JP5581704B2 - X-ray equipment - Google Patents

Description

This invention relates to X-ray imaging equipment.

  In such an X-ray imaging apparatus, conventionally, an imaging position is confirmed by irradiating a subject with light using a collimator lamp (see Patent Document 1). However, even if the imaging position is confirmed using a collimator lamp, it is difficult to confirm a subtle angle error of the imaging region or overlapping of the body. In addition, it is impossible to confirm the position of a part in the body, such as the overlap of the internal organs and bones.

  For this reason, before performing actual X-ray imaging, perform fluoroscopy for position confirmation, and confirm the position of the subject by performing fluoroscopy for position confirmation, and then perform actual X-ray imaging. An X-ray imaging apparatus has also been proposed (see Patent Document 2).

2007-229387 No. 2000-12280

  In the X-ray imaging apparatus described in Patent Document 2, since it is necessary to perform a fluoroscopic work before actual X-ray imaging, it is impossible to execute the inspection quickly. In addition, X-ray imaging apparatuses that can perform fluoroscopic imaging are generally expensive and are not installed in all inspection facilities.

The present invention has been made to solve the above-mentioned problems, and it is not necessary to use an expensive and time-consuming X-ray fluoroscopic imaging apparatus, and the position of the imaging position can be easily confirmed and X-ray imaging can be performed quickly. and to provide an X-ray imaging equipment capable of executing.

The invention according to claim 1 is an X-ray tube that irradiates a subject with X-rays, an X-ray detection unit that detects X-rays irradiated from the X-ray tube and passed through the subject, and the X-rays An image display unit that displays an X-ray image based on an X-ray detection value detected by the detection unit; an operation button that can be pressed in two stages; and a hand switch that can transmit first and second signals; When the first signal is transmitted from the hand switch, an instruction to start rotating the anode and energize the cathode filament is transmitted to the X-ray tube, and a low dose or low energy is transmitted from the X-ray tube. Control means for irradiating X-rays and irradiating X-rays with a normal dose or normal energy necessary for X-ray imaging from the X-ray tube when a second signal is transmitted from the hand switch . It is characterized by that.

According to a second aspect of the present invention, in the first aspect of the present invention, when a low dose or low energy X-ray is irradiated from the X-ray tube, an image to be displayed on the image display unit has a low resolution. In addition, the image processing unit includes a high-resolution image displayed on the image display unit when the normal dose or normal energy X-rays necessary for X-ray imaging are irradiated from the X-ray tube.

According to a third aspect of the present invention, in the first aspect of the present invention, when a low dose or low energy X-ray is irradiated from the X-ray tube, the image signal input to the image display unit is multiplied. An image processing unit that increases the gain and decreases the gain that is multiplied by the image signal input to the image display unit when the normal dose or normal energy X-ray necessary for X-ray imaging is irradiated from the X-ray tube Is provided.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the low dose or low energy X-ray is irradiated, the tube voltage applied to the X-ray tube is The value is the same as when irradiating a normal dose or normal energy X-ray, and the tube current time product applied to the X-ray tube is smaller than that when irradiating the normal dose or normal energy X-ray.

The invention according to claim 5 is the invention according to any one of claims 1 to 4 , further comprising a collimator mechanism including a collimator lamp and a movable diaphragm, and an exposure range defined by the collimator mechanism. Are irradiated with low dose or low energy X-rays from the X-ray tube.

  According to the first aspect of the present invention, after confirming the position by displaying an image for position confirmation with a low dose or low energy X-ray, X-ray imaging is performed with the normal dose or normal energy X-ray. Therefore, the position of the imaging position can be easily confirmed and X-ray imaging can be executed quickly. At this time, it is not necessary to use an X-ray fluoroscopic apparatus that is expensive and takes time to operate.

