JP4665847B2 - Breast image processing method, apparatus and program - Google Patents

Description

  The present invention relates to an image processing method for automatically processing a breast image (mammography), which is a medical image, and an apparatus and program capable of executing this method.

  As a conventional breast image processing method, the one described in Patent Document 1 below is known. In this method, digital breast images taken with CR (Computed Radiography) or the like are processed, but they are taken over a wide range for the purpose of obtaining a high-definition image or capable of dealing with a large breast. As shown in FIG. 6 of the document, a large number of breast images with a large number of background portions (margin portions) are currently stored, and in particular, the majority is mainly photographed for orientals with small breasts. The tendency is remarkable.

JP 2006-43187 A

  In such a conventional breast image processing method, a large number of breast images with many background portions are stored, and therefore the storage capacity of the recording medium is wasted even for background portions that need not be saved, and image data transfer is performed. And wasteful time is required for output. In order to make a more accurate diagnosis, the breast image has a capacity of about 30 to 130 MB (megabit) at the present time, and has a higher number of pixels or lightness (brightness), that is, higher definition or higher. Although the capacity is gradually increased in the tendency to be photographed in stages, the waste is increased as the number of pixels and the brightness are increased.

  Accordingly, the inventions according to claims 1, 3, and 5 provide a breast image processing method and a breast image processing apparatus capable of significantly reducing the volume (size) of a breast image while retaining a breast portion necessary for diagnosis. An object of the present invention is to provide a breast image processing program.

In order to achieve the above object, the invention according to claim 1 is a method in which a computer generates a processed image of a breast image having a smaller capacity from an original image of a breast image, wherein the original image is reduced. The pixel value of the sample image is divided into a large part and a small part with a predetermined value as a boundary, so that the breast part and the background part are separated, and a breast boundary that is the boundary is set, and the breast boundary in the sample image The line is moved upward, downward, and toward the breast by a specific value to set a secondary boundary line for grasping a large breast part, and the secondary boundary line in the sample image is enlarged to obtain a second boundary line in the original image. so as to leave a partial breast side of the next boundary, cut the original image horizontally or vertically, the steps of the processed image, mosquitoes Tsu in the original image after bets, pixels of the background portion side of the secondary boundary line While a constant, it is characterized in that it comprises a step of inserting a symbol indicating the inspection method in the background portion side.

The invention according to claim 2 is an apparatus including control means for generating a processed image of a breast image having a smaller capacity from an original image of a breast image, wherein the control means is a sample image obtained by reducing the original image. By separating the breast part and the background part by dividing the pixel value into a large part and a small part with a predetermined value as a boundary, a breast boundary line is set as the boundary line, and a breast boundary line in the sample image is specified. Set a secondary boundary line that moves the value upward, downward, and toward the front of the breast so that the breast part can be grasped larger, and then expand the secondary boundary line in the sample image to obtain the secondary boundary line in the original image. so as to more leaving partial breast side, cut the original image horizontally or vertically, and the processed image, the original image after mosquito Tsu DOO, with a constant pixel value of the background portion side of the secondary boundary line This It is characterized in inserting a symbol indicating the inspection method in the background portion side.

According to a third aspect of the present invention, there is provided a program for causing a computer to generate a processed image of a breast image having a smaller capacity from an original image of a breast image, wherein the pixel value of a sample image obtained by reducing the original image is a predetermined value. Separating the breast part from the background part by separating the large part and the small part from the border, and setting the breast boundary that is the boundary, and the breast boundary in the sample image above and below by a specific value And moving to the front of the breast to set a secondary boundary line for grasping the breast part greatly, and enlarging the secondary boundary line in the sample image to move the breast part side from the secondary boundary line in the original image so as to leave, to cut the original image horizontally or vertically, the steps of the processed image, the original image after mosquito dot and the pixel value of the background portion side of the secondary boundary line one While the, it is characterized in that it comprises the step of inserting a symbol indicating the inspection method in the background portion side.

