TWI587844B - Medical image processing apparatus and breast image processing method thereof - Google Patents

Description

Medical image processing device and breast image processing method thereof

The present invention relates to an image processing technology, and more particularly to a medical image processing apparatus and a breast image processing method thereof.

Mammary carcinoma is one of the common malignant tumors in women. The main symptoms include breast tumor, abnormal secretion or shape variation. Screening for abnormal symptoms of the breast early will help treat the tumor as early as possible to reduce the deterioration or spread of cancer cells. Screening methods such as clinical or self-breast testing, biopsy, mammography, ultrasound or magnetic resonance imaging have been widely used clinically or have become an important topic in academic research.

According to the study, women with high-density breasts have a relatively high risk of developing breast cancer compared with low-density breasts. Therefore, density analysis of breast and breast tissue is also an important factor in breast cancer assessment. On the other hand, although computer Aided Detection (CADe) systems have been used clinically to automatically identify tumors, bumps or calcifications, there is still a risk of high false positive rates.

The invention provides a medical image processing device and a breast image processing method thereof, which can assist the breast tissue density analysis and effectively reduce the false positive of the computer aided detection system.

The present invention provides a breast image processing method suitable for use in a medical image processing apparatus, and includes at least, but not limited to, the following steps. A breast image of at least one slice is obtained. The mammary gland tissue in the breast image of each segment is detected by a breast tissue detector. This breast tissue detector is based on texture characteristic analysis.

In an embodiment of the invention, after the obtaining the breast image, the following steps are further included. Converting the breast image of the first view into a turning breast image of the second view. This first view is different from the second view. The rib information is determined based on the turning breast image. Based on the rib information, the breast area in the breast image is determined.

In another aspect, the present invention provides a medical image processing apparatus including, but not limited to, a storage unit and a processing unit. The storage unit stores at least one segment of the breast image and records a plurality of modules. The processing unit is coupled to the storage unit and accesses and executes the module recorded by the storage unit. These modules include an image input module and a breast detection module. The image input module acquires a breast image. The mammary gland detection module detects breast tissue in each breast image through a breast tissue detector. This mammary tissue detector is based on texture feature analysis.

Based on the above, the medical image processing apparatus and the breast image processing method thereof according to the embodiments of the present invention can detect the breast image based on the texture feature analysis. Breast tissue. Accordingly, the embodiment of the present invention can improve the accuracy of detecting breast tissue, and can better analyze the density of breast tissue and reduce the false positive of the computer-aided detection system.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧ medical image processing device

1615‧‧‧ chest area

110‧‧‧ storage unit

1631‧‧‧ chest wall line

111‧‧‧Image Input Module

1635‧‧‧non-thoracic area

113‧‧‧Mammary Detection Module

Hr‧‧‧ highest point of rib shadow

114‧‧‧Breast area cutting module

Rb‧‧ reference point

115‧‧‧Detection Training Module

116‧‧‧Density Module

117‧‧‧false positive comparison module

118‧‧‧Lactation assessment module

191‧‧‧About breast mammary gland density symmetry measurement module

150‧‧‧Processing unit

S210~S230, S515, S535, S559, S570, S750, S830, S1020, S1040, S1110~S1130‧‧

310, 330, 410, 510, 530‧‧ ‧ breast training images

331‧‧‧ Breast tissue type

333‧‧‧Subcutaneous fat type

335‧‧‧post-fat fat and chest muscle type

337‧‧‧Shadow type

411‧‧‧Part image

411_1, 711, 713, 715, 721, 811, 813, 814, 951, 953, 955‧‧‧ image blocks

551, 553, 555, 557‧‧‧ image block groups

610, 810, 850, 1010, 1030, 1050, 1210‧‧ ‧ breast images

611, 851, 853 ‧ ‧ image area

1051‧‧‧Breast tissue area

1250, 1310, 1410, 1510, 1610, 1650‧ ‧ turn to breast image

1411‧‧‧ chest wall reference line

1513‧‧‧Other organization areas

1515‧‧‧ Rib shadow area

1613, 1633, 1653‧‧‧ chest area

1 is a block diagram showing a medical image processing apparatus in accordance with an embodiment of the present invention.

2 is a flow chart illustrating a breast image processing method according to an embodiment of the invention.

Figure 3 is an example of a distinction type.

Figure 4 is an example of an image block.

