JP5454868B2 - Medical image processing apparatus, ultrasonic diagnostic apparatus, and medical image diagnostic apparatus - Google Patents

Description

  The present invention relates to a medical image processing apparatus that identifies the contour of an inspection object in a subject from a medical image generated by an ultrasonic diagnostic apparatus or the like, and an ultrasonic diagnostic apparatus or medical image having such an image processing function. The present invention relates to a diagnostic device.

  2. Description of the Related Art There is known an ultrasonic diagnostic apparatus having a function of specifying an endocardial contour by analyzing a change in luminance in an image obtained by imaging the heart.

  In this type of ultrasonic diagnostic apparatus, the contour of the endocardium is specified by tracing a portion having a large luminance change in an image obtained by imaging the heart.

JP-A-10-99328

  However, it has been pointed out that a portion that has been regarded as an endocardium based on a change in luminance or the like may correspond to a portion of the myocardium that is raised rather than the actual endocardium.

  Therefore, if the automatically specified contour does not match the actual contour of the endocardium, changing the contour according to the user's instruction greatly increases the burden on the user.

  Such a phenomenon may occur even in an image captured by a medical image diagnostic apparatus other than the ultrasonic diagnostic apparatus, or even when the inspection target is other than the myocardium.

  The present invention has been made in view of such circumstances, and the object of the present invention is to correct the contour automatically extracted for the inspection object automatically according to the user's wishes and to correct the contour. Is to be easily specified.

First state like the present invention, a medical image processing apparatus for processing a medical image showing the form of the test object within the object, based on the reflected wave at the test object of the ultrasonic wave transmitted into the object In either of the ultrasonic diagnostic apparatus that generates a medical image that represents the form of the inspection object or the medical image diagnostic apparatus that includes a generation unit that generates a medical image that represents the form of the inspection object in the subject. Extraction means for extracting a contour of the surface of the inspection object based on an image, measurement means for measuring a feature value related to the contour extracted by the extraction means, and setting means for setting a correction factor according to a user instruction And correction means for correcting the contour extracted by the extraction means so as to change the feature value measured by the measurement means according to the correction rate set by the setting means.

According to a second aspect of the present invention, in a medical image processing apparatus that processes a medical image representing a form of an inspection target in a subject, extraction for extracting a contour of a surface of the inspection target based on the medical image Means, a measuring means for measuring a feature value relating to the contour extracted by the extracting means, a setting means for setting a correction factor according to a user instruction, and a feature value measured by the measuring means is set by the setting means Correction means for correcting the contour extracted by the extraction means so as to change according to the corrected correction rate, and the correction means uses a predetermined standard value of the feature value measured by the measurement means. The contour extracted by the extraction unit is corrected so as to change according to the correction rate, and the setting unit is corrected by the correction unit according to the standard correction rate. A correction factor is set in accordance with a later user instruction, and the correction unit is further extracted by the extraction unit so as to change the feature value measured by the measurement unit according to the correction factor set by the setting unit. Correct the contour.

According to a third aspect of the present invention, in a medical image processing apparatus that processes a medical image representing a form of an inspection object in a subject, extraction for extracting a surface contour of the inspection object based on the medical image means and the feature values for the extracted contour by the extracting means, measuring means for measuring for each of the plurality of divided regions set by dividing the test object, each of the divided regions according to a user instruction and setting means for setting a correction factor with respect to, so as to vary in accordance with the correction rate set for each of the divided regions by the setting means each measured feature value for each of the plurality of divided regions by said measuring means Correction means for correcting the contour extracted by the extraction means.

  According to the present invention, it is possible to easily specify a correct contour by automatically correcting a contour automatically extracted for an inspection object according to a user's desire.

1 is a block diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The flowchart which shows the process sequence of the control processor in FIG. 1 in the automatic trace of the outline of a test subject. The figure which shows the relationship between a display image and the outline extracted from the display image. The figure which shows the mode of the measurement of the thickness of a myocardium. The figure which shows the mode of correction | amendment of an inner contour. The figure which shows a mode that the outline image was superimposed and displayed on the display image.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus 100 according to the present embodiment.

