JP2010179094A - Radiation tomographic image generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation tomographic image generator which can improve working efficiency and does not cause wasted exposure to radiation of a patient or wasted binding hour of the patient. <P>SOLUTION: The image generator 10 includes: a radiation image acquisition part 14 which acquires several radiation images from a radiation detection instrument 12 as it moves an irradiation part 20 opposed to the radiation detection instrument 12 to several positions for emitting radioactive rays 26 from different directions to a subject 24 on the radiation detection instrument 12 from the radiation part 20 in the different positions; and an image reconstruction part 16 which reconstructs the several radiation images acquired by the radiation image acquisition part 14 and generates tomographic images of the subject 24 which are parallel to the detection surface of the radiation detection instrument 12. It has a body movement detection part 100 which detects movement of the subject 24 during tomography and a tomography continuation determination part 102 which determines whether the tomography should be continued or not on the basis of the level of movement of the subject 24 which is detected by the movement detection part 100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiation tomographic image generation apparatus that acquires a tomographic image by radiography.

  In recent years, in order to observe the affected area in more detail, an X-ray imaging apparatus also performs imaging by moving the X-ray tube and irradiating the subject with X-rays from different angles, and adding the obtained radiographic images to obtain a desired result. Tomosynthesis imaging (Tomosynthesis) that can obtain a tomographic image in which the tomographic plane is emphasized has been proposed (see, for example, Patent Document 1).

  In tomosynthesis imaging, the X-ray tube is moved in parallel with a detector such as a flat panel, or moved so as to draw a circle or ellipse arc, and multiple radiation images obtained by imaging the subject at different imaging angles are acquired. These tomographic images are created by reconstructing these radiation images. This tomographic image can be acquired by translating a plurality of radiographic images or adjusting and adding the sizes of the images (see, for example, Patent Document 2).

JP-A-57-203430 JP 2008-43757 A

  However, as shown in Patent Document 1 and Patent Document 2, a radiation tomographic image generation apparatus capable of reconstructing an arbitrary tomographic image captures a plurality of images of a subject based on a single imaging start instruction. The shooting time from the start of shooting to the end of shooting takes several seconds, and the subject may move within this shooting time.

  There is no problem if the level of movement (body movement) of the subject within the shooting time does not affect the reconstruction, but if the body movement level affects the reconstruction, the subsequent shooting is useless. It will be something. Moreover, there is a problem that waste is increased in terms of work efficiency, patient exposure, and patient restraint time, such as the need for re-imaging.

  Therefore, the operator continues to observe the body movement of the subject over the period during which tomosynthesis imaging is performed, and determines whether to continue or stop the imaging when there is a body movement that affects the imaging. However, there is a possibility that an operator's work load becomes large and a work mistake due to fatigue may be caused.

  The present invention has been made in view of such problems, and a radiation tomographic image generation apparatus that can improve work efficiency and does not cause waste in patient exposure and patient restraint time. The purpose is to provide.

  Another object of the present invention is that it is not necessary for the operator to continue observing the body movement of the subject over the period during which tomosynthesis imaging is performed, and the work burden on the operator can be effectively reduced. An object of the present invention is to provide a radiation tomographic image generation apparatus that can improve efficiency and does not cause waste in patient exposure and patient restraint time.

[1] The radiation tomographic image generation device according to the first aspect of the present invention is configured to move the radiation irradiation unit provided facing the radiation detection device to a plurality of positions while moving the radiation irradiation unit from the radiation irradiation unit to the radiation detection device at each position. Radiation image acquisition means for irradiating the upper subject with radiation from different directions and acquiring a plurality of radiation images output from the radiation detection device; and the plurality of sheets acquired by the radiation image acquisition means In the radiation tomographic image generation apparatus having the reconstruction means for reconstructing the radiographic image of the subject and generating the tomographic image of the subject, the body motion detection means for detecting the motion of the subject being photographed, and the body motion detection Photographing continuation determining means for determining whether or not to continue photographing based on the level of movement of the subject detected by the means.

  As a result, when the level of body movement of the subject has an effect on reconstruction, it is possible to stop subsequent imaging, improve work efficiency, and increase patient exposure and patient restraint time. There is no waste.

[2] In the first aspect of the present invention, the body movement detecting means detects the movement of the subject by a contact type or a non-contact type, and converts it into an electric signal corresponding to the level of movement of the subject and outputs the electric signal. You may make it have.

[3] In the first aspect of the present invention, the imaging continuation determining means determines to continue the imaging while the level of the electrical signal output from the sensor never exceeds the threshold level, and the electrical When the signal level exceeds the threshold level, it may be determined to stop the imaging.

[4] In the first aspect of the present invention, the body motion detecting means includes an optical camera that captures the subject, and a motion vector (two-dimensional) of the subject from the shooting start point based on a captured image from the optical camera. And a means for detecting the above vector).

[5] In the first aspect of the present invention, the shooting continuation determining means determines to continue the shooting while the magnitude of the detected motion vector of the subject never exceeds a threshold level, and the motion vector It may be determined that the shooting is stopped when the size of the image exceeds a threshold level.

[6] In the first aspect of the present invention, the body movement detection means includes means for extracting a region of interest of the subject from the sequentially acquired radiographic images, and means for estimating a three-dimensional coordinate of the extracted region of interest. And a means for detecting a movement vector (three-dimensional vector) of the region of interest from the imaging start time point based on the estimated three-dimensional coordinates.

[7] In the first aspect of the present invention, the imaging continuation determining unit determines to continue the imaging while the magnitude of the detected movement vector of the attention area has never exceeded the threshold level, and the movement It may be determined that the shooting is stopped when the magnitude of the vector exceeds a threshold level.

[8] The first aspect of the present invention may further include body movement warning means for issuing a warning when the photographing continuation determining means determines that the photographing is to be stopped.

[9] In the first aspect of the present invention, re-determining whether or not re-imaging is necessary based on the number of radiographic images acquired by the radiographic image acquisition means during a period when the determination of continuing the imaging is made. You may make it have an imaging | photography determination means.

[10] In the first aspect of the present invention, the re-imaging determination unit sets the number of radiographic images acquired by the radiological image acquisition unit during a period in which the determination to continue the imaging is made in advance. You may make it determine that re-imaging is required when it is less than the predetermined ratio of the total number of sheets which should be acquired by the radiographic image acquisition means.

[11] Next, the radiation tomographic image generation device according to the second aspect of the present invention is configured to move the radiation irradiation unit provided facing the radiation detection device to a plurality of positions from the radiation irradiation unit at each position. Radiation image acquisition means for irradiating a subject on the radiation detection apparatus from different directions and acquiring a plurality of radiation images output from the radiation detection apparatus, and acquired by the radiation image acquisition means Reconstructing means for reconstructing the plurality of radiographic images to generate a tomographic image of the subject, a radiation tomographic image generating apparatus, and a body motion detecting means for detecting movement of the subject being imaged, And a warning output means for outputting a warning when the level of movement of the subject detected by the body motion detection means exceeds a threshold level.

