JPH0497304A - Radiation image reader - Google Patents

Abstract

PURPOSE:To enable efficient manual adjustment by displaying a visible image which is adjusted by using previous manually adjusted read conditions, etc., when the read conditions, etc., which are manually adjusted are stored. CONSTITUTION:A storage means 33 is stored with read conditions and/or image process conditions which are corrected as to previous radiation images, group by group. Then if it is decided that read conditions and/or image process conditions which are found by an arithmetic means 34 are wrong read conditions and/or image process conditions, the visible image is displayed first according to a preread image signal SP obtained by simulating the read conditions corrected as to a previous radiation image belong in the same group stored in the storage means 33. Consequently, an operator only adjusts them slightly when required and this adjusting operation is performed efficiently.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a radiation image reading device that reads a radiation image from a recording sheet such as a stimulable phosphor sheet on which radiation image information of a subject is recorded and obtains an image signal. It is related to.

(Prior Art) It is practiced in various fields to read a recorded radiation image to obtain an image signal, perform appropriate image processing on the image signal, and then reproduce and record the image. For example, an X-ray image is recorded using an X-ray film with a low gamma value designed to be compatible with later image processing, and the x41 image is read from the film on which this X-ray image was recorded and converted into an electrical signal. However, by performing image processing on this electrical signal (image signal) and then reproducing it as a visible image in a photocopy, etc., it is possible to obtain a reproduced image with good image quality performance such as contrast sharpness and graininess. (Refer to Japanese Patent Publication No. 61-5193).

In addition, the applicant has proposed radiation (X-rays, α-rays).

When irradiated with β rays, γ rays, electron beams, ultraviolet rays, etc., a part of this radiation energy is accumulated, and then when irradiated with excitation light such as visible light, stimulable fluorescence exhibits stimulated luminescence depending on the accumulated energy. Radiographic image information of a subject such as a human body is partially recorded on a sheet of stimulable phosphor using a stimulable phosphor, and this stimulable phosphor sheet is scanned with excitation light such as a laser beam. The resulting stimulated luminescent light is read photoelectrically to obtain an image signal, and based on this image data, a radiation image of the subject can be recorded on a recording material such as a photographic light-sensitive material, a CRT, etc. A radiation image recording and reproducing system that outputs visual images has already been proposed (Japanese Unexamined Patent Publication No. 5
No. 5-12429, No. 5B-11395.

No. 55-163472, No. 5B-104845, No. 55-118340, etc.).

This system has the practical advantage of being able to record images over a much wider range of radiation exposure compared to conventional radiographic systems using silver halide photography. In other words, in a stimulable phosphor, it is recognized that the amount of emitted light that is stimulated to emit light due to excitation after accumulation is proportional to the amount of radiation exposure over an extremely wide range.
Therefore, even if the amount of radiation exposure varies considerably due to various imaging conditions, the amount of stimulated luminescence emitted from the stimulable phosphor sheet can be read by the photoelectric conversion means by setting the reading gain to an appropriate value. By converting the radiation image into an electric signal and using this electric signal to output the radiation image as a visible image to a recording material such as a photographic light-sensitive material or a display device such as a CRT, a radiation image that is not affected by fluctuations in radiation exposure amount can be obtained. be able to.

In the above system, the stimulable phosphor sheet is scanned in advance with a low-level light beam before obtaining an image signal by reading it under optimal reading conditions depending on the dose of radiation applied to the stimulable phosphor sheet. Pre-reading is performed to read the outline of the radiation image recorded on this sheet, the pre-read image signal obtained by this pre-reading is analyzed, and then the sheet is irradiated with a high-level light beam and scanned, and this radiation image is There are systems configured to perform actual reading in which image signals are obtained by reading under optimal reading conditions.

Here, reading conditions are a general term for various conditions that affect the relationship between the amount of stimulated luminescence light and the output of the reading device during reading, such as reading gain, scale factor, or , the power of excitation light during reading, etc.

