JP5534648B2 - X-ray diagnostic apparatus, image data processing apparatus, and image data processing method - Google Patents

Description

  The present invention relates to an X-ray diagnostic apparatus, an image data processing apparatus, and an image data processing method that are capable of diagnosing esophageal reflux symptoms and the like by examining the upper gastrointestinal tract and the like to observe peristaltic movement of the esophagus.

  Conventionally, X-ray diagnostic apparatuses, MRI apparatuses, X-ray CT apparatuses, and the like have been widely used as medical image diagnostic apparatuses, and various types of medical image data can be generated by using computer technology.

  By the way, when diagnosing gastrointestinal tract diseases such as esophagus, such as esophageal reflux symptoms, the patient is administered a contrast medium such as barium, and X-rays are irradiated and photographed in the supine state. I try to observe. However, in X-ray photography, it is difficult to obtain information about the peristaltic movement of the esophagus even though the state of the esophagus can be confirmed through fluoroscopy.

Patent Document 1 describes an X-ray diagnostic apparatus that administers a contrast medium to a patient and diagnoses a digestive system such as an esophagus. In this example, X-ray irradiation is controlled based on the arrival timing of the contrast agent to the diagnostic site such as the esophagus, and imaging can be performed without increasing the exposure dose. However, although the example of Patent Document 1 is effective for reducing the exposure dose, it is difficult to observe the peristaltic movement of the esophagus, and there is room for further improvement.
JP 2006-136500 A

  In the conventional X-ray diagnostic apparatus, the state of the esophagus can be confirmed by fluoroscopy, but it is difficult to obtain information about the peristaltic movement of the esophagus. For this reason, further improvement is required in diagnosing esophageal reflux symptoms.

  The present invention has been made in view of the above circumstances, and an X-ray diagnosis capable of acquiring information on the peristaltic movement of the esophagus based on the flow rate of the contrast medium, the change in the diameter of the esophagus or the like in the examination of the esophagus or the like. An object is to provide an apparatus, an image data processing apparatus, and an image data processing method.

The X-ray diagnostic apparatus according to the first aspect of the present invention includes an X-ray irradiation unit and an X-ray detection unit, irradiates a subject with X-rays from the X-ray irradiation unit, and detects the X-ray detection unit. An imaging system for generating a plurality of phases of esophagus in time series based on an X-ray image obtained by imaging the subject after administration of a contrast medium with the imaging system; Each of the plurality of phases of esophagus image data, each image data is divided into a plurality of regions of interest along the flow of the contrast agent, and the respective average pixel values of the same region of interest continuously in time series And calculating a difference between the average pixel value and the minimum average pixel value for each phase of the target region with reference to a minimum average pixel value among the average pixel values, to calculate the temporal change amount of the pixel value based on the difference in A calculation unit, an information generation unit that generates display information for visually displaying the amount of change for each of the plurality of regions of interest using calculation results in the calculation unit, and display information from the information generation unit And a display unit for displaying an image based on the above.

The image data processing apparatus of the present invention according to claim 6 is an image data acquisition unit for capturing image data of a plurality of phases of the esophagus continuous in time series obtained by X-ray imaging of a subject after administration of a contrast medium. And dividing each image data of the esophagus captured by the image data acquisition unit into a plurality of regions of interest along the flow of the contrast medium, and calculating respective average pixel values of the same region of interest continuously in time series And calculating a difference between the average pixel value and the minimum average pixel value for each phase of the target region with reference to a minimum average pixel value among the average pixel values, and for each target region A calculation unit that calculates a temporal change amount of the pixel value based on the difference, and display information that visually displays the change amount for each of the plurality of regions of interest using a calculation result in the calculation unit. Information generation unit to generate and the information generation A display unit that displays an image based on the display information from, characterized by comprising a.

