Ultrasonic diagnostic device, method, and program

Abstract

To enable proper measurement on a thickness-added image.SOLUTION: An ultrasonic diagnostic device includes a generation part and an estimation part. The generation part generates a thickness-added image on the basis of a reflection wave signal of an ultrasonic wave that is transmitted to a subject. The estimation part estimates a three-dimensional location of a measurement point that is specified on the thickness-added image on the basis of image information on a periphery of the measurement point.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The embodiments disclosed in this specification and the like relate to an ultrasonic diagnostic apparatus, method, and program.

Background Art

[0002] Conventionally, an ultrasonic diagnostic apparatus can generate MPR (Multi Planer Reconstruction) images and CPR (Curved Planar Reconstruction) images based on reflected wave signals of ultrasonic waves three-dimensionally transmitted from an ultrasonic probe. Further, the ultrasonic diagnostic apparatus can also generate a thickened image obtained by projecting pixel values with a predetermined thickness onto a predetermined cross section (for example, a cross section of an MPR image or a cross section of a CPR image).

[0003] The above-described thickened image can be used not only for applications in obstetrics such as observation of a fetus's spine, evaluation of preterm birth risk by measuring the distance of the cervical canal, and measurement of the length of a fetus's thigh bone, but also for measuring the size of a tumor, and is expected to be used in future clinical practice.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the like is to enable appropriate measurement in a depth image. However, the problems solved by the embodiments disclosed in this specification and the like are not limited to the above problems. The problems corresponding to the respective effects of each configuration shown in the embodiments described later can also be regarded as other problems solved by the embodiments disclosed in this specification and the like.

Means for Solving the Problems

[0006] The ultrasonic diagnostic apparatus according to the embodiment includes a generation unit and an estimation unit. The generation unit generates a depth image based on the reflected wave signal of the ultrasonic wave transmitted to the subject. The estimation unit estimates the three-dimensional position of the measurement point based on the image information around the measurement point specified on the depth image.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiment for Carrying Out the Invention

[0008] Hereinafter, embodiments of the ultrasonic diagnostic apparatus, method, and program according to the present application will be described in detail with reference to the accompanying drawings. Note that the ultrasonic diagnostic apparatus, method, and program according to the present application are not limited to the embodiments shown below.

[0009] (First Embodiment) FIG. 1 is a block diagram showing an example of the configuration of an ultrasonic diagnostic apparatus 10 according to the first embodiment. As shown in FIG. 1, the ultrasonic diagnostic apparatus 10 according to the present embodiment includes an ultrasonic probe 1, a display 2, an input interface 3, and a device body 4, and the ultrasonic probe 1, the display 2, and the input interface 3 are communicably connected to the device body 4.

[0010] The ultrasonic probe 1 has a plurality of piezoelectric vibrators, and these plurality of piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from a transmission / reception circuit 41. Further, the ultrasonic probe 1 receives a reflected wave from a subject and converts it into an electrical signal. The ultrasonic probe 1 also has a matching layer provided on the piezoelectric vibrator and a backing material or the like that prevents the propagation of ultrasonic waves backward from the piezoelectric vibrator. Note that the ultrasonic probe 1 is detachably connected to the device body 4.

[0011] When ultrasonic waves are transmitted from the ultrasonic probe 1 to a subject, the transmitted ultrasonic waves are successively reflected at the discontinuous surfaces of the acoustic impedance in the body tissues of the subject, and are received by the plurality of piezoelectric vibrators included in the ultrasonic probe 1 as reflected wave signals. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic waves are reflected. Note that when the transmitted ultrasonic pulse is reflected at the surface of a moving blood flow or a heart wall, etc., the reflected wave signal undergoes a frequency shift depending on the velocity component of the moving object with respect to the ultrasonic transmission direction due to the Doppler effect.