According to the first to third aspects of the invention, since the processed image is generated by cutting the original image based on the secondary boundary line, the capacity is significantly reduced while sufficiently retaining a portion necessary for diagnosis. In addition to the above effects, the compression ratio can be reduced when breast images are compressed to significantly reduce the cost and time of storing, transferring, and querying breast images, and to keep the pixel values in the background portion constant. can be increased, further Ru can be possible to reduce an effect that the capacitance of the breast image.

  Hereinafter, a breast image processing method, apparatus, and program according to an embodiment of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is a block diagram of a breast image processing apparatus 1, and FIG. 2 is a flowchart of a breast image processing program executed by the breast image processing apparatus 1 or a breast image processing method executed by the breast image processing apparatus 1. A storage unit 2 for storing various information, a display unit 4 for displaying an image, an operation unit 6 for receiving an input by an operator, a communication unit 8 for communicating with an external device, and a control unit 10 for controlling them.

  The storage means 2 is composed of a hard disk or a removable disk, a memory, the display means 4 is composed of an LCD (liquid crystal display) or a CRT (CRT), and the operation means 6 is a keyboard or a pointing device (such as a mouse or a trackball). The communication means 8 is constituted by a LAN controller, and the control means 10 is constituted by a combination of a CPU and a RAM.

  The storage unit 2 stores a breast image processing program and stores breast images before and after processing. A breast image is a rectangular digital image in which pixels are arranged vertically and horizontally, the breast part is relatively bright (the pixel value of the breast part is relatively large), and the remaining background part is relatively It is dark (the pixel value of the breast is relatively small). The unprocessed breast image is obtained through a communication unit 8 from a modality (imaging device) (not shown). Modality includes CR (Computed Radiography), digital mammography (FP) (Flat Panel Detector), CT (Computed Tomography), MRI (Magnetic Resonance Imaging) and the like.

  In the breast image processing apparatus 1, when the breast image processing program is sequentially read out and executed by the control means 10, a breast image processing method is implemented, and the control means 10 first determines a breast image to be subjected to image processing. (Step (stage) S1 in FIG. 2, hereinafter simply referred to as S1 etc.). This determination is made when there is an input for starting processing via the operation means 6, or when the communication means 6 newly receives a breast image before processing.

  Next, the control means 10 sets a breast boundary line in the breast image to be processed (FIG. 3A), and separates the breast portion from the background portion (masking, S2). That is, the control means 10 first generates a sample image from the breast image (original image). The sample image is reduced to one-fourth by setting the length and width to one-half. Next, the control means 10 acquires a masking image from the sample image. In the masking image shown in FIG. 3B, the pixel values of the pixels of the sample image (values representing the brightness or lightness of the pixels) are sequentially viewed. If the image is larger than a predetermined minimum value, It is obtained by setting the pixel value of the pixel at the corresponding position to 1, otherwise setting the corresponding pixel value in the masking image to 0. The predetermined minimum value is determined in advance with a value slightly larger than the average value of the pixel values of the background portion in consideration of average pixel values of the breast portion and the background portion. In the masking image obtained in this way, the boundary line between the pixel value 1 (corresponding to the breast part, non-masking part) and 0 (corresponding to the background part, masking part) is the breast boundary line A. A breast boundary line is set by acquiring an image for use.

  A program relating to acquisition of an image for masking is shown below. Here, the width (number of horizontal pixels) of the sample image is W, the height (number of vertical pixels) is H, the minimum value is Min, and the pixel value of the pixel at the position (x, y) of the sample image is P ( x, y), and similarly, the pixel value of the masking image is M (x, y). The origin (0, 0) of the pixel position is the upper left, the x axis is rightward from the origin, the y axis is downward from the origin, and the base side (body center side) of the breast is located on the right side. .

for (y = 0; y <H; y ++)
for (x = 0; x <W; x ++)
if (P (x, y)> Min) then
M (x, y) = 1
else
M (x, y) = 0
end if
end for
end for

  Moreover, the control apparatus 10 grasps | ascertains as a function E (y) (0 <= y <= H) of y which has the value from the breast image left side about a breast boundary line. The program at that time is as follows.

for (y = 0; y <H; y ++)
for (x = 0; x <W; x ++)
if (M (x, y) == 1) then
E (y) = x
break;
end if
end for
end for

  Subsequently, the control means 10 sets a secondary boundary line (S3). The secondary boundary line is set at a certain distance from the breast boundary line outside the breast part, that is, on the background part side. The control means 10 sets the secondary boundary line by expanding the non-mask portion of the masking image outward by the predetermined distance and generating a secondary masking image. The boundary line between the non-masked part of the secondary masking image (the breast part grasped larger) and the mask part (the background part grasped smaller) is the secondary boundary line.