Furthermore, the image data processing method of the present invention according to claim 10 captures image data of a plurality of phases of the esophagus that are obtained in time series and obtained by X-ray imaging of a subject after administration of a contrast medium. The plurality of phases of the esophagus image data is divided into a plurality of regions of interest along the flow of the contrast medium, and the average pixel value of each of the same regions of interest consecutive in time series is calculated. based on the minimum mean pixel value in the calculated average pixel value and a difference between the smallest average pixel value for each phase of the attention area, the pixel value based on the difference for each of the target sites A temporal change amount is calculated, and display information for visually displaying the change amount for each of the plurality of regions of interest is generated using the calculation result of the change amount, and an image based on the display information is displayed. It is characterized by doing.

  According to the present invention, based on image data acquired by X-ray irradiation, it is possible to visually calculate and display the flow rate and flow rate of a contrast medium, changes in the diameter of the esophagus, etc. It can be performed.

  Hereinafter, an X-ray diagnostic apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the overall configuration of the X-ray diagnostic apparatus of the present invention. In FIG. 1, an X-ray diagnostic apparatus 100 two-dimensionally detects an X-ray generator 10 for generating X-rays with respect to a subject P, and X-rays that have passed through the subject P, and generates a detection result. An X-ray detection unit 20 that generates X-ray projection data based on the X-ray projection data is provided.

  The X-ray generation unit 10 includes an X-ray irradiation unit 13 including an X-ray tube 11 and an X-ray restrictor 12, and a high voltage generator 14. The X-ray tube 11 is a vacuum tube that generates X-rays, and accelerates electrons emitted from a cathode (filament) by a high voltage to collide with a tungsten anode to generate X-rays.

  The X-ray diaphragm 12 is provided for the purpose of reducing the exposure dose to the subject P and improving the image quality by irradiating only the region to be imaged with X-rays. Thereby, the flat panel detector 21 to be described later can detect an X-ray image by X-rays that have passed through the opening formed by the X-ray diaphragm 12 and transmitted through the region of interest of the subject P.

  The X-ray detector 20 includes a flat panel detector (FPD) 21, a charge / voltage converter 22, an A / D converter 23, and a parallel / serial converter 24.

  The flat detector 21 converts X-rays transmitted through the region of interest of the subject P into electric charges and accumulates them, and minute detection elements that detect X-rays are arranged two-dimensionally in the column direction and the line direction. Configured. Each detection element senses X-rays and generates a charge according to the incident X-ray dose, a charge storage capacitor that stores the charge generated in the photoelectric film, and a predetermined charge stored in the charge storage capacitor TFT (thin film transistor) that is read out at the timing shown in FIG. The X-ray image detection method includes a method of converting X-rays into light and then converting them into charges in addition to a method of directly converting X-rays into charges.

  The charge / voltage converter 22, the A / D converter 23, and the parallel / serial converter 24 generate X-ray projection data based on the charges read from the flat detector 21. The charge / voltage converter 22 converts the charge read from the flat detector 21 into a voltage, and the A / D converter 23 converts the output of the charge / voltage converter 22 into a digital signal. The parallel / serial converter 24 converts the X-ray projection data read out in parallel in units of lines from the flat detector 21 and converted into digital signals into time series signals.

  The X-ray generation unit 10 and the X-ray detection unit 20 are supported by a support device 31, and the support device 31 is movable in the body axis direction of the subject P, for example. The X-ray generator 10 and the X-ray detector 20 constitute an imaging system.

  Furthermore, the X-ray diagnostic apparatus 100 has a computer system 30. The computer system 30 includes a system control unit 31, an operation unit 32, a display unit 33, an image data generation unit 34, a storage unit 35, and an information processing unit 36.

  The system control unit 31 includes a CPU, a ROM, and the like, and comprehensively controls each unit of the X-ray diagnostic apparatus 100 to process and display image data. The operation unit 32 is used by a user such as a doctor to input various commands. The operation unit 32 is an interactive interface including an input device such as a keyboard, a trackball, a joystick, and a mouse, a display panel, and various switches.

  The operation unit 32 inputs subject information and inputs a movement instruction signal to the X-ray restrictor 32. In addition, the position of the top 12 and the setting of X-ray irradiation conditions including the tube voltage and tube current of the imaging system are performed. The display unit 33 displays image data and the like.

