JP4897293B2 - Medical image display device - Google Patents

Description

  The present invention relates to a medical image display apparatus that displays a medical image obtained by a medical image diagnostic apparatus such as an X-ray CT apparatus, an MRI apparatus, or an ultrasonic diagnostic apparatus, and in particular, a display area for medical images and related information. It is about the technology to arrange.

Conventionally, medical images and incidental information indicating the properties and attributes of the images have been adjusted so as to avoid overlapping them. (For example, Patent Document 1)
JP 2004-194704 A

  However, in Patent Document 1, since the operator looks at the screen and operates with a mouse or the like so as to avoid the overlap between the image and the accompanying information, it can satisfy the request to omit the avoidance operation. It was not.

  An object of the present invention is to provide a medical image display device that can omit an operation for confirming an overlap between a medical image and its accompanying information.

The object is to display a medical image measured by the medical image diagnostic apparatus and related information related to the medical image on a screen, a subject area extracting unit that extracts a subject area from the medical image, and An overlap amount calculating means for calculating an overlap amount between the subject region and the relationship information; and a display control means for controlling display of the subject region or the relationship information based on the overlap amount . Achieved.

  The present invention has an effect that the operation for confirming the overlap between the medical image and the accompanying information can be omitted easily without bothering the operator and the operability can be improved.

A preferred embodiment of a medical image display apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a system example in which a medical image display apparatus and a medical image diagnostic apparatus adopting the present invention are connected by a network, and FIG. 2 is a flowchart in which input, processing, and output of the system of FIG. is there.

  As shown in FIG. 1, the medical image display apparatus 110 includes an input unit 111, a central processing unit (CPU) 112 connected to the input unit 111, a main storage unit 113 connected to the central processing unit 112, and an auxiliary storage. Unit 114 and output unit 115 connected to central processing unit 112.

  The input unit 111 is used to input desired character information that the operator wants to display together with setting of control parameters of the apparatus, medical images, and the like such as a keyboard, a mouse, and a trackball. The central processing unit 112 controls the entire apparatus based on the control parameters input by the input unit 111. The main storage unit 113 stores a diagnostic image (medical image) obtained by the medical image diagnostic apparatus 100 including an X-ray apparatus, an X-ray CT apparatus, an MRI apparatus, and an ultrasonic apparatus, and inputted character information. The auxiliary storage unit 114 is an alias called an external storage device, and generally has a larger capacity than the main storage unit 113. For example, when the amount of medical image data is enormous, the auxiliary storage unit 114 is used as an auxiliary to the main storage unit 113. Etc. The output unit 115 outputs a medical image and character information as an image, such as a CRT or a liquid crystal display.

In the medical image display device 110, the medical image obtained by the medical image diagnostic device 100 is transferred to the main storage unit 113 through the network 101, and the medical image stored in the main storage unit 113 is displayed on the output unit 115.
Here, the medical image display apparatus 110 and the medical image diagnostic apparatus 100 will be described separately. However, the medical image display apparatus 110 may be integrated in the medical image diagnostic apparatus 100.
In addition, here, the image data transfer illustrated is performed via a network, but the image data transfer may be performed via a storage medium such as a so-called magneto-optical disk (MO) or DVD-RAM disk in an offline manner. .

Each step of inputting, processing, and outputting data to the medical image display device 110 will be described with reference to FIG.
In the input step, the medical image 120 from the medical image diagnostic apparatus 100 and character information 121 related to the image are input as data. As the character information 121, information such as a patient number, a patient name, an imaging date, imaging conditions, a comment input by an operator, and a result of image analysis processing are input from the input unit 111. The shooting date, time, etc. may be obtained from a clock built in the computer. In this input step, each data may be input in advance before being measured by the medical image diagnostic apparatus 100.

  In the processing step, an occupation area for displaying a medical image obtained by the medical image diagnostic apparatus 100, that is, an image area is calculated, and character information or the like is displayed in a display area that avoids overlapping with the calculated image area. Control to be displayed. Specifically, it has a subject region determination unit 1221 and a display position calculation unit 1222 configured by a program of the central processing unit 112 or an electric circuit.

  The subject region determination unit 1221 determines the subject region based on the size of the portion of the subject. The display position calculation unit 1222 performs calculation for avoiding overlapping of character information on the image according to the determined size of the part of the subject.