  The ultrasonic diagnostic apparatus 100 is configured by connecting an ultrasonic probe 12, an input apparatus 13, and a monitor 14 to an apparatus main body 11. The apparatus main body 11 further includes a transmission / reception unit 21, a B-mode processing unit 22, a Doppler processing unit 23, an image generation circuit 24, an image memory 25, a control processor (CPU) 26, an internal storage device 27, a software storage unit 28, and an image analysis unit. 29 and the interface unit 30.

  The ultrasonic probe 12 has a plurality of piezoelectric vibrators as acoustic / electric reversible conversion elements such as piezoelectric ceramics. The plurality of piezoelectric vibrators are arranged in parallel and are provided at the tip of the ultrasonic probe 12. The ultrasonic probe 12 generates an ultrasonic wave based on the drive signal from the transmission / reception unit 21 and converts the reflected wave from the subject P into an electric signal (echo signal).

  The input device 13 inputs designations such as various conditions and a region of interest (ROI) from the operator. The input device 13 may appropriately include a known input device such as various switches, buttons, a trackball, a mouse, a keyboard, or a touch command screen.

  The monitor 14 displays an image represented by the image signal from the image generation circuit 24. As the monitor 14, for example, a known display device such as a liquid crystal display or a CRT (cathode-ray tube) can be used.

  The transmission / reception unit 21 includes a trigger generation circuit, a delay circuit, a pulsar circuit, and the like. The pulsar circuit repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency. The delay circuit focuses the ultrasonic wave into a beam for each channel, and gives each rate pulse a delay necessary to determine the transmission directivity. The trigger generation circuit outputs to the ultrasonic probe 12 a drive signal that generates a pulse at a timing based on the rate pulse. The transmission / reception unit 21 includes an amplifier circuit, an A / D converter, an adder, and the like. The amplifier circuit amplifies the echo signal output from the ultrasonic probe 12 for each channel. The adder individually gives a delay necessary for determining the reception directivity to the echo signal of each channel, and then adds them. By this addition, the reflection component from the direction corresponding to the reception directivity of the echo signal is emphasized, and a comprehensive beam for ultrasonic transmission / reception is formed by the reception directivity and the transmission directivity. The transmission / reception unit 21 sends the synthesized echo signal to the B-mode processing unit 22 and the Doppler processing unit 23.

  The B-mode processing unit 22 includes a logarithmic converter, an envelope detection circuit, an analog / digital (A / D) converter, and the like. The logarithmic converter logarithmically converts the echo signal. The envelope detection circuit detects the envelope of the output signal from the logarithmic converter. The analog-digital converter digitizes the detection signal from the envelope detection circuit and outputs it as detection data.

  The Doppler processing unit 23 performs frequency analysis on velocity information from the echo signal, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, obtains blood flow information such as average velocity, dispersion, and power at multiple points. Outputs blood flow information.

  The image generation circuit 24 calculates spatial distribution information such as frame correlation and coordinate transformation based on the detection data output from the B-mode processing unit 22, and generates an ultrasound diagnostic image representing the spatial distribution information. . The image generation circuit 24 generates an average velocity image, a dispersion image, a power image, or a combination image thereof as an ultrasound diagnostic image based on the blood flow information output from the Doppler processing unit 23. The image generation circuit 24 develops these ultrasonic diagnostic images in the image memory 25 as display images. Then, the image generation circuit 24 outputs an image signal representing the display image developed in the image memory 25 to the monitor 14.

  The image memory 25 stores display image data to be displayed on the monitor 14 in a developed state.

  A transmission / reception unit 21, an image memory 25, an internal storage device 27, a software storage unit 28, an image analysis unit 29, and an interface unit 30 are connected to the control processor 26 via a bus. The control processor 26 operates in accordance with a device control program stored in the internal storage device 27, thereby realizing the following various functions. One of these functions controls each part of the ultrasonic diagnostic apparatus 100 so as to realize various functions of the existing ultrasonic diagnostic apparatus. One of the functions is to set a correction rate in accordance with a user instruction by operating the input device 13, for example. Another of the above functions is to update the standard correction factor in consideration of the setting of the correction factor according to the user instruction.

  The internal storage device 27 stores a device control program and a data group. The data group stored in the internal storage device 27 includes data representing a diagnostic protocol and transmission / reception conditions. The data group includes data representing a standard correction value described later.

  The software storage unit 28 stores software describing a procedure for the control processor 26 to execute the above control.