  The image data generation unit 34 generates diagnostic image data based on the X-ray image data (X-ray projection data) generated by the X-ray detection unit 20. The storage unit 35 stores the generated image data. Image data generation processing in the image data generation unit 34, storage of image data in the storage unit 35, and readout of image data are performed under the control of the system control unit 31.

  The system control unit 31 is connected to an information processing unit 36 that is a feature of the present invention. The information processing unit 36 has a function of generating, for example, information on peristaltic movement of the esophagus using the image data generated by the image data generation unit 34 and the image data stored in the storage unit 35 and displaying the information on the display unit 33. doing. Details of the information processing unit 36 will be described later.

  The X-ray diagnostic apparatus 100 also determines the position of the high voltage control unit 41 that controls the high voltage generator 14, the diaphragm control unit 42 that controls the X-ray diaphragm 12, and the top plate 32 on which the subject P is placed. The high-voltage control unit 41, the aperture control unit 42, and the top plate control unit 43 are controlled by the system control unit 31.

  The high voltage generator 14 generates a high voltage to be applied between the anode and the cathode in order to accelerate the thermoelectrons generated from the cathode of the X-ray tube 11, and the high voltage controller 41 includes: Based on the X-ray irradiation conditions input from the operation unit 32, the tube current / tube voltage of the high voltage generator 14, the irradiation time, the irradiation repetition period, and the like are controlled.

  Next, the information processing unit 36 that is a feature of the present invention will be described. The X-ray diagnostic apparatus 100 of the present invention is characterized in that in the examination of the esophagus and the like, information on the peristaltic movement of the esophagus is acquired based on the flow rate of the contrast agent, the change in the diameter of the esophagus, and the like. The information processing unit 36 includes a calculation unit 361 and an information generation unit 362, and uses the image data generated by the image data generation unit 34 or the image data stored in the storage unit 35 to quantitatively display the peristaltic movement of the esophagus. Generate information.

  The image data processing operation in the information processing unit 36 will be described below with reference to the flowchart of FIG. 2 and the image information of FIGS.

  In FIG. 2, step S0 is a start step of image processing. In the X-ray diagnostic apparatus 100 of the present invention, there are provided two types of modes, a “measurement mode” for capturing an image collected by X-ray fluoroscopy in real time and a “reference mode” using an image collected in advance.

  The mode setting can be selected by pressing a switch provided on the operation unit 32. When “measurement mode” is selected, the image data generated by the image data generation unit 34 is transferred to the information processing unit 36 in real time. The When “reference mode” is selected, pre-collected image data is read from the storage unit 35 and transferred to the information processing 36.

  In the following description, the case where “reference mode” is selected will be described. When the “reference mode” is selected, an image selection menu is displayed on the display unit 33, and the user can select which image data stored in the storage unit 35 is to be used.

  By the above image selection, for example, a plurality of time-series image data when a contrast medium such as barium is administered and imaged to the diagnosis site (esophagus) of the subject is transferred to the information processing unit 36.

  In the next step S1, each image data transferred to the information processing unit 36 is divided into arbitrary attention parts in the form as shown in FIG. 3, and the calculation part 361 calculates an average pixel value of each attention part. To do.

The image in FIG. 3 (a) shows one of the photographed images of the diagnostic site (esophagus in this example), and is divided into A to J continuous sites of interest. For example, as shown in FIG. 3B, the target portion A is composed of a plurality of pixels (a1, 1 to am.n) in the row direction and m in the column direction, and the gray value of each pixel is white. When expressed in 256 levels from level (0) to black level (255), the average pixel value Aave of the site of interest A can be obtained by the following equation.

  In this way, in step S1, the average pixel value of each attention site AJ of the acquired image is calculated. In addition, since the image data acquired by the information processing unit 36 actually uses a plurality of continuous image data in time series, as shown in FIG. In FIG. 4, the average pixel values of the target regions A to J are similarly calculated for the image data of Phase 1 to Phase 8).

