JP2000338942A - Medical image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical image display device capable of displaying suitably contrast of a region concerned, confirming simultaneously positional relationship with the whole image of an object image. SOLUTION: In this medical image display device equipped with an image data input part 1 for inputting an X-ray image data or the like, an image data memory part 2 for memorizing the image data, an image display memory part 3 for recording the image data for display, a display part 6 for displaying the image data, and a CPU for controlling these instruments, an image of a region concerned having suitable brightness and contrast is displayed together with display of the whole image, by installing a region-concerned data input part 8 and a region-concerned setting information memory part 9, for inputting region-concerned specifying information and for specifying a region concerned on a display screen, a region-concerned memory part 3 for memorizing temporarily image data of the region concerned, and a brightness operation part 4 for obtaining the optimum display gradation in the region concerned, based on the image data of the region concerned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical image display device used for medical diagnosis, and more particularly to a medical image display device capable of easily displaying a region of interest without losing the information value of the entire medical image. Related to the device.

[0002]

2. Description of the Related Art Image diagnosis of a subject is performed by displaying an image of the subject taken by various means, that is, a fluoroscopic image or a CT tomographic image on a display. At this time, in the X-ray image, the properties of the image greatly change depending on the target region, and an optimum gradation may not be obtained by a normal image display method.

For example, in gastrointestinal examination using X-rays, a so-called double contrast method in which a contrast agent (a barium agent) is attached to the inner wall of an organ and air is injected to inflate the organ to give a contrast is generally adopted. Have been. In this case, the information of diagnostic value does not exist in the gas portion or the portion where the barium agent has accumulated, but exists in the portion where the gas and the barium agent are mixed (double contrast portion). Therefore, when a method of determining the display gradation based on the image data of the entire screen is adopted, it is difficult to optimize the display in the area where the information having diagnostic value exists.

In order to solve this problem, a region of interest is designated in the whole image displayed on the display, and this region of interest is displayed separately from other regions, thereby providing an image of the subject. The diagnostic ability of the stomach has been improved.

[0005] In a conventional medical image display apparatus, as an example of a method of displaying a region of interest in an identifiable manner, a solid line is drawn on a display on which a medical image is displayed, and a region surrounded by the solid line is processed as a region of interest. A method for performing this is disclosed in JP-A-55-103639. Also,
As another example, Japanese Patent Publication No. Hei 4-3969 discloses a method in which the luminance in the region of interest is made higher than the luminance outside the region of interest so that the region of interest can be identified without displaying the outline. I have.

[0006]

However, when a region of interest is specified and displayed using the above-described medical image display device,
The continuity of the image data inside and outside the region of interest is divided, which causes a problem in accurate medical image diagnosis.

[0007] In addition, as if illuminated by a spotlight, the region of interest can be observed with optimal brightness.
There has been a demand for a medical image display apparatus capable of observing a continuous image of diagnostic value even at the boundary of the region of interest in order to improve diagnostic efficiency.

In order to set the center luminance in the region of interest, an average value of the image data in the region of interest is determined, and the average value of the image data to be displayed (hereinafter also referred to as “display window”) is determined. The difference obtained by subtracting the average value from the intermediate value was used as the correction value for the center position of the region of interest. However, if the image data at the center position is significantly different from the average value, the image data at the center position after correction is displayed in the middle of the display window. It is necessary to consider the case where the luminance deviates greatly from the value and the luminance of the center of the region of interest of interest is too high or too low.

Further, even when the center luminance is originally at the gray gradation near the middle of the luminance range and there is no need to correct the gradation, unnecessary luminance control processing is performed and the natural gradation is lost. Also needed to be considered.

For this reason, according to the present invention, a medical image capable of obtaining an optimum luminance with respect to image data of a region of interest having diagnostically effective information while maintaining continuity of information inside and outside the region of interest. It is an object to provide a display device.