[0012] The ultrasonic probe 1 may be a one-dimensional ultrasonic probe in which a plurality of piezoelectric vibrators are arranged in a row, or an ultrasonic probe that mechanically oscillates the plurality of piezoelectric vibrators of the one-dimensional ultrasonic probe, or a two-dimensional ultrasonic probe in which a plurality of piezoelectric vibrators are arranged two-dimensionally in a lattice pattern.

[0013] The display 2 is a GUI (Graphical User Interface) for an operator of the ultrasonic diagnostic apparatus 10 to input various setting requests using the input interface 3, and displays ultrasonic images and the like generated in the apparatus main body 4. Further, the display 2 displays various messages and display information in order to notify the operator of the processing status and processing results of the apparatus main body 4. Further, the display 2 has a speaker and can also output sound.

[0014] The input interface 3 is operated to set a predetermined position (for example, the position of an ROI (Region Of Interest), etc.), and is realized by, for example, a trackball, a switch button, a mouse, a keyboard, a touch pad that performs an input operation by touching an operation surface, a touch monitor in which a display screen and a touch pad are integrated, a non-contact input circuit using an optical sensor, and an audio input circuit. The input interface 3 is connected to a processing circuit 45 described later, and converts an input operation received from an operator into an electrical signal and outputs it to the processing circuit 45. Note that in this specification, the input interface 3 is not limited to only those having physical operation components such as a mouse and a keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the apparatus and outputs this electrical signal to the processing circuit 45 is also included in the example of the input interface.

[0015] The apparatus main body 4 is an apparatus that generates an ultrasonic image based on the reflected wave signal received by the ultrasonic probe 1. As shown in FIG. 1, it includes a transmission / reception circuit 41, a signal processing circuit 42, an image memory 43, a storage circuit 44, and a processing circuit 45. The transmission / reception circuit 41, the signal processing circuit 42, the image memory 43, the storage circuit 44, and the processing circuit 45 are connected to each other so as to be able to notify each other. In the ultrasonic diagnostic apparatus 10 shown in FIG. 1, each processing function is stored in the storage circuit 44 in the form of a program executable by a computer. The transmission / reception circuit 41, the signal processing circuit 42, and the processing circuit 45 are processors that realize the functions corresponding to the respective programs by reading and executing the programs from the storage circuit 44. In other words, each circuit in the state of having read each program has the function corresponding to the read program.

[0016] The transmission / reception circuit 41 includes a pulse generator, a transmission delay unit, a pulsar, etc., and supplies a drive signal to the ultrasonic probe 1. The pulse generator repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency. The transmission delay unit focuses the ultrasonic waves generated from the ultrasonic probe 1 into a beam shape, and gives the delay time for each piezoelectric vibrator necessary for determining the transmission directivity to each rate pulse generated by the pulse generator. The pulsar applies a drive signal (drive pulse) to the ultrasonic probe 1 at a timing based on the rate pulse. That is, the transmission delay unit arbitrarily adjusts the transmission direction of the ultrasonic waves transmitted from the piezoelectric vibrator surface by changing the delay time given to each rate pulse.

[0017] Note that the transmission / reception circuit 41 has a function of instantaneously changing the transmission frequency, the transmission drive voltage, etc. in order to execute a predetermined scan sequence based on an instruction from the processing circuit 45 described later. In particular, the change of the transmission drive voltage is realized by a linear amplifier type transmission circuit capable of instantaneously switching its value, or a mechanism for electrically switching a plurality of power supply units.

[0018] In addition, the transmission / reception circuit 41 includes a preamplifier, an A / D (Analog / Digital) converter, a reception delay unit, an adder, etc., and performs various processes on the reflected wave signal received by the ultrasonic probe 1 to generate reflected wave data. The preamplifier amplifies the reflected wave signal for each channel. The A / D converter performs A / D conversion on the amplified reflected wave signal. The reception delay unit provides the delay time necessary to determine the reception directivity. The adder performs an addition process on the reflected wave signal processed by the reception delay unit to generate reflected wave data. By the addition process of the adder, the reflection component from the direction corresponding to the reception directivity of the reflected wave signal is emphasized, and a comprehensive beam for ultrasonic transmission / reception is formed by the reception directivity and the transmission directivity.