Also, the high level and low level of the light beam are, respectively.
If the energy of the light beam irradiated per unit area of the sheet or the energy of stimulated luminescence light emitted from the sheet depends on the wavelength of the light beam (has a wavelength sensitivity distribution), It refers to the weighting energy after weighting the energy of the light beam irradiated per unit area of the sheet with the wavelength sensitivity.As a method of changing the level of the light beam, light beams of different wavelengths are used. methods to use, methods to change the intensity of the light beam itself emitted from a laser light source, methods to change the intensity of the light beam by inserting or removing an ND filter, etc. on the optical path of the light beam, methods to change the beam diameter of the light beam. Various known methods can be used, such as a method of changing the scanning density and a method of changing the scanning speed.

In addition, regardless of whether the system performs this pre-reading or the system that does not, the obtained image signal (including the pre-read image signal) is analyzed and the optimal image processing conditions are determined when applying image processing to the image signal. Some systems let you decide. The method of determining the optimal image processing conditions based on this image signal is not limited to systems using stimulable phosphor sheets, and for example, image signals are obtained from radiation images recorded on recording sheets such as conventional X-ray films. It is also applied to the system.

Reading conditions and/or image processing conditions (hereinafter referred to as reading conditions etc.) are based on the image signal (including the pre-read image signal).

) (hereinafter referred to as EDR) is a calculation that calculates the imaged part of the subject (head, chest, abdomen, etc. if the subject is a human body).
, based on the results of statistically processing a large number of image signals obtained from each of a large number of radiographic images classified by imaging conditions such as imaging methods (normal imaging, contrast imaging, enlarged imaging, etc.).
An algorithm is determined for each imaging condition, and it is widely practiced to automatically perform EDR.

However, as mentioned above, the EDH algorithm is determined based on the results of statistical processing, so even if the algorithm is determined for each imaging condition, it is suitable for all radiographic images. isn't it. If the EDR is incompatible, there is a problem that when a visible image is reproduced and output based on the image signal obtained from the radiographic image, a visible image with inappropriate density and contrast that is unbearable for observation will be output. In the worst case, the output visible image does not contain any necessary image information, and it becomes necessary to start over from radiographic imaging, which is a waste of time.
Furthermore, when the subject is a human body, there is also the problem that the amount of radiation irradiated to the human body is doubled due to re-imaging.

An example where the above problem occurs will be described below.

One of the conditions to consider when determining the above EDH algorithm is that unnecessary parts recorded on the recording sheet during imaging, such as parts with only scattered radiation, and
The purpose of this method is to remove the portions where radiation is directly irradiated onto the recording sheet without transmitting or reflecting (transmission or reflection), and to distinguish image signals corresponding to necessary radiation images from unnecessary image signals.

FIG. 3A and FIG. 3B are diagrams each showing a histogram of the pre-read image signal Sp. These figures show a system that uses the stimulable phosphor sheet described above and performs pre-reading.

FIG. 3A shows most of the large number of radiographic images (e.g. 99
．． 5%) is an example of a histogram obtained from a radiation image suitable for EDR.

The preread image signal Sp, which is proportional to the amount of stimulated luminescence light obtained by reading the stimulated luminescence light emitted from the stimulable phosphor sheet during prereading, is plotted on the horizontal axis (logarithmic axis). The frequency of appearance of each value of Sp is plotted on the vertical axis (upper side), and the image signal obtained by the main reading is plotted on the lower side of the vertical axis (logarithmic axis). At this time, the histogram obtained from the pre-read image signal Sp has three peaks A as shown in the figure.
.

B and C, and the part corresponding to the necessary radiographic image is the part B. At this time, in order to find the mountain B, for example, search should be performed in the direction in which the value of the pre-read image signal Sp increases from the position of the minimum value sL of the pre-read image signal Sp using the threshold value T, which corresponds to the two-dot chain line in the figure. ), find the second rising point a and the next falling point d. This 2
When the maximum and minimum values of the range between points a and b are respectively Ssaw (corresponding to point S) and 5sln (corresponding to point a), image information included in this range is properly displayed in the visible output image. The reading conditions for the main reading are determined so that the image is reproduced. That is, S■aX and 5sin in the pre-read image signal Sp are the maximum density Dsax and the minimum density Dsin of the appropriate density range in the visible output image.
The reading conditions for the main reading are determined so that the maximum main reading image signal Qwax and the minimum main reading image signal Qmin in the main reading respectively correspond to the main reading, that is, along the straight line G1 in the figure.