  As a result, when there is a body movement that affects the photographing, the operator can be notified of this, and the operator observes the body movement of the subject and continues the photographing at the stage of the warning. Or just decide to cancel. In other words, it is not necessary for the operator to continue observing the body movement of the subject over the period during which tomosynthesis imaging is performed, the operator's work burden can be effectively reduced, and work efficiency can be improved. At the same time, there is no waste in patient exposure and patient restraint time.

[12] In the second aspect of the present invention, the radiographic image output from the radiation detection device further includes an imaging state monitoring means for displaying the radiation image on a display device.

[13] In the second aspect of the present invention, the radiographing state monitoring means may sequentially display the radiographic images output from the radiation detection apparatus in units of one sheet.

[14] In the second aspect of the present invention, the radiographing state monitoring means may sequentially display the radiographic images output from the radiation detection apparatus together with a reference pattern in units of one sheet.

[15] In the second aspect of the present invention, the imaging state monitoring means may display the radiographic images output from the radiation detection device while sequentially shifting and adding them.

  As described above, according to the radiation tomographic image generation apparatus according to the present invention, it is possible to improve the working efficiency and to avoid waste in patient exposure and patient restraint time.

  Further, according to the radiation tomographic image generation apparatus according to the present invention, it is not necessary for the operator to continuously observe the body motion of the subject over the period during which tomosynthesis imaging is performed, and the work burden on the operator can be effectively reduced. In addition, work efficiency can be improved, and patient exposure and patient restraint time are not wasted.

1 is a configuration diagram illustrating an image generation apparatus according to a first embodiment. FIG. FIG. 2A is an explanatory diagram illustrating an example in which the radiation irradiation unit and the radiation detection apparatus are synchronously moved in opposite directions with the subject interposed therebetween, and FIG. 2B is an explanatory diagram illustrating an example in which the radiation irradiation unit is moved along an arc trajectory. It is. It is a circuit diagram which shows the structure of the radiation detector incorporated in a radiation detection apparatus. It is a block diagram which shows a 1st image generation apparatus. It is a flowchart which shows operation | movement of a 1st image generation apparatus. It is a block diagram which shows a 2nd image generation apparatus. It is a block diagram which shows a 3rd image generation apparatus. It is a block diagram which shows a 4th image generation apparatus. It is a block diagram which shows a 5th image generation apparatus. FIG. 10A is a front view showing a radiation image forming apparatus such as a cone beam CT partially omitted, and FIG. 10B is a side view showing a radiation image forming apparatus such as a cone beam CT partially omitted. It is a block diagram which shows the image generation apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the image generation apparatus which concerns on a 1st modification. It is a block diagram which shows the image generation apparatus which concerns on a 2nd modification.

  Embodiments of a radiation tomographic image generation apparatus according to the present invention (hereinafter referred to as an image generation apparatus) will be described below with reference to FIGS.

  The image generation apparatus 10 according to the first embodiment includes a radiation detection apparatus 12, a radiation image acquisition unit 14, an image reconstruction unit 16, and a console 18 (control unit) that controls them.

  The radiation image acquisition unit 14 includes a radiation irradiation unit 20 provided to face the radiation detection device 12, a moving mechanism 22 that moves the radiation irradiation unit 20 to a plurality of preset positions, and the radiation irradiation unit 20. When reaching a plurality of preset positions, the radiation control unit 28 that controls the radiation 24 to irradiate the subject 24 on the radiation detection device 12 from the radiation irradiation unit 20, and the radiation detection device 12 sequentially. For example, the image memory 30 includes an image storage unit 32 that stores the transmitted radiation image in time series. That is, the radiation image acquisition unit 14 moves the radiation irradiation unit 20 provided facing the radiation detection device 12 to a plurality of positions while moving the radiation irradiation unit 20 from the radiation irradiation unit 20 to the subject 24 on the radiation detection device 12 at each position. On the other hand, by irradiating the radiation 26 from different directions, the radiation detection apparatus 12 operates to acquire a plurality of radiation images. In the example of FIG. 1, an example in which the radiation irradiation unit 20 is moved along the linear trajectory by the moving mechanism 22 is shown. In addition, as shown in FIG. 2A, the radiation irradiation unit 20 and the radiation detection device 12 are connected. The subject 24 may be synchronously moved in opposite directions with the subject 24 interposed therebetween. Or as shown to FIG. 2B, you may make it move the radiation irradiation part 20 along a circular arc track | orbit.

  Note that the radiographic image acquisition unit 14 captures the concept of individual radiographing performed when the radiation irradiation unit 20 reaches a plurality of preset positions, and the concept of capturing these individual radiographs as one radiography. Exists. Therefore, each radiography is referred to as “radiation radiography”, and radiography that captures each individual radiography as one radiography is referred to as “tomosynthesis radiography”.

  The image reconstruction unit 16 reconstructs a plurality of radiation images stored in the image memory 30, and a tomographic image of the subject 24, particularly a tomogram parallel to the detection surface of the radiation detection device 12 in the region of interest 34 of the subject 24. Generate an image. As a reconstruction method, for example, a simple back projection method or a filtered back projection method can be employed. Here, the simple backprojection method is a method in which a plurality of radiographic images are respectively backprojected as they are without applying a reconstruction filter to the plurality of radiographic images, and then subjected to addition processing to obtain a reconstructed image. On the other hand, in the filter back projection method, a reconstruction filter is applied to a plurality of radiation images as a convolution filter, back projection is performed, and then addition processing is performed to obtain a reconstruction image, and a plurality of radiation images are temporarily Fourier transformed. There is a method of obtaining a reconstructed image by performing addition processing after replacing the data with frequency space data, applying a reconstruction filter to the data, and then performing back projection. Any method may be adopted. The simple backprojection method and the filtered backprojection method are collectively referred to as a backprojection method.

  On the other hand, the radiation detection apparatus 12 includes a housing 36, a battery 38 (see FIG. 2) accommodated in the housing 36, a radiation detector 40, and a detector control unit 42.

  As shown in FIG. 3, the radiation detector 40 includes a thin film transistor (TFT) made of a photoelectric conversion layer 51 made of a material such as amorphous selenium (a-Se) that senses the radiation 26 and generates charges. ) The structure is arranged on the array of 52, and the generated charges are stored in the storage capacitor 53, and then the TFTs 52 are sequentially turned on for each row to read out the charges as an image signal. In FIG. 2, only the connection relationship between one pixel 50 including the photoelectric conversion layer 51 and the storage capacitor 53 and one TFT 52 is shown, and the configuration of the other pixels 50 is omitted. Amorphous selenium must be used within a predetermined temperature range because its structure changes and its function decreases at high temperatures. Therefore, it is preferable to provide means for cooling the radiation detector 40 in the housing 36.