In addition, preparation for X-ray imaging can be performed when a position confirmation image is displayed by displaying a low dose or low energy X-ray. For this reason, it becomes possible to perform subsequent X-ray imaging promptly, and it is possible to execute position confirmation and X-ray imaging quickly and continuously by sequentially pressing the operation buttons on the hand switch. .

According to the second aspect of the present invention, when the position confirmation is performed by displaying the image for position confirmation with the low dose or low energy X-ray, the image displayed on the image display unit is set to the low resolution. The time required for displaying an image can be shortened. For this reason, the position confirmation can be completed quickly, and the subsequent X-ray imaging can be performed quickly.

According to the third aspect of the present invention, when the position confirmation is performed by displaying an image for position confirmation with a low dose or low energy X-ray, it is displayed on the image display section due to the low energy of the X-ray. It is possible to prevent a phenomenon that an image becomes dark.

According to the fourth aspect of the present invention, it is possible to reduce the exposure dose of X-rays to the subject while appropriately displaying the site necessary for imaging.

According to the fifth aspect of the present invention, since the X-ray tube irradiates the exposure range defined by the collimator mechanism with a low dose or low energy X-ray, the exposure dose to the subject is further reduced. It becomes possible.

1 is a schematic diagram of an X-ray imaging apparatus according to the present invention. It is a block diagram which shows the main electrical structures of the X-ray irradiation apparatus which concerns on this invention. 3 is a perspective view of a collimator mechanism 7. FIG. 1 is a schematic diagram of an X-ray tube 3. FIG. 3 is a schematic diagram of a hand switch 80. FIG. It is a flowchart which shows the X-ray imaging operation | movement by the X-ray imaging apparatus which concerns on this invention. It is a flowchart which shows the X-ray imaging operation | movement by the X-ray imaging apparatus which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an X-ray imaging apparatus according to the present invention.

  This X-ray imaging apparatus includes a table 2 on which a subject 1 as a subject is placed, an X-ray tube 3 that emits X-rays toward the subject 1, and a flat panel detector as an X-ray detection means. 4 and a collimator mechanism including a collimator lamp 5 and a movable diaphragm 6. X-rays irradiated from the X-ray tube 3 pass through the subject 1 and enter the flat panel detector 4. The flat panel detector 4 outputs an image signal corresponding to the incident X-ray.

  FIG. 2 is a block diagram showing the main electrical configuration of the X-ray irradiation apparatus according to the present invention.

  The X-ray irradiation apparatus includes a control unit 10 that controls the entire apparatus, and a storage unit 11 that stores data during control and the like. The control unit 10 is connected to a collimator mechanism 7 including a collimator lamp 5 and a movable diaphragm 6 shown in FIG. The control unit 10 is connected to the keyboard 84, the hand switch 80, and the flat panel detector 4 described above. The control unit 10 is connected to the X-ray tube 3 described above via the X-ray tube control unit 8. Further, the control unit 10 is connected to a display unit 91 such as a CRT via the image processing unit 9.

  FIG. 3 is a perspective view of the collimator mechanism 7 described above.

  The collimator mechanism 7 includes a collimator lamp 5 and four movable diaphragms 6. When performing X-ray imaging, the X-ray exposure range E is set by moving the movable diaphragm 6 with a drive motor (not shown) while the collimator lamp 5 is lit. In this state, X-rays are irradiated only from the X-ray tube 3 to the exposure range E defined by the four movable diaphragms 6.

  FIG. 4 is a schematic diagram of the X-ray tube 3 described above.

  The X-ray tube 3 includes a casing 36 having a radiation window 37 and lined with lead to shield X-rays. A glass bulb 31 that is evacuated is disposed in the casing 36. The glass bulb 31 has a pair of filaments (not shown), a cathode 32 that generates thermoelectrons A, and a rotating anode that generates X-rays B upon receiving the thermoelectrons A emitted from the cathode 32. (Target) 33 is provided. The rotating anode 33 is connected to the motor rotor 34. The motor rotor 34 is rotated at a high speed by a motor stator 35 disposed outside the glass bulb 31. X-rays B generated from the rotating anode 33 are radiated from a radiation window 37 provided in the casing 36.

