JPS58116530A - X-ray photographing device - Google Patents

Abstract

PURPOSE:To set automatically optimum photographic conditions by deciding on the photographic conditions under measured fluoroscopic conditions on the basis of different fluoroscopic conditions of a subject and the stored value of optimum photographic conditions corresponding to them. CONSTITUTION:A phantom is used as a sample 5 and a signal processing part 10 performs control through a fluoroscopy controller 2 to optimum an image on a monitor TV9 obtained through an image preamplifier 7. The thickness of a human body and current fluoroscopic conditions are stored in a memory 12 through a microcomputer 11. Said operation is repeated with respect to different thickness of phantoms. Optimum photographic conditions for respective thicknesses are stored in the memory 12. In fluoroscopy of the sample 5, a voltage corresponding to the thickness of the sample 5 is applied to an X-ray tube 4 through the signal processing part 10 and a high-voltage generator 3 on the basis of data in the memory 12 to set optimum photographic conditions.

Description

[Detailed Description of the Invention] The present invention provides optimal photographic conditions for obtaining optimal photographs regardless of changes in transmittance due to changes in subject thickness, etc. X@ Photographic equipment that can be automatically set based on the conditions, especially the conditions of the photographing system (different depending on the XaI tube, film, intensifying screen, grid, etc. used) and X! I
The present invention relates to an X-ray photographing apparatus that allows the setting of optimal photographing conditions that take into account the preferences of a doctor by taking photographs and making a single diagnosis, and that has a degree of freedom in setting the optimal photographing conditions.

In order to obtain the optimal X, @ photograph, the imaging system (X-ray tube,
The most suitable photographing conditions must be set for the subject (example, film, photosensitive paper, etc.).

As one means for this purpose, a concept has been proposed in which the optimum photographing conditions are obtained based on the fluoroscopic conditions performed prior to X@photography.

In this method, the imaging conditions are determined from the fluoroscopic conditions. First, the fluoroscopic conditions (tube voltage, tube current R) and the imaging conditions (tube voltage) are determined.

For example, if the fluoroscopy tube voltage is determined with the fluoroscopy tube current constant,
The imaging tube voltage is determined based on a certain relationship, and at the same time, the imaging tube current imaging time is also uniquely determined. Moreover, this relationship only changes uniformly from a low fluoroscopy tube voltage to a high fluoroscopy tube voltage.

Therefore, since the perspective conditions and photographing conditions are uniquely determined, it is optimal for all changes in the subject.
I cannot set the optimal imaging conditions (tube voltage, tube current, exposure time) to obtain my xlI photos.

In addition, there is no consideration given to the differences between the image forming systems of the fluoroscopy system and the imaging system, and there is no consideration given to the differences between the imaging systems and the tube voltages due to differences in film, intensifying screen, etc., which are selected depending on the imaging subject. It is practically impossible to set the optimum shooting conditions for each situation. Furthermore, the true image quality of X*'4 also depends on the preference of the doctor who makes the diagnosis, and the optimal imaging conditions differ depending on the preference of the doctor, but no consideration has been given to this point.

In view of the above, this invention has a degree of freedom in determining the photographing conditions from the fluoroscopic conditions in response to changes in the subject. The aim is to provide the Xi1 photographic device, which automatically adjusts the optimal imaging conditions for XJI photographs that are optimal for diagnosis, by adjusting settings rather than using fluoroscopic conditions, while also reflecting physicians' preferences. It is something to do.

For this purpose, the X4ii imaging device of the present invention obtains the relationship between the object thickness and the optimal fluoroscopy conditions through actual fluoroscopy. Furthermore, regarding imaging, the operator (doctor) uses an imaging system (X-ray tube, film) in advance.

Optimal subject and shooting conditions (tube voltage, etc.) for photosensitive materials, etc.

The operator sets and stores data with @gk (tube current, exposure time) optional or omitted. Practical data regarding this fluoroscopy and photography are memorized, and from then on, fluoroscopy conditions (8) photography conditions are determined from the stored data according to the subject, and are used as t% images.

Examples will be described below. FIG. 1 is a characteristic diagram showing the relationship between object thickness and fluoroscopic tube voltage using tube flow as a parameter. A-C): 1 is 1j! K
For example, using a human equivalent phantom.

This is the optimum fluoroscopic tube voltage obtained by a known fluoroscopic brightness automatic adjustment mechanism by varying the phantom thickness.

1 to C correspond to the points A to C when changing the fluoroscopic tube current. Obtaining this data is easy by using Phant^.

Diagram M2 (m) shows the relationship between object thickness and imaging tube voltage.