  A gate line 54 extending parallel to the row direction and a signal line 56 extending parallel to the column direction are connected to the TFT 52 connected to each pixel 50. Each gate line 54 is connected to a line scanning drive unit 58, and each signal line 56 is connected to a multiplexer 66 constituting a reading circuit.

  Control signals Von and Voff for controlling on / off of the TFTs 52 arranged in the row direction are supplied from the line scanning drive unit 58 to the gate line 54. In this case, the line scan driving unit 58 includes a plurality of first switches SW1 that switch the gate lines 54, and a row address decoder 60 that outputs a selection signal for selecting one of the first switches SW1. The row address decoder 60 is supplied with an address signal from the detector control unit 42.

  In addition, the charge held in the storage capacitor 53 of each pixel 50 flows out to the signal line 56 through the TFTs 52 arranged in the column direction. This charge is amplified by the amplifier 62. A multiplexer 66 is connected to the amplifier 62 via a sample and hold circuit 64. The multiplexer 66 includes a plurality of second switches SW2 for switching the signal lines 56, and a column address decoder 68 for outputting a selection signal for selecting one of the second switches SW2. The column address decoder 68 is supplied with an address signal from the detector control unit 46. An A / D converter 70 is connected to the multiplexer 66, and a radiation image converted into a digital signal by the A / D converter 70 is output via the detector control unit 42. As shown in FIG. It is stored in the memory 30. That is, every time radiation imaging is performed in the image generation apparatus 10, a radiation image is output from the radiation detection apparatus 12, and the output radiation image is stored in the image memory 30 in time series, for example.

  The image generation apparatus 10 detects the movement of the subject 24 during radiography, and the tomosynthesis imaging based on the level of movement of the subject 24 detected by the body movement detection unit 100. And a photographing continuation determination unit 102 for determining whether or not to continue.

  Here, a specific example of the image generation apparatus 10A according to the first embodiment will be described with reference to FIGS.

  First, the image generation apparatus according to the first specific example (hereinafter referred to as the first image generation apparatus 10Aa), as shown in FIG. It has a sensor 104 that detects and converts it into an electrical signal (detection signal) corresponding to the level of movement of the subject. As the sensor 104, a distance sensor (ultrasonic distance sensor, infrared distance sensor, etc.) for measuring the distance from the sensor 104 to the subject, a displacement sensor (eddy current type displacement sensor, capacitance type displacement) for detecting the displacement of the subject. Sensors, differential transformers, laser displacement sensors, optical fiber displacement sensors, wire displacement sensors, magnetostrictive displacement sensors, etc.), for example, pressure sensors installed on the bed where the subject sleeps, etc. to detect the movement of the center of gravity of the subject Can be preferably employed.

  Further, the first image generation apparatus 10 </ b> Aa serves as the imaging continuation determination unit 102 and compares the level of the detection signal Sa output from the sensor 104 with the threshold level L <b> 1 stored in the first register 108. Part 106. If the level of the detection signal Sa is equal to or lower than the first threshold level L1, the first comparison unit 106 outputs a signal (imaging continuation signal Sb) that logically indicates “0”, and the level of the detection signal Sa is When the threshold level L1 is exceeded, a signal (shooting stop signal Sc) that logically indicates “1” is output. Once the shooting stop signal Sc is output, the output of the shooting stop signal Sc is maintained until the first comparison unit 106 is reset. The imaging continuation signal Sb and the imaging stop signal Sc from the first comparison unit 106 are supplied to the radiation image acquisition unit 14 by cable or wirelessly.

  The radiographic image acquisition unit 14 sequentially performs radiographic imaging as usual and continues tomosynthesis imaging while the imaging continuation signal Sb is input from the first comparison unit 106. However, once the imaging stop signal Sc is input, the tomosynthesis imaging is stopped, and the subsequent radiography that was scheduled to be performed in the tomosynthesis imaging is not performed. That is, the emission of the radiation 26 from the radiation irradiation unit 20 is stopped, and the radiation irradiation unit 20 is returned to the initial position by the moving mechanism 22.

  The first image generation apparatus 10 </ b> A includes a body movement warning unit 110, a re-shooting determination unit 112, and a re-shooting warning unit 114 in addition to the sensor 104 and the first comparison unit 106 described above.

  The body movement warning unit 110 issues a warning based on the input of the shooting stop signal Sc from the shooting continuation determination unit 102. The warning is displayed on the monitor 116 connected to the first image generating apparatus 10Aa by displaying a message indicating that the shooting has been stopped, by turning on (or blinking) the warning lamp 118, or by a message indicating that the shooting has been stopped (set in advance). Audio data) is output through the speaker 120. By this warning, the operator knows that the subject 24 has moved to such an extent that the shooting should be stopped, and that the shooting of the subject 24 has been stopped. Furthermore, preparation for re-shooting the subject 24 is performed.

  By the way, depending on the part to be imaged and the purpose, there is a possibility that a sufficient tomographic image can be obtained even if all the radiographic images acquired by one tomosynthesis imaging are not all prepared. Therefore, the re-imaging determination unit 112 has a configuration for changing a determination criterion as to whether or not to re-image according to the imaging region and the imaging purpose when the tomosynthesis imaging is stopped. That is, the re-imaging determination unit 112 receives a counter 122 that counts the number of times of radiation imaging, and a comparison unit 126 that compares the count value n of the counter 122 with the determination reference value Da stored in the register 124. A reference value determination unit 128 that determines the determination reference value Da stored in the register 124 with reference to the imaging region, the imaging purpose, and the like in the imaging condition data.

  For example, when data of imaging conditions is supplied from the console 18 to the reference value determining unit 128 before the start of tomosynthesis imaging, the reference value determining unit 128 refers to the imaging region, the imaging purpose, etc., and determines the determination reference value. Da is determined. An example of determination of the determination reference value Da when the number of radiographic images is 100 is shown in Table 1 below.

  For example, if the imaging region is an extremity and the purpose of imaging is follow-up imaging, the determination reference value = 100 × 50% = 50 is set as the determination reference value Da. For example, if the imaging region is the chest and the imaging purpose is imaging of the affected area, the determination reference value = 100 sheets × 90% = 90 is set as the determination reference value Da. The determined determination reference value Da is stored in the register 124.

  When tomosynthesis imaging is started, a predetermined number of radiographing operations are sequentially performed, and the counter 122 of the reimaging determination unit 112 counts the number of radiographic imaging operations. When the tomosynthesis imaging is stopped due to the body movement of the subject 24 during the tomosynthesis imaging, the counting operation in the counter 122 is terminated, and the count value n in the counter 122 is supplied to the comparison unit 126. The comparison unit 126 compares the count value n supplied from the counter 122 with the determination reference value Da stored in the register 124. If the count value n is equal to or greater than the determination reference value Da, a signal ( A re-shooting unnecessary signal Sd) is output, and if the count value n is less than the determination reference value Da, a signal indicating that re-shooting is required (re-shooting required signal Se) is output. The re-shooting unnecessary signal Sd or the re-shooting required signal Se is supplied to the re-shooting warning unit 114.