[0011]

To achieve the above object, a medical image display apparatus of the present invention comprises: an image data storage means for storing medical image data; an image display means for displaying the medical image data; Control means for controlling a medical image to be displayed on a display screen of the image display means based on the medical image data stored in the image data storage means, and an interest on the display screen on which the medical image is displayed In a medical image display apparatus for designating and displaying a region, the center luminance in the designated region of interest is set to an arbitrary value, and the luminance at the boundary of the region of interest continuously changes inside and outside the region of interest. Brightness control means for controlling the brightness of the region of interest.

In this configuration, in addition to the image data storage means and the image display means, there is provided a region of interest setting unit and a luminance control unit of the region of interest. A region of interest having an arbitrary shape and size can be set, and the luminance of the region of interest can be controlled by the luminance control means of the region of interest such that the luminance value inside and outside the boundary of the region of interest is continuous. . For this reason,
The region of interest can be observed at an optimum brightness in a spotlight manner, and a continuous image of diagnostic value can be observed at the boundary of the region of interest.

[0013] In the medical image display apparatus of the present invention, the brightness control means sets the center brightness in the region of interest based on any one of an average value, a maximum value, and a minimum value of the image data in the region of interest. Things. In this configuration, by setting the center luminance in the region of interest based on the average value of the image data in the region of interest, the luminance in the region of interest is set to be different from the luminance of other parts, and The image can be brightened like a spotlight for easy viewing.

In the medical image display apparatus according to the present invention, the brightness control means uses a bell-shaped curve function to control the brightness of each pixel in the region of interest.
In this configuration, since the function of the bell-shaped curve is used to correct the brightness in the region of interest, the brightness at the center in the region of interest is increased, and the brightness of the peripheral portion is continuous inside and outside the region of interest. Therefore, the image of the central portion in the region of interest is bright and easy to see, and the image of the peripheral portion maintains the diagnostic value.

Further, the brightness control means sets the brightness value of all pixels in the region of interest based on the brightness value of a pixel located substantially at the center in the region of interest. In other words, the brightness control means, if the center brightness in the region of interest before the brightness control by the brightness control means is performed is lower than the set value for the center brightness in the region of interest, the set value If the brightness is high, the brightness may be kept as it is, or the brightness control means may adjust the center brightness in the region of interest before the brightness control is performed by the brightness control means. If the set value is higher than the set value for the center luminance in the area, the set value is set.
Alternatively, two set values for the center luminance in the region of interest are set, and the luminance control unit sets the center luminance in the region of interest before the luminance control is performed by the luminance control unit, according to the two settings. If it is lower than the lower value, it will be lower, if it is higher than the higher value,
It was configured to be set to the higher set value, and if it was between the two set values, it would remain the same.

Thus, in order to set the center luminance in the region of interest, the average value of the image data in the region of interest is determined, and the difference obtained by subtracting the average value from the intermediate value of the display window is calculated as the center position of the region of interest. However, if the image data at the center position is significantly different from the average value, the image data at the center position after the correction greatly deviates from the intermediate value of the display window, and the luminance of the center of interest of interest is high. It is possible to cope with cases that are too low or too low, and even when the center luminance is originally at the gray gradation near the middle of the luminance range and there is no need to correct the gradation, unnecessary luminance control processing is performed, It is possible to cope with a case where natural gradation is lost.

The region of interest can be arbitrarily moved on the image displayed on the screen in cooperation with a pointing device such as a mouse, and the size of the region of interest can be arbitrarily moved by dragging the mouse. It can be changed to. Therefore, for example, based on the entire image, for an X-ray image displayed with a display gradation in which a low-brightness state is black and a high-brightness state is white, some of the X-ray images are only visible as white or black By moving the region of interest to the region and renewing the gradation within the region of interest, it is possible to find a lesion lurking in the part of the region that could be overlooked in the conventional whole display, In some cases, it is not necessary to perform re-imaging for clear imaging of the region, and this can contribute to a reduction in the amount of X-ray exposure to the patient.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the medical image display device according to the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a block diagram showing the overall configuration of a medical image display apparatus according to the present invention. This medical image display device is used as an image display device of a medical imaging device such as an X-ray imaging device.