FIG. 5B is a characteristic diagram showing the relationship between object thickness and tube current x imaging time. Point A1-C' and point A1-C' are conditions corresponding to the thickness of point A-C in FIG.

In this case, the photographic data corresponding to A-C', A1-C', and aK is one room that can be used in the bedroom according to the surgeon's will.

It is possible to consider the optimal conditions for a single imaging system that the operator knows from experience, or the imaging conditions for photographs that are easy to diagnose and desired by the operator, who have great significance in the XII imaging technique.

In addition, in the imaging system, it is also possible to determine the data of A' to C' and A' to C' by using a phantom in the same way as data collection of fluoroscopic conditions. is shown in Fig. 2(b) K tube current x imaging time (mA
ec) may be determined by decomposing them into IIIA and se@fC, respectively (1.

A-C, A'~C', a' determined in this way
The data of each of C' to C' are stored in a memory described later. During actual photographing, when a certain subject is viewed through the camera, an amned viewing tube voltage is obtained by the automatic viewing brightness adjustment mechanism so as to obtain the optimum viewing angle.

This tube voltage gives an indication of the thickness of the subject, including the effects of scattered radiation, etc. Therefore, using this tube voltage as an index, the thickness of the subject can be determined from the characteristic diagram in Figure 1. Diagram II2 (Tube voltage at the time of photographing that is most suitable for the subject with reference to the data of the characteristic diagram in 13(b)).

Tube current and imaging time can be determined. Of course, points other than the stored data can also be calculated by linear interpolation or the like.

Fig. 3 is a book diagram showing the configuration of an apparatus for carrying out the present invention.
An imaging control unit that sets and controls exposure time.

2: Setting and controlling the tube voltage and tube current during fluoroscopy / fluoroscopy control;
3 is the Xll high voltage generator, 4 is the X-ray tube,
5. 6 is a photographic film holding device.

7 is image amblifier (■t), s is I
A television camera and a camera control unit capture the output image of I7 and convert it into an electrical signal, and 9 is a monitor TV.

IO is a signal processing unit that samples the electric signal of the camera control unit 8, and controls the perspective control s2 so that the monitor TVII follows a predetermined value jljiil' to adjust the perspective brightness. 11 is a microcomputer (computing device), 12 is! microcomputer 11
This is the memory that is combined with

In the above configuration, first, a phantom is inserted as the object to be examined in order to determine the fluoroscopy conditions. When the operator performs a fluoroscopy operation by controlling the fluoroscopy control section 2, the fluoroscopy control section 2 is controlled by the operation of the signal processing section 10 so that the monitor TV 9 is optimized, and the fluoroscopy conditions (fluoroscopy tube voltage) are adjusted. Automatically set. At this time, if necessary, the phantom thickness is converted to human body thickness, and the human body thickness and the fluoroscopy conditions at that time are stored in the memory 12 through the microcomputer 11 manually or automatically using a keyboard or the like.

Furthermore, the fluoroscopy conditions are actually measured at 2 to 3 points (the more data there is, the more accurate the system will be) and the phantom thickness of each machine. Through this series of operations, the data shown in FIG. 91 is stored in the memory 12.

Next, to determine the imaging conditions, enter a phantom with the same phantom thickness as when the fluoroscopy conditions were determined earlier.

Pfr+il at each thickness! The conditions for obtaining a photograph are set using the photographing control sl, and the photograph is taken. The optimal imaging conditions (tube voltage) obtained for each thickness in this way.

Tube charge Rat-Memo IJ- in the same way as in the case of fluoroscopic condition
12. When determining the photographing conditions, it is also possible to determine the photographic conditions in such a way that a photograph containing much of the information required by the surgeon can be obtained. By memorizing the fluoroscopic imaging conditions for several points within the range of human body thickness that the surgeon would use on a daily basis as described above, the imaging conditions for body thicknesses that have not yet been collected can also be adjusted according to the surgeon's will. is reflected. In other words, by using a well-known interpolation method such as linear interpolation or dark number interpolation between the data input and stored using the method described above, a microcomputer can calculate the user's intention reflected in the input data. It also applies to human body thickness.

At this time, for example, if you want to keep the imaging time constant for a certain part regardless of the body thickness, by making the imaging time term of the input data constant, the imaging time for other points corresponding to the human body thickness will also be constant. Can be done.

In this way, data regarding the optimal perspective and optimal imaging conditions for the object thickness, ie, FIG. 1, is obtained! After storing the characteristic diagram shown in FIG. 2 in the memory 12, by performing perspective photography of the subject, optimal photography conditions corresponding to the subject are automatically set based on the perspective conditions.

That is, it is positioned in front of the subject 511I7.

