JPS6217875A - Image processor for x-ray image - Google Patents

Abstract

PURPOSE:To display an objective image at real time while changing factors by inputting various factors used for calculation from the external and executing energy subtracting calculation on the basis of hard logic. CONSTITUTION:The values of the factors (a)-(d) are changed from a factor input part 3 until the objective image displayed on an image display part 13 is cleared. When the factors are changed, a factor control part 4 supplies the changed factor values to an arithmetic part 6. The various factors (a)-(d) are supplied from the factor input part 3 and the factor control part 4 immediately outputs signal data corresponding to the inputted factors to the arithmetic part 6. The calculated results are successively stored in the 3rd image memory 7 and the objective image data stored in the memory 7 are successively read out by the 3rd image display control part 10 and displayed on an image display part 13 as the objective image (energy-subtracted image).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image processing apparatus for X-ray images, and more particularly to an image processing apparatus for X-ray images that can obtain a clear target image of a subject.

(Prior Art) In the field of medical image diagnosis, X-ray images are most widely used. However, with the conventional xwAm imaging method, it is difficult to distinguish, for example, soft tissues overlying bones or organs overlying intestinal gas, and therefore, accurate image diagnosis cannot be performed. Therefore, the energy sub-1 helix method is used to obtain only a clear image of the target region (target image).

The energy subtraction method is a method of obtaining two types of X-ray images of the same subject with different energy spectra, and obtaining a difference signal between these two types of X-ray images to obtain a target image.

Since the X-ray absorption characteristics of living tissue have an X-ray energy dependence, the living tissue is irradiated with X-rays with different Nerky distributions.1. : If the specific structure is extracted differently. The information on the two X-ray images, in which the specific structure (target object) is extracted differently, is transferred to an X-ray film or a photostimulable phosphor panel (MP) that is placed behind the subject. It can remain at 1=. Thereafter, the X-ray image information is read using a method such as optical scanning and converted into a digital image to obtain two types of images for which subtraction is performed. Here, image data is data obtained by reading an X-ray film, stimulable phosphor panel, etc. using a method such as optical scanning, which has image information with a different energy spectrum for energy subtraction, and A/D conversion. Refers to a gradation image.

Thereafter, subtraction is performed between correspondingly overlapping pixels of the two types of X-ray images. This subtraction is performed by multiplying the previous corresponding pixel image (signal by a weighting coefficient and subtracting it,
This means obtaining an energy retraction image.

This weighting and subtraction is shown below.

S=a-P-b-Q (1)
Here, S is the target image obtained as a result of subtraction, P and Q are the two original images to be subtracted, and a and b are weighting coefficients. Here, the weighting coefficient a, 1
) are selected so that the gradation of the structure to be erased is the same between the two types of X-ray images.

In short, the energy subtraction method is (1)
Delete unnecessary images by performing subtraction processing expressed by the formula,
This method leaves only the desired image. By using the energy sub-1 helix method, it is possible to observe specific structures, such as organs and bone canals, independently of other overlapping structures, which was not possible with conventional methods. Diagnostic information can be obtained.

(Problem to be Solved by the Invention) By the way, since there are individual differences in the composition of each tissue in a living body, when erasing a target tissue, the weighting coefficients a and b are generally not the same. cannot be determined. Therefore, in order to obtain the desired subtraction image, a cut-and-try method is used while changing the weighting coefficients. Conventionally, digital
Subtraction angiography (DSA) and devices using hard processors exist, and each is used for medical image diagnosis. However, there is no device that performs subtraction by multiplying both images P and Q by appropriate weighting coefficients as shown in equation (1) for the purpose of energy sub 1 to luxion.

If the deception represented by equation (1) is performed using a conventional device, it will be performed by software processing. However, if it is performed by software, the processing time will take, for example, several minutes. Therefore, changing the weighting coefficients to obtain a desired processed image takes time, making it difficult to use it for routine use in actual medical diagnosis. Furthermore, since conventional devices are equipped with only one display, even if a target image is obtained by energy subtraction, when examining this target image, the original image must be viewed from the X-ray film on the Scherkasten. It was complicated because it had to be read from

The present invention has been made in view of these points, and
The first purpose is to realize an image processing device for X-ray images that can display the target image obtained by energy→''btraction in real time while changing the weighting coefficient. , in addition to the target image 2
The object of the present invention is to realize an image processing device for lζ x line images by making it possible to display the inserted original image (1) to improve operability.

(Means for Solving the Problems) The present invention, which solves the above-mentioned problems, performs energy retraction processing between two types of digital image signals with different energy spectra obtained for the same subject. The X-ray image processing apparatus for obtaining a target image is characterized in that it is configured to display the target image fγ1 in real time while avoiding changes in the weighting coefficient during energy subtraction processing.

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

The figure is a configuration block diagram showing one embodiment of the present invention.

In the figure, 1 and 2 are sub 1 - image memories in which the original image data to be processed are stored, and 3 is sub 1 -
This is a coefficient input section for inputting each fi and iE coefficient used when running the friction calculation section. For example, a RAM is used as the image memories 1 and 2, and as the coefficient input section 3, for example, a mouse, a 1-rack ball, a joystick, or the like is used.

4 is a coefficient control unit that outputs various coefficient values according to the weighting coefficients input from the coefficient input unit 3; 5 is a coefficient control unit that receives various coefficient values from the coefficient control unit 4 and generates character signals corresponding to the coefficient values; This is the character generating part that occurs.

Reference numeral 6 denotes an arithmetic unit that receives original image data from the first and second image memories 1 and 2 and each pole coefficient data from the coefficient control unit 4, and performs a subtraction operation; 7, the arithmetic unit 6;
This is a third image memory that sequentially stores the calculation results. As the calculation unit 6, for example, a hard logic circuit is used.