  The control means 10 moves the non-mask portion of the masking image upward by a predetermined value corresponding to the predetermined distance to expand the upper portion of the non-mask portion for the secondary masking image (FIG. 4A). . Similarly, the control means 10 moves the non-mask portion of the masking image downward and to the left by a predetermined value to expand the upper and left portions of the non-mask portion (FIGS. 4B and 4C). ). As a result, the secondary masking image shown in FIG. 4D is obtained, and the secondary boundary line B is obtained with respect to the breast boundary line A. The program at this time is as follows, where the predetermined value is P.

for (y = 0; y <H; y ++)
for (i = 0; i <P; i ++)
M (E (y) -i, y) = 1
M (E (y), y−i) = 1
M (E (y), y + i) = 1
end for
end for

  As for the setting of the secondary boundary line, the breast boundary line is moved upward, downward, and leftward by a predetermined value corresponding to the predetermined distance to generate the upper part, the lower part, and the left part of the secondary boundary line. It can also be taken as.

  Thereafter, the control means 10 cuts the background portion of the original image corresponding to the mask portion of the secondary masking image to form a cut image (S4). The control means 10 quadruples the secondary masking image to return it to the same size as the original image (FIG. 5 (a)), grasps the left edge, top edge and bottom edge of the non-masked part, and from this, the left side, top side and bottom side The original image is divided horizontally or vertically at a position corresponding to the side (line C in FIG. 5B, lines D and E in FIG. 5C), and the inside is left as a cut image. A program for grasping each end of the non-masked portion is as follows, with the left end, the upper end, and the lower end in order as Xmin, Ymin, and Ymax. Note that the boundary line (secondary boundary line) F (y) between the mask part and the non-mask part in the quadrupled secondary masking image is obtained in the same manner as the breast boundary line E (y).

Xmin = 2 * W
Ymin = 2 * L
Ymax = 0
for (y = 0; y <H; y ++)
if F (y) <Xmin then
Xmin = F (y)
if F (y)! = 0 and y <Ymin then
Ymin = y
end if
if F (y)! = 0 and y> Ymax then
Ymax = y
end if
end for

  And the control means 10 produces | generates a finishing image as the completely same pixel value (black) about the background part (part outside a secondary boundary line) in a cut image (S5). Here, the pixel value of a pixel having an x coordinate smaller than F (y) in the cut image is set to 0.

  In addition, the control means 10 inserts a symbol indicating the inspection method into the background portion of the cut image to obtain a processed image (S6, FIG. 5 (d)). As is well known, this symbol indicates the imaging direction of the breast image (“CC” indicating the vertical direction craniocaudal in FIG. 5D), and “R” indicating the right in the left and right of the imaging target (FIG. 5D). ). The control means 10 discriminates the shooting direction and the left and right from the header of the original image, selects the symbol type based on the discrimination result, and inserts the symbol.

  The control means 10 saves the processed image in the storage means 2 while maintaining the header of the original image, while appropriately deleting the corresponding original image from the storage means 2.

  As described above, the control means 10 separates the breast portion from the background portion by dividing the pixel value of the original image into a large portion and a small portion with a predetermined value as a boundary (S2), and is the boundary line. A breast boundary line is set, and the breast boundary line is moved to the background part side to set a secondary boundary line for grasping the breast part largely (S3), and the breast part side is left behind the secondary boundary line. Then, the original image is cut horizontally or vertically (S4) to form a processed image, and a processed image of a breast image having a smaller capacity is generated from the original image of the breast image, which is necessary for diagnosis. While retaining the breast portion sufficiently, the volume of the breast image can be significantly reduced, greatly reducing the cost and time of storing, transferring, and querying the breast image.