In FIG. 1, a medical image display device includes an image data input unit 1 for receiving digital image data measured by a medical imaging device, and an image data memory for recording image data read from the image data input unit 1. Part 2
A region-of-interest memory unit 3 for temporarily recording image data of a region of interest selected from the image data memory unit 2 for diagnosis of the region of interest; A brightness calculation unit 4 for obtaining brightness;
The luminance calculation unit 4 optimizes the luminance and records the image data of the region of interest and the remaining part of the image data for image display. The image display memory unit 5 converts the image data of the image display memory unit 5 into an analog image. And a control unit (hereinafter abbreviated as CPU) 7 for controlling these components.

Further, as components related to the region of interest, a region of interest data input unit 8 and a region of interest setting information memory unit 9 are provided. The region of interest data input unit 8 inputs data such as the position and size of the region of interest in order to set a desired region of interest on the display screen of the image data displayed on the display unit 6. The setting information of the region of interest is stored in the CPU 7
Is recorded in the region-of-interest setting information memory unit 9 via the.

In the present embodiment, the digital image data is a digestive tract examination image obtained by X-ray photography, and this X-ray image is inputted as a digital value from the image data input unit 1 and recorded in the image data memory unit 2. . One image designated for diagnosis among a series of images recorded in the image data memory unit 2 is first transferred to the image display memory unit 5. The display unit 6 displays the image data of the one image recorded in the image display memory unit 5.

Next, the display of the region of interest will be described. The observer of the image selects a desired region of interest while viewing the screen displayed on the display unit 6 and sets data for designating the region of interest in the region of interest data input unit 8.
For example, the position and size of the region of interest are designated using a mouse as a pointing device. Further, the region of interest can be arbitrarily moved on an image displayed on the screen in cooperation with a pointing device such as a mouse, and the size of the region of interest can be arbitrarily changed by dragging and moving the mouse. It has a configuration. Here, for example, a circle of about 20% of the width of the display screen of the display unit 6 is designated as the region of interest.

When the setting data of the position and size of the region of interest is input from the region of interest data input unit 8, the setting information is recorded in the region of interest setting information memory unit 9 via the CPU 7, and the region of interest is recorded. Are stored in the region-of-interest memory unit 3 from the image data memory unit 2.

The brightness calculation unit 4 performs a preset display brightness setting process (details will be described below) on the image data recorded in the region of interest memory unit 3. The image data of the region of interest subjected to the display luminance setting processing is overwritten and recorded in the image display memory unit 5.

Next, a display luminance setting process is shown in FIGS.
This will be described with reference to FIG. FIG. 2 shows a display screen of the display unit 6.
Things. This display shows an X-ray image on the surface 20.
Which medical image is displayed. Interest on this display screen 20
Region 21 will be selected. In this embodiment
In this case, a circular region is set as the region of interest 21.
The region of interest 21 is not limited to a circle, but may be a square.
Or a rectangle. In the case of the present embodiment, the region of interest
Since 21 is circular, it is setting information of the region of interest 21.
As the position and size, the coordinates of the center position of the region of interest 21
The radius R of the region of interest 21 is specified. In the region of interest 21
The coordinates of the center position 0 are (x ₀, Y₀). Area of interest
The point Pi (xi, yi) in 21 is from the center position 0
, The square root of the difference between the coordinate points (= √ ((xi−
x₀)^Two+ (Yi-y₀)^Two)) Is less than or equal to R
It is.

In the present invention, in order to make it easier to observe the image in the region of interest 21 selected above, the region of interest 2
Correct the luminance of the pixels in 1. This luminance correction is performed so that the luminance is normally increased. For this reason, the region of interest 21 is displayed brighter than other portions, and this display is hereinafter referred to as spotlight display. In this spotlight display, the display window output value of the luminance of the region of interest 21 is higher than the luminance before correction, and the increase width is based on the average value, the maximum value, the minimum value, and the like of the image data in the region of interest 21. Is set. Here, the case of setting based on the average value will be described. In this example, the average value Xa of the image data in the region of interest 21 is obtained,
This is converted and displayed so as to correspond to an intermediate value (hereinafter, also referred to as center luminance) of the display window output of 1 luminance.