  In the X-ray tube 3, a time for starting up the filament of the cathode 32 and a time for the rotating anode 33 to reach a predetermined rotational speed are required. For this reason, it is possible to irradiate only a low dose of X-rays immediately after the operation of the apparatus. Then, when a time of about several seconds elapses after the operation of the apparatus, it becomes possible to irradiate a normal dose of X-rays necessary for X-ray imaging.

  FIG. 5 is a schematic diagram of the hand switch 80 described above.

  The hand switch 80 functions as input means of the present invention, and includes a gripping portion 83 held by an operator, and first and second operation buttons 81 and 82 disposed at one end of the gripping portion 83. . These first and second operation buttons 81 and 82 are buttons that can be pressed continuously in two stages. When the first operation button 81 is pressed, the first signal is transmitted toward the control unit 10, and when the second operation button 82 is pressed, the second signal is transmitted toward the control unit 10. .

  Next, an X-ray imaging operation by the above-described X-ray imaging apparatus will be described. 6 and 7 are flowcharts showing an X-ray imaging operation by the X-ray imaging apparatus according to the present invention.

  In the X-ray imaging method according to this embodiment, a low-dose X-ray is irradiated to display a position confirmation X-ray image on the image display unit 91 and preparation for X-ray imaging by the X-ray tube 3 is performed. And an X-ray imaging process of irradiating a normal dose of X-rays necessary for X-ray imaging and displaying an X-ray imaging image on the image display unit 91 are executed.

  When starting X-ray imaging, first, initial setting is performed (step S1). At the initial setting, the low-dose X-ray irradiation conditions irradiated in the preparation process and the normal-dose X-ray irradiation conditions irradiated in the X-ray imaging are set. For example, when X-ray imaging conditions for appropriately capturing an image during X-ray imaging are set as follows: the tube voltage is set to 75 kilovolts, the tube current is set to 320 milliamperes, and the X-ray pulse width is set to 80 milliseconds. The X-ray imaging conditions in the process are determined as follows.

  That is, since the tube voltage is mainly determined by the site necessary for imaging, the tube voltage is set to 75 kilovolts in the preparation process in order to appropriately display the site required for imaging. . As for the tube current time product, taking into consideration that it is possible to set the imaging position even if this is set to about 1/200 of the X-ray imaging, and that the pulse width is desired to be about 10 milliseconds or less. For example, the tube current is set to 16 milliamperes and the X-ray pulse width is set to 8 millisecond. Thereby, it becomes possible to significantly reduce the amount of X-ray exposure to the subject 1.

  When the initial setting is completed, the approximate photographing position is confirmed by the collimator mechanism 7 (step S2). Specifically, the four movable diaphragms 6 are moved while the collimator lamp 5 is lit, so that the subject 1 is irradiated with light, and the irradiation area is confirmed, as shown in FIG. An X-ray exposure range E is set.

  If an appropriate shooting position can be confirmed (step S3), the control unit 10 issues a command to the image processing unit 9, and sets the resolution of the image displayed on the image display unit 91 to a low resolution (step S4). For example, when an image is displayed with a normal resolution of 2000 pixels × 2000 pixels of 4 megabytes, at a low resolution, an image is displayed with 500 pixels × 500 pixels of 0.25 megabytes. As a result, the amount of data required for display becomes 1/16. Further, the gain multiplied by the image signal detected by the flat panel detector 4 and input to the image display unit 91 via the image processing unit 9 is set to a large value (step S5).

  In this state, the operator waits for the first button 81 on the hand switch 80 to be pressed. When the first button 81 on the hand switch 80 is pressed by the operator and the first signal is transmitted from the hand switch 80 to the control unit 10 (step S6), the X-ray tube 3 is instructed by an instruction from the X-ray tube control unit 8. Are irradiated with a low dose of X-rays (step S7).