Figure 5 is a flow chart of the training classifier.

Figure 6 shows an example of breast tissue detection.

Figure 7 is an example of breast tissue filling.

Figure 8 is another example of breast tissue filling.

Fig. 9 is an example of a noise removal operation.

Fig. 10 is an example of the flow of contour conversion.

11 is a flow chart illustrating a method of cutting a breast region in accordance with an embodiment of the present invention.

Figure 12A is a fragmentary breast image illustrating a cross-sectional view.

Figure 12B is an illustration of a turning mammogram that converts Figure 12A into a sagittal view image.

Fig. 13 is a schematic view showing the adjustment of the turned breast image of Fig. 12B.

Figure 14 is a schematic illustration of a chest wall reference line formed after average projection filtering of the turned breast image of Figure 13.

Fig. 15 is a view showing an example of a rip map formed by performing a large law binarization of the turned breast image of Fig. 13.

Fig. 16A is a schematic view showing an adjustment of the steering breast image according to the chest wall reference line.

Fig. 16B is a schematic view showing an adjustment of the average thickness of the pectoralis major muscle to the turned breast image.

Figure 16C is a schematic illustration of the acquisition of the chest region in the turned breast image of Figure 12B.

1 is a block diagram showing a medical image processing apparatus in accordance with an embodiment of the present invention. Referring to FIG. 1 , the medical image processing apparatus 100 includes at least, but is not limited to, a storage unit 110 and a processing unit 150. The medical image processing apparatus 100 can be a server, a client, a desktop computer, a notebook computer, a network computer, a workstation, a personal digital assistant (PDA), a personal computer (PC), and the like. Device, and not limited to this.

The storage unit 110 can be any type of fixed or removable random access A random access memory (RAM), a read-only memory (ROM), a flash memory or the like or a combination of the above elements. In this embodiment, the storage unit 110 is configured to store at least one segment of the breast image and the breast training image, the program code, the device configuration, the buffered or permanent data, and record the image input module 111 and the mammary gland detection mode. Group 113, breast region cutting module 114, detection training module 115, density quantification module 116, false positive comparison module 117, lactation evaluation module 118, and mammary gland density symmetry measurement mode Group 119 and other software programs. The processing unit 150 can access and execute the foregoing modules, and the detailed operation contents thereof will be described in detail later in the embodiments. The storage unit 110 described in this embodiment is not limited to a single memory component, and each of the above software modules may be separately stored in two or more memory components of the same or different types.

The function of the processing unit 150 can be achieved by using, for example, a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processing (DSP) chip, and a field programmable logic gate array (Field). Programmable Gate Array; FPGA) and other programmable units to implement. The function of the processing unit 150 can also be implemented by a separate electronic device or an integrated circuit (IC), and the processing unit 150 can also be implemented by hardware or software.

In order to facilitate the understanding of the operation flow of the embodiment of the present invention, the flow of the breast image processing by the medical image processing apparatus 100 in the embodiment of the present invention will be described in detail below. 2 is a diagram showing a breast image according to an embodiment of the invention Processing method flow chart. Referring to FIG. 2, the method of the present embodiment is applied to the medical image processing apparatus 100 of FIG. Hereinafter, the method described in the embodiments of the present invention will be described in conjunction with various components and modules in the medical image processing apparatus 100. The various processes of the method can be adjusted accordingly according to the implementation situation, and are not limited thereto.

In step S210, the image input module 111 obtains a breast image of at least one segment. The breast image can be two-dimensional or three-dimensional medical treatment for the breast site, such as automated breast ultrasound (ABUS), digital breast tomosynthesis (DBT), magnetic resonance imaging (MRI), and the like. image. In screening, three-dimensional imaging techniques can provide a more reliable breast density assessment for cancer risk, but embodiments of the invention are not limited to three-dimensional images.

The image input module 111 can be from the storage unit 110, through a wireless or wired communication unit (for example, Wi-Fi, Ethernet), a medical image scanner (for example, an ABUS scanning instrument, an MRI scanning instrument, etc.) or A storage device (eg, a DVD, a flash drive, a hard drive, etc.) takes a breast image.

In step S230, the mammary glandular tissue is detected by the mammary gland detection module 113 through the mammary tissue detector. This breast tissue detector is based on texture characteristic analysis. In this embodiment, the detection training module 115 can train the breast tissue detector based on the texture feature analysis.

Specifically, before the mammography detection module 113 detects through the mammary tissue detector, the detection training module 115 can train the milk according to the plurality of breast training images. Room tissue detector. The detection training module 115 can divide the content of the plurality of breast training images into several feature types. These types of features include, but are not limited to, breast tissue type, Subcutaneous Fat type, Retromammary Fat and Pectroralis Muscle types, and shadow types.

Figure 3 is an example of a distinction type. Referring to FIG. 3, the medical image processing apparatus 100 can transmit a display unit (for example, a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting diode (organic light emitting diode); The OLED) or the like displays the breast training image 310 and provides an input unit (eg, a touch device, a keyboard, a mouse, etc.) to receive a user's distinguishing operation on the breast training image 310. The detection training module 115 can detect the feature type corresponding to the distinguishing operation and the selection area (or position) on the breast training image 310. The breast training image 330 is an image that has been distinguished by feature type, which may include breast tissue type 331, subcutaneous fat type 333, post-mammary fat and chest muscle type 335, and shadow type 337.

The detection training module 115 performs the texture feature analysis on several image blocks in the breast training images. The detection training module 115 can first define the unit size of the image block (for example, 11 * 11, 12 * 12 or 15 * 20 pixels, etc.). For example, Figure 4 is an example of an image block. Referring to FIG. 4, a portion of the image 411 in the breast training image 410 may have 11 * 11 pixels as the unit size of the image block (eg, image block 411_1).

Then, the detection training module 115 monitors each image in each breast training image. Like block extraction texture features. For example, the detection training module 115 can use the gray-level co-occurrence matrix (GLCM) method to obtain the average and standard deviation, energy, and entropy of the eight different GLCM estimates. (entropy), correlation (correlation), difference moment, inertia, cluster shade, cluster prominence, and Haralick's correlation. A texture feature of one or a combination thereof. It should be noted that the detection training module 115 can also extract any desired texture features by using any texture feature related algorithms such as Markov Random Field (MRF) and Gabor Filter. The embodiments of the present invention are not limited thereto.

The detection training module 115 analyzes the training classifier based on the texture features of each image block for these feature types. In other words, the detection training module 115 can determine which image block corresponding to the extracted texture feature belongs to breast tissue type, subcutaneous fat type, post-mammary fat and chest muscle type, and shadow type, and respectively for different features. Type, training the classifier with the corresponding texture features.

In this embodiment, the detection training module 115 can pass, for example, but not limited to, Logistic Regression, Support Vector Machine (SVM), Neural Network (NN), etc. The texture features extracted in each image block are used to train the classifier.

For example, FIG. 5 is a schematic flow chart of a training classifier. Referring to FIG. 5, the detection training module 115 obtains the breast training image 510, and generates a breast training image 530 according to the user's distinguishing operation for each feature type (step S515). milk Different feature types are represented by different background colors in the room training image 530. In step S535, the detection training module 115 classifies the image blocks corresponding to different feature types to generate image block groups corresponding to breast tissue type, subcutaneous fat type, post-mammary fat and chest muscle type, and shadow type. 551, 553, 555, 557. Each of the image block groups 551-557 may have one or more image blocks, and the image blocks of the same feature type belong to the same image block group. In step S559, the detection training module 115 extracts texture features for each image block group 551~557. In step S570, the detection training module 115 trains the classifiers that can distinguish different feature types by using the logistic regression model.

In this embodiment, the detection training module 115 can use one of the types of breast tissue in the classifier as a breast tissue detector. In other words, the classifier trained by the detection training module 115 can be used as a detector for feature types such as breast tissue type, subcutaneous fat type, post-mammary fat and chest muscle type, and shadow type.

After training the breast tissue detector, the breast detection module 113 can detect the breast image obtained by the image input module 111 by using a breast tissue detector. The mammography detection module 113 can use the texture feature correlation algorithm used by the detection training module 115 to capture the texture features of all or part of the image blocks in each segment of the breast image, and use the classifier to detect the training. The texture features recorded by the module 115 are compared to classify the image blocks. For example, Figure 6 is an example of breast tissue detection. Referring to FIG. 6, the image area 611 (presented in white color) in the breast image 610 is an area where the breast tissue is detected by the mammary tissue detector.

Since the mammary tissue detector is in the size of the image block (for example, 11 * 11, 12 * 12 or 15 * 20 pixels, etc. to classify, so the breast image classified by the classifier will be presented in the form of image blocks (for example, the breast image 610 of Figure 6 is composed of several image blocks) composition). In one embodiment, the mammary gland detection module 113 further performs image post-processing on the classified breast images to adjust the shape of the breast tissue.

The mammography detection module 113 can fill at least one hollow region of the breast tissue in the breast image classified by the classifier. The mammography detection module 113 determines whether there are at least two second image blocks classified as breast tissue adjacent to the first image block. For example, Figure 7 is an example of breast tissue filling. Please refer to FIG. 7. The left image is a partial image block in the classified breast image. The image blocks 711, 713, and 715 are classified into a breast tissue type by a classifier, and the image block 721 is classified into a subcutaneous fat type by a classifier. The mammography detection module 113 determines that there are at least two image blocks classified as breast tissue types (ie, image blocks 711, 713, and 715) adjacent to the image block 721, and then passes the filling operation (step S750) to display the image area. Block 721 is converted to a breast tissue type. The image on the right shows some of the image blocks that have been filled. The image blocks 711, 713, 715, and 721 all belong to the breast tissue category.

It should be noted that the decision mechanism for converting a non-mammary tissue type image block into a breast tissue type may also be to determine whether there are one, two or four image blocks belonging to the breast tissue type in the adjacent image block, and Not limited to this.

Figure 8 is another example of breast tissue filling. Referring to Figure 8, the image blocks 811, 813, 814 in the classified breast image 810 are classified into breast tissue categories without classifiers. In step S830, since the image blocks 811, 813, 814 are adjacent There are at least two image blocks belonging to the breast tissue category, so the mammography detection module 113 fills the image blocks 811, 813, 814 to convert the image blocks 811, 813, 814 into breast tissue categories. The filled breast image 850 can be divided into image regions 851 (presented in white color) and 853 (black dots) belonging to the breast tissue category and non-breast tissue types (for example, subcutaneous fat type, shadow type, etc.). The image blocks 811, 813, and 814 in the breast image 810 belong to the image area 851.

In an embodiment, the mammary gland detection module 113 can further remove the mottle blocks in the breast tissue. Specifically, there may be several image blocks belonging to the breast tissue category and connected in the classified breast image, and the mammography detection module 113 may determine an image region formed by one or more connected image blocks (for example, a map) The image area 851 of 8 is a decision image area of the breast tissue type. Next, the mammary gland detection module 113 removes the image block that is not connected to the decision image region and belongs to the breast tissue category as a mottle block (ie, converts to a non-breast tissue category). For example, FIG. 9 is an example of a noise removal operation. The breast image 850 of FIG. 9 has image blocks 951, 953, and 955 that are not connected to the largest image area 851 belonging to the breast tissue category, that is, a dot block. The mammography detection module 113 can perform a mottle removal operation to convert the image blocks 951, 953, and 955 into image regions 853 that are not of the breast tissue type.

Next, the mammary gland detection module 113 can further obtain the outline of the breast tissue. The mammography detection module 113 converts the outline of the breast tissue presented in the image block into a smooth contour. For example, FIG. 10 is an example of a flow of contour conversion. Please refer to Figure 10, The mammography detection module 113 erodes the mammogram 1010 (for example, the mammogram through the mottle removal operation), and then blurs it with a Gaussian filter (step S1020) to form the mammogram 1030. . Next, the mammary gland detection module 113 converts the mammary gland tissue into a binarized breast image 1050 using Otsu thresholding (or maximum inter-class variance) (step S1040). The breast tissue region 1051 (presented in white background) in the binarized breast image 1050 is the last determined breast tissue of the mammary gland detection module 113.

In one embodiment, in order to determine whether it is a dense breast (more breast and connective tissue, but less fat), the density quantification module 116 can calculate the area of the breast tissue in each breast image and based on the breast tissue in the breast image. Area, calculate the quantitative value of breast tissue. Specifically, the density quantification module 116 respectively obtains the area of the mammary gland in the breast image of each segment of the breast detecting module 113, and divides the area of the breast tissue of each segment of the breast image by the total area of the breast image of the segment to calculate Breast tissue density of each segment of the breast image. The density quantification module 116 averages the breast tissue density of all segmented breast images to calculate a breast tissue quantified value. The density quantification module 116 can further determine whether the breast tissue quantized value exceeds the density threshold value according to the density threshold value to determine the dense breast. Conversely, if the quantitative value of the breast tissue does not exceed the density threshold, it is determined to be a non-dense breast.

In another embodiment, the false positive alignment module 117 can detect at least one abnormal location using a computer aided detection (CADe) system and compare the abnormal locations to breast tissue in the corresponding breast image. Specifically, the false positive comparison module 117 can record the milk in each segment of the breast image obtained by the breast detecting module 113. The location of the breast tissue in the atrial tissue. The processing unit 150 may additionally load a computer-aided detection program or an external computer-assisted detection system to obtain a suspicious lesion (eg, a tumor, a lump, etc.) in the breast image input in step S210 (ie, an abnormality) position). The false positive comparison module 117 compares the position of the breast tissue with the position of the suspected lesion to determine whether the position of the suspected lesion overlaps with the position of the breast tissue. Due to clinical statistics, most lesions grow along the gland, so the removal of suspicious lesions that are not located in the breast tissue position can reduce false positives (computer-aided detection system determines lesions, but facts are not lesions). In other words, if the false positive comparison module 117 determines that the position of the suspected lesion overlaps with the position of the breast tissue, it can further confirm that the probability of occurrence of the lesion at the position of the suspected lesion is extremely high (for example, greater than 50%, 75%, 80%) Etc.), allowing medical personnel to further diagnose the location of this suspected lesion.

In addition, since the milk is secreted by the glands in the breast, it is determined that the amount of lactation is related to the development and integrity of the breast. In one embodiment, the lactation assessment module 118 can quantify the amount of lactation based on the quantified results of the density quantification module 116. The more breast tissue, the higher the amount of milk, and there is usually a positive correlation. For example, the lactation amount assessment module 118 can determine whether the quantitative value of the breast tissue is greater than the threshold value of the lactation amount to determine that the amount of milk produced by the subject is higher. Alternatively, the lactation assessment module 118 may set a level of lactation at a level of 5, 7, or 10 and determine which of the lactation levels are located in the breast tissue level.

In another embodiment, the left and right breast gland density symmetry measurement module 119 uses the density quantification module 116 to simultaneously quantify the breast tissue density of the left and right breasts, and to determine the symmetry by comparing the breast tissue density of the left and right breasts (eg, Difference ratio Example, etc.). The left and right breast gland density symmetry measurement module 119 can also visually display the mammary gland tissue density map of the left and right breasts through the display unit (for example, the breast density indicates different density levels in different colors).

In another embodiment, after the foregoing step S210, the medical image processing apparatus 100 can cut the breast area from the breast image, and then perform the breast tissue detecting operation of step S230. 11 is a flow chart illustrating a method of cutting a breast region in accordance with an embodiment of the present invention. Referring to FIG. 11, the method of the present embodiment is applied to the medical image processing apparatus 100 of FIG. Hereinafter, the method described in this embodiment will be described in conjunction with various components and modules in the medical image processing apparatus 100. The various processes of the method can be adjusted accordingly according to the implementation situation, and are not limited thereto.

In step S1110, the breast region cutting module 114 converts the breast image of the first view into the turned breast image of the second view. This first view is different from the second view. In particular, automatic breast ultrasound images typically scan the area of the collar bones down to the nipple and typically present a transverse view. Please refer to FIG. 12A as an example of a fragmented breast image 1210 of a cross-sectional view. Since the texture differences of different tissues are less noticeable in the cross-sectional view, it is often more difficult to distinguish the tissues to distinguish the breast regions.

In order to facilitate subsequent processing, the present embodiment initially performs a pre-processing procedure. In the present embodiment, the first view is a cross-sectional view and the second view is a sagittal view. In other words, after receiving at least one segment of the breast image of the cross-sectional view in step S210, the breast region cutting module 114 converts the breast images of the cross-sectional view into a panned breast image of the sagittal view. Please refer to Figure 12B is an illustration of a turned breast image 1250 that converts Figure 12A into a sagittal view. Compared to the cross-sectional view shown in Figure 12A, the sagittal view provides a wealth of information to identify different tissue types (eg, ribs, rib shadows (black areas where ultrasound cannot pass under the ribs), skin, etc.) .

Next, the breast region cutting module 114 can enhance the contrast of the turned breast image by using an image enhancement filter (eg, a sigmoid filter, a histogram equalization (HE)) to have a reduced pixel intensity. (intensity) The difference between the rib shadow area and other tissues with elevated pixel intensity is more pronounced.

In addition, the breast region cutting module 114 can also perform a noise removal operation on the turned breast image. For example, the breast region cutting module 114 smoothes the turned breast image using an edge preserving filter and removes speckle noise using an anisotropic diffusion filter.

For example, FIG. 13 is a schematic diagram illustrating an adjustment of the turned breast image of FIG. 12B. Referring to FIG. 13, the adjusted steering breast image 1310 is processed by the S-shaped and anisotropic diffusion filter, and the rib shadow contrast is enhanced and the speckle noise is reduced.

After the pre-processing is completed, the breast region cutting module 114 can obtain a blury image with higher contrast and lower noise than the image before the unprocessed image. In step S1120, the breast region cutting module 114 determines the rib information according to the (adjusted) steering breast image. Specifically, this embodiment combines local (local) Information and global information to segment the chest wall. This local information comes from a single segment, and the entire information is from the entire group of turned breast images.

In an embodiment, the rib information includes rib shadow information. From the rib shadow information, it helps to observe the chest cage. Since the segments turn to the breast image to provide only partial rib shadow information, overall information is still needed. The breast region cutting module 114 can calculate the projection values of the pixels in all the turned breast images, and determine the chest wall reference line based on the projected values of the pixels.

In this embodiment, the breast region cutting module 114 can use the average projection method to project different segments to the pixels corresponding to the same coordinate position in the breast image along the segment axis to obtain the projection value, and calculate all the segments to turn to the breast. The average intensity value in the image that corresponds to the same coordinate position. At the same coordinate position, the average intensity value of each pixel is used as a threshold value to classify the projection results into two categories (for example, the first type of pixels and the second type of pixels). The breast region cutting module 114 can determine whether the intensity value of each pixel in each segment of the turned breast image is greater than the average intensity value of the associated coordinate position, and retain and/or record the pixel whose intensity value is greater than the average intensity value of the associated coordinate position. (hereinafter referred to as the first type of pixels). If the intensity value of a certain pixel (hereinafter referred to as the second type of pixel) is not greater than the average intensity value of the coordinate position, the breast region cutting module 114 discards the second type of pixel and/or is different from the first pixel. A type of pixel records the number, symbol, code, and style of the record. For example, the breast region cutting module 114 sets the first type of pixels to one and the second type of pixels to zero.

In this way, part of the rib shadow information of each segment will be combined into the overall chest information (for example, the outline of the thorax and the distribution of the ribs) to determine the chest wall reference line. Lift For example, FIG. 14 is a schematic diagram illustrating a chest wall reference line 1411 formed after average projection filtering of the turned breast image of FIG. Referring to FIG. 14, in the average projection filtered steering breast image 1410, the white region represents all rib positions in the chest, which illustrates the rib position cross-sectional area (this region includes all ribs, and includes the overall rib shadow position information). ). On the other hand, the black area represents the chest area, which illustrates the distribution area of all breast tissues in the breast image. The boundary line between the white and black areas is the chest wall reference line 1411.

In another embodiment, the rib information includes rib shadow information. The breast region cutting module 114 can determine rib shadow information in each turned breast image by image cutting method (for example, metrology binarization, region growing, etc.). This rib shadow information includes the chest wall line.

In this embodiment, the breast region cutting module 114 can switch the rib shadow region to the breast image (adjusted by the S-shaped and anisotropic diffusion filter), and perform image binarization processing based on the clustering basis. Thus, the steering breast image is divided into a foreground portion (a rib shadow area) and a background portion (other tissues). The binarization value used in image binarization is the maximum between-class variance.

For example, FIG. 15 is a schematic diagram illustrating a rip map formed by performing a large law binarization of the turned breast image of FIG. Referring to FIG. 15, in the binarized turning breast image 1510, the rib shadow area 1515 in white color can be regarded as a rib map, and the other tissue regions 1513 are presented in a black background. Local rib shadow shadow information obtained from each segment turned to the breast image (ie, local Information) will include local rib position (eg, rib length and width information). The area between these ribs (intercostal space) does not belong to the breast area and will be removed later in the procedure.

In step S1130, the breast region cutting module 114 determines to turn the breast region in the breast image based on the rib information. Specifically, after the foregoing procedure, the breast region cutting module 114 can obtain the overall information and local information of each segment turning to the breast image, thereby distinguishing the chest wall based on the information. In one embodiment, the breast region cutting module 114 can adjust the chest wall line in each of the turned breast images in accordance with the chest reference line.

Taking FIG. 14 and FIG. 15 as an example, the breast region cutting module 114 can record the highest point Hr of the rib shadow in each segment rib map (for example, as shown in FIG. 15). This highest point, Hr, indicates the minimum chest thickness of the segment turned into the breast image. The breast region cutting module 114 obtains the coordinates of the highest point Hr in the turned breast image, records the number of rows and columns of the coordinate from the rib map, and finds the coordinate position of the corresponding number of rows and columns of the chest wall reference line 1411 in FIG. 14 (ie, reference) Point Rb).

The breast region cutting module 114 can align the chest wall reference line 1411 with the corresponding number of rows according to the highest point Hr and the reference point Rb, and transplant the chest wall line pixels on each segment rib map. In other words, the breast region cutting module 114 overlaps the turned breast images 1410 and 1510, aligns the reference point Rb to the highest point Hr, and maps the rib shadow region 1515 according to the intersection of the other tissue regions 1513 and the chest wall reference line 1411. The pixels of the number of rows and columns are adjusted to the chest wall reference line 1411. For the junction of the rib shadow area 1515 and the chest wall reference line 1411, the outline of the number of rows and columns is retained. Thereby, the chest wall line can be adjusted to allow the other tissue regions 1513 to remove the intercostal space.

For example, FIG. 16A is a schematic diagram illustrating an adjustment of the turned breast image 1510 according to the chest wall reference line 1411. Referring to Figure 16A, in the turned breast image 1610, white (representing chest region 1615 (eg, including ribs, rib shadows, intercostals, etc.)) and black regions (representing chest region 1613, but including pectoral muscles) The boundary line is the adjusted chest wall line 1611.

Next, the breast region cutting module 114 removes the pectoralis major portion from the adjusted turned breast image to determine the breast region. Specifically, the breast region cutting module 114 subtracts the thickness of the thoracic muscle from the bottom of the chest region (eg, the chest region 1613 in FIG. 16A) according to the average thickness of the pectoralis major muscle (about 1.5 to 2.0 cm). The average thickness is adjusted to the chest wall line 1631 (eg, translated upward), which in turn removes the pectoralis major portion of the chest region 1613.

The height of the adjusted chest wall line (for example, chest wall line 1611) is subtracted from the average thickness of the pectoralis major muscle to remove the pectoralis major portion, thereby further adjusting the chest wall line. For example, FIG. 16B is a schematic diagram illustrating an adjustment of the average breast thickness of the pectoralis major muscle to the turned breast image 1610. In the turned breast image 1630, the white (representing the non-thoracic region 1635 (eg, including ribs, rib shadows, intercostals, pectoral muscles, etc.)) and the black region (representing the chest region 1633) are adjusted. The chest wall line 1631. That is, the thickness of the chest region 1613 in Fig. 16A is subtracted from the chest wall line 1631 formed by the average thickness of the pectoralis major muscle.

In some embodiments, the breast region cutting module 114 can further remove portions of the skin in the chest region (eg, the chest region 1633 of FIG. 16B). Take 16B is an example in which the breast region cutting module 114 adjusts the chest region 1633 by subtracting a skin thickness of 1.5 to 1.7 cm from the uppermost portion of the chest region 1633.

Next, the breast region cutting module 114 can convert the area below the chest wall line (eg, the chest wall line 1631 of FIG. 16B) in the turned breast image that was originally converted into a sagittal view according to the chest region (eg, the chest region 1633 of FIG. 16B). Remove to obtain a turned breast image that includes only the chest area. Please refer to FIG. 16C as a schematic diagram for obtaining a chest region in the turned breast image 1250 of FIG. 12B. In the turned breast image 1650, only the image of the chest region 1653 is retained.

In still another embodiment, the breast region cutting module 114 can restore the turned breast image to a breast image of a cross-sectional view or other view to facilitate subsequent operations.

In some embodiments, the processing unit 150 may further present a breast tissue quantitative value such as a breast tissue quantitative value, a dense breast determination result, a suspicious lesion position, a breast tissue position, a lactation amount, a different view of the breast image, and a breast tissue density map of the left and right breasts through the display unit. And one of the lesion prompt messages or a combination thereof to assist the medical staff to clearly understand the detection status.

In summary, the medical image processing apparatus and the breast image processing method thereof according to the embodiments of the present invention detect a breast image based on a texture feature analysis method such as a gray level co-occurrence matrix, a Markov random field or a Jaber filter. The breast tissue is further calculated based on the detected breast tissue to quantify the breast tissue and assist in confirming the suspected lesion detected by the computer-aided detection system. Accordingly, the embodiments of the present invention can improve the accuracy of detecting breast tissue, and can reduce the false positive of the computer-aided detection system. On the other hand, the embodiment of the present invention can also be based on the rib information. The breast area in the breast image is segmented to aid in the correlation of subsequent density results.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S210~S230‧‧‧Steps

Claims (10)

A breast image processing method is applicable to a medical image processing apparatus, the method comprising: obtaining at least one breast image; and dividing the content of the plurality of breast training images into a plurality of feature types, wherein the feature types include a breast tissue (Mammary Glandular Tissue) type, Subcutaneous Fat type, Retromammary Fat and Pectroralis Muscle types, and a type of shadow; a texture for multiple image blocks in these breast training images Feature analysis to analyze the feature types; and detecting a breast tissue in each of the at least one breast image based on the texture feature analysis by a breast tissue detector. The breast image processing method of claim 1, further comprising: training, for each of the feature types, a classifier based on the texture feature of each of the image blocks, wherein the classifier is targeted to the breast One of the tissue types serves as the breast tissue detector. The breast image processing method of claim 1, wherein the step of detecting the breast tissue in each of the at least one breast image through the breast tissue detector comprises: filling in each of the at least one breast image The breast tissue; removing the mottle blocks in the breast tissue; Obtain the outline of the breast tissue. The breast image processing method of claim 1, wherein the step of detecting the breast tissue in each of the at least one breast image through the breast tissue detector further comprises: calculating each of the at least one breast image a breast tissue area; and calculating a breast tissue quantified value based on the breast tissue area in the at least one breast image. The breast image processing method of claim 1, wherein the step of detecting the breast tissue in each of the at least one breast image through the breast tissue detector further comprises: using a computer-assisted detection ( The computer Aided Detection; CADe) system detects at least one abnormal position, wherein the abnormal position is a suspicious lesion position in the breast image; and comparing the at least one abnormal position with the breast tissue in the at least one breast image. The breast image processing method of claim 1, wherein the step of detecting the breast tissue in each of the at least one breast image through the breast tissue detector comprises: at least one of a first view Converting the breast image into at least one turned breast image of a second view, wherein the first view is different from the second view; determining a rib information according to the at least one turned breast image; and determining the at least one according to the rib information Turning to a breast area in the breast image area. The breast image processing method according to claim 6, wherein the rib information includes a chest wall reference line and a rib shadow information, and the step of determining the rib information according to the at least one turning breast image includes Calculating a projection value of all the pixels in the at least one turning breast image; determining the chest wall reference line according to the projection value of the pixels; and determining, by the image cutting method, each of the at least one turning breast image The rib shadow information, wherein the rib shadow information includes a chest wall line. The breast image processing method of claim 7, wherein the step of determining the at least one breast region in the breast image according to the rib information comprises: adjusting each of the at least one turning breast image according to the chest reference line The chest wall line in the middle; and the self-adjusting at least one turned breast image to remove a pectoralis major portion to determine the breast area. The breast image processing method of claim 6, wherein the first view is a transverse view, and the second view is a sagittal view, and the first view is The step of converting the at least one breast image into the at least one turned breast image of the second view comprises converting the at least one breast image of the cross-sectional view into the at least one turned breast image of the sagittal view. A medical image processing apparatus comprising: a storage unit storing at least one breast image and recording a plurality of modules; and a processing unit coupled to the storage unit and accessing and executing the modules recorded by the storage unit, the modules comprising: An image input module obtains the at least one breast image; and a breast detection module that divides the content of the plurality of breast training images into a plurality of feature types, wherein the feature types include a Mammary Glandular Tissue type a Subcutaneous Fat type, a Retromammary Fat and a Pectroralis Muscle type, and a shadow type for performing a texture feature analysis on a plurality of image blocks in the breast training images for analysis The feature types are configured to detect a breast tissue in each of the at least one breast image based on the texture feature analysis by a breast tissue detector.