In this way, the reading conditions for the main reading are correctly determined for the majority of radiographic images, but there are rare cases in which the correct reading conditions cannot be found using this method.

FIG. 3B is a diagram showing a histogram obtained from a radiographic image of a subject similar to that shown in FIG. 3A (for example, the chest of a human body in both cases) taken under similar imaging conditions.

Comparing Figure 3B with Figure 3A, mountains B' and C' are similar to mountains B and C, respectively, but mountain A' is different from mountain A and is divided into two mountains, Al and A2'. .

When the above-described method is applied to the histogram of FIG. 3B, a search is performed in the direction in which the value of the pre-read image signal Sp increases from the position of the minimum value SL' of the pre-read image signal Sp at a predetermined threshold value T, and 2 The second rising point a' and the next falling point b' are found. However, these two points a'
, b' is far away from the range corresponding to the required radiographic image (corresponding to mountain B'). When this is converted into a straight line G2 and an image signal is obtained by reading, this image signal does not contain any necessary image information, and a visible image is reproduced and output based on this image signal. This results in a completely meaningless output image. In this case, for example, the human subject must be brought to the hospital again, and the photographing must be started again.

Also, even if it is not an extreme case like the example above, EDR
In some cases, the image quality of the reproduced and output visible image may deteriorate due to the fact that this is not carried out effectively.

In order to solve the above-mentioned problems associated with automatic EDR, is the accuracy of automatically determined reading conditions and/or image processing conditions approximated to average reading conditions and/or image processing conditions? Judgment is made based on the criterion of whether the difference is greater than a predetermined value, and if it is judged that incorrect reading conditions and/or image processing conditions have been obtained, a visible image is displayed on a display means such as a CRT display device, and this visible image is It is proposed that the correct reading conditions and/or image processing conditions be manually determined by manually adjusting the density (including brightness when displayed on a CRT display device, etc.) and contrast of the image. (Refer to Japanese Unexamined Patent Publication No. 2-14376).

(Problem to be Solved by the Invention) However, if it is determined that incorrect reading conditions and/or image processing conditions are required, what kind of reading conditions and/or image processing conditions should be used for actual reading and/or image processing? The problem is whether to display a visible image that simulates the actual state first. Since the rest is to be adjusted manually, first, for example, display a visible image that simulates the state in which actual reading and/or image processing has been performed under automatically determined incorrect reading conditions and/or image processing conditions. is possible. In this case as well, it is possible to find the correct reading conditions and/or image processing conditions by making manual adjustments sequentially, but since the reading conditions and/or image processing conditions are originally incorrect, it is not possible to obtain the correct reading conditions and/or image processing conditions. In many cases, the reading conditions and/or the image processing conditions are significantly different from the image processing conditions, and in this case, manually adjusting the reading conditions and/or the image processing conditions one by one takes time and effort, resulting in poor workability.

In addition, the average reading conditions and/or the average reading conditions and/or the standards for determining whether the obtained reading conditions and/or image processing conditions are correct or incorrect are also included.
Alternatively, it is also possible to first display a visible image adjusted using image processing conditions.

In this case, if the average reading conditions and/or image processing conditions are truly average, it is considered that they are often close to the correct reading conditions and/or image processing conditions for the radiation image.

However, the true average value is determined after reading a large number of radiographic images, and the average value is not determined at the time of system startup. The standards are only provisional, and even if a visible image adjusted using this provisional average value is reproduced and displayed, the density (brightness) and contrast of the reproduced visible image may be significantly distorted. Therefore, the problem arises that the adjustment takes a lot of effort.

In view of the above-mentioned problems, the present invention displays a visible image with approximately correct density (brightness) and contrast not only after the system has been used, but also at the time of starting up the system, thereby improving the reading conditions and/or image processing conditions. It is an object of the present invention to provide a radiation image reading device that can efficiently perform adjustment work.