[0019] The signal processing circuit 42 performs, for example, logarithmic amplification, envelope detection processing, etc. on the reflected wave data received from the transmission / reception circuit 41 to generate data (B-mode data) in which the signal intensity for each sample point is represented by the brightness of the luminance. The B-mode data generated by the signal processing circuit 42 is output to the processing circuit 45.

[0020] In addition, the signal processing circuit 42 generates data (Doppler data) in which motion information based on the Doppler effect of the moving body is extracted at each sample point in the scanning region from the reflected wave data received from the transmission / reception circuit 41, for example. Specifically, the signal processing circuit 42 performs frequency analysis on the velocity information from the reflected wave data, extracts the blood flow, tissue, and contrast agent echo components due to the Doppler effect, and generates data (Doppler data) in which moving body information such as average velocity, variance, and power is extracted for multiple points. Here, the moving body is, for example, blood flow, tissue such as the heart wall, or a contrast agent. The motion information (blood flow information) obtained by the signal processing circuit 42 is sent to the processing circuit 45 and is color-displayed on the display 2 as an average velocity image, a variance image, a power image, or a combined image of these.

[0021] The image memory 43 is a memory that stores the display image data generated by the processing circuit 45. Also, the image memory 43 can store the data generated by the signal processing circuit 42. The B-mode data and Doppler data stored in the image memory 43 can be called by the operator, for example, after diagnosis, and become ultrasonic images for display via the processing circuit 45.

[0022] The storage circuit 44 stores control programs for ultrasonic transmission / reception, image processing, and display processing, diagnostic information (such as patient ID, doctor's findings, etc.), diagnostic protocols, and various data such as various body marks. Also, the storage circuit 44 stores the processing results of the transmission / reception circuit 41, the signal processing circuit 42, and the processing circuit 45. Further, the storage circuit 44 is also used for storing the image data stored in the image memory 43 as needed. Also, the data stored in the storage circuit 44 can be transferred to an external device via an interface (not shown).

[0023] The processing circuit 45 controls the overall processing of the ultrasonic diagnostic apparatus 10. Specifically, the processing circuit 45 controls the processing of the transmission / reception circuit 41 and the signal processing circuit 42 based on various setting requests input from the operator via the input interface 3 and various control programs and various data read from the storage circuit 44. Also, the processing circuit 45 controls the ultrasonic image for display stored in the image memory 43 to be displayed on the display 2.

[0024] As shown in FIG. 1, the processing circuit 45 executes a control function 451, an image generation function 452, an estimation function 453, and a measurement function 454. Here, the control function 451 is an example of a reception unit and a display control unit. The estimation function 453 is an example of an estimation unit. The measurement function 454 is an example of a measurement unit.

[0025] The control function 451 controls the processing of the transmission / reception circuit 41 and the signal processing circuit 42 based on various setting requests input from the operator via the input interface 3, various control programs read from the memory circuit 44, and various data. Here, the control function 451 can control the transmission and reception of ultrasonic waves for generating a thickness image of the target part of the subject. Also, the control function 451 controls the display of ultrasonic images and various display information on the display 2. For example, the control function 451 causes a display image showing the three-dimensional position of the measurement point estimated by the estimation function 453 to be displayed. Further, the control function 451 receives an operation from the user via the input interface 3 and executes processing corresponding to the received operation. The processing by the control function 451 will be described in detail later.

[0026] The image generation function 452 generates an ultrasonic image from the data generated by the signal processing circuit 42. That is, the image generation function 452 generates an ultrasonic image representing the intensity of the reflected wave as luminance from the B-mode data generated by the signal processing circuit 42. Also, the image generation function 452 generates an ultrasonic image representing moving body information (blood flow information or tissue movement information) from the Doppler data generated by the signal processing circuit 42. The ultrasonic image based on the Doppler data is velocity image data, variance image data, power image data, or image data combining these.

