JP2014121346A - Medical image processor and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical image processor and program which, when X-ray photography is performed under improper X-ray photography conditions in bone mineral density measurement, allows a user to quickly recognize that such an improper X-ray photography has been performed.SOLUTION: A control part 31 acquires medical image data obtained by performing X-ray photography on a subject. The control part 31 measures bone mineral density based on the acquired medical image data. The control part 31 determines whether or not the dose of X-ray irradiated from a radiation source for irradiating X-rays is within a predetermined range based on the acquired medical image data. A display part 35 performs predetermined notification when the control part 31 determines that the dose is outside of the predetermined range before the bone mineral density is measured by the control part 31.

Description

  The present invention relates to a medical image processing apparatus and a program.

  Conventionally, a bone mineral density examination is performed for diagnosis of osteoporosis and determination of therapeutic effect. There are various bone mineral quantitative tests. Among them, the DIP (Digital Image Processing) method is widely used as a simple and highly accurate test. In the DIP method, an aluminum slope and the left second metacarpal bone are simultaneously radiographed, and the bone mineral density is measured by comparing the shadow density of the aluminum slope and the left second metacarpal bone in the obtained X-ray image. It is a technique.

  As a flow of bone mineral density examination by the DIP method, X-ray imaging of the left second metacarpal bone is performed at a hospital or clinic, and the X-ray image (recording medium on which film or electronic data is recorded) is passed to the clinical laboratory center. In general, the X-ray image is analyzed at a clinical laboratory center to measure the bone mineral content, and the result is returned to the requesting hospital or clinic.

  Further, in recent years, there is a medical image processing apparatus provided with a bone mineral quantification unit that performs bone mineral quantification based on X-ray image data. By installing such a medical image processing apparatus in a hospital or clinic, It has also become possible to carry out bone mineral quantitative tests at clinics (for example, Patent Document 1).

JP 2010-200844 A

  By the way, in the bone mineral quantitative examination, in X-ray imaging, X-ray imaging conditions such as the X-ray dose determined from the tube voltage, the tube current, the irradiation time, and the imaging distance and the way of placing the hand need to be appropriately set. If the X-ray imaging conditions are not appropriate, bone mineral quantification cannot be measured accurately, and therefore an accurate diagnosis cannot be made. In X-ray imaging, imaging is performed for various parts, but X-ray imaging conditions are changed according to the imaging part. In particular, the X-ray imaging conditions differ greatly between chest imaging and hand imaging. For example, when hand imaging is performed under X-ray imaging conditions for chest imaging, the bone mineral content measurement result is It will be quite different. As described above, when an image is taken under an inappropriate X-ray imaging condition, it is necessary to perform the imaging again after making the X-ray imaging condition appropriate.

  However, in practice, it is often the case that a bone mineral quantitative test is performed and a measurement result is obtained before it is noticed that the image was taken under inappropriate X-ray imaging conditions. For example, when there is a history of measurement results of a patient, it can be seen that an accurate measurement result is not obtained when the history and the current measurement result differ greatly. And in order to elucidate the cause, it is necessary to check the previous captured image, contact the manufacturer, etc., and it takes a considerable time to solve the problem, and the diagnostic efficiency is not good There was a problem.

  An object of the present invention is to provide a medical image processing apparatus and a program that allow a user to quickly recognize when X-ray imaging is performed under inappropriate X-ray imaging conditions in bone mineral content measurement. is there.

In order to solve the above problems, the invention according to claim 1 is a medical image processing apparatus,
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measuring means for measuring bone mineral content based on medical image data acquired by the image acquisition means;
A dose determination unit that determines whether or not the dose of X-rays emitted from a radiation source that emits X-rays based on the medical image data acquired by the image acquisition unit is outside a predetermined range;
A notification means for performing a predetermined notification when the dose determination means determines that the dose is out of a predetermined range before the measurement of the bone mineral quantity measurement by the bone mineral quantity measurement means;
It is provided with.

The invention according to claim 2 is the medical image processing apparatus according to claim 1,
A position detection means for detecting that the position of the subject exceeds a predetermined range based on the medical image data acquired by the image acquisition means;
The notification means performs a predetermined notification when the position detection means detects that the position of the subject exceeds a predetermined range before performing the bone mineral quantitative measurement by the bone mineral quantitative measurement means. It is characterized by that.

The invention according to claim 3 is a medical image processing apparatus,
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measuring means for measuring bone mineral content based on medical image data acquired by the image acquisition means;
Position detection means for detecting that the position of the subject exceeds a predetermined range based on medical image data acquired by the image acquisition means;
A notification means for performing a predetermined notification when the position detection means detects that the position of the subject exceeds a predetermined range before the measurement of the bone mineral quantity measurement by the bone mineral quantity measurement means;
It is provided with.

The program of the invention according to claim 4 is:
Computer
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measurement means for measuring bone mineral content based on medical image data acquired by the image acquisition means,
Dose determination means for determining whether or not the dose of X-rays irradiated from a radiation source that emits X-rays based on the medical image data acquired by the image acquisition means is outside a predetermined range;
Informing means for performing a predetermined notification when the dose determining means determines that the dose is out of a predetermined range before carrying out the measurement of the bone mineral quantity by the bone mineral quantity measuring means,
To function as.

The program of the invention described in claim 5 is:
Computer
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measurement means for measuring bone mineral content based on medical image data acquired by the image acquisition means,
Position detection means for detecting that the position of the subject exceeds a predetermined range based on medical image data acquired by the image acquisition means;
Informing means for performing a predetermined notification when the position detecting means detects that the position of the subject exceeds a predetermined range before performing the measurement of the bone mineral quantity by the bone mineral quantity measuring means;
To function as.

  According to the present invention, in measurement of bone mineral content, when X-ray imaging is performed under an inappropriate X-ray imaging condition, the user can be promptly recognized.