(Means for Solving the Problems) A first radiation image reading device of the present invention that solves the above object is a radiation image reading device that uses a stimulable phosphor sheet and performs pre-reading. That is, the first radiation image reading device of the present invention irradiates excitation light onto a stimulable phosphor sheet on which a radiation image is recorded, and stimulates luminescent light emitted from the stimulable phosphor sheet by irradiating the excitation light. a pre-reading means for reading a pre-reading image signal representing the radiation image; irradiating the stimulable phosphor sheet with excitation light again; and stimulating luminescence emitted from the stimulable phosphor sheet by irradiation with the excitation light; a main reading means for reading light to obtain a main reading image signal representing the radiation image; a reading condition for obtaining the main reading image signal based on the preread image signal; and/or the obtained main reading image signal. a calculation means for determining image processing conditions when performing image processing on the image;
or a determining means for determining whether the image processing conditions are correct, at least the reading conditions and/or the image processing conditions determined by the calculating means are determined by the determining means to be incorrect reading conditions and/or image processing conditions; display means for displaying a visible image based on the pre-read image signal that is the basis for determining the reading conditions and/or the image processing conditions, at least the reading conditions and/or the image processing conditions determined by the calculation means; Correction of inputting correction information for correcting the incorrect reading conditions and/or image processing conditions when the image processing conditions are determined by the determining means to be incorrect reading conditions and/or image processing conditions. information input means, and the reading conditions and/or image processing conditions corrected using the correction information input from the correction information input means, each group into which the radiographic images are classified based on a predetermined classification system. In the radiation image reading device, the display means stores in the storage means the reading conditions and/or the image processing conditions that have been corrected for previous radiation images belonging to the same group. If the actual reading image signal is obtained using the reading conditions stored in the storage means before the correction information is input, and/or the reading conditions stored in the storage means are obtained before the correction information is input. Displaying a visible image that simulates the case where image processing is performed on the main reading image signal using image processing conditions, and thereafter, each time the correction information is input, the image is corrected based on the input correction information. The case where the main reading image signal is obtained using the reading condition and/or the case where image processing is performed on the main reading image signal using the image processing condition modified based on the input correction information. It is characterized by displaying a simulated visible image.

Furthermore, the second radiation image reading device of the present invention for achieving the above object is applicable not only to devices using a stimulable phosphor sheet but also to devices using, for example, an X-ray film. That is, the second radiation image reading device of the present invention comprises: a reading means for reading the radiation image from a recording sheet on which the radiation image is recorded and obtaining an image signal representing the radiation image; a calculation means for determining image processing conditions when performing image processing; a determination means for determining whether the image processing conditions determined by the calculation means are correct; at least the image processing conditions determined by the calculation means are determined by the determination means; correction information input means for inputting correction information for correcting the incorrect image processing conditions when it is determined that the image processing conditions are incorrect; and using the correction information input from the correction information input means. In the radiographic image reading device, the display means includes a storage means for storing the image processing conditions corrected by the image processing conditions for each group into which the radiation images are classified based on a predetermined classification system. If the image processing conditions that have been corrected for previous radiation images belonging to the same group are stored in the storage means, before the correction information is input, the image processing conditions stored in the storage means are used to process the image processing conditions. Displaying a visible image after image processing is performed on the image signal, and thereafter, each time the correction information is input, image processing is performed on the image signal using the image processing conditions corrected based on the correction information. It is characterized by displaying a visible image after the application.

Here, the above-mentioned "predetermined classification system" does not necessarily have to be a specific classification system, but for example, in the case of a large number of radiographic images of the human body, it may be necessary to This refers to classification according to imaging conditions such as imaging methods (normal imaging, contrast imaging, enlarged imaging), etc.

In addition, the above-mentioned “reading conditions and/or image processing conditions modified for previous radiation images belonging to the same group”
``Previous radiation image j'' refers to the previous radiation image that belongs to the same group (for example, radiation images that belong to the same imaging conditions are considered as one group), or the previous radiation image that belongs to the same group and has been This refers to the average radiographic image of a large number of radiographic images obtained.