[0027] Here, the image generation function 452 generally converts (scan-converts) the scan line signal sequence of the ultrasonic scan into a scan line signal sequence in a video format typified by a television or the like, and generates a display ultrasonic image. Specifically, the image generation function 452 generates a display ultrasonic image by performing coordinate conversion according to the scanning form of the ultrasonic wave by the ultrasonic probe 1. Also, in addition to scan conversion, the image generation function 452 performs various image processes such as an image process (smoothing process) for regenerating an average value image of luminance using a plurality of image frames after scan conversion, and an image process (edge enhancement process) using a differential filter within the image. Further, the image generation function 452 synthesizes character information, scales, body marks, etc. of various parameters on the ultrasonic image.

[0028] That is, the B-mode data and Doppler data are ultrasonic image data before scan conversion processing, and the data generated by the image generation function 452 is ultrasonic image data for display after scan conversion processing. Note that when the signal processing circuit 42 generates three-dimensional data (three-dimensional B-mode data and three-dimensional Doppler data), the image generation function 452 generates volume data by performing coordinate conversion according to the scanning pattern of ultrasonic waves by the ultrasonic probe 1. Then, the image generation function 452 can also perform various rendering processes on the volume data to generate two-dimensional image data for display.

[0029] For example, the image generation function 452 can generate an MPR image by cutting out and reconstructing the volume data at an arbitrary cross-section, or generate a CPR image by cutting out and reconstructing the volume data at a curved surface along an arbitrary curve.

[0030] Here, the image generation function 452 according to the present embodiment generates a thickness image based on the reflected wave signal of ultrasonic waves transmitted to the subject. Specifically, the image generation function 452 generates a thickness image by projecting pixel values at a predetermined thickness onto a predetermined cross-section. For example, the image generation function 452 generates a thickness image by performing various processes in the thickness direction on the reflected wave signals of a plurality of cross-sections (slices) included in the thickness direction. Taking an example, the image generation function 452 generates a thickness image by adding the luminance information of a plurality of slices in the thickness direction. Note that the image generation function 452 can generate a thickness MPR image based on the cross-section of the MPR image, a thickness CPR image based on the curved surface of the CPR image, a thickness MIP (Maximum Intensity Projection) image obtained by projecting the maximum luminance in the thickness direction, and the like.

[0031] The estimation function 453 estimates the three-dimensional position of the measurement point based on the image information around the measurement point specified on the depth image. Here, the image information includes the reflected wave signal, the reflected wave data obtained by performing various processes on the reflected wave signal, the B-mode data obtained by performing envelope detection processing or the like on the reflected wave data, and the ultrasonic image generated from the B-mode data. Note that the processing by the estimation function 453 will be described in detail later.

[0032] The measurement function 454 executes measurement processing based on the three-dimensional position of the measurement point estimated by the estimation function 453. Specifically, for the measurement point specified on the depth image, measurement processing based on the three-dimensional position of the measurement point estimated by the estimation function 453 is executed. For example, the measurement function 454 measures the length of a straight line or curve formed by the measurement points estimated by the estimation function 453, the area of the region formed by the measurement points, and the like.

[0033] Here, the ultrasonic diagnostic apparatus 10 according to the first embodiment enables appropriate measurement in the depth image. For example, in the depth image, data in the depth direction may be missing, and there is a possibility of measuring a position different from the position assumed by the user, and appropriate measurement may not be possible. FIG. 2A is a diagram for explaining an example of generating a depth image according to the first embodiment. FIG. 2B is a diagram showing an example of a depth image according to the first embodiment.