FIG. 4 shows eight images taken continuously by shifting the esophageal region in time, and the time interval between the images of Phase 1 to Phase 8 is, for example, 3 seconds. According to the image of FIG. 4, the state of the contrast agent flowing through the esophagus (the white portion of the image) can be observed.
However, it is difficult to read even the peristaltic movement of the esophagus with this image alone. Therefore, in step S2, the calculation unit 361 obtains a change amount from the average pixel value of the average pixel values of the target portions A to J of the images of a plurality of phases (Phase 1 to Phase 8) with reference to the minimum average pixel value. For example, regarding the attention site A, if the average pixel value in Phase 1 to Phase 8 is Amin, and the average pixel value in the nth phase is An, the change amount Avn for each phase is obtained by the following equation. be able to.

  In this way, the amount of change for each phase is calculated for each region of interest AJ. For example, considering the region of interest A, it can be seen that Phase 1 and Phase 3 to Phase 8 have almost no change, and Phase 2 has changed greatly. Since the average pixel value does not become zero in the result of actual photographing, the amount of change can be calculated by obtaining the difference with respect to the minimum average pixel value.

  In the next step S3, the maximum value is selected from the amount of change obtained in step S2, the difference from the previous phase (previous phase) is divided by the time information between the phases, and each region of interest A Calculate the flow velocity at ~ J.

For example, phase 2 has the largest amount of change in attention site A, the value of change amount of Phase 2 is Avmax, the value of Phase immediately before (Phase 1) is Avbefore, and the time difference between phases is t At this time, the flow velocity v of the site of interest can be calculated by the following equation.

  In this way, the flow rate of the contrast agent at each site of interest A to J is obtained, and the calculation process ends in step S4.

  Using the calculation results obtained in steps S2 and S3, the information generation unit 362 generates display information for visually displaying the temporal change amount of the pixel value for each of the plurality of target regions (A to J). . The display information generated by the information generation unit 362 is supplied to the display unit 32 and displayed, and is provided to the doctor as information indicating the peristaltic movement of the diagnosis site (for example, the esophagus).

  FIG. 5 shows an example of display information generated based on the amount of change calculated in step S2, and the amount of change for each region of interest (A to J) and each phase (Phase 1 to Phase 8), that is, the progress of the contrast agent. It is the graph which displayed the situation visually.

  In FIG. 5, the vertical axis represents the amount of change, and the horizontal axis represents time change (Phase). For example, the amount of change of the attention site A is maximum in Phase 2 and low in other Phases, and the slope of the graph is steep. That is, it can be seen that the contrast agent passes through the attention site A quickly and is close to normal.

  On the other hand, in the region of interest F, the amount of change is the largest in Phase 5, and the slope of the graph is gentle because the difference between Phase 3 and Phase 4 before and after that is small. This indicates that the flow of contrast medium is slow in the attention site F. Similarly, in the attention site G, the amount of change is the maximum in Phase 6, and the difference between Phase 5 and Phase 7 before and after that is small, so the slope of the graph is further gentle. That is, it can be estimated from FIG. 5 that the peristaltic activity of the portions of interest F and G is inactive, the esophageal tube diameter becomes small, and the esophagus is clogged.

  FIG. 6 shows an example of display information generated based on the flow velocity calculated in step S3, in which a captured image X of the diagnostic region and a graph Y indicating the flow velocity of the target region (A to J) are displayed side by side. is there. When the graph Y of FIG. 6 is seen, it is estimated that the flow velocity of the attention site G is significantly lower than the others, the peristaltic activity of the portion of the attention region G is inactive, and the esophagus is clogged. it can.

  The results calculated in steps S2 and S3 and the display information generated based on the calculation results may be stored in the storage unit 35, and the data stored by the user may be arbitrarily selected and used. The display information is not limited to the graph, and may be displayed in a table format or a real value.

  In the above description, an example in which image data collected in advance in the “reference mode” is read from the storage unit 35 and processed and displayed by the information processing unit 36 has been described. However, in the “measurement mode”, X-ray imaging is performed. The sequentially collected image data may be taken into the information processing unit 36 and processed in real time.