(Function) It is empirically known that reading conditions and/or image processing conditions corresponding to radiographic images belonging to the same group have values that are substantially similar to each other even if the radiographic images are different.

Therefore, in the first radiation image reading device of the present invention, reading conditions and/or image processing conditions corrected for previous radiation images are stored for each group in the storage means, and at least reading conditions determined by the calculation means are stored in the storage means. When it is determined that the conditions and/or image processing conditions are incorrect reading conditions and/or image processing conditions, the reading conditions and/or the corrected reading conditions and/or image processing conditions for the previous radiation images belonging to the same group stored in the storage means are corrected. Or, since the visible image is first displayed based on the pre-read image signal that simulates the case where actual reading and/or image processing is performed using image processing conditions, the reading conditions and/or image processing determined by the calculation means Even if the conditions are far from the correct reading conditions and/or image processing conditions, by using the previous almost similar reading conditions and/or image processing conditions, even at startup and during the first adjustment of the same group. With the exception of can be done.

The same applies to the second radiation image reading device of the present invention, and the visible image after image processing is performed using the corrected image processing conditions for the previous radiation image belonging to the same group stored in the storage means. Since the image is displayed first, when adjusting subsequent images belonging to the same group, a visible image with approximately correct sensitivity and contrast is displayed from the beginning, making it easy to make manual adjustments. It turns out.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the radiation image reading device of the present invention. This embodiment is a system that uses a stimulable phosphor sheet and performs pre-reading.

The stimulable phosphor sheet 11 on which the radiation image has been recorded is set at a predetermined position in a pre-reading means 100 that performs pre-reading by scanning with a weak light beam and emitting only a part of the radiation energy stored in the sheet 11. be done. The stimulable phosphor sheet 11 set at this predetermined position is moved by the motor 12.
The sheet is transported (sub-scanning) in the direction of arrow Y by a sheet transport means 13 such as an endless belt driven by. On the other hand, a weak light beam 15 emitted from a laser light source 14 is reflected and deflected by a rotating polygon mirror 16 that is driven by a motor 23 and rotates at high speed in the direction of the arrow, passes through a focusing lens 17 such as an fθ lens, and then passes through a mirror 18 to is incident on the sheet 11 in the sub-scanning direction (direction of arrow Y)
The main scan is performed in the direction of the arrow X, which is substantially perpendicular to the main image. Stimulated luminescent light 19 is emitted from the portion of the sheet 11 irradiated with this excitation light 15 in an amount corresponding to the radiation image information stored and recorded, and this stimulated luminescent light 19 is guided by a light guide 20. , is photoelectrically detected by a photomultiplier (photomultiplier tube) 21 as a photodetector. The light guide 20 is made by molding a light-guiding material such as an acrylic plate, and is arranged so that the linear entrance end surface 20a extends along the main scanning line on the stimulable phosphor sheet ll. is,
The light receiving surface of the photomultiplier 21 is coupled to the annularly formed output end surface 20b. The stimulated luminescence light 19 entering the light guide 20 from the input end face 20a travels through the light guide 20 through repeated total reflection, exits from the output end face 20b, and is received by the photomultiplier 21, resulting in a radiographic image. The photomultiplier 21 converts the amount of stimulated luminescent light 19 representing .

The analog output signal S outputted from the photomultiplier 21 is amplified by an amplifier 26 and digitized by an A/D converter 27 to obtain a pre-read image signal Sp.

In the above-mentioned pre-reading, reading conditions such as the voltage value applied to the photomultiplier 21 and the amplification factor of the amplifier 2B are determined so that the radiation energy accumulated in the stimulable phosphor sheet 11 can be read over a wide range. ing.