It is a figure which shows the whole structure of the system in a facility in this Embodiment. It is a block diagram which shows the functional structure of a medical image processing apparatus. It is a figure which shows the example of data storage of an image information table. It is a figure which shows the example of data storage of bone mineral quantitative determination DB. It is a figure for demonstrating the method of the X-ray imaging in a bone mineral quantitative examination. It is a flowchart which shows the diagnostic assistance process performed by the control part of a medical image processing apparatus. It is a figure which shows an example of a viewer screen. It is a figure which shows an example of a warning screen. It is a figure which shows an example of a warning screen. It is a flowchart which shows the bone mineral quantitative measurement process performed in step S8 of FIG. It is a figure which shows an example of a bone mineral fixed quantity screen. It is a figure for demonstrating L value. It is a figure for demonstrating the bone width D and the bone marrow width d. It is a figure which shows an example of the bone mineral quantitative screen after a bone mineral quantitative measurement. It is a figure which shows an example of the viewer screen on which the graph which is a bone mineral quantitative measurement result was displayed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples. In addition, in the following description, what has the same function and structure attaches | subjects the same code | symbol, and abbreviate | omits the description.

[Configuration of in-facility system 1]
FIG. 1 is a block diagram showing a system configuration of an in-facility system 1 according to the present embodiment.
The in-facility system 1 is a system applied to a relatively small-scale medical facility such as a medical practitioner or a clinic. As shown in FIG. 1, the modality 2, the medical image processing device 3, the reception device 4, the i A major 5, a general-purpose printer 6, and a client PC (Personal Computer) 7 are provided. Each device constituting the in-facility system 1 is connected to a communication network (hereinafter simply referred to as “network”) 8 such as a LAN (Local Area Network) via a switching hub (not shown), for example. The medical image processing apparatus 3 is preferably a WS (workstation) provided in an examination room where a doctor is resident. The WS that operates as the medical image processing apparatus 3 may be configured to control the activation of the modality 2, processing conditions, and the like.

  In general, the DICOM (Digital Image and Communications in Medicine) standard is used as a communication method in hospitals, and DICOM MWM (DICOM Modality Worklist Management) or DICOM MPPS is used for communication between devices connected to a LAN. (DICOM Modality Performed Procedure Step) is used. Note that the communication method applicable to this embodiment is not limited to this.

[Device configuration of each device of the in-facility system 1]
Hereinafter, each apparatus which comprises the in-facility system 1 is demonstrated.
The modality 2 is an image generation apparatus that performs imaging using a patient's diagnosis target region as a subject and digitally converts the captured image to generate a medical image.

  Examples of the modality 2 include a CR (Computed Radiography) apparatus, an ultrasonic diagnostic apparatus, an endoscope apparatus, a CT (Computed Tomography) imaging apparatus, and a magnetic resonance imaging apparatus (MRI). In the present embodiment, modality 2 is described as a CR device, but a configuration having other modalities may be used.

In the present embodiment, the modality 2 is a CR device that includes an X-ray imaging device, a CR cassette, and a reading device. The modality 2 arranges a subject between the X-ray imaging apparatus and the CR cassette to perform X-ray imaging, and reads a radiographic image recorded on the CR cassette with a reading apparatus to acquire digital image data.
Here, the CR cassette has a built-in radiation image conversion plate including a stimulable phosphor sheet that accumulates radiation energy, for example, and when irradiated with radiation, an amount of radiation according to the radiation transmittance distribution of the subject is emitted. The stimulable phosphor sheet is accumulated in the stimulable phosphor layer, and a radiographic image of the subject is recorded on the stimulable phosphor layer.
The reading device irradiates the stimulable phosphor sheet in the CR cassette with excitation light, photoelectrically converts the stimulated light emitted from the sheet, and A / D converts the obtained image signal to obtain image data. Is generated.
The modality 2 is not limited to a CR device, and may be an FPD (Flat Panel Detector) device.

  In the present embodiment, the modality 2 has a function of giving image attribute information such as a UID, an imaging date / time, an examination ID, and an imaging site to each medical image in a format conforming to the DICOM standard. The UID is a unique ID for specifying a medical image in the in-facility system 1.

The modality 2 includes an input unit (not shown) such as a keyboard having character input keys, numeric input keys, and the like, and inputs patient information for specifying a patient to be imaged from the input unit.
The patient information input here is, for example, patient ID, patient name (kanji), patient name (Kana), patient name (ASCII), gender, date of birth, and the like. Note that it is not necessary to input all of them in the modality 2, and it is possible to not input any patient information. When the modality 2 has a specification for inputting only a patient ID as patient information, the input unit of the modality 2 may be a numeric keypad, for example.

  The image attribute information and the patient information are incidental information attached to the medical image generated by the modality 2. Modality 2 generates a medical image in a DICOM file format that conforms to the DICOM standard. The DICOM file is composed of an image part and a header part. In the image portion, image data of a medical image is written, and in the header portion, incidental information related to the medical image is written.

The medical image processing apparatus 3 is installed, for example, in an examination room. The medical image processing apparatus 3 stores the medical image generated by the modality 2 in the database in association with the patient information, or performs image processing on the medical image and displays it on the display unit for diagnosis by the doctor. And may be provided with a monitor with higher definition than a monitor used in a general PC (Personal Computer).
Further, the medical image processing apparatus 3 has a bone mineral density inspection function. The bone mineral density examination is an examination for measuring bone mineral density from a medical image in which a left hand and an aluminum slope (described later in detail) are taken.

  As shown in FIG. 2, the medical image processing apparatus 3 includes a control unit 31, a RAM 32, a storage unit 33, an operation unit 34, a display unit 35, a communication unit 36, a media drive 37, a timing unit 38, and the like. Each part is connected by a bus 39.

  The control unit 31 is configured by a CPU (Central Processing Unit) or the like, reads various programs such as system programs and processing programs stored in the storage unit 33, expands them in the RAM 32, and performs diagnosis support described later according to the expanded programs. By executing various processes such as processing and bone mineral quantitative measurement processing, it functions as an interpretation image creating means, a bone mineral quantitative optimized image creating means, and a bone mineral quantitative measuring means.