[0034] For example, as shown in FIG. 2A, when scanning is performed on the target site T of the subject P with five cross-sections (slices s1 to s5) and a thickened image is generated by adding in the thickness direction, a thickened image in which one region including the target site T depicted in each slice is shown as the target site T will be displayed. That is, in the slices s1 to s5 arranged in the thickness direction, although the depicted target sites T1 are different from each other, the thickened image does not reflect that information (the information on the size and shape of the target site T1 in each slice is missing). Therefore, when the user performs a designation operation on the target site T1 depicted on the thickened image, there is a possibility that a position different from the position intended by the user in the thickness direction will be designated.

[0035] For example, when the target site t1 is in the state shown in FIG. 2B in a three-dimensional space and a thickened image observed by the user from the left side is generated, the thickened image observed by the user will be in the state shown on the left side surface of FIG. 2B. Here, when the user performs a designation operation on the position of the end portion of the thickened image shown on the left side surface of FIG. 2B in order to measure the length of the target site t1 (the distance from one end portion A to the other end portion A' of the target site t1), the information in the thickness direction is not reflected and the length within the left side surface will be measured.

[0036] Specifically, when designating the end portion of the target site t1 in the thickened image shown on the left side surface of FIG. 2B, the position on the left side surface will be designated. That is, although the length of the target site t1 that is originally intended to be measured is the length represented by the following formula (1), the actually measured length is the length represented by the following formula (2).

[0037]

Equation

[0038]

Equation

[0039] As described above, in the measurement of a thick image, the length actually measured may not be the length of the target part itself, but may be the length when the target part is projected onto an arbitrary two-dimensional cross-section, and appropriate measurement may not be possible in the thick image. Therefore, the ultrasonic diagnostic apparatus 10 enables appropriate measurement in the thick image by estimating the three-dimensional position of the measurement point based on the image information around the measurement point specified on the thick image.

[0040] Hereinafter, after explaining the procedure of the processing by the ultrasonic diagnostic apparatus 10 with reference to FIG. 3, the details of each processing will be described. FIG. 3 is a flowchart showing the procedure of the processing of the ultrasonic diagnostic apparatus according to the first embodiment.

[0041] For example, as shown in FIG. 3, in the present embodiment, the control function 451 executes a scan for generating a thick image (step S101). For example, the control function 451 executes a scan for three-dimensionally collecting reflected wave signals by scanning the target part with a plurality of cross-sections. The processing of step S101 is realized, for example, by the processing circuit 45 calling and executing a program corresponding to the control function 451 from the storage circuit 44.

[0042] Subsequently, the image generation function 452 generates a thick image (step S102). Further, the control function 451 causes the generated thick image to be displayed on the display 2. The processing of step S102 is realized, for example, by the processing circuit 45 calling and executing a program corresponding to the image generation function 452 from the storage circuit 44.

[0043] Subsequently, the estimation function 453 determines whether a measurement point is specified for the thick image (step S103). When a measurement point is specified (step S103, Yes), the three-dimensional position (position in the thickness direction) of the measurement point is estimated (step S104). The processing of steps S103 and S104 is realized, for example, by the processing circuit 45 calling and executing a program corresponding to the estimation function 453 from the storage circuit 44.

[0044] Subsequently, the control function 451 causes the estimated position to be displayed on the display 2 (step S105). The process of step S106 is realized, for example, by the processing circuit 45 calling and executing a program corresponding to the control function 451 from the storage circuit 44.

[0045] Furthermore, the control function 451 causes the measurement result based on the estimated position to be displayed on the display 2 (step S106). The process of step S106 is realized, for example, by the processing circuit 45 calling and executing programs corresponding to the measurement function 454 and the control function 451 from the storage circuit 44.

[0046] Hereinafter, the details of each process executed by the ultrasonic diagnostic apparatus 10 will be described. Note that, prior to the following scan, the user registers the subject in the ultrasonic diagnostic apparatus 10 and executes an operation to start an examination using a thick image. In the following description, an example is given in which the user places the ultrasonic probe 1 on the mother's body to depict the fetus's thigh in a thick two-dimensional image and measures the femur length (FL).