  The re-shooting warning unit 114 issues a warning or warning based on the input of the re-shooting unnecessary signal Sd or the re-shooting necessity signal Se from the reshooting determination unit 112. The alert displays a message on the monitor 116 connected to the first image generating apparatus 10A indicating that the tomosynthesis imaging is stopped but the re-imaging is not necessary. Of course, in the reconstructed tomographic image, a mark indicating that the tomosynthesis imaging has been stopped may be displayed at a position where the interpretation is not affected (for example, a surrounding portion). The number (number or ratio) of radiation imaging may be displayed together with this mark. Thereby, at the stage of interpretation, it can be easily recognized that this tomographic image has been reconstructed even though tomosynthesis imaging has been stopped.

  On the other hand, the warning displays a message indicating that re-shooting is necessary on the monitor 116, turns on (or blinks) the warning light 118, and indicates a message indicating that re-shooting is necessary (set in advance). Audio data) through the speaker 120, and the like. By this warning, the operator can know that the subject 24 needs to be re-photographed, and can quickly prepare for the subject 24 to be re-photographed.

  The first image generating apparatus 10A is basically configured as described above. Next, the operation of the first image generating apparatus 10A will be described with reference to FIG.

  First, in step S1 of FIG. 5, patient information of a patient to be imaged (subject 24) is registered in advance in the console 18 prior to imaging. If the imaging region and imaging method are determined in advance, these imaging conditions are also registered in advance. The imaging conditions are supplied to the re-imaging determination unit 112.

  Thereafter, in step S <b> 2, the reference value determination unit 128 of the re-imaging determination unit 112 determines the determination reference value Da based on the imaging region and imaging purpose of the imaging conditions supplied from the console 18, and stores the determination reference value Da in the register 124. .

  Thereafter, in step S3, the counter 122 of the re-shooting determination unit 112 resets the count value n to 0.

  Thereafter, in step S4, the subject 24 (patient) is guided to the first image generating apparatus 10A, and positioning according to the imaging region or the like is performed.

  When the positioning is completed, the process proceeds to step S5, and tomosynthesis imaging is started based on an operation instruction from the operator to the console 18. At the same time, a detection operation (detection of movement of the subject 24) by the sensor 104 of the body movement detection unit 100 and a comparison process by the first comparison unit 106 of the imaging continuation determination unit 102 are also started. That is, the sensor 104 converts into an electrical signal (detection signal Sa) corresponding to the level of movement of the subject 24 and outputs it. The first comparison unit 106 compares the level of the detection signal Sa output from the sensor 104 with the threshold level L1 stored in the first register 108, and the level of the detection signal Sa is equal to or lower than the threshold level L1. If so, the imaging continuation signal Sb is output, and the imaging stop signal Sc is output when the level of the detection signal Sa exceeds the threshold level L1.

  In step S <b> 6, the radiation image acquisition unit 14 controls the movement mechanism 22 so that the radiation irradiation unit 20 reaches the nth position.

  When the radiation irradiating unit 20 reaches the nth position, the process proceeds to the next step S7, where it is determined whether or not the photographing is stopped. This determination is made based on whether or not the shooting stop signal Sc is supplied from the shooting continuation determination unit 102.

  If the imaging stop signal Sc is not supplied, that is, if the imaging continuation signal Sb is supplied, the process proceeds to step S8, and the n-th radiation imaging is performed. The nth radiographic image obtained by the nth radiography is stored in the image memory 30. That is, the nth radiation image is acquired.

  Thereafter, in step S9, the count value n of the counter 122 of the re-shooting determination unit is updated by +1.

  Thereafter, in step S10, it is determined whether or not radiation imaging has been performed a prescribed number of times (for example, 100 times). This determination is made based on whether the count value n of the counter 122 is 100 or more, for example.

  If the number of radiation imaging is less than the prescribed number, the process returns to step S6, and the processes after step S6 are repeated.

  In step S10, when the number of times of radiation imaging has reached the prescribed number, the process proceeds to the next step S11, and the prescribed number of radiation images stored in the image memory 30 are re-examined using the back projection method. By constructing, a tomographic image of the subject is generated. The generated tomographic image is displayed on the monitor 116 connected to the first image generating apparatus 10A.

  On the other hand, if it is determined in step S7 that the imaging stop signal Sc is supplied, the process proceeds to step S12, and the body movement warning unit 110 is based on the input of the imaging stop signal Sc from the first comparison unit 106. Issue a warning.

  Thereafter, in step S <b> 13, the radiation image acquisition unit 14 stops tomosynthesis imaging, stops emission of the radiation 26 from the radiation irradiation unit 20, and returns the radiation irradiation unit 20 to the initial position by the moving mechanism 22.

  Thereafter, in step S14, it is determined whether or not re-shooting is necessary. This determination is performed by the comparison unit 126 of the re-shooting determination unit 112. If the count value n supplied from the counter 122 is equal to or greater than the determination reference value Da stored in the register 124, the re-shooting unnecessary signal Sd is output. If the count value n is less than the determination reference value Da, the re-shooting necessity signal Se is output.

  When the re-shooting unnecessary signal Sd is output from the comparison unit 126, the process proceeds to step S15, and a warning is issued through the re-shooting warning unit 114. This alerting is, for example, displaying a message on the monitor 116 connected to the first image generating apparatus 10A indicating that the tomosynthesis imaging is stopped but the re-imaging is unnecessary.

  Thereafter, the process proceeds to step S16, and a tomographic image of the subject is generated by reconstructing the radiographic images for the number of times of radiography using the back projection method. At this time, in the reconstructed tomographic image, a mark indicating that tomosynthesis imaging has been stopped, or a text indicating the number of times (number of sheets or ratio) of radiation imaging, at a portion that is not affected by interpretation (for example, a surrounding portion). Append data. This tomographic image is displayed on the monitor 116.

  On the other hand, if it is determined in step S14 that the re-shooting necessity signal Se is output from the comparison unit 126, the process proceeds to step S17, and a warning indicating re-shooting is issued through the re-shooting warning unit 114. For example, the speaker 120 displays a message indicating that reshooting is necessary, turns on (or blinks) the warning light 118, and displays a message (preset voice data) indicating that reshooting is necessary. For example, outputting a voice via. This warning allows the operator to know that the subject 24 needs to be re-photographed, and prepares for the subject 24 to be re-photographed.

  As described above, in the first image generation apparatus 10A, when the level of body movement of the subject 24 affects the reconstruction, it is possible to stop the subsequent radiography, thereby improving work efficiency. In addition, there is no waste in patient exposure and patient restraint time.

  In addition, when tomosynthesis imaging is stopped, the criteria for determining whether or not to re-image is changed according to the imaging region and imaging purpose. It is possible to eliminate the waste of shooting.

