JP2005176973A - Radiographic image processing device, radiographic image processing system, radiographic system, radiographic device, radiographic image processing method, computer-readable storage medium, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein the radio output should be reduced to 1mW or lower and therefore, the rate of transmission is reduced when the worst case of the photography of the thoracic region of a patient wearing a pace-maker is always assumed in considering the radio-transmission of X-ray data, and to solve a problem wherein the performance of the apparatus on the whole is always deteriorated when a large quantity of image data are transmitted always at the low transmission rate because the opportunity of photographing a patient wearing a pace-maker is 1% or lower. <P>SOLUTION: The radiographic apparatus consists of a two-dimensional X-ray detecting means, a radio-transmitting means for radio-transmitting X-ray data, and a radio-control means for controlling the transmission output and/or the transmission rate of the radio-transmitting means. The apparatus also has an analysis means for analyzing an image from the X-ray detecting means, and the radio-control means is controlled based on the result of analysis by the analysis means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation image processing apparatus, a radiation image processing system, a radiation imaging system, a radiation imaging apparatus, a radiation image processing method, a computer readable storage medium, and a program for processing a radiation image.

  In recent years, a system for taking a radiographic image of a subject using a large area semiconductor image sensor (FPD, Flat Panel Detector) has been developed. This system has a practical advantage that an image can be recorded over a very wide range of radiation exposure compared to a conventional radiographic system using silver salt photography. That is, X-rays with a very wide dynamic range are read as electrical signals using photoelectric conversion means, and the electrical signals are further converted into digital signals. By processing this digital signal and outputting the radiation image as a visible image to a recording material such as a photographic photosensitive material or a display device such as a CRT, a good radiation image can be obtained even if the radiation exposure varies to some extent. It is done.

  In an X-ray imaging apparatus using FPD, it is conceivable to transmit data generated by the sensor unit wirelessly. This is because, assuming a cassette type FPD, the usability of the user is improved by wireless.

  Prior art for transmitting X-ray data wirelessly includes: (1) Even if the normal control circuit of the image sensor breaks down, the D / A switching circuit is switched to analog, and a plurality of pixels are combined into one by the pixel control circuit. Control and scan the image sensor through the gate driver circuit with the TV standard scanning signal generated by the TV reference signal circuit. (2) The X-ray image signal from the readout amplifier is converted to the TV by the video signal superimposing circuit. It is superimposed on a standard scan TV frame sync signal and output as an analog video signal. (3) And, if necessary, it is transmitted to an external monitor and displayed using radio transmission means such as radio waves or infrared rays. There is a technique that is configured (see, for example, Patent Document 1).

(1) A rotating shaft is provided at one end of the detector unit, and the fluoroscopic imaging table is held by the rotating shaft and can be opened 90 degrees by rotating 90 degrees. (2) The rotating shaft 3 is provided with a sliding electrode 4 to input / output signals of the detector unit 1 and supply power. The control unit 44 controls the detection unit 2 having an X-ray conversion layer and an active matrix substrate therein, the gate circuit unit 5 and the reading circuit unit 6, and reads the pixel signal of the detection unit 2 to the reading circuit unit 6. Sending data to the outside via the sliding electrode 4 (3) Also, a communication circuit unit 7 that can send and receive data to and from the outside wirelessly is provided, and data can be sent to the outside wirelessly by the non-contact input / output means 8 Is disclosed (for example, see Patent Document 2).
JP 2001-189929 A Japanese Patent Laid-Open No. 2002-52015

  Considering electromagnetic waves in wireless media, obstacles to the human body or medical equipment become a problem. For example, a cellular phone has 600-800 mW, and there is data that even a distance of about 1 m can affect a syringe pump and a pacemaker. On the other hand, the PHS has an output of 10-20mW, and there was a problem that it could cause trouble when taken right next to the device. On the other hand, telemetry used for medical purposes is considered to have no effect on equipment at 1 mW or less.

  In data transfer when an X-ray image is taken, the biggest problem is the malfunction of the pacemaker, but IEEE802.11b, which is a wireless LAN standard, has an output of about 2 mW and is a border that is not suitable for use. However, what should be noted here is that, considering that the pacemaker is implanted near the heart, chest radiography, which is most frequently used in X-ray imaging, means that the radio transmitter is close to the pacemaker, It is a dangerous state.