  The number of points of interest (number of A to J) and the size can be arbitrarily set by the user operating the operation unit 32. Alternatively, a plurality of setting information relating to the number of points and the size may be prepared in advance, and the setting may be performed by the user selecting one of the setting items.

  Further, in the above description, an example in which the flat detector 21 is used to detect X-rays has been described. I (image intensifier) is opposed to the X-ray diaphragm 12, and this I.I. A television camera is disposed on the output surface of I through an optical system, and an X-ray image transmitted through the subject P is obtained from the I.I. You may make it convert into an electrical signal with I and a television camera. In short, any image data capable of digital processing can be obtained.

  In the above example, an example has been described in which various display information is created by calculating the average pixel value of the region of interest, the amount of change for each phase, or the flow velocity using the computer system 30 provided in the X-ray diagnostic apparatus 100. However, various display information can be created using a computer system different from the X-ray diagnostic apparatus 100.

 That is, image data captured by the X-ray diagnostic apparatus 100 is stored in an image server (not shown) on the network, a computer terminal that can access the image server is arranged, and the computer terminal is similar to the information processing unit 36. You may make it perform the process of.

 FIG. 7 is a block diagram illustrating an example of an image data processing apparatus 200 according to another embodiment of the present invention. The image data processing apparatus 200 is configured as a computer terminal, and includes a computer main body 51 such as a personal computer, a keyboard connected to the computer main body 51, an input device 52 such as a mouse, an output device 53 such as a printer, a display device 54, a memory, and the like. And a network interface 56 for controlling connection to the network 57.

  The computer main body 51 incorporates a CPU and a ROM, and processes image data in accordance with a program stored in the ROM. That is, the computer main body 51 has functions of a calculation unit and an information generation unit, like the information processing unit 36. The network interface 56 constitutes an image data acquisition unit that takes in a plurality of image data continuous in time series from an image server (not shown).

  The computer main body 51 processes the image data fetched from the image server via the network interface 56, calculates various arithmetic processes, for example, the average pixel value of the target region, the amount of change for each phase, or the flow velocity, and the calculation Various display information is displayed on the display device 54 using the result.

  Alternatively, printing processing may be performed by the output device 53. In addition, data of the arithmetic processing result and display information can be stored in the storage unit 55. Therefore, by using the computer terminal 200, arithmetic processing can be executed at a location away from the X-ray diagnostic apparatus 100.

  As described above, according to the present invention, a change in the flow of contrast medium, a flow velocity, a flow rate, or a change in the diameter of the esophagus is estimated based on an image fluoroscopically or photographed by an X-ray diagnostic apparatus. Quantitative information can be displayed, and a doctor's diagnosis support effect can be improved.

  The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the claims.

The block diagram of the X-ray diagnostic apparatus which concerns on one Embodiment of this invention. 6 is a flowchart for explaining an image processing operation in an embodiment of the present invention. Explanatory drawing explaining the example of calculation of the average pixel value of the image data image | photographed with the X-ray diagnostic apparatus of this invention. Explanatory drawing which shows an example of several time-sequential image data image | photographed with the X-ray diagnostic apparatus of this invention. Explanatory drawing which shows an example of the display information in one Embodiment of this invention. Explanatory drawing which shows the other example of the display information in one Embodiment of this invention. The block diagram which shows the image data processing apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... X-ray diagnostic apparatus 10 ... X-ray generation part 11 ... X-ray tube 12 ... X-ray aperture 13 ... X-ray irradiation part 14 ... High voltage generator 20 ... X-ray detection part 21 ... Planar detector 30 ... Computer system 31 ... System control unit 32 ... Operation unit 33 ... Display unit 34 ... Image data generation unit 35 ... Storage unit 36 ... Information processing unit 361 ... Calculation unit 362 ... Information generation unit 41 ... High voltage control unit 42 ... Aperture control unit 43 ... Top panel control unit 200 ... image data processing device 51 ... computer main body 52 ... input device 53 ... output device 54 ... display device 55 ... storage device 56 ... network 57 ... network interface