  In the above example, the criterion for determining whether or not to re-image is changed according to the imaging region and the imaging purpose. However, it may be uniformly 50% of the total number of images.

  Next, an image generation apparatus according to a second specific example (hereinafter referred to as a second image generation apparatus 10Ab) will be described with reference to FIG.

  As shown in FIG. 6, the second image generation device 10Ab has substantially the same configuration as the first image generation device 10A described above, but the configuration of the body motion detection unit 100 and the imaging continuation determination unit 102 is as follows. Different.

  That is, the body motion detection unit 100 captures the motion vector of the subject 24 from the start of tomosynthesis imaging (based on the optical camera 130 as a viewpoint) based on the optical camera 130 that captures the subject 24 and the captured image from the optical camera 130. And a motion vector detecting unit 132 for detecting a two-dimensional vector). The optical camera 130 is fixed at a preset position to be a fixed viewpoint. The motion vector detection unit 132 has an algorithm that incorporates the idea of motion vectors used in image compression technology and moving object recognition technology, and takes a difference between captured frames or between several frames. An image that has moved between one frame or several frames is extracted, and how much the image has moved from the start of tomosynthesis imaging is acquired as, for example, the number of pixels.

  On the other hand, the imaging continuation determination unit 102 compares the magnitude Ma (number of pixels) of the motion vector output from the motion vector detection unit 132 with the second threshold level L2 stored in the second register 134. 2 comparison unit 136. If the magnitude Ma of the motion vector is equal to or smaller than the second threshold level L2, the second comparison unit 136 outputs the imaging continuation signal Sb, and the magnitude Ma of the motion vector exceeds the second threshold level L2. At this stage, a shooting stop signal Sc is output.

  The other operations of the radiation detection device 12, the radiation image acquisition unit 14, the image reconstruction unit 16, the console 18, the body movement warning unit 110, the re-imaging determination unit 112, and the re-imaging warning unit 114 are the same as those of the first image generation device 10A. Therefore, the duplicate description is omitted.

  Even in the second image generation device 10Ab, when the level of body movement of the subject 24 affects the reconstruction, it is possible to stop the subsequent radiographic imaging, and to improve the work efficiency. There is no waste in patient exposure and patient restraint time.

  Next, an image generation apparatus according to a third specific example (hereinafter referred to as a third image generation apparatus 10Ac) will be described with reference to FIG.

  As shown in FIG. 7, the third image generation apparatus 10Ac has substantially the same configuration as the first image generation apparatus 10Aa described above, but the configuration of the body motion detection unit 100 and the imaging continuation determination unit 102 is as follows. Different.

  That is, the body motion detection unit 100 includes an attention region extraction unit 138 that sequentially extracts the attention region of the subject 24 from sequentially acquired radiographic images (two-dimensional images), and a coordinate estimation unit that estimates the coordinates of the extracted attention region. 140 and a movement vector detection unit 142 that detects a movement vector (a three-dimensional vector in world coordinates) of the region of interest from the start time of tomosynthesis imaging based on the estimated coordinates.

  The attention area can be determined manually in advance or automatically by image processing.

  In the case of manual determination, for example, a marker is attached to the subject 24 in advance before tomosynthesis imaging, and the radiation image of this marker is set as a region of interest. As the marker, for example, a lead ball of about 5 mm or a disk can be used.

  As an example in the case of automatic determination, for example, an image having, for example, a geometric shape is extracted from a radiographic image. Examples of the geometric image include an image in which a linear image extends over several tens of pixels, and an image including the linear image.

  Then, the attention area extraction unit 138 extracts an image of the attention area from the first radiation image. From the second and subsequent radiation images, the position of the extracted image of the attention area is tracked using pattern matching or the like.

  The coordinate estimation unit 140 estimates the three-dimensional coordinates of the attention region based on the attention region tracking result obtained by the attention region extraction unit 138. The three-dimensional coordinates of the attention area are obtained by, for example, the intersection (or closest point) between the projection path of the attention area in the first radiographic image and the projection path of the attention area in each radiographic image.

  The movement vector detection unit 142 detects the movement vector of the attention area based on the three-dimensional coordinates of the attention area obtained by the coordinate estimation section 140 and the three-dimensional coordinates of the attention area at the start of tomosynthesis imaging. The movement vector is obtained on a scale such as μm or mm.

  On the other hand, the imaging continuation determination unit 102 compares the magnitude Mb of the movement vector output from the movement vector detection unit 142 with the third threshold level L3 stored in the third register 144. Have If the magnitude Mb of the movement vector is equal to or smaller than the third threshold level L3, the third comparison unit 146 outputs the imaging continuation signal Sb, and the magnitude Mb of the movement vector exceeds the third threshold level L3. At this stage, a shooting stop signal Sc is output.

  The other operations of the radiation detection device 12, the radiation image acquisition unit 14, the image reconstruction unit 16, the console 18, the body movement warning unit 110, the re-imaging determination unit 112, and the re-imaging warning unit 114 are the same as those of the first image generation device 10A. Therefore, the duplicate description is omitted.

  Even in the third image generation apparatus 10Ac, when the level of body movement of the subject 24 affects the reconstruction, it is possible to stop the subsequent radiography and improve the work efficiency. There is no waste in patient exposure and patient restraint time.

  Next, an image generation apparatus according to a fourth specific example (hereinafter referred to as a fourth image generation apparatus 10Ad) will be described with reference to FIG.

  As shown in FIG. 8, the fourth image generation device 10Ad has substantially the same configuration as the third image generation device 10Ac described above, but the configuration of the body motion detection unit 100 and the imaging continuation determination unit 102 is as follows. It is different.

  That is, the body motion detection unit 100 extracts the attention area of the subject 24 in order from the sequentially acquired radiographic images (two-dimensional images), and the attention area extraction section 138 similar to the above, and based on the extracted attention area, A movement vector calculation unit 148 that calculates a movement vector of a region of interest between two temporally adjacent radiographic images and a difference calculation unit 150 that calculates a difference between movement vectors that are sequentially calculated.

  On the other hand, the imaging continuation determination unit 102 compares the magnitude Mc of the difference (movement vector difference) output from the difference calculation unit 150 with the fourth threshold level L4 stored in the fourth register 152. 4 comparison section 154 is provided. The fourth comparison unit 154 outputs the imaging continuation signal Sb if the movement vector difference Mc is equal to or less than the fourth threshold level L4, and the movement vector difference Mc exceeds the fourth threshold level L4. Then, the photographing stop signal Sc is output.

  The other operations of the radiation detection device 12, the radiation image acquisition unit 14, the image reconstruction unit 16, the console 18, the body movement warning unit 110, the re-imaging determination unit 112, and the re-imaging warning unit 114 are the same as those of the first image generation device 10A. Therefore, the duplicate description is omitted.

  Even in the fourth image generation device 10Ad, when the level of body movement of the subject 24 affects the reconstruction, it is possible to stop the subsequent radiography and improve work efficiency. There is no waste in patient exposure and patient restraint time.