  On the other hand, the wireless LAN controls the speed of 11 Mbps-> 5 Mbps-> 2 Mbps-> 1 Mbps according to the electric field strength. That is, if the wireless output (electric field strength) is reduced, the transfer rate must be reduced.

  In other words, if the worst case of taking a chest image of a pacemaker patient is always assumed, the wireless output must be set to 1 mW or less, and the transfer rate is steadily decreasing. As a matter of course, the rate of radiographing of pacemaker patients is 1% or less, and because of this 1% or less, constantly sending a large amount of image data at a low transfer rate always lowers the performance of the entire apparatus. Become.

  Therefore, in the present invention, when the photographed image is analyzed and there is no object causing radio wave interference such as a pacemaker, the output is increased and data is transferred. In another invention, it is also possible to control the electromagnetic wave output using patient information.

  As described above, according to the present invention, at the time of wireless transmission of data, it is possible to perform high-performance data transfer by minimizing electromagnetic interference to the subject, thereby maximizing examination efficiency. It is possible to do.

  A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings (FIGS. 1 to 11).

  FIG. 1 shows a block diagram of this embodiment. The X-ray sensor means 11 is a two-dimensional sensor formed of amorphous silicon. In a preferred embodiment, the X-ray sensor means 11 is composed of 160 μ resolution and 2688 × 2688 pixels. X-rays emitted from an X-ray generation unit (not shown) pass through a subject (not shown) and reach the X-ray sensor unit 11.

  The reached X-ray is converted into a charge proportional to the incident X-ray by the X-ray sensor means 11, and the charge is converted into digital data for each pixel by the AD converter. The pixel data is subjected to image processing such as offset correction and gain correction, and is input to the image analysis means 12.

  The image analysis unit 12 determines whether or not a pacemaker is included in the image. As shown in FIG. 3, the image analysis unit 12 includes a lung field region extraction unit 31, a right lung identification unit 32, and a pacemaker detection unit 33. The lung field region extraction means 31 extracts a lung field region from the chest front image. FIG. 4 shows a typical lung field histogram. The histogram is made up of three peaks. As shown in FIG. 2, there are a lung field region, a nest removal region, and other regions (mediastinum, heart, subdiaphragm, etc.). In order to specify the lung field region, the image may be binarized in the interval between threshold 1 and threshold 2 shown in FIG.

  FIG. 5 shows a cumulative histogram for the histogram shown in FIG. 4 and a line obtained by linear regression of the cumulative histogram. Empirically, the pixel value at which the cumulative histogram and linear regression intersect indicates the threshold value 1. Specifically, as shown in FIG. 6, the difference between the cumulative histogram and the linear regression is calculated, and the point at which the difference zero-crosses indicates the threshold 1.

  As described above, since the threshold value 1 is obtained, the histogram shown in FIG. 7 can be calculated by excluding the area having the threshold value 1 or more from the image and calculating the histogram of the area. Although the figure is omitted, a cumulative histogram is further calculated with respect to the histogram of FIG. 7 to calculate a difference from linear regression, and when a point where the difference zero-crosses is obtained, the value generally corresponds to the threshold 2. . A lung field region can be extracted by binarizing the input image of the chest so that the pixel value between the threshold value 1 and the threshold value 2 is 1 and the other pixel values are 0. This binary image is called a lung field binary image.

  The lung field binary image corresponds to a region which is a lung field region in FIG. As shown in FIG. 2, a pacemaker is generally embedded at a location of several centimeters in the right clavicle, and a signal is guided to the heart by a lead wire. In the present invention, since it is only necessary to detect the presence or absence of the pacemaker main body, the right lung specifying means 32 performs labeling from the lung field binary image, is located on the right side of the image, and has the lung field binary image area. About half of the area is identified as the right lung area.

  The pacemaker detecting means 33 calculates a histogram of the input image corresponding to the right lung region specified by the right lung specifying means 32, and determines whether there is a distribution that may correspond to the pacemaker in the histogram. . An example of a histogram of the right lung in which the pacemaker is reflected is shown in FIG. As a means for detecting the distribution by the pacemaker, it is possible to perform a first-order approximation on the cumulative histogram as described above and judge from the error amount. Further, binarization is performed with a threshold value at which the error amount crosses zero, and it is also possible to determine whether or not the binary image has a circular outer circumference unique to a pacemaker by a light circle calculation.