  X-rays irradiated from the X-ray tube 3 and passing through the subject 1 are detected by the flat panel detector 4. The detection value by the flat panel detector 4 is input to the control unit 10, and the control unit 10 transmits an image signal to the image display unit 91 via the image processing unit 9. The image display unit 91 displays an X-ray image for position confirmation according to the image signal. At this time, as described above, the image processing unit 9 sets the resolution of the image displayed on the image display unit 91 to a low resolution. For this reason, it is possible to shorten the time required to display an image, quickly complete position confirmation, and perform subsequent X-ray imaging promptly. At this time, as described above, the gain multiplied by the image signal input to the image display unit 91 is set to a large value. For this reason, it is possible to prevent a phenomenon in which an image displayed on the image display unit 91 becomes dark despite the low dose of X-rays emitted from the X-ray tube 3.

  Note that the resolution setting and gain setting described above may be performed before the initial setting step (step S1), and the first button 81 in the hand switch 80 is pressed by the operator, and the first signal is set. May be performed when the hand switch 80 is transmitted to the control unit 10.

  In this state, the operator looks at the X-ray image displayed on the image display unit 91 to determine whether the imaging position is appropriate (step S8). That is, the approximate imaging position is confirmed using the collimator mechanism 7 in advance, but in the confirmation of the imaging position by the collimator mechanism 7, it is not possible to confirm a subtle angle error of the imaging region or an overlap of the body. It is difficult, and it is impossible to confirm the position of a part in the body such as the overlap between the internal organs and the bone. For this reason, in this imaging position confirmation step, the suitability of the imaging position is determined based on the X-ray image displayed on the image display unit 91. At this time, although the resolution of the image displayed on the image display unit 8 is low, there is no problem because the diagnosis is not performed and only the position is confirmed.

  If the shooting position is not appropriate, the operator releases the first button 81 on the hand switch 80 and stops shooting (step S9). And it returns to step S1 again and image | photographs again. At this time, since the X-ray dose to which the subject 1 is exposed is extremely small, there is no problem even if re-imaging is performed.

  Further, as described above, after the resolution of the image displayed on the image display unit 91 is set to a low resolution and the gain for multiplying the image signal is set to a large value, the display state on the image display unit 91 remains as it is. In the maintained state, the control unit 10 issues a command to the image processing unit 9, and sets the resolution of the image displayed on the image display unit 91 to a high resolution (step S10). Further, the gain multiplied by the image signal detected by the flat panel detector 4 and input to the image display unit 91 via the image processing unit 9 is set to a small value (step S11).

  In this state, the operator waits for the second button 82 in the hand switch 80 to be pressed. If the photographing position is appropriate (step S9), the operator presses the second button 82 on the hand switch 80. If the operator presses the second button 82 in the hand switch 80 and a second signal is transmitted from the hand switch 80 to the control unit 10 (step S12), the X-ray tube 3 is instructed by a command from the X-ray tube control unit 8. To the normal dose of X-rays required for normal imaging (step S13).

  X-rays irradiated from the X-ray tube 3 and passing through the subject 1 are detected by the flat panel detector 4. The value detected by the flat panel detector 4 is input to the control unit 10, and the control unit 10 captures this image signal into the storage unit 11 (step S 14), and sends the image signal to the image display unit 91 via the image processing unit 9. Send. The image display unit 91 displays an X-ray image for position confirmation according to the image signal.

  At this time, as described above, the image processing unit 9 sets the resolution of the image displayed on the image display unit 91 to a high resolution. For this reason, a high-resolution image necessary for diagnosis is displayed on the image display unit 91. Further, as described above, the gain multiplied by the image signal input to the image display unit 91 is set to a small value. For this reason, an image with brightness corresponding to the dose of X-rays emitted from the X-ray tube 3 is displayed on the image display unit 91.