In other words, since the X-ray CT apparatus usually obtains a plurality of tomographic images continuously in the body axis direction of the subject, the size varies depending on the region of the subject. If the image area of the tomographic image is recognized, the image area of the tomographic image is obtained, and the overlap of character information on the image is avoided, the image and Overlap with character information can be avoided without fail.
As a result of processing in the output process, the medical image is displayed in the image area, and the character information is displayed outside the image area.

Next, the principle of avoiding overlapping of medical images and character information will be described with reference to FIGS.
FIG. 3 is a diagram illustrating the principle of calculation of the lower end of the subject region in the image, and FIG. 4 is a diagram illustrating the principle of calculation of the overlap amount between the medical image and the character information.

  The central processing unit 112 calculates the lower end 300 of the subject region in the image as shown in FIG. The principle of this calculation will be described using an example of an X-ray CT apparatus. Air has a CT value of −1000. On the other hand, since the subject region has a CT value other than -1000 except for the air portion of the lung, it can be calculated by threshold processing, for example.

As shown in FIG. 4, the central processing unit 112 compares the positional relationship between the character region upper end 401 and the subject region lower end 300, and if the subject region lower end 300 is located below the character region upper end 401 in the drawing, the overlap amount Move the image upward by 400.
Thereby, it is possible to avoid the overlap between the subject area and the character area. Of course, since it is only necessary to relatively avoid overlapping of both the subject area and the character area, the character area may be moved, or both the image and the character may be moved.

  Further, if the central processing unit 112 calculates not only the lower end of the subject area 310 but also the upper end, it is determined whether the subject area 310 does not protrude from the display frame 420 when moving the image upward. It can also be judged.

Next, processing for avoiding overlap between both regions will be described in more detail with reference to FIGS.
FIG. 5 is a flowchart showing the procedure of the subject area calculation process.
This process is described for a case where the subject area is one. When two areas are shown, one large area may be left.
This is because only the maximum area is left in order to delete areas other than the subject such as a bed and a tube connected to the patient.

In most cases, the region to be imaged by the X-ray CT apparatus is a torso or head cross section, so if only one maximum area is left, only the subject region remains.
However, when shooting the lower limbs (both legs), rather than `` leave the maximum area area '', `` delete the area of 1 / N or less compared to the maximum area area (N is 10 for example) '' You should do it. Under this condition, an area other than the subject can be deleted.
In this case, it is not necessary to forcibly narrow down the area of the subject to one, and it is sufficient if the area other than the subject can be deleted, so there are two or more areas of the subject as shown on both legs of the subject. However, the processing is not different from the case of one subject region at all.

  The central processing unit 112 binarizes the original image so as to extract the entire subject area. In the case of a CT image, it may be binarized with a CT value of about -400. Further, the threshold value may be appropriately changed depending on the CT value unique to the extraction target organ. (Step 501)

  The central processing unit 112 performs a process (labeling process) for assigning a different number to each continuous area. As the algorithm, a general algorithm described in the following document is used. (Reference: Basic Techniques of Image Processing <Introduction to Techniques> Hasegawa et al., Technical Critics Company, First Edition, 1986, P.46-49) (Step 502)

The central processing unit 112 counts the number of pixels for each labeled area. (Step 503)
The central processing unit 112 leaves only the maximum area among the labeled areas and deletes other areas. (Step 504)
As shown in FIG. 3, the central processing unit 112 performs raster scanning to calculate the lower end coordinates of the subject region. (Step 505)

Next, the display position calculation process will be described with reference to FIG.
FIG. 6 is a flowchart showing the procedure of the display position calculation process.
The central processing unit 112 calculates the distance (= number of pixels) where the image and the character overlap. Here, the coordinates for displaying the characters are known because they are usually displayed at positions designated in the program. Therefore, like the overlap amount 400 in FIG. 4, the difference between the known character display coordinates and the subject region lower end coordinates obtained in step 505 is the overlap amount. (Step 601)

  The central processing unit 112 translates the image upward in the drawing by the overlap amount calculated in the previous step. Here, the central processing unit 112 may move the character, move both the image and the character, or limit the movement amount so as not to protrude from the display frame. (Step 602).

  In the following, six specific examples will be given.

The first embodiment recognizes a subject area in a medical image, determines an overlap between the subject area and a character display area, and calculates an amount of movement based on the amount of overlap and moves the image when overlapping. "Priority, image movement method".
FIG. 7 is a flowchart for explaining the processing procedure of the character priority and image moving method.