  The image analysis unit 29 extracts the surface contour of the inspection object based on the display image data stored in the image memory 25. The image analysis unit 29 measures feature values related to the extracted contour. The image analysis unit 29 corrects the contour so that the measured feature value is changed according to the correction rate set by the control processor 26.

  The interface unit 30 mediates exchange of information between the control processor 26 and the input device 13, a network, or an external storage device (not shown).

  Next, the operation of the ultrasonic diagnostic apparatus 100 configured as described above will be described.

  An ultrasonic diagnosis generated by the transmission / reception unit 21, the B-mode processing unit 22 or the Doppler processing unit 23, and the image generation circuit 24 based on an echo signal output from the ultrasonic probe 12 upon receiving a reflected wave from the subject P. The image is developed in the image memory 25 as a display image. Then, when the image generation circuit 24 outputs an image signal representing the display image developed in the image memory 25 developed in the image memory 25 to the monitor 14, the display image is displayed on the monitor 14.

  Now, if the user has requested execution of automatic tracing of the contour of the inspection object, the control processor 26 starts processing as shown in FIG.

  In step Sa1, the control processor 26 instructs the image analysis unit 29 to perform analysis. Upon receiving this instruction, in step Sb1, the image analysis unit 29 analyzes the display image developed in the image memory 25 in the image memory 25, extracts the outline of the myocardium, and measures the thickness of the myocardium based on the outline. To do.

  Specifically, the image analysis unit 29 detects a large number of changing points at which the luminance of the display image changes greatly, and extracts the outline of the myocardium as a trace line for tracing these changing points. Thus, for example, when the display image is an image as shown by a thin line in FIG. 3, for example, a contour as shown by a broken line in FIG. Similarly, contours are extracted from the surface of the right ventricle on the side of the heart chamber and the surface of the outer side of the myocardium. Hereinafter, the contour extracted for the surface on the heart chamber side is referred to as the inner contour, and the contour extracted for the outer surface of the myocardium is referred to as the outer contour.

  Further, as shown in FIG. 4, the image analysis unit 29, for each of a plurality of change points Pd on the inner contour, includes an inner contour of a straight line (indicated by a broken line in FIG. 4) orthogonal to the inner contour at the change point Pd. The thickness of the myocardium is measured as the length between the outer contour or as the length between the inner contour of the left ventricle and the inner contour of the right ventricle. Note that the change points Pd for which the thickness is to be obtained may be all or only a part of the change points detected for extracting the inner contour.

  In step Sb2, the image analysis unit 29 notifies the control processor 26 of the extracted contour and the measured thickness. Then, the image analysis unit 29 ends the processing of FIG.

  In step Sa2, the control processor 26 generates a contour image for representing the extracted contour in the display image based on the contour notified from the image analysis unit 29 as described above.

  In step Sa3, the control processor 26 confirms whether or not the automatic correction function based on the standard correction rate (hereinafter referred to as standard correction) is set to be valid. Note that the validity / invalidity of the standard correction is set in advance by the control processor 26 in accordance with a user instruction.

  If the standard correction is set to be effective, the control processor 26 proceeds from step Sa3 to step Sa4. In step Sa4, the control processor 26 corrects the contour image with the standard correction rate. When the inspection object is a myocardium, only the inner contour is corrected.

  Specifically, for example, as shown in FIG. 5, a plurality of correction points Pc are obtained by moving each of the plurality of change points Pd so as to change the thickness measured for each change point Pd with a standard correction factor. More specifically, the position on the vertical line of the inner contour is defined as a position where the position intersecting the inner contour (position of the change point Pd) is 0%, and a position intersecting the outer contour is 100%. A correction point Pc is obtained as a position corresponding to. Then, an inner contour corrected as a trace line for tracing the plurality of correction points Pc is obtained.

  If the correction at step Sa4 is completed, the control processor 26 proceeds to step Sa5. On the other hand, if the standard correction is disabled, the control processor 26 proceeds from step Sa3 to step Sa5. In step Sa5, the control processor 26 displays the contour image corrected in step Sa4 in step Sa4 when the standard correction is valid, and the contour image generated in step Sa2 in the case where the standard correction is invalid. As shown in FIG. 6, the image is superimposed on the display image on the monitor 14. At this time, the control processor 26 also displays on the monitor 14 a GUI (graphical user interface) 51 representing the applied correction factor as shown in FIG.