When there are N pixels in the region of interest 21,
Since the N pieces of image data in the region of interest 21 are stored in the region of interest memory section 3, the N pieces of image data are read out, and the average value Xa = 1 / N (Σ × i) of the N pieces of image data is obtained.
Assuming that the intermediate value of the display window output corresponding to the display pixel value of the region of interest in the spotlight display is Xm, the correction value ΔΧ of the pixel value at the center position 0 of the region of interest 21 for the spotlight display is Xm−Xa. Given.

In the present invention, when the above-mentioned region of interest 21 is displayed in spotlight, the luminance value of the pixel is changed by a bell-shaped curve so that the luminance value of the pixel continuously changes at the boundary of the peripheral portion of the region of interest 21. This is an approximation.
This bell-shaped curve is a curve having a maximum value at the center and zero at both ends. By performing the luminance correction in this manner, the luminance gap around the region of interest 21 disappears,
The image of the peripheral portion of the region of interest 21 is easy to see, and the diagnosis is easy.

FIG. 3 shows an example of a brightness correction function used for spotlight display according to the present invention. This brightness correction function ΔΧ (r) is a function that draws a bell-shaped curve and is given by equation (1). ΔΧ (r) = (Xm−Xa) g (r / R) (1) where Xm is the central luminance of the region of interest after luminance correction, Xa is the average value of image data in the region of interest before correction, R is the radius of the region of interest 21, and r is the distance from the center position 0 of each pixel in the region of interest. g (r / R) is a function that is 1 when r = 0 and 0 when r = R, and a typical example of the function is a part of a Gaussian function. The value of g (r / R) is given in a table.

By performing the above-described luminance correction, the display pixel value Xi of each pixel in the region of interest 21 is corrected as in the following equation (2). X'i = Xi + (Xm-Xa) g (ri / R) (2) where Xi is the display pixel value before correction of the pixel at point Pi (xi, yi), and X'i is the display after correction. The pixel value, ri, is the distance between the center position 0 and the point Pi.

FIG. 4 shows an example in which the brightness of the region of interest 21 is corrected according to the present invention. In FIG. 4, a curve A is a pixel value before correction on a line passing through the center position 0 in the region of interest 21, and a curve B is a pixel value obtained by performing luminance correction on the curve A. The brightness correction function used here is the bell-shaped curve shown in FIG.

According to FIG. 4, the pixel value curve A before correction has a low peak on the left side and a shallow valley on the right side.
In the pixel value curve B after the correction, the mountain on the left side is emphasized and displayed, and the image in the region of interest becomes easy to see, and the boundary portion of the region of interest has almost the same pixel value as before the correction,
There is no discontinuity of the pixel values in this part.

The observer of the image looks at the above-mentioned spotlight display and, if necessary, further inputs a region of interest data input unit 8.
Is operated to correct the position, size, and luminance of the region of interest. The radius R for determining the size of the region of interest can be set freely. In addition, it is sufficient to prepare one Gaussian function table for use.

The brightness correction function has been described by taking a bell-shaped function as an example. However, the present invention is not limited to this, and is 0 at the peripheral boundary of the region of interest and 1 at the center position.
Any function can be used as long as it smoothly connects the middles, and a function of a curve constituted by a line graph can also be used.

When the observer of the image adds a region of interest, setting information relating to the position and size of the region of interest to be newly added is input from the region of interest data input unit 8, and the setting information is transmitted via the CPU 7. Region of interest setting information memory unit 9
And the image data in the additional region of interest is additionally recorded from the image data memory unit 2 to the region of interest memory unit 3.

When the setting of the region of interest is completed, the image data of the region of interest recorded in the region of interest memory unit 3 is referred to the setting information of the region of interest setting information memory unit 9 and the display luminance is calculated by the luminance calculation unit 4. After receiving the setting process, the image display memory unit 5 overwrites the same position as the original image data (the position of the corresponding region of interest).

The order in which the image data of the region of interest is overwritten follows the order in which the setting information of the region of interest is recorded in the region of interest setting information memory section 9. Therefore, the image data of the region of interest set later is overwritten on the upper part. On the screen of the display unit 6, the image data of the image display memory unit 5 including the image data of the region of interest subjected to the display luminance setting process is displayed.