The central processing unit 112 reads the processing target image (original image) from the auxiliary storage unit 114 into the main storage unit 113. (Step 701)
The central processing unit 112 calculates a subject area from the read processing target image. As shown in step 501 to step 504 in FIG. 5, the binarized image is created by threshold processing for the original image read in step 701, and if only the maximum area is left, the subject area Can be calculated. (Step 702)

The central processing unit 112 raster scans the image obtained in step 702 to obtain the lower end of the subject area. That is, the lower end 300 (FIG. 3) is the point that has been scanned. (Step 703)
The central processing unit 112 is known because the coordinates for displaying characters are specified in the program. Therefore, the coordinates 401 (FIG. 4) of the upper end of the character display area are compared with the subject lower end coordinates 300,
{Subject lower coordinate 300 value}> {Upper coordinate 401 value of character display area}
Then, it can be judged that there is duplication.

The overlap amount 400 can be calculated by the following equation.
Overlap amount 400 = Subject lower end 300-Character upper end 401
The coordinate system here is the upper left corner of the display screen as the origin, x (positive) in the right direction, and y (positive) in the downward direction. (Step 704)

If there is overlap in the previous step, the central processing unit 112 moves the image upward by the overlap amount 400.
The movement of the image is expressed by the following equation.
X = x + x0
Y = y + y0
Coordinates before movement (x, y)
Coordinates after movement (X, Y)
Movement amount x0 in x direction, y0 in y direction
In the case of the first embodiment, x0 = 0, y0 = overlap amount 400.
Further, if the upper end of the subject area is also obtained, it can be determined whether or not the image protrudes from the upper side of the frame 201 (FIG. 2) by movement, so that the movement amount can be limited to such an extent that it does not protrude. (Step 705)

The central processing unit 112 displays character information at a predetermined position. (Step 706)
Thus, when the medical image and the character information are displayed on the same screen, the character information can be preferentially displayed.

The second embodiment is an “image priority character display method” in which a subject area in an image is recognized, a lower end of the subject area is searched, and characters are displayed below the lower end.
FIG. 8 is a flowchart for explaining the processing procedure of the image priority character display method.

Steps 801 to 803 are the same as steps 701 to 703 in FIG. Here, only step 804 that is different from the first embodiment will be described.
The central processing unit 112 displays the character information with the character display coordinates below the lower end point obtained in step 803. (Step 804)
As a result, when the medical image and the character information are displayed on the same screen, the image information can be preferentially displayed.

In the third embodiment, an image is displayed on the screen, and the operator sets the region of interest on the screen, searches for the lower end of the region of interest, and displays it while avoiding the overlap between the region of interest and the character display region. “Region of interest setting method”.
In other words, the present embodiment is an embodiment in which the operator designates a portion of the subject that the user wants to see (a region that is difficult to be hidden by characters) and does not display characters in that region.

FIG. 9 is a flowchart for explaining a processing procedure of the region of interest setting method.
The central processing unit 112 reads the processing target image (original image) from the auxiliary storage unit 114 onto the main storage unit 113 and displays it on the output unit 115. (Step 901)
The operator sets a region of interest on the image using the input unit 111 while viewing the screen of the output unit 115. The region of interest is set by a general method such as drawing a circle, a rectangle, or a closed curve with a mouse at a portion where character overlay display is prohibited. The data holding format of the region of interest is a mask image (binary image in which the region of interest is filled), but is not limited thereto. Other than the mask image, if the region of interest is a circle, it may be a center coordinate and radius, if it is a rectangle, the coordinates of the four corners, if it is a closed curve, it may be a point sequence of coordinate points. (Step 902)

The central processing unit 112 searches the lower end of the region of interest by raster scanning from the lower side of the mask image set in the previous step. (Step 903)
The central processing unit 112 sets a region below the lower end of the region of interest found in the previous step as a character region display region, and displays character information in the display region. (Step 904)
Accordingly, when the medical image and the character information are displayed on the same screen, the image information of the set region of interest can be preferentially displayed.

Example 4 avoids overlapping with characters by reducing the image according to the amount of character information to be displayed. When the amount of character information to be displayed is large, for example, a report display method showing the findings of the image, etc. Useful for.
In other words, the report assumes a use in which a comment is added to an image as an explanatory image when a doctor introduces a patient to another doctor, and the image is stored and output. In this case, since it is not intended for careful interpretation, image quality deterioration due to reduction is not a problem in many cases, so that arbitrary images such as reduced images and characters can be arranged.