  Next, an image generation apparatus according to a fifth specific example (hereinafter referred to as a fifth image generation apparatus 10Ae) will be described with reference to FIG.

  As shown in FIG. 9, the fifth image generation device 10 </ b> Ae has substantially the same configuration as the above-described third image generation device 10 </ b> Ac (see FIG. 7), but differs in the following points.

  That is, first, the radiation control unit 28 performs thinning irradiation during the forward movement operation of the radiation irradiation unit 20 by the moving mechanism 22 and performs thinning irradiation during the backward movement operation of the radiation irradiation unit 20 by the movement mechanism 22. The irradiation is controlled to be completed. For example, when it is assumed that radiation irradiation is performed at 70 positions (P1, P2, P3... P70), the forward movement operation is performed at thinned positions, for example, P1, P3, P5. Radiation irradiation is performed, and in the backward movement operation, the irradiation is controlled to be performed at thinned-out positions, for example, P70, P68, P66... P2.

  Further, the radiation control unit 28 sends an image reading command signal to the attention area extraction unit 138 of the body motion detection unit 100 at the time of performing radiation irradiation at a preset irradiation position among a plurality of irradiation positions in the forward movement operation. Sg is output, and control is performed so as to output an image reading command signal Sg to the attention area extraction unit 138 at the time when radiation irradiation is performed at a preset irradiation position among a plurality of irradiation positions in the backward operation. .

  The attention area extraction unit 138 reads a radiation image at a preset irradiation position based on the input of the image reading command signal Sg from the radiation control unit 28, and extracts the attention area of the subject 24 from the read radiation image. Specifically, the attention area extraction unit 138 extracts an image of the attention area from a radiation image at a preset irradiation position at the time of forward movement based on the input of the first image reading command signal Sg, and then Based on the input of the second image reading command signal Sg, an image of the region of interest is extracted from the radiation image at the preset irradiation position during the backward movement. The movement vector detection unit 142 calculates the movement vector of the attention area extracted during the forward movement and the attention area extracted during the backward movement.

  The third comparison unit 146 of the imaging continuation determination unit 102 outputs the imaging continuation signal Sb if the movement vector magnitude Mb is equal to or less than the third threshold level L3, and the movement vector magnitude Mb is third. When the threshold level L3 is exceeded, a shooting stop signal Sc is output.

  There is a certain time interval between the first extraction time point and the second extraction time point as the timing at which the attention region extraction unit 138 extracts the attention region, and there is a body movement that leads to the stop of the photographing. In such a case, a timing at which the backward movement operation is not performed as much as possible is preferable. Therefore, in the present embodiment, the radiation control unit 28 outputs the image reading command signal Sg at the time when radiation irradiation is performed at the center of the forward movement (P35) and the center of the backward movement (P36). I have control. Alternatively, the image reading command signal Sg is output a plurality of times (for example, P13, P35, P57 during the reciprocating operation, P58, P36, P14, etc. during the reciprocating operation) in each of the forward operation and the backward operation. The presence / absence of body movement may be detected from the relationship between the regions of interest in each set of radiation images (P57 and P58, P35 and P36, and P13 and P14).

  The other operations of the radiation detection device 12, the radiation image acquisition unit 14, the image reconstruction unit 16, the console 18, the body movement warning unit 110, the re-imaging determination unit 112, and the re-imaging warning unit 114 are the same as those of the first image generation device 10A. Therefore, the duplicate description is omitted.

  Even in the fifth image generation device 10Ae, when the level of body movement of the subject 24 affects the reconstruction, it is possible to stop the subsequent radiography and improve work efficiency. There is no waste in patient exposure and patient restraint time.

  The fifth image generating apparatus 10Ae can also be applied to a radiation image forming apparatus that can generate a three-dimensional image such as a cone beam CT described in, for example, Japanese Patent Application Laid-Open No. 2000-139901.

  As shown in FIGS. 10A and 10B, the radiation image forming apparatus 170 such as a cone beam CT is installed at a position facing the radiation irradiation unit 20 with the subject 24 on the imaging table 172 sandwiched therebetween. The radiation irradiation device 20 and the radiation detection device 12 are supported by a C-shaped arm suspended from the ceiling. The beam shape of the radiation is changed to, for example, a pyramid shape by the collimator 178 according to the shape of the radiation detection device 12.

  Then, the moving mechanism 22 (see FIG. 9) rotates the C-shaped arm 360 ° to move the radiation irradiation unit 20 to a plurality of preset positions. The radiation control unit 28 performs control so that the radiation 26 is irradiated from the radiation irradiation unit 20 to the subject 24 on the imaging table when the radiation irradiation unit 20 reaches a plurality of preset positions.

  At this time, the radiation control unit 28 performs thinning irradiation during the first 360 ° rotation operation of the radiation irradiation unit 20 by the movement mechanism 22, and thinning out during the second 360 ° rotation operation of the radiation irradiation unit 20 by the movement mechanism 22. By performing irradiation, control is performed so that all-point irradiation is completed. For example, assuming that irradiation is performed at 360 positions (0 °, 1 °, 2 °... 359 °), in the first rotation operation, the thinned positions, for example, 0 °, 2 °, Radiation irradiation is performed at 2 ° intervals of 4 ° to 358 °, and in the second rotation operation, thinned positions, for example, 1 °, 3 °, 5 ° to 359 ° at 2 ° intervals. It is controlled to perform radiation irradiation at the position. As a result, a radiation image in a 360 ° direction with respect to the subject 24 is acquired. The acquired radiographic image is three-dimensionally reconstructed by the image reconstruction unit 16 and is generated as a three-dimensional image. For reconstruction processing, several types of algorithms such as the Feldkamp method and the Grangeat method are known.

  Also in this case, as described above, the radiation control unit 28 pays attention to the body motion detection unit 100 when the radiation irradiation is performed at a preset irradiation position among a plurality of irradiation positions in the first rotation operation. When the image reading command signal Sg is output to the region extraction unit 138 and radiation irradiation is performed at a preset irradiation position among a plurality of irradiation positions in the second rotation operation, the image is similarly output to the attention region extraction unit 138. Control is performed to output the read command signal Sg. Since the operations in the attention area extraction unit 138, the coordinate estimation unit 140, the movement vector detection unit 142, and the imaging continuation determination unit 102 have already been described, they are omitted here.

  As the timing at which the attention area extraction unit 138 extracts the attention area, there is a certain time interval between the first extraction time and the second extraction time, as described above, and the photographing is stopped. When there is a body movement, it is preferable that the backward scanning is not performed as much as possible. Therefore, the radiation control unit 28 performs control so that the image reading command signal Sg is output at the time when the radiation irradiation is performed at the beginning and the end (0 ° position and 358 ° position) of the first rotation operation. Alternatively, control is performed so that the image reading command signal Sg is output at the time of radiation irradiation at the beginning of the first rotation operation and the first rotation operation (0 ° position and 1 ° position), respectively. To do. Alternatively, the presence or absence of body movement may be detected from the relationship between the regions of interest in each set of captured images by outputting the image reading command signal Sg a plurality of times in each of the forward movement operation and the backward movement operation.

