and saved as the moving image file 2.

  According to the present embodiment, the target area is re-designated only when the difference value between successive frames is equal to or greater than the threshold value, so that the processing speed can be increased.

  As another embodiment, when the difference value is equal to or greater than the threshold value, the elapsed time from the start time of the moving image file is recorded in a time stamp, and when the moving image file 2 is played back, fast forward is performed and the time stamp is referred to. Then, it may be stopped at a frame whose difference value is equal to or greater than a threshold value. As a result, the area designation and the result of character recognition / erasure can be confirmed in a shorter time than the case of reproducing the entire program.

<Fourth embodiment>
In the fourth embodiment, instead of the character erasing process of the first, second, and third embodiments, text information indicating personal information is replaced with dummy characters. The fourth embodiment will be described below based on FIG. FIG. 9 is a block diagram illustrating a configuration of the recording unit 30 according to the fourth embodiment. In addition, about the structure similar to 1st, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The image processing control unit 35 according to the fourth embodiment includes a replacement data storage unit 354 and a character replacement processing unit 355 instead of the character erasing processing unit 352. The character recognition unit 351 performs part-of-speech analysis on the extracted text information, and determines text information attributes (for example, name, address, ID, etc.). The replacement data storage unit 354 stores dummy text information corresponding to the attribute of the text information in advance. The character replacement processing unit 355 refers to the replacement data storage unit 354 and rewrites the text information extracted in the moving image file to dummy text information that matches the attribute of the text information. Thereafter, the storage processing unit 331 stores data in which the personal information is replaced with dummy text information in the moving image file 1 as the moving image file 2 in the recording device 332. Further, the extracted text information in the moving image file may be stored in the replacement data storage unit 354. Thus, the original text information can be confirmed by referring to this data.

  According to the present embodiment, personal information is not simply erased, but is converted into text information corresponding to the attribute, so that it is possible to know what the originally included text information indicates.

  As another embodiment, in the second embodiment, the area recognition is not performed, and the character recognition process may be performed on the entire frame as in the first embodiment. Further, the character replacement process of the fourth embodiment may be replaced with the character erasure process of the second and third embodiments. In the above embodiment, the deletion of personal information using text information has been described. However, when the personal information includes a patient's face photo, the face recognition processing unit replaces the character recognition unit 351 of the image processing control unit 35. In addition, a face erasure processing unit may be provided instead of the character erasure processing unit 352 or the character replacement processing unit 355. The face recognition processing unit may specify the size and position of the face, and the face erasing processing unit may perform processing that makes the face unreadable, such as painting the specified face image with a background color or black.

  The said embodiment is only an example of embodiment of this invention, and the change in the range which does not deviate from the meaning of this invention belongs to the technical scope of this invention.

DESCRIPTION OF SYMBOLS 1 ... X-ray image diagnostic apparatus, 10 ... Imaging part, 20 ... Image processing part, 201 ... Perspective image, 30 ... Recording part, 31 ... Video signal synthetic | combination part, 32 ... Image reception control part, 33 ... Storage control part, 34 ... Reading unit, 35 ... Image processing control unit, 40 ... Monitor, 41 ... Mouse, 50 ... External camera image data storage device

Claims (10)

Personal information extracting means for extracting the personal information from a video signal obtained by imaging a subject by a medical imaging apparatus, personal information for identifying the subject, and a moving image file including the video information;
Personal information deleting means for erasing the extracted personal information or replacing the personal information with non-specific information;
A medical image processing apparatus comprising: In each frame of the video file, further comprising an area designating unit for designating an area from which the personal information is to be extracted,
The personal information extraction means performs a process of extracting personal information for the designated extraction target area.
The medical image processing apparatus according to claim 1. The area specifying means acquires layout information indicating a position where the video signal is inserted in each frame, and specifies the extraction target area using the layout information.
The medical image processing apparatus according to claim 2. The moving image file includes a first video signal obtained from the medical imaging device used for the examination and a second video signal captured by a medical imaging device different from the medical imaging device. Each of the first region and the second region of
The layout information includes position information of the first area and the second area in each frame,
The area designating unit designates the extraction target area in each of the non-first area excluding the first area in each frame and the second area based on the layout information.
The medical image processing apparatus according to claim 3. The area designating unit designates an area within a predetermined range from the four corners of each frame as the extraction target area.
The medical image processing apparatus according to claim 2 or 3, characterized by the above. Further comprising difference processing means for calculating a difference value between successive frames constituting the moving image file;
The area designating unit designates the same area as the extraction target area designated for the immediately preceding frame as an extraction coping area in a frame that is continuous with the immediately preceding frame when the difference value is less than a predetermined threshold, If the difference value is equal to or greater than the predetermined threshold, a new extraction target area in a frame that is continuous with the immediately preceding frame is designated.
The medical image processing device according to claim 2, wherein the medical image processing device is a medical image processing device. The personal information is composed of text information,
The personal information extraction means is a character recognition means for recognizing text information;
The personal information deletion means is character replacement processing means for replacing text information recognized by the character recognition means with dummy text information different from the text information.
The medical image processing apparatus according to claim 1, wherein the medical image processing apparatus is a medical image processing apparatus. The text information is at least one of a name, age, address, and subject identification number that identifies the subject,
The character recognition means identifies whether the extracted text information corresponds to an attribute of a name, age, address, and subject identification number that identifies the subject,
The personal information deletion means, based on the identification result, the extracted text information, at least one dummy text information of name, age, address, and subject identification number that matches the attribute of the text information Replace with
The medical image processing apparatus according to claim 7. The personal information is composed of text information,
The personal information extraction means is a character recognition means for recognizing text information;
The personal information deletion means is a character erasure processing means for erasing text information recognized by the character recognition means.
The medical image processing apparatus according to claim 1, wherein the medical image processing apparatus is a medical image processing apparatus. A medical image processing apparatus according to any one of claims 1 to 9,
An imaging means for imaging a video signal obtained by imaging a subject,
The medical image processing apparatus reads a moving image file created using a video signal obtained by the imaging means, extracts personal information included in the moving image file, and deletes or replaces the extracted personal information. Do,
A medical image diagnostic apparatus characterized by that.

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