The RAM 32 temporarily stores a work area for temporarily storing various programs, input or output data, parameters, and the like that can be executed by the control unit 31 read from the storage unit 33 in various processes controlled by the control unit 31. Form.
The RAM 32 stores the patient information list received from the receiving device 4.

  The storage unit 33 is configured by an HDD (Hard Disk Drive), a semiconductor nonvolatile memory, or the like. The storage unit 33 stores various programs as described above, and image processing parameters for adjusting a medical image to an image quality suitable for interpretation diagnosis (lookup defining a gradation curve used for gradation processing). Table (LUT) etc. are stored. In addition, fixed values of various parameters used in bone mineral quantitative measurement (for example, LUT, G value, S value, etc. used to create bone mineral quantitative optimized images), young adult average value (YAM), by age group by gender Average values and the like are stored.

In addition, the storage unit 33 includes an image DB (Data Base) 331 and a bone mineral content determination DB 332.
The image DB 331 is a database for storing a medical image and a bone mineral quantitative graph image. The image DB 331 has an image information table 331a for storing various information related to images stored in the image DB 331.
As shown in FIG. 3, the image information table 331 a includes “UID”, “imaging date / time”, “examination ID”, “imaging region”, “patient ID”, “patient name”, “age”, “sex”, It has items such as “image storage destination”, and stores examination information, patient information, image storage destination path, and the like related to each image stored in the image DB 331. As an image storage destination, a medical image (referred to as an original image) transmitted from the modality 2, a processed image created from the original image, a thumbnail image created from the original image, and a graph image created by a bone mineral quantitative examination , And a graph thumbnail image created from the graph image, each image storage destination path is stored. Based on the information stored in the image information table 331a, medical images and graph images are associated with patient information, examination information, and the like, and are stored so as to be searchable using patient information, imaging date and time as keys.

  The bone mineral content determination DB 332 is a database for storing the results of bone mineral content inspection, parameters used for bone mineral content inspection, and the like. As shown in FIG. 4, the bone mineral content determination DB 332 includes “examination ID”, “measurement date / time”, “patient ID”, “patient name”, “age”, “gender”, “result value”, “parameter”, etc. This information is stored for each bone mineral quantitative examination. The result value is, for example, an L value, a DIP value, an MCI, or the like. The parameters are, for example, the coordinates of two points designated at the time of inspection ((X1, Y1), (X2, Y2)), the coordinates of the measurement target area (upper left (X3, Y3), lower right (X4, Y4)), The coordinates of the aluminum slope (upper left (X5, Y5), lower right (X6, Y6)). Details of the result values and parameters will be described later.

  The operation unit 34 includes a keyboard having cursor keys, numeric input keys, various function keys, and the like, and a pointing device such as a mouse, and a key pressing signal pressed by the keyboard and an operation signal by the mouse. Is output to the control unit 31 as an input signal.

  The display unit 35 is configured to include a monitor such as a CRT (Cathode Ray Tube) or an LCD (Liquid Crystal Display), for example, and displays various screens according to instructions of display signals input from the control unit 31.

  The communication unit 36 is configured by a network interface or the like, and transmits / receives data to / from an external device connected to the network 8 via a switching hub.

  The media drive 37 is a device that reads or writes data from / to a portable recording medium M such as a CD-R (Compact Disk Recordable), DVD-R (Digital Versatile Disk Recordable), or MO (Magnet Optical) disk. .

  The reception device 4 is a computer device for performing registration, accounting calculation, insurance score calculation, etc. of patients who come to the hospital, and is composed of a storage unit composed of a CPU, ROM, RAM, etc., an input composed of a keyboard, a mouse, etc. , A display unit configured by a CRT, an LCD, and the like, a communication unit (none of which is shown) that controls communication with each device connected to the network 8, and the like. When receiving a reception input screen is instructed from the input unit, the reception device 4 displays a reception input screen (not shown) on the display unit by software processing in cooperation with the CPU and a program stored in the storage unit. When reception information (reception number + patient name, etc.) is input by the input unit via this reception input screen, a patient information list of the received patients is created (updated), stored in the storage unit, and transmitted by the communication unit. It transmits to the medical image processing apparatus 3 as appropriate.

  The imager 5 records a latent image by laser exposure on a transmissive recording medium (film) based on the medical image transmitted from the medical image processing apparatus 3, and visualizes the latent image by thermal phenomenon processing. It is a salt printer.

  The general-purpose printer 6 is a printer that records an image on a reflective recording medium (paper medium, sticker, etc.) by an ink jet method or a laser method.

  The client PC 7 is a computer device that displays a medical image or a graph image transmitted from the medical image processing device 3, for example.

[Flow of bone mineral quantity inspection]
Next, the flow (1) to (5) of the bone mineral density inspection in the medical facility where the in-facility system 1 is installed will be described.
(1) First, a patient is accepted at the reception. The received patient information of the patient is input by the receiving device 4, and a patient information list including this patient information is transmitted to the medical image processing device 3. In the medical image processing apparatus 3, the patient information list transmitted from the reception apparatus 4 is stored in the RAM 32.
(2) Next, in the examination room, examinations and necessary examination decisions are made. The examination is performed by an inquiry, a patient's past medical record, browsing of images and reports, and the like.
(3) When it is determined that the bone mineral content quantitative examination is necessary, X-ray imaging of the patient's left hand is performed by the modality 2 in the imaging room.
In the present embodiment, it will be described as performing a bone mineral density examination by the DIP method. In the DIP method, as shown in FIG. 5, the aluminum slope AL and the left hand second metacarpal bone B are arranged side by side and X-ray photographed at the same magnification, and the aluminum slope AL and the second metacarpal bone B in the obtained medical image This is a comparative analysis of shadow density. The aluminum slope AL is a slope member made of aluminum having an inclination of 1 cm in thickness and 1 mm in the longitudinal direction. At the time of radiography, the aluminum slope AL is arranged right next to the patient's left hand so that the thick side is in front, and X-ray imaging is performed by the modality 2.
As will be described later, the medical image processing apparatus 3 can create an image for interpretation that is suitable for interpretation, regardless of individual differences in the body type of the patient that is the subject. Therefore, in the modality 2, no particular adjustment is performed at the time of photographing, and photographing conditions suitable for the bone mineral density examination are set in advance, and photographing is performed under these photographing conditions. As the imaging conditions, the tube voltage, the tube current, the irradiation time, and the imaging distance are appropriately set so that the tube voltage and the X-ray dose are preferably measured values. In the present embodiment, for example, the tube voltage is set to 50 kV and the X-ray dose is set to 4 mR. However, the preferable tube voltage and X-ray dose differ depending on the performance characteristics of the modality 2 and the like.
(4) After the X-ray imaging of the left hand, the medical image obtained by the imaging is captured by the medical image processing apparatus 3 and bone mineral quantification is measured, and the measurement results (inspection results) such as result values and graphs are obtained. Is output.
(5) Diagnosis and treatment are performed based on the measurement result.