Reference numeral 8 denotes a first image display control unit which receives the output of the first image memory 1 and the output of the character generation unit 5 and performs various controls for image display; 9 receives the output of the second image memory 2; 11 to 13 are respectively a second image display control section that performs control for image display, and a third image display control section that receives the output of the third image memory 7 and performs control for image display. This is an image display unit that displays the outputs of the first to third image display control units 8 to 10 as images. For example, CRTs are used as the image display units 11 to 13. The operation of the device configured as described above will be explained as follows.

The original image data having different energy spectra stored in the first and second image memories 1.2 are read out by the first and second image display control sections 8.9, respectively, and are read out by the corresponding image display section 11. It is displayed at ゜12. On the other hand, the calculation unit 6 receives the image data stored in the first and second image memories 1.2 and various coefficients provided by the coefficient control unit 4, and performs the energy subtraction calculation as shown below. .

S= <a −P ~ b −Q−+−c ) ・d
(2) Here, S, P, Q, a, b
Ha (1) Formula te theory 11 + 1 (.

S is the target image obtained as a result of the energy sub 1 to luxion calculation, P is the original image given from the first image memory 1, and Q is the original image given from the second image memory 2. or vice versa), a and b are weighting coefficients. C is a coefficient that sets brightness, and d is a coefficient that determines gradation.

The various coefficients a to d shown in equation (2) are given from the coefficient input section 3, and the coefficient control section 4 promptly outputs digital data corresponding to the input coefficients to the calculation section 6. The results of the calculations are sequentially stored in the third image memory 7, and the target image data stored in the image memory 7 is sequentially read out by the third image display control unit 10, and the target image is displayed on the image display unit 13. (Energy subtraction image).

The operator changes the values of coefficients a to d from the coefficient input section 3 until the target image displayed on the image display section 13 becomes clear. When the coefficient is changed, the coefficient control unit 4 immediately provides the changed coefficient value to the calculation unit 6. The calculation unit 6 quickly performs the calculation shown in equation (2) and displays it on the image display unit 13 in real time.Here, the weighting coefficient 1 expressed by equation (2) is normally set to 1. At this time, it is desirable to change the weighting coefficient a in the range of 0.1 to 3.0 in steps of 0.1, and it is desirable to set the coefficient C to ±(the gradation level of the original picture). . If the number of bits of the original image data is 8 bits, the value of coefficient C is -255 to 255.
selected within the range. Further, the coefficient (1) is preferably changed in steps of 0.1 in the range of 1 to 10.

Here, various coefficients inputted from the coefficient input section 3 are converted into character patterns by the character generation section 5, and are converted into character patterns by the image display section 1.
1, so the operator (or operator) can know the value of the input coefficient. In other words, the operator can check the coefficient value on the image display and change the coefficient value. It's convenient to be able to do it.

According to the present invention, in addition to the 1J-like image generated by the J-Nel key 4 knob 1 to the traction, two types of original images can also be displayed on the image display section, so that the energy sub-1-heraxis image (1J-like image) can be displayed. When inspecting the instrument, it is no longer necessary to view the original image recorded in real time from above the Scherkasten, so the operation ('I) is greatly improved.
Image diagnosis can also be performed more accurately.

J: In the explanation of 5ai, the one given by equation (2) was used as the arithmetic expression, but the coefficients c and d are factors to determine the ease of display, and other expressions It may be. For example, even if the formula is as shown below, J: Yes.

S = <a -P-Q) -d -c (
3) However, the coefficient b was set to 1.

In addition, a plurality of image memories, image display control sections, and image display sections shown in the figure are each provided.

With this configuration, images processed with a certain width coefficient can be displayed and compared with images processed with other width coefficients. In the description of 1- above, the coefficient values are displayed on the image display unit 11, but the display is not limited to this, and may be displayed on other image display units 12, 13.

(Effects of the Invention) As described in detail above, according to the present invention, by performing the energy sub 1 to traction calculations using hard logic together with the JZ unit that allows input of various coefficients used for energy subtraction calculations from the outside, It is possible to realize an image processing device for X-ray images that can display a target image in real time while changing coefficients.

According to the present invention, the operator (for example, a doctor) can select the desired living body 1f while changing the weighting coefficients. woven image (e.g. bone removed,
Soft tissue silk weaving, affected area extracted images, etc.) can be easily and quickly obtained. Furthermore, since the original image can be displayed in addition to the target image, comparison operations (4J: <) can be performed during image diagnosis.

[Brief explanation of drawings]

The figure is a configuration block diagram showing one embodiment of the present invention. 1.2.7... Image memory 3... Coefficient input section 4... Coefficient control section 5...
・Character generation section 6...Arithmetic section 8-1o...Image display control section 11-13...Image display section Patent applicant Roku Konishi Photo Industry Co., Ltd. Agent Patent attorney Fuji Ijima 1 person

Claims (3)

[Claims] (1) In an image processing device for X-ray images that performs energy subtraction processing between two types of digital image signals with different energy spectra obtained for the same subject to obtain a target image, the weighting coefficient during energy subtraction processing is An image processing device for an X-ray image, characterized in that it is configured to display a target image in real time while changing the target image. (2) The image processing apparatus for X-ray images according to claim 1, characterized in that it is configured to display two types of original images in addition to the target image. (3) The image processing apparatus for X-ray images according to claim 1, characterized in that the following equation is used as an arithmetic equation during the subtraction processing. S=(a・P−b・Q+c)・d However, S is the target image, P and Q are each two types of original images,
a and b are weighting coefficients, c is a coefficient for setting brightness, and d is a coefficient for setting gradation.