When the setting of the region of interest is changed, the image data of the image under diagnosis is transferred again from the image data memory unit 3 to the image display memory unit 5, and the procedure of setting the region of interest is performed. Redo. As a result, the position of the spotlight displayed on the screen of the display unit 6 moves to the changed position, and the region of interest is displayed on the screen in the changed size.

By the above operation, on the screen of the display unit 6,
With respect to the entire image, it is possible to display only the region of interest within the entire image while enhancing the contrast. Since the density level of the image continuously changes in the peripheral portion of the region of interest, the diagnosis of the region of interest is facilitated.

<Second Embodiment> Next, a second embodiment will be described with reference to FIGS. FIG. 5 is a block diagram showing the overall configuration of the medical image display device of the present invention. This medical image display device is used as an image display device of a medical imaging device such as an X-ray imaging device.

In FIG. 5, a medical image display device has an image data input unit 1 for receiving digital image data measured by a medical imaging device, and an image data memory for recording image data read from the image data input unit 1. Part 2
A region-of-interest memory unit 3 for temporarily recording image data of a region of interest selected from the image data memory unit 2 for diagnosis of the region of interest; Calculation unit 4 for obtaining an appropriate luminance according to the formula (1), and an image for recording the image data of the region of interest and the remaining part of the image data for displaying the image processed by the luminance calculation unit 4 so as to have an appropriate luminance. The display device includes a display memory unit 5, a display unit 6 that converts the image data in the image display memory unit 5 into an analog image and displays the image, and a CPU 7 that controls these components.

Further, as components related to the region of interest, there are provided a region of interest data input unit 8 and a region of interest setting information memory unit 9. The region of interest data input unit 8 inputs data such as the position, size, and center luminance setting value of the region of interest in order to set a desired region of interest on the display screen of the image data displayed on the display unit 6. The region of interest setting information is stored in the region of interest setting information memory 9 via the CPU 7.
, A region-of-interest coordinate memory 91, a region-of-interest radius memory 92, a region-of-interest center image data set value (1) memory 93, a region-of-interest center image data set value (2) memory 9
4 recorded.

In the present embodiment, the digital image data is a digestive tract examination image obtained by X-ray photography, and this X-ray image is inputted as a digital value from the image data input unit 1 and recorded in the image data memory unit 2. . One image designated for diagnosis among a series of images recorded in the image data memory unit 2 is first transferred to the image display memory unit 5. The display unit 6 displays the image data of the one image recorded in the image display memory unit 5.

Next, the display of the region of interest will be described. The observer of the image selects a desired region of interest while viewing the screen displayed on the display unit 6 and sets data for designating the region of interest in the region of interest data input unit 8.
The position and size of the region of interest are specified using, for example, a mouse that is a pointing device. Here, a circle having a radius of about 10% of the display screen width of the display unit 6 is designated as the region of interest, and the center position coordinates are set in the region of interest center position coordinate memory 91 and the radius is set in the region of interest radius memory 92. The center luminance of the region of interest is set by setting image data corresponding to the center luminance from a keyboard. Two types of values can be set, and the smaller value (hereinafter referred to as X _S1 ) is the region of interest center image data set value (1) memory 93.
The larger value (hereinafter referred to as X _S2 ) is recorded in the region of interest center image data set value (2) memory 94. The data in the region-of-interest setting information memory unit 9 is set to an initial value by the CPU 7 when the power is turned on.

Setting data of the position, size, and center luminance setting value of the region of interest are input from the region of interest data input section 8,
When a double click of the left mouse button is input, the setting information is recorded in the region of interest setting information memory unit 9 via the CPU 7 and the image data in the region of interest is stored in the image data memory unit. 2 is recorded in the region of interest memory unit 3.

Under the control of the CPU 7, the brightness calculation section 4 performs a region-of-interest image data correction process on the image data in the region-of-interest memory section 3 as needed, and displays the processed region-of-interest image data on an image. Overwrites the memory unit 5.