It is removed from the front of the film holding device 6fII7.
When the fluoroscopy tube (not shown) provided in the fluoroscopy control unit 2 is closed in the state (as shown *), the X@ tube 4 is energized, the subject 5 is irradiated with X-rays, and fluoroscopy is performed.

At this time, the signal processing section 10 automatically sets the fluoroscopic conditions, that is, the fluoroscopic tube voltage corresponding to the thickness of the subject 5, so that the image on the monitor TV has a predetermined brightness.

This automatically set fluoroscopy tube voltage I memo +4-12
Based on the data stored in the camera, the data is combined with the interpolated data using the microcombi-tar, and the optimal imaging conditions (tube 1 pressure) corresponding to the thickness of the subject 5 are set.

Tube current, exposure time) continue from memory 12 Memesa 1 = -
.

It is set to shooting cap 1.

After that, the film holding device 6 is placed in front of the II 7, and when the exposure switch (XXII) provided in the photographic control unit 1 is closed, the thickness of the subject automatically set during the fluoroscopy process is adjusted. Photographs can be taken under the corresponding optimal photographing conditions.

As described above, according to the present invention, when determining the imaging conditions from the fluoroscopic conditions, the surgeon's intention is to use a large amount of information regarding the imaging conditions for each site.

Information on the differences between the image forming systems σ between the fluoroscopy system and the imaging system,
It allows doctors to automatically set the optimal imaging conditions (tube voltage, tube current, exposure time) for the subject, regardless of its thickness or location. I want to know which XJl #top most suitable drawing photograph I want.

In addition,! I! In this example, in order to obtain the optimal fluoroscopic tube voltage corresponding to the thickness of the subject, it is possible to use an automatic fluoroscopic brightness adjustment mechanism or to manually store it in memory using a numeric keypad or the like.

In short, any method that automatically determines the imaging conditions using data input by the operator separately from the tube voltage and tube current of the fluoroscopy conditions is sufficient. As described above, data tubes regarding the optimal fluoroscopic conditions for the subject thickness are collected with the settings set to .
This value is changed depending on the subject. So in practice.

Data on the relationship between human body thickness and fluoroscopy tube voltage is collected and stored for fluoroscopy tube currents at two or more points. If a fluoroscopic tube current that has not been collected or stored is set, the human body thickness can be determined from the optimal fluoroscopic tube voltage at that time using a data interpolation method, and the optimal imaging conditions can be calculated. Human body thickness and optimal fluoroscopy conditions change due to changes in Fire's *Rin effective field of view. Therefore, in this case as well, it is conceivable to treat the problem in the same way as when the fluoroscopic tube current changes.

Furthermore, if you use Phototie 1 when shooting.

The shooting time that is automatically set by the device of this invention is:

It is only necessary to make it work for Pa, Kua, and Gu.

In this case, it is sufficient to store in memory the photographing conditions set to be slightly longer than the photographing time by the phototimer.

Furthermore, in the configuration of the embodiment, C-
If a rewritable memory element such as a MOS RAM is used in combination with a microcomputer, it becomes possible to change the optimal fluoroscopy conditions and the corresponding optimal imaging conditions as needed.

[Brief explanation of the drawing]

Figure 1 is a characteristic diagram showing the relationship between object thickness and imaging tube voltage; Figure 2 (a) is a characteristic diagram showing the relationship between object thickness and imaging tube voltage; and Figure 2 (b) is a characteristic diagram showing the relationship between object thickness and imaging tube voltage. A characteristic diagram showing the relationship between thickness and photographing-1, and FIG. 3 is a block diagram showing the configuration of an embodiment of the apparatus of the present invention. 1: Shooting control unit 2: Fluoroscopic control unit 3: High voltage generator 4: Xll tube 5: Subject 6: Film holding device 7: II 8: Television camera and camera control unit 9: Monitor TV 10: Fluoroscopic brightness m* Signal processing section 11 11: Microcombi, -ta 12: Memory (calculation equipment) Karasu Seisakusho Co., Ltd.

Claims (2)

[Claims] (1) A memory that stores data regarding optimal fluoroscopic conditions corresponding to different thicknesses of the subject and optimal imaging conditions that approximately correspond to the thickness of the subject indicated in #, and the subject between each data based on the data stored in this memory. The X-photo is characterized in that it is equipped with an arithmetic unit that interpolates the optimum fluoroscopic conditions corresponding to the thickness and the optimum photographing conditions, and automatically sets the optimum photographing conditions C corresponding to the thickness of the subject from the fluoroscopic conditions. Photography equipment. (2) The XLS photographing apparatus according to claim N, wherein the memory is capable of externally setting and storing data for at least the optimum photographing conditions KFR corresponding to the thickness of the subject. .