[0047] (Scan) As described in step S101, the control function 451 executes a scan for generating a thick image. For example, the control function 451 executes a scan for generating a thick image of the target site t1 (fetus's thigh) shown in FIG. 2B. As an example, the control function 451 controls the transmission / reception circuit 41 to three-dimensionally scan the target site t1 included in the thick imaging region of FIG. 2B with a predetermined number of cross-sections (slices). Here, the number of slices within the thick imaging region can be arbitrarily set.

[0048] Note that for the scan to generate a thickness image, any scan may be performed as long as the reflected wave signal can be collected three-dimensionally. That is, it may be the case where the reflected wave signal is collected by scanning while manually or automatically moving a one-dimensional ultrasonic probe in which a plurality of piezoelectric vibrators are arranged in a row, or alternatively, it may be the case where the reflected wave signal is collected by scanning with a two-dimensional ultrasonic probe in which a plurality of piezoelectric vibrators are arranged two-dimensionally in a lattice pattern.

[0049] (Thickness Image Generation Process) As described in step S102, the image generation function 452 generates a thickness image based on the B-mode data generated under the control of the control function 451. For example, the image generation function 452 generates a thickness image based on a plurality of straight cross-sections with the direction indicated by the arrow in the thickness imaging region of FIG. 2B as the slice direction. Taking an example, the image generation function 452 generates a thickness image by adding the luminance values of a plurality of slice images arranged in the slice direction. That is, the image generation function 452 generates a thickness image with the direction indicated by the arrow in the thickness imaging region as the thickness direction.

[0050] Note that the image generation function 452 can generate a thickness image by setting an arbitrary cross-section for the three-dimensionally collected B-mode data. That is, the image generation function 452 can generate a plurality of slice images using the MPR image obtained by setting and reconstructing an arbitrary straight cross-section for the three-dimensional B-mode data, and generate a thickness image from the generated slice images. Also, the image generation function 452 can generate a plurality of slice images using the CPR image obtained by setting and reconstructing an arbitrary curved cross-section for the three-dimensional B-mode data, and generate a thickness image from the generated slice images.

[0051] (Designation of Measurement Point) As described in step S103, the estimation function 453 determines whether a measurement point has been specified for the depth image generated by the image generation function 452. For example, when the depth image is generated by the image generation function 452, the control function 451 controls to display the generated depth image on the display 2.

[0052] While observing the depth image displayed on the display 2, the user specifies a measurement point for the depth image by operating the input interface 3. For example, while observing the depth image, the user operates the GUI for measurement to specify measurement points for distance measurement, area measurement, etc. on the depth image. To give an example, for the depth image of the fetus's thigh, the user specifies measurement points at both ends of the thigh bone to measure FL. That is, the user specifies the positions of A and A' in FIG. 2B shown in the depth image on the depth image.

[0053] The estimation function 453 determines whether a measurement point has been specified on the depth image by the user. When a measurement point has been specified, the estimation function 453 performs the estimation process of the three-dimensional position of the measurement point described below.

[0054] (Estimation process of measurement point) As described in step S104, when a measurement point is specified by the user, the estimation function 453 executes an estimation process to estimate the three-dimensional position of the specified measurement point. Specifically, the estimation function 453 estimates the position of the measurement point specified on the depth image by the user in the depth direction.

[0055] For example, the estimation function 453 sets a region including the measurement point in the depth image, and estimates the position of the measurement point in the depth direction based on the luminance information of the pixels included in the region at each position in the depth direction of the depth image. FIG. 4 is a diagram for explaining an example of the estimation process by the estimation function 453 according to the first embodiment. In FIG. 4, a case is shown where four cross-sections (slice images s11 to s14) are generated for the depth image region, and the generated slice images s11 to s14 are added to generate a depth image.