  Thus, even when applied to the radiation image forming apparatus 170 that can generate a three-dimensional image such as a cone beam CT, if the body movement level of the subject 24 affects the reconstruction, the subsequent radiation The imaging can be stopped, the working efficiency can be improved, and there is no waste in patient exposure and patient restraint time.

  Next, an image generation apparatus 10B according to a second embodiment will be described with reference to FIG.

  As shown in FIG. 11, the image generation device 10B has substantially the same configuration as the image generation device 10A described above, but the level of movement of the subject 24 detected by the body motion detection unit 100 is a threshold level. The difference is that a warning output unit 156 for outputting a warning is provided at a time when the value exceeds. The warning is displayed on the monitor 116 connected to the image generating device 10B by displaying a message indicating that the shooting is stopped, turning on (or blinking) the warning lamp 118, ) Through a speaker 120. The reason for setting the threshold level is that if the subject 24 is a human being, for example, it is difficult to maintain the posture set by the operator's positioning without moving at all, and some body movement occurs. If the sensitivity of the body motion detection unit 100 is high, even a slight body motion is detected, and as a result, there is a problem that a warning is continuously output or a warning is frequently output and is troublesome. Therefore, in this example, a threshold level is set so that a warning is not issued if there is a slight body movement that does not hinder photographing. That is, the output of the warning from the warning output unit 156 indicates that there has been a body movement that affects the shooting. Therefore, the operator does not need to continue to observe the body movement of the subject over the period during which tomosynthesis imaging is performed, and observes the body movement of the subject 24 for the first time when a warning is given, and continues or cancels the imaging. You just have to judge. That is, the operator's work burden can be reduced effectively.

  Specific examples of the body motion detection unit 100 include the sensor 104 of the first image generation device 10Aa, the optical camera 130 and the motion vector detection unit 132 of the second image generation device 10Ab, and the attention area extraction of the third image generation device 10Ac. The unit 138, the coordinate estimation unit 140, the movement vector detection unit 142, the attention area extraction unit 138, the movement vector calculation unit 148, and the difference calculation unit 150 of the fourth image generation device 10Ad can be used.

  On the other hand, the warning output unit 156 can employ the same configuration as the imaging continuation determination unit 102 of the image generation apparatus 10A. In this case, the 156 threshold level of the warning output unit is used by the imaging continuation determination unit 102. The same level as the threshold level used may be used, or a different level may be used. Therefore, as a specific example of the warning output unit 156, corresponding to the specific example of the body motion detection unit 100, the first comparison unit 106, the first register 108, and the second image generation device of the first image generation device 10Aa described above. The second comparison unit 136 and the second register 134 of 10Ab, the third comparison unit 146 and the third register 144 of the third image generation device 10Ac, and the fourth comparison unit 154 and the fourth register 152 of the fourth image generation device 10Ad are used. be able to.

  Next, a modification of the image generation apparatus 10B according to the second embodiment will be described with reference to FIGS.

  First, as shown in FIG. 12, the image generation device 10 </ b> Ba according to the first modified example has substantially the same configuration as the image generation device 10 </ b> B described above, but the radiation image output from the radiation detection device 12 is monitored 116. And a shooting state monitor unit 158 that assists the operator in determining whether or not to continue tomosynthesis shooting.

  The imaging state monitor unit 158 includes a radiation image receiving unit 160 that receives a radiation image output from the radiation detection device 12 in units of one sheet, and a radiation image that displays the received radiation images on the monitor 116 sequentially in units of one sheet. And a display portion 162. The radiographic image display unit 162 may display the radiographic image together with the reference pattern. Examples of the reference pattern include a cross pattern whose intersection is the center position of the screen of the monitor 116, and a lattice pattern in which a frame pattern and a cross pattern are combined.

  The operator can easily recognize the body movement of the subject 24 by, for example, viewing the radiation image displayed on the monitor 116 together with the reference pattern, and can easily determine whether tomosynthesis imaging should be continued or stopped. it can.

  As described above, in the image generation device 10Ba, by displaying the captured image of the subject 24 during radiography on the monitor 116, the operator can easily grasp the level of body movement of the subject 24, and The warning output from the warning output unit 156 can prompt the operator to be alerted, thereby improving work efficiency and causing waste in patient exposure and patient restraint time. Absent.

  Next, an image generation device 10Bb according to a second modification will be described with reference to FIG.

  As shown in FIG. 13, the image generation device 10Bb has substantially the same configuration as the above-described image generation device 10Ba, but the imaging state monitor unit 158 is different in the following points.

  That is, the imaging state monitor unit 158 shifts and adds the received radiographic images in order, and the reconstructed image gradually by adding the radiographic image receiving unit 160 that receives the radiographic images output from the radiation detecting device 12 in units of one sheet. A simple reconstruction unit 164 to be generated and a radiation image display unit 162 for displaying on the monitor 116 the reconstructed image gradually generated by the simple reconstruction unit 164 are provided. That is, the imaging state monitor unit 158 displays the radiation image output from the radiation detection device 12 on the monitor 116 while sequentially shifting and adding.

  If the body movement of the subject 24 is small, it is possible to recognize that a tomographic image is gradually generated by displaying the radiation image from the radiation detection device 12 while sequentially shifting and adding, so tomosynthesis imaging should be continued. It can be easily determined that there is. On the other hand, if the movement of the subject 24 is large, a tomographic image should not be generated because a tomographic image is not generated even if the radiographic images from the radiation detection device 12 are displayed while being sequentially shifted and added. Can be easily performed.

  Also in this image generation apparatus 10Bb, by displaying the captured image of the subject 24 during radiography on the monitor 116, the operator can easily grasp the level of body movement of the subject 24, and a warning output unit. The warning output from 156 can prompt the operator to call attention.

  In addition, the radiation tomographic image generation apparatus according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

  For example, the radiation detector 40 of the radiation detection device 12 converts the dose of the incident radiation 26 into an electrical signal directly by the photoelectric conversion layer 51 (direct conversion method), but instead, the incident radiation X Using a radiation detector configured to convert the visible light into an electrical signal using a solid-state detection element such as amorphous silicon (a-Si) after being converted into visible light by a scintillator (See Japanese Patent No. 3494683).

  Further, radiation image information can be acquired by using a light readout type radiation detector. In this optical readout type radiation detector, when radiation is incident on the solid detection elements arranged in a matrix, an electrostatic latent image corresponding to the dose is accumulated and recorded on the solid detection elements. When reading the electrostatic latent image, the radiation detector is irradiated with reading light, and the value of the generated current is acquired as radiation image information. The radiation detector can erase and reuse the radiation image information that is the remaining electrostatic latent image by irradiating the radiation detector with erasing light (refer to Japanese Patent Laid-Open No. 2000-105297). .