[Operation of Medical Image Processing Device 3]
Next, the operation of the medical image processing apparatus 3 will be described.
FIG. 6 shows a flowchart of a diagnosis support process executed by the control unit 31 of the medical image processing apparatus 3. The diagnosis support process is executed in cooperation with the control unit 31 and the program stored in the storage unit 33.

  First, the control unit 31 causes the display unit 35 to display a viewer screen 351 for the diagnosis target patient (step S1). The viewer screen 351 is a screen for taking a medical image from the modality 2 and displaying it for interpretation. The viewer screen 351 can instruct execution of bone mineral content measurement and display the measurement result. . The viewer screen 351 is displayed on the patient list screen of the patient to be diagnosed by the operation unit 34 from the patient list screen (screen on which the patient information list transmitted from the receiving device 4 is displayed) displayed on the display unit 35 by a predetermined operation of the operation unit 34. Displayed by selecting patient information.

  FIG. 7 shows an example of the viewer screen 351. As shown in FIG. 7, the viewer screen 351 has an image display field 351a for displaying an image, an image capture button 351b, a measurement button 351c, various tool buttons 351d, a print button 351e, a patient display field 351f, and a thumbnail display. A column 351g, a display image selection column 351h, and the like are provided.

The image display column 351a is a column for displaying a medical image captured from the modality 2, a graph image of a test result, a past image of the same patient, and the like. FIG. 7 shows an example in which an image is displayed in the image display field 351a, but no image is displayed yet in step S1 (the image for interpretation in FIG. 7 is displayed in step S4).
The image capture button 351b is a button for instructing to capture a medical image transmitted from the modality 2 as an image of a patient currently being diagnosed (a patient displayed in the patient display field 351f). When the image capture button 351b is pressed, the modality 2 is displayed until the image capture button 351b is pressed next to cancel capture or the viewer screen 351 is closed or transitions to another screen. The medical image received from is captured as an image of the patient currently being diagnosed.
The measurement button 351c is a button for instructing display of a measurement menu. The measurement menu includes bone mineral quantitative measurement.

  The various tool buttons 351d are buttons for performing image processing such as density contrast adjustment processing and image quality adjustment processing on the displayed medical image, for example. When a button of a desired item of the tool button 351d is pressed, an input field, a button, a toolbar, or the like corresponding to the item is displayed. When an input to the displayed input field or an operation of a button or a toolbar is performed by the operation unit 34, processing corresponding to the operation is performed on the displayed image. For example, when the density contrast button is pressed, a slide bar for density adjustment, a slide bar for contrast adjustment, and the like are displayed. When the slide bar is operated by the operation unit 34, the control unit 31 sets the density and contrast according to the operation. The image displayed in the image display field 351a is adjusted.

The print button 351e is a button for instructing to print the selected image from the general-purpose printer 6.
The patient display column 351f is a column for displaying patient information of a patient currently selected as a diagnosis target.
The thumbnail display column 351g is a column for displaying thumbnail images of medical images (including images taken in the past) of the same patient in order to select a medical image to be displayed in the image display column 351a.
The display image selection field 351h is a field for selecting the classification (CR, bone mineral content determination (graph)) of the images displayed in the thumbnail display field 351g.

When the image capture button 351b is pressed by the operation unit 34 and imaging is performed in the modality 2, the control unit 31 captures a medical image obtained by imaging (step S2).
In step S2, when a medical image is received from the modality 2 by the communication unit 36, the received medical image is associated with the patient information of the patient selected on the patient list screen, and stored in the image DB 331 as an original image. Is done. In the image information table 331a, the UID written in the header part of the received image, the photographing date and time, the examination site, the original image storage destination path, and the like are written. A thumbnail image is created from the original image and stored in the image DB 331. Further, the storage destination path of the created thumbnail image is written in the image information table 331a.
Thus, in the present embodiment, the control unit 31 functions as an image acquisition unit that acquires medical image data obtained by X-ray imaging of a subject.

Next, the control unit 31 executes an image interpretation image creation process to create an image for image interpretation from the original image (step S3).
Here, in the modality 2, shooting is performed under fixed shooting conditions without performing individual adjustments at the time of shooting each time. Therefore, the original image varies depending on the patient's body shape (the thickness of the hand in the case of bone mineral quantitative examination) and the like. However, if there are variations in the images to be interpreted, stable interpretation diagnosis cannot be performed. Therefore, in order to stably output an image suitable for interpretation, the medical image processing apparatus 3 performs image processing on the original image to create an interpretation image that satisfies a predetermined standard for interpretation. The Examples of the contents of the image processing include gradation conversion processing, frequency enhancement processing, dynamic range compression processing, and the like. The created image for interpretation is stored in the image DB 331 and the storage destination path is written in the image information table 331a.