  In step Sa6, the control processor 26 waits for a request to change the correction factor. For example, the control processor 26 accepts a request to change the correction factor as an operation of moving the slider 51a included in the GUI 51 to the left or right.

  If the change of the correction factor is requested by the user, the control processor 26 proceeds from step Sa6 to step Sa7. In step Sa7, the control processor 26 sets a correction factor according to the user's request. Specifically, the control processor 26 sets the correction rate according to the position of the slider 51a, for example.

  In step Sa8, the control processor 26 corrects the contour image with the correction rate newly set in step Sa7. The process for this correction is the same as the standard correction.

  In step Sa9, the control processor 26 updates the contour image superimposed and displayed on the display image to the one corrected in step Sa8. Thereafter, the control processor 26 shifts to the standby state of steps Sa10 and 11.

  When the control processor 26 is in the standby state of steps Sa10 and 11 and the user requests further change of the correction rate, the control processor 26 proceeds from step Sa10 to step Sa7, and processes steps Sa7 to Sa9 in the same manner as described above. To do.

  The control processor 26 proceeds from step Sa11 to step Sa12 if the user requests the confirmation of the correction factor in the standby state of steps Sa10 and 11. In step Sa12, the control processor 26 updates the standard correction factor so that the correction factor set at this time is taken into account. How to calculate the updated standard correction factor is arbitrary, but for example, obtain a statistical value such as the average value of correction factors determined in the past, and use this as the updated standard correction factor Can be considered.

  If the standard correction factor has been updated, the control processor 26 ends the processing shown in FIG. Even when step Sa12 is not completed, the control processor 26 terminates the processing shown in FIG. 2 if an end instruction is given by the user.

  Thus, according to the ultrasonic diagnostic apparatus 100 of the present embodiment, the inner contour is corrected so as to change the thickness of the myocardium according to the correction rate. Therefore, if the user determines that the automatically extracted inner contour is an inadequate portion of the myocardium and is inappropriate, the inner contour can be moved to the original inner surface of the myocardium simply by adjusting the correction factor. It can be easily adjusted to match.

  Further, according to the ultrasonic diagnostic apparatus 100, correction at a predetermined standard correction rate is automatically performed, so that quantitative correction can be made without depending on the user's individual feeling. Thereby, for example, the influence of the error based on the difference in skill for each doctor can be reduced, and quantitative diagnosis and data collection can be performed.

  Further, according to the ultrasonic diagnostic apparatus 100, whether or not to perform standard correction can be arbitrarily set, so that flexible operation according to user needs is possible.

  Further, according to the ultrasonic diagnostic apparatus 100, further correction with a correction value set in accordance with a user instruction can be performed even after the standard correction is performed. It is possible to perform further appropriate correction when the correction is not completed.

  Further, according to the ultrasonic diagnostic apparatus 100, the standard correction factor is updated based on the correction value set in accordance with the user's instruction. Therefore, the standard is set in consideration of the setting of the correction factor by a doctor with high skill as described above. It can automatically learn to make the correction rate more appropriate.

  This embodiment can be variously modified as follows.

  The correction factor may be a different value for each part of the inspection object. For example, the correction rates may be different for the right ventricle and the left ventricle. Alternatively, the correction rate may be different between the myocardium between the inner contour and the outer contour and the myocardium between the inner contours. Furthermore, for example, a single site such as the myocardium between the inner contour and the outer contour in the left ventricle may be divided into a plurality of regions, and different correction factors may be applied to the respective regions.

  A plurality of standard correction factors may be set for each doctor or each department, and an appropriate standard correction factor may be selected and applied according to the user.

  The inspection object is not limited to the myocardium. Since the contour to be corrected differs depending on the inspection object, the contour to be corrected is determined according to the inspection object. A data table showing which contour to be corrected in association with a plurality of inspection objects may be prepared, and the contour to be corrected may be automatically set according to the actual inspection object. Also, the feature value used for correcting the contour is not limited to the thickness, and an appropriate feature value should be used in consideration of how the inspection target appears in the medical image.