Next, the region-of-interest image data correction processing and the control of the CPU 7 for the processing will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 2 shows a display screen of the display unit 6.
is there. This display screen 20 displays a medical image such as an X-ray image.
Image is displayed. The region of interest 2 is displayed on the display screen 20.
1 will be selected. In the present embodiment,
A circular region is set as the region of interest 21. This function
The heart region 21 is not limited to a circle, but may be a square or a rectangle.
The shape may be used. In the case of the present embodiment, the region of interest 21 is
Since it is circular, the position and the setting information of the region of interest 21
As the size, the coordinates of the center position of the region of interest 21 and the region of interest
The radius R of the area 21 is specified. Center position of region of interest 21
The coordinates of O are (x ₀, Y₀). In the region of interest 21
Is the distance from the center position O as the point Pi (xi, yi)
ri (= √ ((xi−x₀)^Two+ (Yi-y₀)^Two)) Is R or more
The point below is selected.

In the present invention, in order to make it easy to observe the image in the region of interest 21 selected above, the region of interest 2
Correct the luminance of the pixels in 1. That is, when the luminance of the region of interest is low and the image data at the center of the region of interest is lower than X _S1 , a correction to increase the image data in the region of interest is performed so that the image data at the center of the region of interest becomes X _S1. I do. In this correction process, the luminance at the boundary of the region of interest continuously changes inside and outside the region of interest.

On the other hand, when the luminance of the region of interest is high and the image data at the center of the region of interest is higher than X _S2 , the correction image processing for lowering the image data within the region of interest is performed, and the image data at the center of the region of interest is obtained. Becomes X _S2 . The correction processing is the same as the correction processing for increasing the image data in the region of interest described above, except that the processed image data of the center of the region of interest is X _S1 or X _S2 , and in this case, Also at the boundary of the region of interest, the luminance changes continuously inside and outside the region of interest.

Further, in the present invention, when the luminance of the region of interest is originally at an intermediate value that is easy to observe and the image data at the center of the region of interest is between X _S1 and X _S2 , the correction processing is not performed and the correction is not performed. The overwriting of the image data memory unit 5 with the region of interest image data is not performed.

Depending on the type of image, the correction may cause unnaturalness in the image. Therefore, in some cases, one or both of the above-described correction processing for increasing the image data in the region of interest and the correction processing for reducing the image data may be unnecessary. is there. In such a case,
By setting X _S1 to the minimum value (0 in this embodiment) that can be taken by the image data, the correction processing for increasing the image data does not work, and X _S2 is the maximum value that the image data can take (4095 in this embodiment). ), The corrected image processing for lowering the image data does not work.

The change in the processing contents according to the above case is the CP
U7 is performed by controlling the region-of-interest image data correction in the luminance calculation unit 4 according to the flowchart of FIG. That is,
First, an image data average value Xc of an area of three pixels vertically and three pixels horizontally centered on the center position O (x ₀ , y ₀ ) of the region of interest 21 is determined and used as image data of the center of the region of interest (process 30). Then compare Xc and X _S1 (decision 31), Xc <For X _S1, central image data correction Δc the X _S1 -Xc and from it (processing 32), the region of interest image data by the luminance calculation section 4 A correction process (details will be described later) is performed, and the corrected region-of-interest image data is overwritten on the image display memory unit 5 (process 35). In this case, Δc is positive, and correction for increasing the image data value of the region of interest is performed, and the luminance value in the region of interest increases.

In the judgment 31, Xc ≧ X_S1In the case of, Xc is X
_S2Xc> X_S2If, the center image
X is the data correction amount Δc_S2After -Xc (process 32),
Region-of-interest image data correction processing to be described later in the luminance calculation unit 4
And display the corrected region of interest image data
It overwrites the remote unit 5 (process 35). In this case, Δc is negative
Correction to reduce the image data value of the region of interest.
The brightness value in the region of interest is reduced. Xc ≦ X in judgment 33
_S2In the case of, no processing is performed. In this case, Xc is X_S1
And X _S2Is equivalent to the case where no correction is considered necessary.
You.