FIG. 10 is a flowchart for explaining the processing procedure of the image reduction method.
The central processing unit 112 reads the processing target image (original image) from the auxiliary storage unit 114 onto the main storage unit 113 and displays it on the output unit 115. (Step 1001)
The central processing unit 112 calculates a subject area from the read processing target image. As shown in Step 501 to Step 504 in FIG. 5, when the original image read in Step 1001 is binarized by threshold processing and only the maximum area is left, the subject area Can be calculated. (Step 1002)

The central processing unit 112 performs raster scanning of the subject region to obtain the coordinates of the upper and lower ends of the region, and sets the difference between these upper and lower ends as “subject thickness d1” (step 1003).
The operator inputs desired text (character information) to the input unit 111 in a character input area on the screen. The central processing unit 112 immediately displays the input text on the screen. In addition, the size and display position can be changed by an operation of the input unit 111 by the operator. Further, the coordinates of the character display area are such that the central processing unit 112 can know the arguments of the program executing the text input. (Step 1004)

The central processing unit 112 calculates an overlap amount d0 between the subject area and the character area. (Step 1005)
The central processing unit 112 calculates the image reduction rate from the subject thickness d1 and the overlap amount d0 by the following calculation formula.
Reduction ratio m = (d1-2 × d0) ÷ d1
(Step 1006)

The central processing unit 112 displays the reduced image and character information. (Step 1007)
As a result, when a medical image and character information are displayed on the same screen, a set character region having a relatively large number of characters (for example, a report display region) can be displayed with priority over the image information.

  The fifth embodiment is an “image display position adjustment” method in which the subject region is moved to the center of the frame when the subject is biased with respect to the image display frame (201 in FIG. 2). In this case, it does not matter whether or not character information is displayed.

FIG. 11 is a flowchart for explaining the procedure of the image display position adjustment method.
The central processing unit 112 reads the processing target image (original image) from the auxiliary storage unit 114 into the main storage unit 113. (Step 1101)
The central processing unit 112 calculates a subject area from the read processing target image. As shown in step 501 to step 504 in FIG. 5, when the original image read in step 1101 is binarized by threshold processing and only the maximum area is left, the subject area Can be calculated. (Step 1102)

The central processing unit 112 searches for the top, bottom, left and right end points of the subject region by raster scanning. The search for the top edge starts at the upper left corner and scans down one line at a time in the horizontal right direction. The search for the lower edge starts at the lower left corner and scans up one line at a time in the horizontal right direction. The search for the left edge starts from the upper left corner and scans one line at a time in the vertical downward direction. The search for the right edge starts at the upper right corner and scans left one line at a time in the vertical downward direction. (Step 1103)
The central processing unit 112 determines the horizontal and vertical deviations of the subject area and calculates the movement amount of the image display area.

FIG. 12 is a diagram illustrating an example in the case of horizontal deviation of an image. The same idea can be applied to the vertical direction as long as the direction of bias changes from the horizontal direction to the vertical direction in the drawing.
First, the distances between the left end and right end of the subject region and the frame are a and b, respectively. (a> b)
Since a> b, since the image is biased to the right in the drawing, the movement of the image region is in the left direction. To equalize the space on both sides of the subject, the movement amount is calculated so that the image is moved to the left by [(a−b) ÷ 2]. (Step 1104)

The central processing unit 112 moves the image by the movement amount obtained in the previous step. (Step 1105)
The central processing unit 112 displays the image moved in the previous step. (Step 1106)
Thereby, the image display position adjustment for moving the subject region to the center of the frame can be performed.

  Example 6 is an example of an image display magnification adjustment method that displays an enlarged image within a range that fits in the frame size when the subject is small relative to the frame. Note that the subject may be moved to the center of the frame according to the fifth embodiment as preprocessing.

FIG. 13 is a flowchart for explaining the processing procedure of the image display magnification adjustment method.
The central processing unit 112 reads the processing target image (original image) from the auxiliary storage unit 114 into the main storage unit 113. (Step 1301)
The central processing unit 112 calculates a subject area from the read processing target image. As shown in step 501 to step 504 in FIG. 5, if the original image read in step 1301 is binarized by threshold processing, and only the maximum area is left, the subject area Can be calculated. (Step 1302)

The central processing unit 112 searches for the top, bottom, left and right end points of the subject region by raster scanning. The search for the top edge starts at the upper left corner and scans down one line at a time in the horizontal right direction. The search for the lower edge starts at the lower left corner and scans up one line at a time in the horizontal right direction. The search for the left edge starts from the upper left corner and scans one line at a time in the vertical downward direction. The search for the right edge starts at the upper right corner and scans left one line at a time in the vertical downward direction. (Step 1303)
The central processing unit 112 determines the horizontal and vertical deviations of the subject area and calculates the movement amount of the image display area. (Step 1304)