  The medical image to be processed may be taken by a medical image diagnostic apparatus other than an ultrasonic diagnostic apparatus such as an X-ray CT (computed tomography) apparatus or an MRI (magnetic resonance imaging) apparatus. Therefore, the characteristic functions of the above-described embodiment can be provided in a medical image diagnostic apparatus other than the ultrasonic diagnostic apparatus. In addition, the characteristic functions of the above-described embodiments can be realized by a medical image processing apparatus that processes a medical image captured by the medical image diagnostic apparatus.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 11 ... Apparatus main body, 12 ... Ultrasonic probe, 13 ... Input device, 14 ... Monitor, 21 ... Transmission / reception unit, 22 ... B mode processing unit, 23 ... Doppler processing unit, 24 ... Image generation circuit, 25 ... Image memory, 26 DESCRIPTION OF SYMBOLS ... Control processor, 27 ... Internal storage device, 28 ... Software storage part, 29 ... Image analysis part, 30 ... Interface part, 100 ... Ultrasonic diagnostic apparatus.

Claims (6)

In a medical image processing apparatus that processes a medical image representing the form of an inspection object in a subject,
Extracting means each for extracting a contour of the two different surfaces of said inspected object based on the medical image,
Measuring means for measuring the thickness between the two surfaces as a characteristic value related to the contours of the two surfaces based on the two contours extracted by the extracting means;
Setting means for setting a correction factor according to a user instruction;
And correction means for correcting one of the two contours extracted by the extraction means so as to change the feature value measured by the measurement means in accordance with the correction factor set by the setting means. Medical image processing apparatus. In a medical image processing apparatus that processes a medical image representing the form of an inspection object in a subject,
Extracting means for extracting a contour of the surface of the inspection object based on the medical image;
Measuring means for measuring feature values relating to the contour extracted by the extracting means;
Setting means for setting a correction factor according to a user instruction;
Correction means for correcting the contour extracted by the extraction means so as to change the characteristic value measured by the measurement means in accordance with the correction rate set by the setting means,
The correction unit corrects the contour extracted by the extraction unit so as to change the characteristic value measured by the measurement unit according to a predetermined standard correction factor,
The setting means sets a correction rate according to a user instruction after the correction by the correction unit according to the standard correction rate,
Wherein the correction means further image for medical you and corrects the contour extracted by the extraction means so as to vary the measured feature value by the measuring means in accordance with the correction factor set by said setting means Processing equipment. The medical image processing apparatus according to claim 2 , further comprising an updating unit that updates the standard correction factor in consideration of the setting of the correction factor by the setting unit according to the user instruction.   In a medical image processing apparatus that processes a medical image representing the form of an inspection object in a subject,
  Extracting means for extracting a contour of the surface of the inspection object based on the medical image;
  Measuring means for measuring the characteristic value related to the contour extracted by the extracting means with respect to each of a plurality of divided areas set by dividing the inspection object;
  Setting means for setting a correction factor for each of the divided regions in accordance with a user instruction;
  Each of the characteristic values measured for each of the plurality of divided regions by the measuring unit is extracted by the extracting unit so as to change according to the correction rate set for each of the plurality of regions and each of the regions by the setting unit. A medical image processing apparatus comprising correction means for correcting an outline. In the ultrasonic diagnostic apparatus for generating a medical image representing the form of the inspection object based on the reflected wave of the ultrasonic inspection object transmitted into the subject,
Extracting means each for extracting a contour of the two different surfaces of said inspected object based on the medical image,
Measuring means for measuring the thickness between the two surfaces as a characteristic value related to the contours of the two surfaces based on the two contours extracted by the extracting means;
Setting means for setting a correction factor according to a user instruction;
And correction means for correcting one of the two contours extracted by the extraction means so as to change the feature value measured by the measurement means in accordance with the correction factor set by the setting means. Ultrasonic diagnostic equipment. Generating means for generating a medical image representing the form of the test object in the subject;
Extracting means each for extracting a contour of the two different surfaces of said inspected object based on the medical image,
Measuring means for measuring the thickness between the two surfaces as a characteristic value related to the contours of the two surfaces based on the two contours extracted by the extracting means;
Setting means for setting a correction factor according to a user instruction;
And correction means for correcting one of the two contours extracted by the extraction means so as to change the feature value measured by the measurement means in accordance with the correction factor set by the setting means. Medical diagnostic imaging device.

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