Claims (10)

An imaging system that includes an X-ray irradiation unit and an X-ray detection unit, irradiates the subject with X-rays from the X-ray irradiation unit, and detects the X-ray detection unit;
An image data generation unit that generates image data of a plurality of phases of the esophagus that are continuous in time series based on an X-ray image obtained by imaging a subject after administration of a contrast medium with the imaging system;
Each of the plurality of phases of esophagus image data is captured, each image data is divided into a plurality of regions of interest along the flow of the contrast medium, and the respective average pixel values of the same region of interest consecutive in time series are obtained. And calculating a difference between the average pixel value and the minimum average pixel value for each phase of the target region with reference to a minimum average pixel value among the average pixel values, and for each target region A calculation unit that calculates a temporal change amount of the pixel value based on the difference ;
An information generation unit that generates display information for visually displaying the amount of change for each of the plurality of regions of interest using a calculation result in the calculation unit;
An X-ray diagnostic apparatus comprising: a display unit configured to display an image based on display information from the information generation unit.   The X-ray diagnosis apparatus according to claim 1, wherein the information generation unit generates graph information representing a progress state of the contrast agent based on an amount of change of the attention site for each phase. The calculation unit further obtains a difference between the phase having the maximum amount of change and the phase preceding in time in the amount of change for each phase of the region of interest, and obtains this difference information as the time between the phases. Divide by information to calculate flow velocity data,
The X-ray diagnostic apparatus according to claim 1, wherein the information generation unit generates graph information representing the flow rate of the contrast agent for each region of interest based on the flow rate data.   The X-ray diagnosis apparatus according to claim 1, further comprising a storage unit that stores a calculation result in the calculation unit and display information generated by the information generation unit.   2. The number of sections and the size of each section area can be arbitrarily set when the plurality of image data are sectioned for each of a plurality of regions of interest along the flow of the contrast medium. The X-ray diagnostic apparatus described. An image data acquisition unit that captures image data of a plurality of phases of the esophagus that are obtained in time series and obtained by X-ray imaging of a subject after administration of a contrast agent;
Each image data of the esophagus captured by the image data acquisition unit is divided into a plurality of regions of interest along the flow of the contrast agent, and average pixel values of the same regions of interest that are continuous in time series are calculated. the based on the minimum average pixel value among average pixel value, the calculated average pixel value and a difference between the smallest average pixel value for each phase of the attention area, the difference for each of the target sites A calculation unit for calculating a temporal change amount of the pixel value based on
An information generation unit that generates display information for visually displaying the amount of change for each of the plurality of regions of interest using a calculation result in the calculation unit;
An image data processing apparatus comprising: a display unit configured to display an image based on display information from the information generation unit.   The image data processing apparatus according to claim 6, wherein the information generation unit generates graph information representing a progress state of the contrast agent based on a change amount of the attention site for each phase. The calculation unit further obtains a difference between the phase having the maximum amount of change and the phase preceding in time in the amount of change for each phase of the region of interest, and obtains this difference information as the time between the phases. Divide by information to calculate flow velocity data,
The image data processing apparatus according to claim 6, wherein the information generation unit generates graph information representing a flow rate of the contrast agent for each region of interest based on the flow rate data.   The image data processing apparatus according to claim 6, further comprising a storage unit that stores a calculation result of the calculation unit and display information generated by the information generation unit. Incorporated image data of multiple phases of esophagus that were obtained by X-ray imaging of the subject after administration of the contrast agent,
Dividing the captured multi-phase esophageal image data into a plurality of regions of interest along the flow of the contrast medium,
The average pixel value of each of the same site of interest that continues in time series is calculated, and the average pixel value and the minimum for each phase of the site of interest with reference to the minimum average pixel value in the average pixel value Calculating the difference between the average pixel value and the temporal change amount of the pixel value based on the difference for each region of interest,
Using the calculation result of the amount of change , generate display information for visually displaying the amount of change for each of the plurality of sites of interest,
An image data processing method, comprising: displaying an image based on the display information.

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