  As described above, the output and transmission rate control means 13 is controlled by the presence / absence of the pacemaker by the image analysis means 12. In FIG. 1, data exchanged between the first wireless transmission / reception means 14 connected to the sensor means and the second wireless transmission / reception means 15 connected to the network means 16 can be classified into control data and image data. The control data is a small amount compared to the image data. As described above, the image data is 2688 × 2688 × 2 bytes, whereas the control data is about several kilobytes.

  In other words, except for image data, the wireless output is set to a low output of 1 mW or less, and there is no problem in use at a transfer rate of about 1 Mbps. If the wireless output is called 1 mW output and the transfer rate of 1 Mbps is called mode 1 for convenience, the first wireless transmission / reception means 14 and the second wireless transmission / reception means 15 communicate in the normal mode 1. In this state, no obstacle occurs even if the pacemaker patient approaches the apparatus.

  If the pacemaker is not detected in the image by the image analysis means 12 as a result of image shooting, the output and transmission rate control means 13 outputs a wireless output of 2 mW and a transfer rate of 11 Mbps (for convenience, mode 2). The setting is changed. Of course, the wireless output may be changed to 5mW output and transfer rate 100Mbps. On the other hand, when a pacemaker is detected in the image by the image analysis means 12, data transfer is performed in the mode 1 without changing the wireless communication mode. In this case, although it takes about 10 times the transfer time of mode 2, it is possible to perform harmless wireless communication for the pacemaker patient.

  In the above embodiment, the output and the transmission rate of only the first wireless transmission / reception unit 14 are controlled. However, the output and the transmission rate of the second wireless transmission / reception unit 15 are simultaneously controlled by the result of the image analysis unit 12. You may control.

  In the above embodiment, the presence / absence of the patient's pacemaker is determined by image analysis. However, it can also be determined by patient information. As shown in FIG. 1, it may be possible to input patient information from the network means 16 to the patient information input means 17. With patient information, in addition to a person's name, patient ID, etc., it is possible to obtain the patient's past history, and it is also possible to detect the presence / absence information of a pacemaker in the patient information.

  These pieces of patient information are transferred in advance to the patient information analysis means 18 on the sensor side and analyzed before X-ray exposure. In addition to directly detecting the presence or absence of the pacemaker from the patient information, the patient information analysis means 18 controls the patient with heart disease to transfer data in the low output mode of mode 1 assuming that the pacemaker has a high probability of wearing the pacemaker. .

Block diagram of radiation imaging equipment Example of chest front image Block diagram of image analysis means Histogram of chest front image Cumulative histogram and linear regression Cumulative histogram and linear regression error Histogram of chest front image below threshold 1 Histogram of right lung with pacemaker

Explanation of symbols

11 X-ray sensor means 12 Image analysis means 13 Output and transmission rate control means 14 First wireless transmission / reception means 15 Second wireless transmission / reception means 16 Network means 17 Patient information input means 18 Patient information analysis means 31 Lung field region extraction means 32 Right lung identification means 33 Pacemaker detection means

Claims (4)

  In the radiation imaging apparatus comprising a two-dimensional X-ray detection means, a wireless transmission means for wirelessly transmitting X-ray data, and a wireless control means for controlling the transmission output and / or transmission rate of the wireless transmission means, Analyzing means for analyzing an image from the line detecting means, and controlling the wireless control means according to a result of the analyzing means.   In Claim 1, When a metal is detected by the said analysis means, the transmission output and / or transmission rate of the said wireless transmission means are set low.   In a radiographic apparatus comprising a two-dimensional X-ray detection means, a wireless transmission means for wirelessly transmitting X-ray data, and a wireless control means for controlling the transmission output and / or transmission rate of the wireless transmission means, It has a patient information input means 17 for a patient, and controls the wireless control means according to the result of the patient information analysis means 18 for analyzing the patient information.   In Claim 3, when the said electromagnetic interference instrument is detected by the said patient information analysis means 18, the transmission output and / or transmission rate of the said wireless transmission means are set low.

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