Hereinafter, the contents of the image interpretation image creation process will be described.
<Irradiation field recognition processing>
As a premise for gradation conversion processing, frequency enhancement processing, etc., irradiation field recognition processing is first executed on the input original image. The irradiation field refers to an area where X-rays have reached through the subject. In the irradiation field recognition processing, the irradiation field area is distinguished from an irradiation field outside area (an area other than the irradiation field). This is because appropriate processing cannot be performed if gradation conversion processing or the like is performed including an irradiation field region with a biased signal value (pixel digital density signal value).

  Any method of irradiation field recognition may be adopted. For example, as disclosed in Japanese Patent Application Laid-Open No. 5-7579, an original image is divided into a plurality of small areas, a variance value is obtained for each divided area, and an irradiation field area is determined based on the obtained variance value. Also good. Usually, since the reaching X-ray dose is substantially uniform in the irradiation field region, the dispersion value of the small region becomes small. On the other hand, in a small region including the edge of the irradiation field region, a portion having a large arrival X-ray dose (outside the irradiation field region) and a portion (irradiation field region) in which the arrival X-ray dose is somewhat reduced by the subject are mixed, and thus the variance value is growing. Therefore, assuming that an edge is included in a small region having a variance value greater than a certain value, the region surrounded by such a small region is determined as an irradiation field region.

<Area of interest setting and reference signal value setting>
When the irradiation field region is determined, a region of interest (hereinafter referred to as ROI: Region Of Interest) is set from this irradiation field region. At this time, the reference signal value is set together with the ROI setting.
For example, the ROI can be specified based on the signal value profile by sequentially scanning the horizontal direction and the vertical direction of the original image to create a signal value profile in each direction. Further, the ROI may be specified by pattern matching, and any method may be applied.

  Then, a histogram of the signal values of the specified ROI region is created, and the signal values having a predetermined frequency from the maximum value side and the minimum value side in the histogram are determined as the maximum reference value H and the minimum reference value L, respectively. To do. The maximum reference value H and the minimum reference value L are used as reference values when the signal value range of the original image is converted into the signal value range (maximum value SH, minimum value SL) in the image for interpretation.

<Tone conversion processing>
When the preprocessing is completed as described above, gradation conversion processing is performed.
The gradation conversion process is a process for adjusting the density and contrast of the original image. When a doctor diagnoses the presence or absence of a human body structure disease by interpretation of an X-ray image, the presence or absence of the disease is determined based on the density and contrast (gradation) of the structure on the X-ray image. Therefore, by adjusting the density and contrast suitable for interpretation, a doctor's disease detection operation can be supported.

  The gradation conversion processing is performed in two stages: (1) normalization processing and (2) conversion processing using a basic LUT (lookup table), and finally a signal value range predetermined as an image for interpretation. Gradation conversion is performed so as to obtain gradation characteristics.

  Conventionally, since a screen / film method has been adopted for photographing, input signal (reading signal) conversion processing is performed with a target of gradation characteristics (contrast) cultivated by the screen / film method. The gradation characteristic obtained by the screen / film system is an S-shaped curve. In the gradation conversion processing, an LUT indicating this gradation characteristic is prepared as a basic LUT for each part, and after performing individual signal adjustment on the original image by normalization processing, the signal value is calculated using this basic LUT. Perform conversion.

<Frequency enhancement processing>
As the frequency enhancement processing, for example, unsharp mask processing disclosed in Japanese Patent Publication No. 62-62373 or multi-resolution analysis disclosed in Japanese Patent Application Laid-Open No. 9-44645 can be applied. By this frequency enhancement processing, an image in which the edge of a structure such as a bone is enhanced can be obtained.

<Dynamic range compression processing>
As the dynamic range compression processing, for example, a technique disclosed in Japanese Patent No. 250950 can be applied.

  As described above, an image for interpretation is created by performing gradation conversion processing, frequency enhancement processing, and dynamic range compression processing on the original image.

  Next, as shown in FIG. 7, the control unit 31 displays the created image for interpretation in the image display field 351a of the viewer screen 351 (step S4). The doctor can confirm whether the imaging has been successful (whether re-imaging is necessary) by observing the image for interpretation. Further, in the case of an examination that does not require measurement, it is possible to make a diagnosis by interpreting an image for interpretation. At this time, the tool button 351d can be operated to adjust to a desired image quality. Although details will be described later, an operator such as a doctor needs to designate two points on the second metacarpal bone of the left hand in measuring bone mineral content. In order to easily specify these two points, the density contrast button and the image quality adjustment button of the tool button 351d are operated in advance to adjust the image so that the operator can easily specify the two points and the edge is emphasized. It can also be left.

The control unit 31 determines whether or not to perform bone mineral content measurement (step S5). That is, the control unit 31 determines whether or not the measurement button 351c is pressed and the bone mineral quantitative measurement menu is selected.
When it is not determined that the bone mineral content measurement is to be performed, that is, when the operation unit 34 determines that an operation other than the pressing of the measurement button 351c and the selection of the bone mineral content measurement menu is performed by the operation unit 34 (step S5; NO), processing according to the operation is executed (step S6). The control unit 31 determines whether or not the end button 351i has been pressed by the operation unit 34 (step S7). When determining that the end button 351i has been pressed by the operation unit 34 (step S7; YES), the control unit 31 ends the diagnosis support process. On the other hand, when the control unit 31 does not determine that the end button 351i is pressed by the operation unit 34 (step S7; NO), the control unit 31 executes the process of step S5.

  In addition, when the control unit 31 determines in step S5 that the measurement button 351c is pressed by the operation unit 34 and the bone mineral quantitative measurement menu is selected (step S5; YES), the control unit 31 executes the bone mineral quantitative measurement process. It is determined as follows whether or not the X-ray imaging conditions are set appropriately.