[0056] For example, as shown in the depth image of FIG. 4, when the measurement point p1 is installed at the end of the target site t1 (fetal thigh), the estimation function 453 sets a region r1 including the measurement point p1 around the installed measurement point p1. Then, the estimation function 453 estimates which position in the depth direction (slice direction) of the measurement point p1 corresponds to the positions of the slice images s11 to s14 based on the luminance information of the pixels included in the set region r1. Note that the size and shape of the region r1 can be arbitrarily set. For example, since the FL of a fetus at 20 weeks of gestation is about 30 mm, the size of the region r1 may be set based on this size.

[0057] For example, the estimation function 453 calculates the luminance differences between the pixels in the region at each position in the depth direction, and estimates the position of the measurement point in the depth direction based on the calculated luminance differences. For example, the estimation function 453 acquires the luminance values of a plurality of pixels included in the region r1 in the slice image s11 shown in FIG. 4, and calculates the luminance values between the acquired plurality of pixels. Here, the estimation function 453 calculates, for example, the difference between the highest luminance value and the lowest luminance value among the plurality of pixels included in the region r1.

[0058] Similarly, the estimation function 453 acquires the luminance values of the pixels included in the region r1 of each image for the slice images s12 to s14 shown in FIG. 4. Then, the estimation function 453 calculates the luminance differences of the acquired luminance values for each image.

[0059] As described above, when the estimation function 453 calculates the luminance differences in the region r1 in each slice image, it estimates the position of the measurement point p1 in the thickness direction based on the calculated luminance differences. Here, for example, the estimation function 453 estimates the position in the thickness direction where the luminance difference exceeds the threshold value as the position of the measurement point. For example, as shown in FIG. 4, the estimation function 453 estimates the position in the thickness direction corresponding to the slice image s13 where the luminance difference exceeds the threshold value as the position in the thickness direction of the measurement point p1. The threshold value for comparison with the above-described luminance difference can be arbitrarily set, and may be set, for example, according to the type of the target site to be measured.

[0060] Note that in FIG. 4, only the case where the measurement point p1 is designated for one end of the target site t1 (fetal thigh) is shown, but actually, the measurement point p2 is also designated for the other end of the target site t1 (fetal thigh). Then, the estimation function 453 similarly executes the above-described estimation process for the designated measurement point p2.

[0061] In the above-described embodiment, the case where the luminance difference between the highest luminance value and the lowest luminance value of the pixels included in the region r1 is calculated and compared with the threshold value has been described, but the embodiment is not limited thereto. For example, it may be a case where the luminance differences between adjacent pixels (or pixels at positions separated by a predetermined number of pixels) in the region r1 are calculated, and the largest luminance difference is compared with the threshold value.

[0062] (Display process of the estimated position) As described in step S105, the control function 451 controls to display the three-dimensional position of the measurement point estimated by the estimation function 453. Specifically, the control function 451 causes the display 2 to display a display image indicating the position of the estimated measurement point. For example, the control function 451 causes a comparative display of the three-dimensional position of the measurement point estimated by the estimation function 453 and the position of the measurement point designated on the image with thickness.

[0063] FIG. 5 is a diagram for explaining an example of display processing according to the first embodiment. Here, in FIG. 5, an example is shown in which the positions in the thickness direction of measurement points p1 and p2 specified by the user are estimated for the target part t1 shown in FIG. 2B. For example, as shown in FIG. 5, when the measurement point P1 is specified for the end A of the target part t1 (the thigh of the fetus) included in the imaged area with thickness, and the measurement point p2 is specified for the end A', the estimation function 453 estimates the estimated point p3 based on the measurement point P1 and the estimated point p4 based on the measurement point p2 by the above-described estimation process.