The obtained pre-read image signal Sp is sent to the computer system 20
It is input to 0. This computer system 200 is
A CRT display 31 that displays visible images and other necessary information based on the pre-read image signal Sp. Keyboard 32 for manually entering necessary information. A floppy disk drive section 33 into which a floppy disk as an auxiliary storage medium is loaded and driven. and a main unit 34 that has a built-in CPU, internal memory, etc., and performs various calculations.
It consists of Here, in this embodiment, the CRT display 31. of the computer system 200 is used. Keyboard 32. The floppy disk loaded in the floppy disk drive unit 33 is considered to be an example of display means, correction information input means, and storage means according to the present invention. In this embodiment, the combination of hardware and software in the main body 34 corresponding to the function of the determining means of the calculating means 1 according to the present invention is considered to be an example of each means. In this embodiment, this computer system 2
Based on the pre-read image signal Sp input in 00, the third
The reading conditions for main reading can be determined using the same method as explained using Figures A and 3B. Here, the reading conditions include the sensitivity Sk, which represents the standard for photoelectrically converting a predetermined amount of stimulated luminescence light into an image signal having a value, and the minimum amount of stimulated light that can be correctly photoelectrically converted. It is defined by a dynamic range cp corresponding to the ratio of the emitted light and the maximum amount of stimulated emitted light that can be correctly photoelectrically converted, and these sensitivity Sk and dynamic range Gp are respectively 3A.
This corresponds to the horizontal position of the straight line IIGI, 02, etc. in the figure and the inclination of the straight line Gl, 02, etc. in FIG.

Here, in the computer system 200, there are judgment criteria provisionally determined for each group of radiation images grouped according to each imaging condition, that is, provisional average values Sk, Gp and provisional allowable fluctuation ranges ΔSk, ΔGp. are stored, and the reading conditions determined based on the currently input pre-read image signal Sp, that is, the sensitivity Sk, the dynamic range Gp, and the group to which the radiation image carried by this input pre-read image signal Sp belongs. A comparison is made with the provisional reading conditions, and the following equation is obtained: Rev.-ΔSk≦Sk≦Revision+ΔSk... (1) 0-
Δcp≦cp≦0+Δcp...If the two equations (2) are satisfied at the same time, the obtained reading condition is determined to be the correct reading condition, and sk<sk−Δsst
−(31Sk+ΔSk<Sk
... (4) Gp < Gp - Δcp ...
・(5) cp+ΔGp<Gp...(■
If either of these conditions is satisfied, it is determined that an incorrect reading condition has been obtained.

Here, a case will be described in which it is determined that an incorrect reading condition has been obtained.

In this case, reading condition SK1. which was manually adjusted in the same manner as last time for radiographic images belonging to the same group.
If the GPI (corresponding to straight line G4 in Figure 3B, for example) is already stored, this reading condition S
Next, the pre-read image signal Sp is adjusted by GP, and the adjusted visible image is reproduced and displayed on the CRT display 31. This reading condition SKl+G, 1 (straight line G4 in Fig. 3B)
) is the correct reading condition for this image Sxz, G
In most cases, the density (brightness) and contrast of this displayed visible image have already been adjusted to approximately correct values, and the operator presses the keyboard 32. It is only necessary to adjust the density (brightness) and contrast of this visible image to a certain extent using this method, and the correct reading conditions S X21 G P2 for this image can be efficiently determined.

The reading conditions SK□, G, 2 adjusted using this manual are stored in place of the reading conditions SKI, GPI for the same group that have been stored up to that point.

In addition, as mentioned above, the reading condition SKI stored up to that time,
Reading conditions S newly required for GPI manually
K2. Instead of replacing it with G P2 and memorizing it,
It is also possible to store an average value of reading conditions for all manually adjusted images belonging to the same group in the past, and to sequentially correct this average value. By memorizing past average values in this way, this average value gradually approaches the true average value for that group, so when it approaches the true average value, this true average value is used to perform the above The provisionally determined criteria may be modified.

Note that the above explanation is for the case where it is determined that an incorrect reading condition has been obtained, but if it is determined that the correct reading condition has been obtained, the above provisional judgment criteria will have a certain degree of reliability. If the above provisional judgment criteria are unreliable and the test is in the very early stages of startup, it is determined that the above incorrect reading conditions were required regardless of the judgment result. The visible image may be displayed in the same manner as when the image is displayed. here,
If it is determined that the correct reading conditions have been obtained, a visible image adjusted using the reading conditions manually adjusted last time may be displayed in the same way as above, but it is not necessary to judge whether the provisional judgment criteria are good or bad. For this purpose, a visible image adjusted under reading conditions automatically determined and determined to be correct may be displayed.