  That is, the control unit 31 first cuts out the original image into, for example, a region corresponding to the size cut into four from the center of the image, and the entire signal value of the imaging region that is a region irradiated with X-rays from the cut out image. Is extracted (step S8). The control unit 31 determines the signal value having the highest density among the entire extracted signal values (step S9). The original image from which the signal value is extracted is, for example, in the Tiff format, but may be a RAW image or an image converted into the DICOM format. Then, the control unit 31 determines whether or not the determined signal value is outside the specified range (step S10). In addition, as the data for determination used for determining whether or not the signal value is outside the specified range, for example, a setting file such as an INI format can be applied. Good. When it is determined that the determined signal value is outside the specified range (step S10; YES), the control unit 31 displays a warning screen D1 as illustrated in FIG. 8A on the viewer screen 351 (step S11). And the control part 31 determines whether the measurement of a bone mineral quantity measurement is complete | finished (step S12). That is, the control unit 31 determines whether or not the stop button (“Stop” button) B1 on the warning screen D1 is operated. When it is determined that the bone mineral content measurement is to be ended (step S12; YES), the control unit 31 ends the diagnosis support process. On the other hand, when the control unit 31 does not determine that the bone mineral content measurement is to be terminated, that is, when it is determined that the button (“Yes” button) B2 to continue the measurement is operated (step S12; NO), the control unit 31 Execute the process. Moreover, the control part 31 performs the process of step S13, without performing the process of step S11-S12, when it determines with the determined signal value not being outside a regulation range in step S10 (step S10; NO). .

As described above, in the processing of steps S8 to S12, the X-ray dose irradiated from the X-ray source of the modality 2 is within an appropriate range for measuring the bone mineral quantity by determining the signal value in the imaging region. Can be determined.
In this way, the control unit 31 determines whether or not the dose of X-rays emitted from the radiation source that emits X-rays is outside the predetermined range based on the medical image data acquired by the image acquisition unit. It functions as a determination means.
If the X-ray dose is not within an appropriate range, for example, by displaying a warning to that effect, before the measurement of bone mineral content is carried out, for example, re-imaging is performed under appropriate imaging conditions. Can prompt the user to. That is, the display unit 35 functions as a notification unit that performs a predetermined notification when the dose determination unit determines that the dose is outside the predetermined range when performing bone mineral quantification measurement.
The signal value to be determined is not limited to that described above, and can be set as appropriate. For example, a signal value in any region of the irradiation field region may be determined. Alternatively, an average value of signal values at the four corners of the imaging region may be obtained and used as a determination target. In addition, a signal value in the irradiation field region may be determined.
Further, instead of the warning display, notification by sound output or lighting or blinking of a light emitting body such as an LED may be performed.

  Next, the control unit 31 extracts the signal values at the four corners from the imaging region and determines them (step S13), and determines whether or not these signal values are all within the specified range (step S14). . When the controller 31 determines that none of the determined signal values at the four corners are within the specified range (step S14; NO), the control unit 31 determines that the irradiation field is not appropriate and displays a warning screen D2 as shown in FIG. The image is displayed so as to overlap the screen 351 (step S15). And the control part 31 determines whether the measurement of a bone mineral quantity measurement is complete | finished (step S16). That is, the control unit 31 determines whether or not the stop button (“Stop” button) B3 on the warning screen D2 is operated. When it is determined that the bone mineral content measurement is to be ended (step S16; YES), the control unit 31 ends the diagnosis support process. On the other hand, when the control unit 31 does not determine that the bone mineral content measurement is to be terminated, that is, when it is determined that the button B4 for continuing the measurement (“Yes” button) B4 has been operated (step S16; NO), the bone mineral content determination. A measurement process is executed (step S17). When the control unit 31 determines in step S14 that all of the determined signal values at the four corners are within the specified range (step S14; YES), the control unit 31 performs step S17 without performing the processing of steps S15 to S16. Execute the process.

As described above, in the processes of steps S13 to S16, by detecting the signal values at the four corners of the imaging region, it is detected that the aperture of the irradiation field is not appropriate or the imaging position of the hand is incorrect. Can do. That is, it can be detected that the position of the hand as the subject is not within the predetermined range.
As described above, the control unit 31 functions as a position detection unit that detects that the position of the subject exceeds the predetermined range based on the medical image data acquired by the image acquisition unit.
If the position of the subject is not within the appropriate range, a warning display to that effect is displayed, for example, before the measurement of bone mineral content is carried out, for example, the amount of restriction of the irradiation field, the position of the hand, etc. It is possible to prompt the user to set the shooting conditions appropriately and reshoot.

  Here, the bone mineral quantitative measurement process will be described with reference to FIG. The bone mineral density measurement process is executed in cooperation with the control unit 31 and a program stored in the storage unit 33.

In the bone mineral density measurement process, first, a bone mineral quantity optimized image creation process is executed, a bone mineral quantity optimized image is created from the created image for interpretation, and is temporarily stored in the RAM 32 (step S101). Specifically, for example, the gradation conversion curve (LUT) is BONE-02, the density correction value (S value) is 250, and the contrast value (G value) is 2.50. Apply tonal processing. In addition, when the image for interpretation is subjected to frequency enhancement processing and dynamic range compression processing, the parameters used when the frequency enhancement processing (dynamic range compression processing) are performed are used. The inverse conversion of the conversion performed by the compression processing) is performed. Note that an image for interpretation that has not been adjusted on the viewer screen 351 is used for the bone mineral quantitative optimization image creation processing.
In this embodiment, the bone mineral density optimized image is created from the image for interpretation, but the bone mineral quantity optimized image may be created from the original image.

Next, the bone mineral content screen 352 is displayed on the display unit 35 (step S102).
FIG. 10 shows an example of the bone mineral content screen 352. On the bone mineral content determination screen 352, patient information 352a, imaging region 352b, measurement date and time 352c, measurement value field 352d, comment field 352e, confirmation button 352f, and the like of the patient to be diagnosed are displayed. In step S102, the final result value (that is, the previous result value) of the patient to be diagnosed stored in the bone mineral quantification DB 332 is read into the measurement value column 352d and initially displayed.
In addition, the bone mineral amount determination screen 352 is provided with a two-point designation field 352g. In bone mineral quantitative measurement, it is necessary to designate two points, the most protruding part at the upper end of the second metacarpal bone of the left hand and the most depressed part at the lower end, and this two-point designation field 352g has two points. Displays an image for specifying.