  In the radiation detector 40 described above, an example in which the TFT 52 is used has been described. Alternatively, the radiation detector 40 may be implemented in combination with another imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. Furthermore, it can be replaced by a CCD (Charge-Coupled Device) image sensor that transfers charges while shifting the charges by a shift pulse corresponding to the gate signal referred to in the TFT 52.

  In the above example, the fifth image generation apparatus 10Ae is applied to a radiation image forming apparatus that can generate a three-dimensional image such as a cone beam CT. The fourth image generation apparatus 10Ad and the image generation apparatus 10B according to the second embodiment (and modifications thereof) are also applied to a radiation image forming apparatus capable of generating a three-dimensional image such as a cone beam CT. Of course, you can make it happen.

10A, 10Aa to 10Ae, 10B, 10Ba, 10Bb ... image generation device 12 ... radiation detection device 14 ... radiation image acquisition unit 16 ... image reconstruction unit 18 ... console 20 ... radiation irradiation unit 24 ... subject 26 ... radiation 30 ... image memory 40 ... Radiation detector 100 ... Body motion detection unit 102 ... Imaging continuation determination unit 104 ... Sensor 106 ... First comparison unit 110 ... Body motion warning unit 112 ... Re-imaging determination unit 114 ... Re-imaging warning unit 116 ... Monitor 130 ... Optical Camera 132 ... motion vector detection unit 136 ... second comparison unit 138 ... attention area extraction unit 140 ... coordinate estimation unit 142 ... movement vector detection unit 146 ... third comparison unit 148 ... movement vector calculation unit 150 ... difference calculation unit 154 ... first 4 comparison unit 156 ... warning output unit 158 ... imaging state monitor unit 160 ... radiation image receiving unit 162 ... radiation image display unit 16 ... simple reconstruction unit

Claims (15)

The radiation irradiating unit provided facing the radiation detecting device is moved to a plurality of positions, and the radiation is irradiated from different directions to the subject on the radiation detecting device from the radiation irradiating unit at each position. A radiological image acquisition unit that acquires a plurality of radiographic images output from the detection device, and reconstructs the plurality of radiographic images acquired by the radiographic image acquisition unit to generate a tomographic image of the subject. In a radiation tomographic image generation apparatus having a reconstruction means,
Body movement detecting means for detecting movement of the subject during photographing;
A radiological tomographic image generation apparatus comprising: an imaging continuation determination unit that determines whether or not to continue imaging based on a level of movement of the subject detected by the body motion detection unit. The radiation tomographic image generation apparatus according to claim 1,
The body movement detecting means includes
A radiation tomographic image generating apparatus, comprising: a sensor that detects the movement of the subject by a contact type or a non-contact type, converts the detected movement into an electrical signal corresponding to the level of movement of the subject, and outputs the electrical signal. The radiation tomographic image generating apparatus according to claim 2,
The photographing continuation determining means is
While the level of the electrical signal output from the sensor does not exceed the threshold level, it is determined to continue the imaging, and when the level of the electrical signal exceeds the threshold level, the imaging is performed. A radiation tomographic image generation apparatus characterized by performing determination to stop. The radiation tomographic image generation apparatus according to claim 1,
The body movement detecting means includes
An optical camera for imaging the subject;
A radiation tomographic image generation apparatus comprising: means for detecting a motion vector of the subject from the start of imaging based on a captured image from the optical camera. The radiation tomographic image generating apparatus according to claim 4,
The photographing continuation determining means is
While the detected motion vector magnitude has never exceeded the threshold level, it is determined to continue the imaging, and the imaging is stopped when the motion vector magnitude exceeds the threshold level. A radiation tomographic image generation apparatus characterized by performing determination. The radiation tomographic image generation apparatus according to claim 1,
The body movement detecting means includes
Means for extracting a region of interest of the subject from the radiographic images sequentially acquired;
Means for estimating the extracted three-dimensional coordinates of the region of interest;
A radiation tomographic image generation apparatus comprising: means for detecting a movement vector of the region of interest from the imaging start time based on the estimated three-dimensional coordinates. The radiation tomographic image generation apparatus according to claim 6.
The photographing continuation determining means is
While the magnitude of the detected movement vector of the attention area has never exceeded the threshold level, it is determined to continue the imaging, and the imaging is stopped when the magnitude of the movement vector exceeds the threshold level. A radiation tomographic image generation apparatus characterized by performing determination to perform. The radiation tomographic image generation device according to claim 3, 5 or 7,
The radiation tomographic image generating apparatus further includes a body motion warning unit that issues a warning when the imaging continuation determination unit determines to stop the imaging. The radiation tomographic image generation apparatus according to claim 3, 5, 7, or 8,
Furthermore, it has re-imaging determination means for determining whether or not re-imaging is necessary based on the number of radiographic images acquired by the radiological image acquisition means during a period in which it is determined to continue the imaging. Radiation tomographic image generator. The radiation tomographic image generation apparatus according to claim 9.
The re-photographing determination means includes
The number of radiographic images acquired by the radiological image acquisition means during a period when the determination to continue the imaging is made is less than a predetermined ratio of the total number of radiographic images to be acquired by the radiographic image acquisition means set in advance. In this case, the radiation tomographic image generating apparatus determines that re-imaging is necessary. The radiation irradiating unit provided facing the radiation detecting device is moved to a plurality of positions, and the radiation is irradiated from different directions to the subject on the radiation detecting device from the radiation irradiating unit at each position. A radiological image acquisition unit that acquires a plurality of radiographic images output from the detection device, and reconstructs the plurality of radiographic images acquired by the radiographic image acquisition unit to generate a tomographic image of the subject. In a radiation tomographic image generation apparatus having a reconstruction means,
Body movement detecting means for detecting movement of the subject during photographing;
A radiation tomographic image generating apparatus, comprising: warning output means for outputting a warning when a level of movement of the subject detected by the body motion detection means exceeds a threshold level. The radiation tomographic image generation apparatus according to claim 11.
A radiological tomographic image generation apparatus comprising imaging state monitoring means for displaying the radiographic image output from the radiation detection apparatus on a display device. The radiation tomographic image generation device according to claim 12,
The photographing state monitoring means includes
A radiation tomographic image generation apparatus, wherein the radiation images output from the radiation detection apparatus are sequentially displayed in units of one sheet. The radiation tomographic image generation apparatus according to claim 13.
The photographing state monitoring means includes
A radiation tomographic image generation apparatus, wherein the radiation images output from the radiation detection apparatus are sequentially displayed together with a reference pattern in units of one sheet. The radiation tomographic image generation device according to claim 12,
The photographing state monitoring means includes
A radiation tomographic image generation apparatus, wherein the radiation images output from the radiation detection apparatus are displayed while being sequentially shifted and added.

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