  Further, the control means 10 generates a finished image by keeping the pixel value on the background portion side of the secondary boundary line constant in the original image after the cut (S5), and therefore, when the breast image is compressed, the compression rate is set. The volume of the breast image can be further reduced.

  In addition, other embodiment of this invention which mainly changes the said embodiment and illustrates is illustrated. For the breast image, the left side is set to the body side, or a relatively small pixel value represents the breast portion, and the program is changed according to the breast image. When acquiring the breast boundary line, a sample image of 1/8, 1/16, or the like is generated or acquired directly from the original image. From the original image stage, the pixel value of the background portion is set to a constant value. Process the original image acquired by other inspection methods (left or diagonal), or process a specific inspection method set (four images in the vertical direction of the left or right or diagonal). . Other program languages.

  The present invention can be implemented in the form of being introduced (incorporated) into a modality, a medical information processing apparatus, or the like, in addition to being implemented alone near the modality or the medical information processing apparatus.

1 is a block diagram of a breast image processing apparatus according to an embodiment of the present invention. It is a flowchart of the breast image processing method (breast image processing program) which concerns on embodiment of this invention. It is a schematic diagram of (a) a breast image to be processed and (b) a masking image according to an embodiment of the present invention. (A)-(c) is a schematic diagram of this invention which shows the process of obtaining a secondary boundary line, (d) is a schematic diagram of the image for secondary masking of this invention. (A)-(c) is a schematic diagram of this invention which shows the process of obtaining a cut image, (d) is a schematic diagram of the processed image of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Breast image processing apparatus 2 Storage means 4 Display means 6 Operation means 8 Communication means 10 Control means

Claims (3)

A method in which a computer generates a processed image of a smaller breast image from an original image of a breast image,
Separating the breast part and the background part by dividing the pixel value of the sample image obtained by reducing the original image into a large part and a small part with a predetermined value as a boundary, and setting a breast boundary line that is a boundary line;
Moving the breast boundary line in the sample image by a specific value upward, downward, and the front of the breast, and setting a secondary boundary line for grasping the breast part largely;
A step of cutting the original image horizontally or vertically so as to leave a breast part side from the secondary boundary line in the original image obtained by enlarging the secondary boundary line in the sample image to be a processed image;
In the original image after mosquito Tsu DOO, with a constant pixel value of the background portion side of the secondary boundary lines, breast image, comprising the step of inserting a symbol indicating the inspection method in the background portion side Processing method. An apparatus comprising control means for generating a processed image of a breast image having a smaller capacity from an original image of a breast image,
The control means separates the breast part from the background part by dividing the pixel value of the sample image obtained by reducing the original image into a large part and a small part with a predetermined value as a boundary, and sets a breast boundary line that is the boundary line As well as
Move the breast boundary in the sample image upward, downward, and towards the breast by a specific value, and set a secondary boundary to grasp the breast part greatly.
Furthermore, the original image is cut horizontally or vertically to leave the breast part side from the secondary boundary line in the original image obtained by enlarging the secondary boundary line in the sample image, and the processed image is obtained.
In the original image after mosquito Tsu DOO, with a constant pixel value of the background portion side of the secondary boundary lines, breast image, characterized in <br/> inserting a symbol indicating the inspection method in the background portion side Processing equipment. A program for causing a computer to generate a processed image of a smaller breast image from an original image of a breast image,
Separating the breast part and the background part by dividing the pixel value of the sample image obtained by reducing the original image into a large part and a small part with a predetermined value as a boundary, and setting a breast boundary line that is a boundary line;
Moving a breast boundary line in the sample image by a specific value upward, downward, and forward of the breast, and setting a secondary boundary line for grasping the breast part largely;
Cutting the original image horizontally or vertically so as to leave the breast part side from the secondary boundary line in the original image obtained by enlarging the secondary boundary line in the sample image, and making it a processed image;
In the original image after mosquito Tsu DOO, with a constant pixel value of the background portion side of the secondary boundary lines, breast image comprising the step of inserting a symbol indicating the inspection method in the background portion side Processing program.

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