The central processing unit 112 obtains the lengths xa and ya of the subject region shown in FIG. 14 from the end points of the subject region. FIG. 14 is a principle diagram showing an example of display magnification adjustment. Since the image matrix sizes xb and yb are determined in advance according to the imaging conditions of the medical image, the enlargement ratio can be obtained from these ratios.
For the enlargement ratio, it is desirable to use the smaller one of xb / xa and yb / ya so as not to protrude from the frame. (Step 1305)

The central processing unit 112 moves the image according to the amount of object bias obtained in step 1304. As a result, the subject is positioned at the center of the frame. (Step 1306)
The central processing unit 112 enlarges the image according to the enlargement ratio obtained in step 1305. (Step 1307)
The central processing unit 112 displays the enlarged image. (Step 1308)
Thereby, the image display magnification of the subject area can be adjusted.

The medical image display device 110 of the present embodiment displays a medical image measured by the medical image diagnostic device 100 and information related to the medical image, and when a plurality of the medical images are obtained, Recognizing each image display area when sequentially displaying medical images, calculating a display position of the related information of the medical image in a display area outside each recognized image area, and adding the display position to the calculated display position A central processing unit 112 that controls display of related information of medical images is included.
As a result, the operation for confirming the overlap between the medical image and the accompanying information can be omitted.

  Further, although various examples have been described in the present embodiment, combinations of the examples and various modifications are included in the present invention.

1 is a block diagram illustrating a system example in which a medical image display apparatus and a medical image diagnostic apparatus adopting the present invention are connected by a network. The flowchart which classified the input of the system of FIG. 1, a process, and an output according to the process. The figure which shows the principle of the calculation of the lower end of the subject area | region in an image. The figure which shows the principle of calculation of the duplication amount of a medical image and character information. The flowchart which shows the procedure of a subject area | region calculation process. The flowchart which shows the procedure of a display position calculation process. The flowchart explaining the procedure of a process of a character priority and an image moving system. The flowchart explaining the procedure of a process of an image priority character display system. The flowchart explaining the process sequence of a region-of-interest setting method. 10 is a flowchart for explaining a processing procedure of an image reduction method. 9 is a flowchart for explaining a processing procedure of an image display position adjustment method. The figure which shows the example in the case of the horizontal deviation of an image. The flowchart explaining the procedure of the process of an image display magnification adjustment system. The principle figure which shows the example of display magnification adjustment.

Explanation of symbols

100 Medical diagnostic imaging equipment
101 network (Ethernet)
110 Medical image display device
111 Input section (keyboard, mouse)
112 Central processing unit (CPU)
113 Main memory (memory)
114 Auxiliary storage (hard disk)
115 Output unit (display device)
120 Medical image (input data)
121 Character information (input data)
122 Medical image display
1221 Subject area determination unit
1222 Display position calculator
123 screens
200 image data
201 Display screen
202 Subject area in the image
210 Character information
211 Character display area
300 Bottom of subject area
310 Subject display position before moving
400 Overlap amount
401 Upper character display area
410 Subject display position after moving
420 display frame

Claims (5)

In a medical image display device that displays a medical image measured by a medical image diagnostic device and related information related to the medical image on a screen,
Subject region extraction means for extracting a subject region from the medical image;
An overlap amount calculating means for calculating an overlap amount between the subject region and the relationship information;
A medical image display device comprising: display control means for controlling display of the subject region or the related information based on the overlap amount. The subject region extraction means includes:
Extracting pixels having pixel values other than air from the medical image;
Extract a region having the maximum area from the region where the extracted pixels are continuous, as a maximum area region,
Extracting the maximum area region as the subject region, or extracting a region having an area larger than an area obtained by multiplying the area of the maximum area region by a predetermined reduction ratio as the subject region together with the maximum area region. The medical image display apparatus according to claim 1.   The medical image display apparatus according to claim 1, wherein the display control unit moves the subject region with reference to a region where the relationship information is displayed.   The medical image display apparatus according to claim 1, wherein the display control unit moves an area in which the relationship information is displayed with reference to the subject area.   The medical image display apparatus according to claim 1, wherein the display control unit reduces the subject region based on a region where the relation information is displayed.

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