When the reading conditions for the main reading are obtained in this way, these reading conditions are output to the main reading means 100', and the voltage applied to the photomultiplier 21' and the amplification factor of the amplifier 26' are determined according to the output reading conditions. is controlled.

The stimulable phosphor sheet ll' which has been pre-readed is set at a predetermined position in the main reading means 100', and the sheet 11' is scanned by a light beam 15' which is stronger than the light beam used for the above-mentioned pre-reading. The image signal SQ is obtained according to the reading conditions determined by the main reading means 100'.
Since the configuration of is similar to the configuration of the above-mentioned pre-reading means 100, components corresponding to each component of the pre-reading means 100 are shown with a dash attached to the number used in the pre-reading means 100,
Explanation will be omitted.

The image signal S0 obtained by being digitized by the A/D converter 27' is sent to the image processing means 50.

The image processing means 50 performs appropriate image processing on the image signal S0. The image signal subjected to this image processing is sent to the reproduction device 60, and a radiation image based on this image signal is reproduced and displayed.

In the above embodiment, a device was described in which the condition determining means (computer system 200) determines the reading conditions for main reading, but during main reading, reading is performed under predetermined reading conditions regardless of the pre-read image signal Sp. , the computer system 200 determines image processing conditions for performing image processing on the image signal SO in the image processing device 50, and applies the image processing conditions determined by the computer system 200 to the image processing means as shown by the broken line in FIG. 50, or the computer system 200 may determine both the reading conditions and the image processing conditions.

In the embodiment described using FIG. 1, the pre-reading means 10
0 and the book reading means 100' are configured separately,
As mentioned above, the structure of the pre-reading means 100 and the main reading means 100' is between the two, so the pre-reading means 100 and the main reading means 1
00' may be combined and used for the same purpose.

In this case, after performing pre-reading by scanning with a weak light beam, the stimulable phosphor sheet 11 may be moved back once, and then main reading may be performed by scanning again with a strong light beam.

When the pre-reading means and the main reading means are used, it is necessary to switch the intensity of the light beam between the pre-reading and the main reading, but this switching method involves switching the light intensity itself from the laser light source. , ND on the optical path of the light beam
Insert filter etc.

Various known methods can be used, such as a method of switching the light intensity by removing the light, a method of changing the beam diameter of the light beam, a method of switching the speed of the main scanning and the speed of the sub-scanning.

FIG. 2 is a perspective view showing another embodiment of the radiation image reading device of the present invention. This embodiment is similar to the previously described embodiment in that it uses a stimulable phosphor sheet, but is a system that does not perform pre-reading.

In this embodiment, the structure of the reading means 100' is similar to that of the main reading means 100' of the embodiment shown in FIG. .

The image signal SQ output from the A/D converter 27' is input to the computer system 200'.

Within the computer system 200', based on the image signal SQ input to the computer system 200', an image signal carrying information on a desired subject area is extracted from the image signal SO, and the extracted image signal is Image processing conditions for converting the image signal so that the based visible image is displayed as a visible image having appropriate density (brightness) and contrast are determined, and it is determined whether the determined image processing conditions are correct or incorrect. If it is determined that the image processing conditions obtained through this determination are incorrect, if the manually adjusted image processing conditions for the previous radiation image belonging to the same group are stored, the image processing conditions will be used. If it is not stored, the visible image adjusted using the image processing condition determined to be incorrect or the image processing condition provisionally determined is displayed on the CRT display 3.
1', and the density (brightness) and contrast of the visible image are manually adjusted.The image signal thus adjusted is sent to the playback device 60, and this playback device 60 A hard copy of the radiation image is output based on the image signal.

In addition, if the image processing conditions obtained by the above judgment are determined to be correct image processing conditions, this image signal is subjected to image processing according to the image processing conditions, and then the image is displayed as it is or for confirmation. The visible image adjusted according to the processing conditions is displayed on the CRT display 31' and then sent to the reproduction device 60.