  Here, it is preferable to display an image for interpretation (or an adjusted image for interpretation) as the image displayed in the two-point designation field 352g. The bone mineral quantification optimized image is generally darker than the image for interpretation (see FIG. 13), and processing for enhancing the edge of the bone portion such as frequency enhancement processing applied to the image for interpretation is performed. It has not been. Therefore, depending on the shape and arrangement of the bone of the patient's left hand, it may be very difficult to specify two points.

  When two points of the left second metacarpal bone are designated from the two-point designation field 352g by the operation unit 34 (for example, clicked with the mouse of the operation unit 34), the coordinates of the designated two points (X1, Y1) , (X2, Y2) are temporarily stored in the RAM 32 (step S103), and the bone mineral is determined using the coordinates (X1, Y1), (X2, Y2) of these two points and the bone mineral quantitative optimization image. Quantitative measurement is performed (step S104).

The measurement of the bone mineral amount in step S104 is performed by the DIP method. As described above, the DIP method is a known method for measuring the bone mineral density by comparing the shadow density of the aluminum slope in the image and the left second metacarpal bone. Hereinafter, measurement of bone mineral content measurement using the DIP method will be described with reference to FIGS. 11A to 11B.
First, as shown in FIG. 11A, a distance between coordinates of two designated points (X1, Y1) and (X2, Y2) is calculated as an L value (bone length). Next, a range of 10% of the bone length in the center between the two points in the bone mineral quantitative optimization image with the vertical width and the horizontal width as fixed values is determined as the measurement region, and in the image by pattern matching etc. The position of the aluminum slope is detected. Then, based on the density of the aluminum slope image, the bone density GS is calculated based on which thickness part of the aluminum slope the bone density in the measurement region matches, and the integrated value of the calculated bone density A value obtained by dividing ΣGS by the bone width D (ΣGS / D (mmAl)) is calculated as the DIP value (bone mineral content). Further, an average bone cortex width MCI (MCI = (D−d) / D) is calculated. D is the bone width and d is the bone marrow width. FIG. 11B is a diagram showing a tomographic plane and a concentration profile of the central portion of the left second metacarpal bone B. The bone width D and the bone marrow width d can be calculated based on, for example, the concentration profile of the center portion of the left second metacarpal bone B as shown in FIG. 11B.
Calculated L value, DIP value, MCI, measurement area coordinates (upper left (X3, Y3), lower right (X4, Y4)), detected aluminum slope position coordinates upper left (upper left (X5, Y5), lower right (X6, Y6)) is temporarily stored in the RAM 32.

  When the measurement of the bone mineral content is finished, the result value is displayed on the bone mineral content screen 352 (step S105). FIG. 12 shows a bone mineral content screen 352 after bone mineral content measurement. As shown in FIG. 12, in step S105, the L value, ΣGS / D, and MCI, which are the results obtained by the measurement in step S104, are displayed in the measurement value column 352d of the bone mineral quantitative screen 352. In addition, on the image displayed in the two-point designation field 352g, the coordinates P1, P2 of the designated two points, the measurement region R1, and the detected position R2 of the aluminum slope are displayed as annotations.

Next, it is determined whether or not the operation unit 34 has instructed to move the coordinates P1 and P2 of the two points on the bone mineral amount determination screen 352 (step S106). P1 and P2 can be moved by dragging and dropping the annotation using the operation unit 34. If it is determined that the movement of the two coordinate points P1 and P2 is instructed by the operation unit 34 (step S106; YES), the process returns to step S104, and the newly designated two points (after the movement) are used. Measurement is executed again.
When the operation unit 34 does not instruct the movement of the two coordinates P1 and P2 (step S106; NO) and the confirm button 352f is pressed (step S107; YES), the measurement result is confirmed and the bone mineral quantity quantification is optimal. The converted image, the result value, and the parameters used for measurement are stored (step S108), and the process proceeds to step S18 in FIG. Specifically, in step S108, a new record is added to the bone mineral quantification DB 332, and the result value and parameters used for measurement (calculated L value, DIP value, MCI, two-point designation coordinates ((X1, Y1), (X2, Y2)), measurement area coordinates (upper left (X3, Y3), lower right (X4, Y4)), detected aluminum slope position coordinates upper left (upper left (X5, Y5), lower right ( X6, Y6)) is written, the bone mineral quantitative optimization image is stored in the image DB 331, and the storage destination path of the processed image of the record of the examination in the image information table 331a is the bone mineral quantitative optimization image. Changed to a path.

The control unit 31 creates a graph image and its thumbnail image based on the result value obtained by the measurement in step S18 of FIG. 6 (step S18).
In step S18, for example, a graph area is drawn with the date on the horizontal axis and ΣGS / D (mmAl) on the vertical axis. Next, a past record having the same patient ID is searched from the bone mineral density DB 332, and ΣGS / D of the searched record is plotted in the graph area in order of date. In addition to the graph, a result list is created that lists changes over time in the values of ΣGS / D and MCI of the retrieved records. Furthermore, based on the result values stored in the bone mineral quantitation DB 332, what percentage of the average value of the same age (the same age ratio), what percentage of the young adult average value (YAM) (YAM ratio), Is calculated, and one graph image including the patient information, the numerical value of the current result value, the age ratio, the YAM ratio, the graph, and the result list is created. The file format of the image may be any of PNG, JPEG, PDF, and the like. The created graph image is stored in the image DB 331, and the storage path of the graph image is stored in the record of the examination in the image information table 331a. Also, a thumbnail image of the graph image is created and stored in the image DB 331, and the storage path of the graph thumbnail image is stored in the record of the examination in the image information table 331a.

When the creation of the graph is completed, the control unit 31 displays the viewer screen 351 on which the created graph image is displayed on the display unit 35 (step S19).
FIG. 13 shows an example of the viewer screen 351 on which a graph is displayed. In the image display field 351a, the graph image created in step S18 and the bone mineral quantitative optimization image serving as the measurement source are displayed side by side.
The doctor can grasp the change in the bone mineral content of the patient by checking the graph screen, and can make the necessity and policy of treatment.