In the processing of FIG. 6, when X _{S1 is set} to the minimum value (0) that can be taken by image data in the present embodiment, a decision 31 is made.
Thus, the case of Xc <X _S1 is eliminated, and the correction for increasing the image data value of the region of interest can be disabled.

If X _{S2 is set} to the maximum value (4095) that the image data can take in this embodiment, Xc
> X _S2 is eliminated, and the correction for reducing the image data value of the region of interest can be disabled. In the present embodiment, the reason that the image data of O (x ₀ , y ₀ ) itself is not used as the image data of the center of interest is that
This is for preventing the central image data correction amount Δc from being excessively changed with respect to the change of the region of interest center position, and for reducing the influence of noise included in the image data.

Next, the region-of-interest image data correction processing performed by the luminance calculator 4 will be described. Region of interest 2 shown in FIG.
The image data Xi of the point Pi (xi, yi) in 1 is added to the image data correction amount ΔΧ (ri) by the region of interest image data correction processing as shown in Expression (3) to become Xi ′. Xi ′ = Xi + ΔΧ (ri) (3) where X _S2 is the region of interest center position O (x ₀ , y ₀ ) and the point P
It is a function of the distance ri of i (xi, yi).

According to the present invention, the image data correction amount ΔΧ (ri) is calculated as shown in equation (4) so that the luminance value of the pixel continuously changes at the boundary of the peripheral part of the region of interest 21. Takes the maximum value given by the central image data correction amount Δc at the center (ri = 0), and becomes 0 at the boundary (ri = R) of the peripheral portion of the region of interest 21 into a bell-shaped curve as shown in FIG. did. By performing the luminance correction in this manner, the luminance gap around the region of interest 21 is eliminated, so that the image of the region around the region of interest 21 is easy to see, and diagnosis is easy. ΔΧ (ri) = ΔC · g (ri / R) (4)

Here, g (x) is the maximum value 1, 1 when x = 0.
Is a function that monotonically changes between 0 and 1 by taking 0, and can be made using, for example, a part of a Gaussian function or using a trigonometric function. In the present embodiment shown in FIG. For simplicity, the cubic function of equation (5) is used. g (x) = 2x ³ −3x ² +1 (5) When the function of equation (5) is used, g (x) is set at the boundary (ri = R) of the peripheral portion of the region of interest 21 as shown in FIG. ) Also becomes 0, so that the luminance change at the boundary of the peripheral portion of the region of interest 21 becomes smooth.

FIG. 8 shows an example in which the image data and the brightness value in the region of interest 21 are corrected to be high according to the present invention, and FIG. 9 shows the correction in which the image data and the brightness value in the region of interest 21 are lowered. An example is shown below. 8 and 9, a curve A is image data before correction on a line passing through the center position O in the region of interest 21, and a curve B is image data corrected for the curve A. The function for giving the image data correction amount used here is the bell-shaped curve shown in FIG.

According to FIG. 8, the image data curve A before correction is shown.
Is a valley-shaped curve having a minimum value on the left side of O, but in the corrected image data curve B, the entire valley becomes shallow and the image in the region of interest becomes easy to see. The corrected image data value of O is X _S1
It has become. Further, the boundary portion of the region of interest has substantially the same pixel value as before correction, and there is no discontinuity in the pixel value at this portion, and the connection is smooth.

On the other hand, according to FIG. 9, the image data curve A before correction is a mountain-shaped curve having the maximum value on the left side of O,
In the image data curve B after the correction, the entire mountain is lowered, and the image in the region of interest becomes easy to see. The image data value of O after the correction is X _S2 . Further, the boundary portion of the region of interest has substantially the same pixel value as before correction, and there is no discontinuity in the pixel value at this portion, and the connection is smooth.

In the present invention, the observer of the image looks at the display of the region of interest corrected as described above, and if necessary, further operates the region of interest data input unit 8 to set the position and size of the region of interest. _Now , the values of X _S1 and X _S2 can be updated. Even if updated as such, the image data correction amount ΔΧ (r
In order to obtain i), a function table of one kind of bell-shaped curve g (x) may be used as in the equation (4).