Although each of the above embodiments is an example of an apparatus using a stimulable phosphor sheet, it goes without saying that the present invention can also be applied to an apparatus using conventional X-ray film, etc. .

(Effects of the Invention) As explained in detail above, the radiation image reading device of the present invention automatically calculates reading conditions, etc. by the calculation means and when the determination means determines that the reading conditions are incorrect, the radiation image reading device according to the present invention If manually adjusted reading conditions, etc. are stored for a group's radiation images, display the adjusted visible image using the previous reading conditions, etc. adjusted in the manual, and adjust the reading conditions, etc. manually. Therefore, manual adjustment can be easily completed and efficient manual adjustment can be performed.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the radiation image reading device of the present invention, FIG. 2 is a perspective view showing another embodiment of the radiation image reading device of the invention, FIG. FIG. 3B is a diagram showing a histogram of the pre-read image signal. 11, 11'... stimulable phosphor sheet 19, 19'.
... Stimulated luminescent light 21 21'... Photo multipliers 26, 26'
...Amplifiers 27, 27'...A/D converters 31, 31'...CRT displays 32, 32'
...Keyboard 100 ...Pre-reading means 100'...Main reading means 100'...Reading means 200, 200'...Computer system third
A diagram

Claims (2)

[Claims] (1) Pre-reading to represent the radiation image by irradiating excitation light onto a stimulable phosphor sheet on which a radiation image has been recorded and reading the stimulated luminescent light emitted from the stimulable phosphor sheet by irradiation with the excitation light. A pre-reading means for obtaining an image signal, which irradiates the stimulable phosphor sheet with excitation light again and reads the stimulated luminescence light emitted from the stimulable phosphor sheet by irradiation with the excitation light, thereby representing the radiation image. Main reading means for obtaining a reading image signal, reading conditions for obtaining the main reading image signal and/or image processing conditions for performing image processing on the obtained main reading image signal based on the pre-read image signal. a calculation means for determining whether the reading conditions and/or the image processing conditions determined by the calculation means are correct; If the determining means determines that the reading conditions and/or image processing conditions are incorrect, displaying a visible image based on the pre-read image signal that is the basis for determining the reading conditions and/or the image processing conditions. Display means, when at least the reading conditions and/or the image processing conditions determined by the calculating means are determined to be incorrect reading conditions and/or image processing conditions by the determining means, displaying the incorrect reading conditions. and/or a modification information input means for inputting modification information for modifying image processing conditions, and the reading conditions and/or the image processing conditions modified using the modification information input from the modification information input means. In the radiation image reading device, the radiation image reading device includes a storage means for storing radiation images classified into each group based on a predetermined classification system, wherein the display means stores previous radiation images belonging to the same group in the storage means. If the reading conditions and/or the image processing conditions that have been corrected for the image are stored, the main reading image is processed using the reading conditions stored in the storage means before the correction information is input. Displaying a visible image simulating the case where the signal is obtained and/or the case where image processing is performed on the main reading image signal using the image processing conditions stored in the storage means, and then the correction information is input. the main reading image signal is obtained using the reading conditions modified based on the input modification information and/or the image processing is modified based on the input modification information. A radiation image reading device characterized in that it displays a visible image that simulates a case where image processing is performed on the main reading image signal using conditions. (2) A reading means for reading a radiation image from a recording sheet on which the radiation image is recorded to obtain an image signal representing the radiation image, and image processing conditions for performing image processing on the image signal based on the image signal. a calculating means for determining, a determining means for determining whether the image processing condition determined by the calculating means is correct, and at least the image processing condition determined by the calculating means is determined to be an incorrect image processing condition by the determining means; correction information input means for inputting correction information for correcting the erroneous image processing conditions; In a radiation image reading device comprising a storage means for storing radiation images classified into groups based on a predetermined classification system, the display means stores information on previous radiation images belonging to the same group in the storage means. If the corrected image processing conditions are stored, the image signal is processed after image processing is performed on the image signal using the image processing conditions stored in the storage means before the correction information is input. Displaying a visible image, and then displaying a visible image after performing image processing on the image signal using the image processing conditions modified based on the modification information each time the modification information is input. A radiation image reading device characterized by: