JP6286926B2 - Ultrasonic diagnostic apparatus, image processing method, and program - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus and method for performing an ultrasonic diagnosis using a B mode for imaging a tissue structure and a Doppler mode for imaging a blood flow.

  Ultrasound diagnostic apparatuses have long been used for diagnosis and observation of the heart, abdomen, fetus, and the like. In recent years, the resolution of an ultrasonic diagnostic apparatus has improved, and it has become possible to observe a region close to the body surface. Along with this, ultrasonic diagnostic devices are also used in the shaping region, and observation of bones, tendons, muscles, etc., and evaluation of inflammation of joints in rheumatic diagnosis are performed using ultrasonic diagnostic devices. .

  Rheumatoid inflammation is evaluated using B-mode images and Doppler mode images (Non-Patent Document 1). Specifically, the thickness of the joint cavity, the presence of bone erosion and the presence of joint fluid accumulation are observed using the B-mode image, and the presence or absence of new blood vessels is observed using the Doppler mode image. However, there is a problem in that it takes a long inspection time due to the large number of joints to be inspected and the need to move slowly so as not to generate motion noise in the Doppler mode. At the clinical research level, reduction of the number of joints to be examined is being considered. However, there is a risk of relapse of inflammation and no conclusion has been reached at this time.

  In order to solve such a problem, a method has been proposed in which a joint which is prone to inflammation is first detected from a B-mode image free from motion noise and Doppler is used only for such a joint.

Takao Koike, “New treatment of rheumatoid arthritis using rheumatoid arthritis”, P40-43, Medical Review, March 10, 2010

  However, it is difficult to interpret the B-mode image, and the diagnosis result is likely to depend on the examiner.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus that can reduce the dependence of diagnostic results on the examiner and shorten the examination time.

To achieve the above object, an ultrasonic diagnostic apparatus according to one embodiment of the present invention includes an imaging mode consisting of B-mode and Doppler mode, the ultrasound images obtained by the B-mode, joint capsule, or, When a predetermined part that is a bone of a joint is searched and the predetermined part exists, the size of the predetermined part and the luminance of the predetermined part are used as feature values indicating the morphological characteristics of the predetermined part. Value, a fitting error with a predetermined function of the boundary of the predetermined part, or
An image analysis unit that calculates a value combining a size of the predetermined part, a luminance value of the predetermined part, and a fitting function with a predetermined function of a boundary of the predetermined part; and the feature value is a predetermined condition A condition determination unit that determines whether or not the condition is satisfied, and a display unit that displays a message prompting the use of the Doppler mode when the condition is satisfied.

  According to the present invention, the operator can know the joint to be confirmed in the Doppler mode. Since the determination is performed by the diagnostic device, the dependency of the diagnostic result on the examiner can be reduced. Further, since the operator can make a diagnosis mainly in the B mode, it is not necessary to move the probe slowly, and the inspection time can be shortened.

Block diagram of an ultrasonic diagnostic apparatus according to the present invention Detailed block diagram of the operation mode manager The figure which showed an example of the display screen of B mode when there is no abnormality The figure which showed an example of the display screen of B mode when abnormality is found Figure showing an example of the Doppler mode display screen The figure which showed another example of the display screen of B mode when abnormality is found State transition diagram managed by the operation mode manager A diagram showing another form of state transition diagram managed by the operation mode manager Flowchart of state A of the operation mode management unit Flowchart of state B of the operation mode management unit Flowchart of state C of the operation mode management unit Flow chart of abnormality detection process The figure explaining the joint capsule search processing Diagram explaining the bone detection process The figure explaining joint capsule boundary detection processing Diagram explaining bone erosion search process Illustration explaining the quantification process of bone erosion A figure showing an example of the setting screen for abnormality determination conditions Diagram explaining the relationship between sensitivity and abnormality judgment conditions

[Constitution]
First, the configuration of the ultrasonic diagnostic apparatus of the present invention will be described.

  FIG. 1 is a block diagram showing the configuration of the ultrasonic diagnostic apparatus of the present invention.

  As shown in FIG. 1, the ultrasonic diagnostic apparatus of the present invention includes an ultrasonic probe 1001, an ultrasonic transmission / reception unit 1002, a B-mode processing unit 1003, a Doppler mode processing unit 1004, a memory 1005, a screen generation unit 1006, and an operation mode management. A unit 1007, a display unit 1008, and an operation unit 1009.

  The ultrasonic probe 1001 transmits the transmission wave generated by the ultrasonic transmission / reception unit 1002 into the body. The ultrasonic wave reflected in the body is received by the ultrasonic probe 1001. The ultrasonic wave received by the ultrasonic probe 1001 is output to the ultrasonic transmission / reception unit 1002 as an ultrasonic reception signal.

  The ultrasonic transmission / reception unit 1002 performs transmission / reception processing in the operation mode (B mode, Doppler mode) specified by the operation mode management unit 1007. In transmission, an electrical transmission wave is generated and output to the ultrasonic probe 1001. In reception, beam forming is performed on the ultrasonic reception signal input from the ultrasonic probe 1001 and output to the B-mode processing unit 1003 or the Doppler mode processing unit 1004 as an acoustic line signal. In the B mode, transmission / reception is performed once for one acoustic line, whereas in the Doppler mode, transmission / reception is performed several times for the same acoustic line.

  The B-mode processing unit 1003 performs processing such as detection and logarithmic compression on the acoustic line signal input from the ultrasonic transmission / reception unit 1002 to generate a B-mode image. The B-mode image generated by the B-mode processing unit 1003 is temporarily stored in the memory 1005.

  The Doppler mode processing unit 1004 performs autocorrelation calculation on the acoustic line signal input from the ultrasonic transmission / reception unit 1002, extracts Doppler components, and changes the intensity of blood flow information such as average velocity, dispersion, and power. A Doppler mode image expressed by The generated Doppler mode image is temporarily stored in the memory 1005.

  The operation unit 1009 is an input device, and specifically corresponds to a keyboard, a trackball, and a touch panel. Information input by the operator includes a patient name, examination date and time, screen playback / stop, storage, image quality adjustment, operation mode switching, and the like. Such input information is stored in the memory 1005.

  The screen generation unit 1006 creates and displays a screen in which the examiner name, patient name, time information, setting information of the ultrasonic diagnostic apparatus, and the like are superimposed on the B-mode image and the Doppler mode image stored in the memory 1005. Part 1008. Further, a predetermined message is displayed based on a display instruction from the operation mode management unit 1007.

  The operation mode management unit 1007 analyzes the B mode image stored in the memory 1005 and determines whether or not an abnormal condition is satisfied. If there is an abnormality, a message prompting the Doppler mode is displayed on the screen generation unit 1006. When the operator switches to the Doppler mode, the ultrasonic transmission / reception unit 1002 is instructed to transmit / receive the Doppler mode.

  Here, the ultrasonic probe 1001, the operation unit 1009, and the display unit 1008 may be configured outside the ultrasonic diagnostic apparatus as necessary. The above is the overall configuration of the ultrasonic diagnostic apparatus according to the present invention.

  FIG. 2 is a detailed block diagram of the operation mode management unit 1007.

  The operation mode management unit 1007 includes an image analysis unit 2001, an abnormality determination unit 2002, and a state management unit 2003. Information relating to this processing includes a B-mode image 3002, an abnormal condition 3001 input by the operator, and operation information 3003.

  The image analysis unit 2001 receives the B mode image 3002 stored in the memory 1005 as an input. Then, the joint capsule of the image is searched, and if there is a joint capsule search result and the joint capsule, the size, brightness, and degree of bone erosion of the joint capsule are output to the abnormality determination unit 2002 as joint capsule information.

  The abnormality determination unit 2002 calculates an abnormality determination evaluation value from the joint capsule information input from the image analysis unit 2001, and determines whether or not a predetermined abnormality condition is satisfied. The determination result is output to the state management unit 2003.

  The state management unit 2003 manages the operation mode based on the determination result of the abnormality determination unit 2002 and the operation information 3003. The operation mode is output to the ultrasonic transmission / reception unit 1002. When an abnormality is detected, a message that prompts the screen generation unit 1006 to switch to the Doppler mode is displayed.

  The above is the configuration of the operation mode management unit 1007.

[Operation]
Next, the operation of the ultrasonic diagnostic apparatus of the present invention will be described.

  First, the operator sets an abnormal condition. This is not set for each inspection, but is set when the apparatus is introduced.

  FIG. 7A is a screen for setting an abnormal condition.

  As shown on the screen, the condition items are the size of the joint capsule, the brightness of the joint capsule, and the presence or absence of bone erosion. Symptoms of rheumatism are suspected of progression if the joint capsule is large, if the joint capsule is low-intensity, or if there is bone erosion. The operator checks a check box 301 for setting whether or not a condition item to be included as an abnormal condition is used. Further, the sensitivity (weight) of each item is input by the slide bar 302 for setting the sensitivity of the condition item. The method for setting the abnormal condition and the sensitivity of each item described here is an example, and is not limited thereto.

  FIG. 7B is a diagram illustrating the relationship between sensitivity and abnormal conditions.

  FIG. 7B shows an example in which the size of the joint capsule and the luminance of the joint capsule are selected as the condition items. Each of the intersection 303 with the x-axis and the intersection 304 with the y-axis corresponds to the sensitivity to the size of the joint capsule and the sensitivity to the brightness of the joint capsule set by the operator. A straight line connecting these intersections becomes an abnormality determination straight line 305. If the size of the joint capsule measured by the image analysis unit 2001 is x, the luminance of the joint capsule is y, and the slope and intercept of the abnormality determination line 305 are a and b, there is an abnormality if the relationship of [Equation 1] is satisfied. If not, it is determined that there is no abnormality.

  Next, the operator starts observing the joint in the B mode.

  First, an outline will be described.

  FIG. 4A is a state (operation mode) transition diagram managed by the state management unit 2003.

  Moreover, Fig.3 (a)-(c) shows the screen of each state.

  The initial state is state A.

  FIG. 3A is a screen in state A. 101 is an ultrasonic image (B-mode image), 102 is a B-mode button, 103 is a Doppler mode button, 104 is a message, and 105 is an enhanced joint capsule boundary.

  The operation mode in state A is the B mode. The operator moves the probe to acquire a B-mode image of the joint. When an abnormality is detected by the abnormality determination unit 2002, the state transitions to state B.

  FIG. 3B is a screen of state B.

  The operation mode of the state B is the B mode as in the state A. However, it differs from the state A in that the message 104 for prompting the Doppler mode is displayed. When the operator presses the Doppler mode button 103 in this state, the state transitions to state C.

  FIG. 3C is a screen in state C.

  The operation mode in state C is the Doppler mode. If inflammation is present, a color 106 indicating blood flow is displayed. In this state, when the B mode button 102 is pressed by the operator, the state returns to the state A.

  Hereinafter, it will be described in detail with reference to a flowchart.

  First, the abnormality detection operation will be described.

  FIG. 5D is a flowchart of the abnormality detection process performed by the image analysis unit 2001 and the abnormality determination unit 2002.

  FIGS. 6A to 6D are diagrams illustrating the B-mode image analysis processing performed by the image analysis unit 2001. FIG.

  First, in step S3001, the image analysis unit 2001 searches for a joint from the B-mode image.

  FIG. 6A illustrates a process for searching for a joint.

  201 is a B-mode image, 202 is a joint detection window, 203 is a scan line of the joint detection window 202, and 204 is a B-mode image obtained by reducing the B-mode image 201.

  The image analysis unit 2001 calculates a joint pattern evaluation value indicating the likelihood of a joint pattern for each joint detection window 202, and searches for a position where the evaluation value is maximized. The evaluation value may be a matching value (an error value, a correlation value, etc.) with a joint pattern template, or may be an identification function obtained by machine learning (SVM, Adaboost, etc.) from learning data of a joint pattern and a non-joint pattern. good.

  The search range is the entire B-mode image 201 as shown in FIG. 6A and is scanned as indicated by an arrow 203. Further, a B-mode image 204 in which the B-mode image 201 is reduced so as to detect joints of various sizes is created and similarly scanned.

  Then, the maximum value of the joint pattern evaluation value in the screen is compared with a threshold value, and if it is equal to or less than the threshold value, “no joint” is output to the abnormality determination unit 2002. In response, in step S3005, abnormality determination unit 2002 outputs “no abnormality” to state management unit 2003.

  On the other hand, if “joint is present”, in step S3002, the image analysis unit 2001 detects a bone / joint capsule.

  In this step, first, a bone is detected.

  FIG. 6B is a diagram illustrating a process for detecting a bone.

  Reference numeral 205 denotes a vertical center position of the joint detection window 202, and 206 denotes a bone.

  The search range is below the vertical center position 205 of the joint detection window 202 (in the direction of the arrow in the figure). The target boundary is detected based on the strength of the edge and the smoothness of the boundary by detecting a high-intensity region of the bone or using an active contour model (SNAKES, etc.).

  Next, the boundary of the joint capsule is detected.

  FIG. 6C illustrates a process for detecting the boundary of the joint capsule.

  Reference numeral 207 denotes a joint capsule boundary.

  The search range is above the detected bone 206 (in the direction of the arrow in the figure). The target boundary is detected based on the strength of the edge and the smoothness of the boundary by using an active contour model in the same manner as the bone.

  Next, in step S3003, the image analysis unit 2001 quantifies the size of the joint capsule, the brightness of the joint capsule, and the degree of bone erosion.

  The size of the joint capsule is an average value or a maximum value of the distance between the bone 206 and the joint capsule.

  The brightness of the joint capsule is the average brightness of pixels located between the bone 206 and the joint capsule boundary 207.

  The degree of bone erosion 208 is evaluated by the smoothness of the bone 206 boundary. Specifically, as shown in FIG. 6D, the evaluation is divided into left and right sides from the deepest part of the boundary. Smoothness is evaluated by fitting error by fitting a boundary with a function. FIG. 6E shows an example of fitting. 208 and 209 are examples of normal bone surface boundaries and fitting straight lines, and 210 and 211 are examples of bone surface boundaries and fitting straight lines. As shown in the figure, the bone erosion has a larger fitting error. Although the function used for the fitting is arbitrary, it is not preferable that the bone erosion part fits, and attention must be paid to the selection of the order.

  Next, in step S3004, abnormality determination unit 2002 determines the presence or absence of abnormality.

  The determination of the abnormality is based on the size of the joint capsule (x), the luminance of the joint capsule (y), and the degree of bone erosion (z) calculated in step S3003. ], The abnormality determination unit 2002 outputs “abnormal” to the state management unit 2003, and otherwise outputs “abnormal” (steps S3004 and S3005).

  The above is the operation of the abnormality detection process.

  Next, the operation of the operation mode management unit 1007 will be described.

  FIGS. 5A to 5C are flowcharts showing the operation of the operation mode management unit 1007.

  FIG. 5A is a flowchart of the state A.

  First, in step S1001, the image analysis unit 2001 and the abnormality determination unit 2002 analyze the B-mode image to check whether or not an abnormal condition is satisfied. Details are as described above.

  If an abnormality is detected, in step S1002, the state management unit 2003 causes the screen generation unit 1006 to display a message that prompts the operator for the Doppler mode. If no abnormality is detected, the state is maintained.

  Finally, in step S1003, the state management unit 2003 transitions the state to the state B.

  The above is the operation in state A.

  FIG. 5B is a flowchart of state B.

  The following are all operations of the state management unit 2003.

  In state B, in order to accept a button input interrupt, processing is performed in parallel with the analysis of the B-mode image.

  Regarding the interruption of the button input, first, in step S1101, the depression of the Doppler mode button is monitored.

  When the pressing is confirmed, the state is changed to the state C in step S1102 and step S1103, and the operation mode is switched to the Doppler mode.

  The above is the button input interruption process.

  On the other hand, regarding the analysis of the B-mode image, abnormality determination is performed in step S1104 and step S1001 in state A.

  If no abnormality is detected, in step S1105 and step S1106, the message that prompts the screen generation unit 1006 to prompt the Doppler mode is deleted, and the state is changed to state A.

  The above is the operation in state B.

  FIG. 5C is a flowchart of the state C.

  The following are all operations of the state management unit 2003.

  First, in step S1201, the depression of the B mode button is monitored.

  If the pressing is confirmed, the operation mode is switched to the B mode in step S1202.

  In step S1203, the state is changed to state A.

  The above is the operation in state C.

[Other forms]
In the present embodiment, as shown in FIG. 4A, the transition condition from the B mode to the Doppler mode is set to the depression of the Doppler mode button. However, as shown in FIG. Transition to the state C may be performed. FIG. 3D shows a screen during the timer operation, but a count 107 may be displayed.

  4A and 4B, the transition condition to state A is that no abnormality is detected or the B mode button is pressed. However, an angle sensor is attached to the ultrasonic probe 1001. It is also possible to make a transition when there is a movement exceeding a predetermined value. Further, when the inter-frame difference value of the B-mode image is greater than or equal to a predetermined value, the area of the low-brightness region of the B-mode image that changes to the state A is analyzed, and the aerial radiation in which the ultrasonic probe 1001 moves away from the body surface is detected. Then, transition to state A may be possible.

  Further, as shown in FIG. 3B, when an abnormality is detected, the message 104 is displayed to prompt the user to use the Doppler mode. , Etc.

  Further, when an abnormality is detected, the Doppler mode image may be saved immediately after switching to the Doppler mode in which the B mode image is saved. This saves the trouble of storage.

  In addition, the abnormality is determined linearly as shown in [Equation 1] and [Equation 2], but may be determined nonlinearly.

  Further, although switching between the B mode and the Doppler mode has been described, an elast mode for measuring hardness may be used.

[effect]
As described above, in the ultrasonic diagnostic apparatus of the present invention, the joint capsule is detected from the B-mode image to determine the possibility of inflammation. When the possibility of inflammation is high, the operator is encouraged to use the Doppler mode.

  By such an operation, the operator can make a diagnosis mainly in the B mode. Interpretation is objectively performed by the ultrasonic diagnostic apparatus. As a result, the probe scan time can be shortened, and as a result, the inspection time can be shortened. In addition, the dependence of the diagnosis result on the examiner can be reduced.

  The ultrasonic diagnostic apparatus according to the present invention can be used for evaluation of disease activity in rheumatic diagnosis.

DESCRIPTION OF SYMBOLS 1001 Ultrasonic probe 1002 Ultrasonic transmission / reception part 1003 B mode processing part 1004 Doppler mode processing part 1005 Memory 1006 Screen generation part 1007 Operation mode management part 1008 Display part 1009 Operation part 2001 Image analysis part 2002 Abnormality judgment part 2003 State management part 3001 Abnormal Condition 3002 B-mode image 3003 Operation information 101 Ultrasound image 102 B-mode button 103 Doppler mode button 104 Message 105 Highlighted joint capsule boundary 106 Color 107 Count 201 B-mode image 202 Joint detection window 203 Arrow 204 Reduced B-mode Image 205 Vertical center position 206 Bone 207 Joint capsule boundary 208 Bone erosion 301 Check box for setting whether to use condition item 302 Setting sensitivity of condition item Slide bar 303 intersection 305 abnormality determination straight intersection 304 y-axis and x-axis

Claims (19)

An ultrasonic diagnostic apparatus having an imaging mode consisting of a B mode and a Doppler mode,
As a feature value indicating a morphological feature of the predetermined portion when a predetermined portion that is a joint capsule or a bone of a joint is searched from the ultrasonic image obtained in the B mode and the predetermined portion exists. , A size of the predetermined part, a luminance value of the predetermined part, a fitting error with a predetermined function of a boundary of the predetermined part, or
An image analysis unit that calculates a value obtained by combining a size of the predetermined part, a luminance value of the predetermined part, and a fitting error with a predetermined function of a boundary of the predetermined part;
A condition determination unit that determines whether or not the feature value satisfies a predetermined condition;
If the condition is satisfied, a display unit that displays a prompt to use the Doppler mode;
An ultrasonic diagnostic apparatus comprising: When the feature value indicating the morphological feature of the predetermined portion is the size of the predetermined portion, the predetermined condition is whether or not the size is larger than the predetermined value.
The ultrasonic diagnostic apparatus according to claim 1. When the feature value indicating the morphological feature of the predetermined part is the luminance value of the predetermined part, the predetermined condition is whether or not the luminance value is greater than the predetermined value.
The ultrasonic diagnostic apparatus according to claim 1. When the feature value indicating the morphological feature of the predetermined part is a fitting error with a predetermined function of the boundary of the predetermined part, the predetermined condition is whether the fitting error is larger than a predetermined value or not. is there,
The ultrasonic diagnostic apparatus according to claim 1. The feature value indicating the morphological feature of the predetermined part is a value obtained by combining the size of the predetermined part, the luminance value of the predetermined part, and a fitting error with a predetermined function of the boundary of the predetermined part. Ah is, the predetermined site is the joint capsule der Rutoki, said predetermined condition,
When the size of the joint capsule is x, the brightness of the joint capsule is y, the fitting error is z, and a, b, and c are constants,

The ultrasonic diagnostic apparatus according to claim 1, wherein: An input receiving unit for receiving an operator's input;
In the state where the condition is satisfied, when the input is accepted, a mode switching unit that switches to the Doppler mode is provided.
The ultrasonic diagnostic apparatus according to claim 1. The condition determination unit includes a mode switching unit that switches to the Doppler mode when a predetermined time elapses in a state where the predetermined condition is satisfied.
The ultrasonic diagnostic apparatus according to claim 1. In the condition determination unit, when the second condition different from the predetermined condition is satisfied in a state where the predetermined condition is satisfied, the display unit cancels the display prompting the use of the Doppler mode.
The ultrasonic diagnostic apparatus according to claim 1. The second condition is when the probe used to acquire the ultrasonic image moves.
The ultrasonic diagnostic apparatus according to claim 8. The determination of whether or not the probe has moved is based on whether or not the change value in the time direction of the ultrasonic image is greater than a predetermined value.
The ultrasonic diagnostic apparatus according to claim 9. The determination of whether or not the probe has moved is based on whether or not the low-luminance area of the ultrasound image is greater than a predetermined value.
The ultrasonic diagnostic apparatus according to claim 9. When the predetermined condition is satisfied, a storage unit that stores the ultrasonic image is provided.
The ultrasonic diagnostic apparatus according to claim 1. When switching to the Doppler mode, comprising a storage unit for storing the ultrasound image immediately after switching,
8. The ultrasonic diagnostic apparatus according to claim 6 or 7, wherein: The display unit displays text on a screen when prompting the use of the Doppler mode.
The ultrasonic diagnostic apparatus according to claim 1. The display unit blinks a button on the screen when prompting the use of the Doppler mode.
The ultrasonic diagnostic apparatus according to claim 1. The display unit changes the color of the button on the screen when prompting the use of the Doppler mode.
The ultrasonic diagnostic apparatus according to claim 1. The display unit moves a button on the screen when prompting the use of the Doppler mode.
The ultrasonic diagnostic apparatus according to claim 1. A predetermined part that is a joint capsule or a bone of a joint is searched from the ultrasonic image obtained in one of the imaging modes of the B mode and the Doppler mode, and the predetermined part exists. In this case, as a feature value indicating a morphological feature of the predetermined part,
Fitting error with the size of the predetermined part, the luminance value of the predetermined part, a predetermined function of the boundary of the predetermined part
An image analysis step of calculating a value obtained by combining a size of the predetermined part, a luminance value of the predetermined part, and a fitting error with a predetermined function of a boundary of the predetermined part;
A condition determination step for determining whether or not the feature value satisfies a predetermined condition;
If the condition is satisfied, a display step for displaying a prompt to use the Doppler mode;
An image processing method comprising:   A program for causing a computer to execute the image processing method according to claim 18.

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