  As described above, according to the X-ray imaging apparatus according to the present invention, the operator can execute the confirmation of the imaging position and the X-ray imaging in a natural flow, and the case where the imaging position is not appropriate. Even during re-imaging, the exposure dose to the subject 1 can be minimized.

  In the embodiment described above, the tube voltage is maintained at a constant value of 75 kilovolts, and the low-dose X-ray irradiation condition is that the tube current is 16 milliamperes and the X-ray pulse width is 8 millisecond. In addition, as a normal dose X-ray irradiation condition, a tube current is set to 320 mA and an X-ray pulse width is set to 80 milliseconds. That is, in the above-described embodiment, the X-ray dose irradiated from the X-ray tube 3 is changed from a low dose to a normal dose.

  On the other hand, the X-ray energy irradiated from the X-ray tube 3 may be changed from low energy to normal energy by changing the tube voltage applied to the X-ray tube 3. In this case, the frequency distribution of X-rays shifts from the normal energy side to the high energy side. Further, the X-ray energy may be changed from low energy to normal energy by changing all of the tube voltage, tube current, and pulse width.

DESCRIPTION OF SYMBOLS 1 Subject 2 Table 3 X-ray tube 4 Flat panel detector 5 Collimator lamp 6 Movable diaphragm 7 Collimator mechanism 8 X-ray tube control part 9 Image processing part 10 Control part 11 Memory | storage part 31 Glass valve 32 Cathode 33 Rotary anode 34 Motor rotor 35 Motor stator 37 Radiation window 80 Hand switch 81 First button 82 Second button 83 Grip part 91 Image display part

Claims (5)

An X-ray tube that irradiates the subject with X-rays;
X-ray detection means for detecting X-rays irradiated from the X-ray tube and passing through the subject;
An image display unit for displaying an X-ray image based on a detection value of X-rays by the X-ray detection unit;
A hand switch that includes an operation button that can be pressed in two stages, and that can transmit first and second signals;
When the first signal is transmitted from the hand switch, an instruction to start rotation of the anode and energization of the cathode filament is transmitted to the X-ray tube, and a low dose or low energy is transmitted from the X-ray tube. And a control means for irradiating the X-ray tube with a normal dose or normal energy X-rays necessary for X-ray imaging when the second signal is transmitted from the hand switch .
An X-ray imaging apparatus comprising: The X-ray imaging apparatus according to claim 1,
When a low dose or low energy X-ray is irradiated from the X-ray tube, the image displayed on the image display unit has a low resolution, and a normal dose or normal dose required for X-ray imaging from the X-ray tube An X-ray imaging apparatus comprising: an image processing unit that sets an image displayed on the image display unit to high resolution when irradiated with energy X-rays. The X-ray imaging apparatus according to claim 1,
When a low-dose or low-energy X-ray is irradiated from the X-ray tube, a gain for multiplying an image signal input to the image display unit is increased, and a normal necessary for X-ray imaging from the X-ray tube An X-ray imaging apparatus including an image processing unit that reduces a gain to be multiplied by an image signal input to the image display unit when X-rays with a dose or normal energy are irradiated. The X-ray imaging apparatus according to any one of claims 1 to 3 ,
When irradiating the low-dose or low-energy X-ray, the tube voltage applied to the X-ray tube is set to the same value as when irradiating the normal dose or normal-energy X-ray, and the tube applied to the X-ray tube An X-ray irradiation apparatus that sets a current-time product to a smaller value when irradiating the X-ray with the normal dose or the normal energy. The X-ray imaging apparatus according to any one of claims 1 to 4 ,
An X-ray irradiation apparatus further comprising a collimator mechanism including a collimator lamp and a movable diaphragm, and irradiating a low dose or low energy X-rays from the X-ray tube to an exposure range defined by the collimator mechanism.

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