Although g (x) has been described by exemplifying a smooth curve such as a cubic function, the present invention is not limited to this, and becomes zero at the boundary of the peripheral portion of the region of interest and becomes the maximum value at the center position. If the function changes uniformly in the middle, a function composed of a polygonal line can be used.

When the observer of the image adds a region of interest, setting information relating to the position and size of the region of interest to be newly added is input from the region of interest data input unit 8, and the setting information is transmitted via the CPU 7. Region of interest setting information memory unit 9
And the image data in the additional region of interest is additionally recorded from the image data memory unit 2 to the region of interest memory unit 3.

When the setting of the region of interest is completed, the image data of the region of interest recorded in the region of interest memory unit 3 refers to the setting information in the region of interest setting information memory unit 9 as described above, and After receiving the region-of-interest image data correction processing in (1), the image display memory unit 5 overwrites the same position as the original image data (the position of the corresponding region of interest).

The order in which the image data of the region of interest is overwritten follows the order in which the setting information of the region of interest is recorded in the region of interest setting information memory 9. Therefore, the image data of the region of interest set later is overwritten on the upper part. On the screen of the display unit 6, the image data of the image display memory unit 5 including the image data of the region of interest subjected to the region of interest image data correction processing is displayed.

When the setting of the region of interest is changed, the image data of the image under diagnosis is transferred from the image data memory unit 3 to the image display memory unit 5 again, and the procedure of setting the region of interest is performed. Redo. As a result, the position of the spotlight displayed on the screen of the display unit 6 moves to the changed position, and the region of interest is displayed on the screen in the changed size.

With the above operation, on the screen of the display unit 6,
With respect to the entire image, it is possible to display only the region of interest within the entire image while enhancing the contrast. Since the density level of the image continuously changes in the peripheral portion of the region of interest, the diagnosis of the region of interest is facilitated.

[0071]

As described above, according to the medical image display apparatus of the present invention, when displaying image data such as a gastrointestinal tract photographed image by X-rays, it is possible to perform image processing only on a region of interest and obtain an overall image. Can be observed well.

Therefore, even if the operator is not proficient in window operations, it is possible to easily obtain an image with an appropriate contrast while grasping the positional relationship with the entire image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a medical image display device according to a first embodiment of the present invention.

FIG. 2 shows a display screen of a display unit of the apparatus shown in FIGS.

FIG. 3 is an example of a brightness correction function used for spotlight display according to the first embodiment of the present invention.

FIG. 4 is an example in which luminance correction of a region of interest is performed according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing the overall configuration of the medical image display device of the present invention.

FIG. 6 is a flowchart of a region of interest image data correction control by a CPU;

FIG. 7 is an example of an image data correction function used in the region of interest image data correction processing of the present invention.

FIG. 8 is a first example in which region-of-interest image data correction is performed according to the present invention.

FIG. 9 is a second example in which region-of-interest image data correction is performed according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image data input part 2 ... Image data memory part 3 ... Area of interest memory part 4 ... Luminance calculation part 5 ... Image display memory part 6 ... Display part 7 ... CPU (control part) 8 ... Interest area data input part 9 ... Interest Area setting information memory unit 20: display screen 21: region of interest

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 5/10 G06F 15/68 310J 5/36 G09G 5/36 520A

Claims (2)

[Claims] 1. An image data storage means for storing medical image data, an image display means for displaying the medical image data, and a medical image based on the medical image data stored in the image data storage means. A medical image display device comprising a control means for controlling the display on the display screen of the medical image display apparatus, wherein the medical image display apparatus displays the medical image by designating the region of interest on the display screen on which the medical image is displayed. A medical device comprising: a brightness control unit configured to set the brightness to an arbitrary value and to control the brightness of the region of interest so that the brightness continuously changes inside and outside the region of interest at the boundary of the region of interest. Image display device. 2. The apparatus according to claim 1, wherein said brightness control means includes means for setting a brightness value of all pixels in said region of interest based on a brightness value of a pixel located substantially at a center in said region of interest. The medical image display device according to claim 1.