The control unit 31 determines whether or not the print button 351e has been pressed by the operation unit 34 (step S20). When it is determined that the print button 351e has been pressed by the operation unit 34 (step S20; YES), the control unit 31 sends the graph image data to the general-purpose printer 6 by the communication unit 36, thereby instructing the printing of the graph image. (Step S21). Then, the graph image is printed out from the general-purpose printer 6. On the other hand, when the control unit 31 does not determine that the print button 351e is pressed by the operation unit 34 (step S20; NO), the control unit 31 executes the process of step S22 without executing the process of step S21.
The control unit 31 determines whether or not the end button 351i has been pressed by the operation unit 34 (step S22). When the control unit 31 determines that the end button 351i has been pressed by the operation unit 34 (step S13; YES), the diagnosis support process ends. On the other hand, when the control unit 31 does not determine that the end button 351i is pressed by the operation unit 34 (step S22; NO), the control unit 31 executes the process of step S20.

  As described above, according to the present embodiment, the control unit 31 acquires medical image data obtained by X-ray imaging of a subject. The control unit 31 measures the bone mineral content based on the acquired medical image data. The control unit 31 determines whether or not the dose of X-rays emitted from the radiation source that emits X-rays is outside a predetermined range based on the acquired medical image data. The display unit 35 performs predetermined notification when the control unit 31 determines that the dose is out of the predetermined range before the control unit 31 performs the measurement of the bone mineral amount. As a result, in the measurement of bone mineral content, when X-ray imaging is performed under inappropriate X-ray imaging conditions, the user can be promptly recognized. Therefore, it is possible to promptly prompt X-ray imaging under appropriate X-ray imaging conditions. In addition, since the cause can be clarified when the bone mineral content measurement is not correctly performed, the action to be taken next by the user can be clarified. In addition, it is possible to infer imaging conditions in modalities such as CR devices.

  Further, according to the present embodiment, the control unit 31 detects that the position of the subject exceeds the predetermined range based on the acquired medical image data. The display unit 35 performs predetermined notification when the control unit 31 detects that the position of the subject exceeds a predetermined range before the control unit 31 performs measurement of the bone mineral amount. As a result, when the X-ray imaging conditions such as the aperture amount of the irradiation field and the hand position are not appropriate and the X-ray imaging is performed, the user can be promptly recognized.

  In addition, the description in this Embodiment mentioned above is an example of the suitable system in a facility which concerns on this invention, and is not limited to this.

  In the present embodiment, it is configured to instruct whether or not to perform bone mineral content measurement after capturing a taken medical image. However, bone mineral content measurement is performed before capturing a medical image. You may comprise so that an instruction | indication can be performed. With this configuration, when a medical image is captured, it can be determined whether or not the X-ray imaging conditions are set appropriately, so that the X-ray imaging conditions are set appropriately and the image is captured. If not, a warning can be promptly displayed.

  For example, in the above-described embodiment, the measurement result of the bone mineral amount is displayed and output on the display unit 35 and output from the general-purpose printer 6 as necessary. However, the measurement result is output to the recording medium M by the media drive 37. Or may be transmitted to the client PC 7 or the like connected to the network 8 via the communication unit 36.

  For example, in the above description, an example in which a hard disk, a semiconductor nonvolatile memory, or the like is used as a computer-readable medium of the program according to the present invention is disclosed, but the present invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. Further, a carrier wave is also applied as a medium for providing program data according to the present invention via a communication line.

  In addition, the detailed configuration and detailed operation of the medical image processing apparatus can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 In-facility system 2 Modality 3 Medical image processing apparatus 31 Control part 35 Display part

Claims (5)

Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measuring means for measuring bone mineral content based on medical image data acquired by the image acquisition means;
A dose determination unit that determines whether or not the dose of X-rays emitted from a radiation source that emits X-rays based on the medical image data acquired by the image acquisition unit is outside a predetermined range;
A notification means for performing a predetermined notification when the dose determination means determines that the dose is out of a predetermined range before the measurement of the bone mineral quantity measurement by the bone mineral quantity measurement means;
A medical image processing apparatus comprising: A position detection means for detecting that the position of the subject exceeds a predetermined range based on the medical image data acquired by the image acquisition means;
The notification means performs a predetermined notification when the position detection means detects that the position of the subject exceeds a predetermined range before performing the bone mineral quantitative measurement by the bone mineral quantitative measurement means. The medical image processing apparatus according to claim 1. Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measuring means for measuring bone mineral content based on medical image data acquired by the image acquisition means;
Position detection means for detecting that the position of the subject exceeds a predetermined range based on medical image data acquired by the image acquisition means;
A notification means for performing a predetermined notification when the position detection means detects that the position of the subject exceeds a predetermined range before the measurement of the bone mineral quantity measurement by the bone mineral quantity measurement means;
A medical image processing apparatus comprising: Computer
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measurement means for measuring bone mineral content based on medical image data acquired by the image acquisition means,
Dose determination means for determining whether or not the dose of X-rays irradiated from a radiation source that emits X-rays based on the medical image data acquired by the image acquisition means is outside a predetermined range;
Informing means for performing a predetermined notification when the dose determining means determines that the dose is out of a predetermined range before carrying out the measurement of the bone mineral quantity by the bone mineral quantity measuring means,
Program to function as. Computer
Image acquisition means for acquiring medical image data obtained by X-ray imaging of a subject;
Bone mineral content quantitative measurement means for measuring bone mineral content based on medical image data acquired by the image acquisition means,
Position detection means for detecting that the position of the subject exceeds a predetermined range based on medical image data acquired by the image acquisition means;
Informing means for performing a predetermined notification when the position detecting means detects that the position of the subject exceeds a predetermined range before performing the measurement of the bone mineral quantity by the bone mineral quantity measuring means;
Program to function as.