[0064] As shown in the right figure of FIG. 5, the control function 451 displays a display image showing the measurement points p1 and p2 and the estimated points P3 and p4. For example, the control function 451 displays a rendering image showing the positions of the measurement point p1, the measurement point p2, the estimated point P3, and the estimated point p4 with respect to the thigh bone of the fetus. In such a case, the image generation function 452 generates a three-dimensional image (for example, a rendering image) based on the reflected wave signal of the ultrasonic wave three-dimensionally transmitted to the subject. Then, the control function 451 displays a display image showing the positions of the measurement point p1, the measurement point p2, the estimated point P3, and the estimated point p4 with respect to the generated three-dimensional image.

[0065] Here, the control function 451 can display the measurement point and the estimated point in different display forms so that the measurement point and the estimated point can be distinguished. For example, the control function 451 displays the measurement points p1 and p2 as white points and the estimated points p3 and p4 as black points.

[0066] Note that the display of the three-dimensional position of the estimated measurement points is not limited to the above-described comparison display. That is, the control function 451 can also display a display image showing only the three-dimensional position of the estimated measurement points. For example, the control function 451 can also display a display image showing only the positions of the estimated points P3 and p4. In such a case, for example, the image generation function 452 generates a cross-sectional image including the positions of the measurement points (estimated points p3 and p4) estimated by the estimation function 453 based on the reflected wave signals of the ultrasonic waves three-dimensionally transmitted to the subject. The control function 451 displays a display image showing the positions of the estimated points P3 and p4 with respect to the generated cross-sectional image.

[0067] (Display process of measurement results) As described in step S106, the control function 451 displays the measurement results based on the positions of the measurement points estimated by the estimation function 453. Specifically, the control function 451 displays the results measured by the measurement function 454 based on the positions of the measurement points estimated by the estimation function 453. For example, the control function 451 displays the distance between the estimated points p3 and p4 shown in FIG. 5 together with the display image. In such a case, first, the measurement function 454 measures the length from the estimated point p3 to the estimated point p4. Then, the control function 451 displays the measured result together with the display image.

[0068] Here, the timing for displaying the measurement results can be set as appropriate. For example, it may be the case where the measurement function 454 executes the measurement process and displays it when the estimated points p3 and p4 are estimated by the estimation function 453, or it may be the case where the measurement function 454 executes the measurement process and displays it when the estimated points p3 and p4 are approved by the user. When receiving the approval of the user, the control function 451 can control to display a GUI for receiving the approval on the display 2 when displaying the display image showing the estimated points p3 and p4.

[0069] As described above, the ultrasonic diagnostic apparatus 10 enables appropriate measurement in a thickness image by executing measurement processing based on the estimated points that estimate the positions in the thickness direction of the measurement points specified by the user. For example, the ultrasonic diagnostic apparatus 10 can measure the FL inclined in the thickness direction (depth direction) of the thickness image without deviation.

[0070] (Modification 1) In the above-described embodiment, the case where one estimated point is estimated for one measurement point specified by the user has been described. However, the embodiment is not limited to this, and a plurality of estimated points may be estimated for one measurement point.

[0071] For example, when the estimation function 453 compares the luminance difference of the pixels in the region including the measurement point specified by the user with a threshold value, there may be a plurality of slice images that exceed the threshold value. In such a case, the control function 451 accepts a selection operation from the user when there are a plurality of positions in the thickness direction where the luminance difference exceeds the threshold value. Specifically, the control function 451 displays a display image showing a plurality of estimated points estimated by the estimation function 453 and also displays a GUI for performing a selection operation on the plurality of estimated points.

[0072] FIG. 6 is a diagram for explaining an example of the display processing according to Modification 1. Here, in FIG. 6, the display processing is shown when the estimated points p3 and p5 are estimated based on the measurement point p1 specified by the user, and the estimated points p4 and p6 are estimated based on the measurement point p2. For example, as shown in FIG. 6, the control function 451 displays a display image showing the measurement points p1 and p2 and the estimated points P3, p4, p5, and p6 with respect to the thigh bone of the fetus.

[0073] Then, the control function 451 receives from the user, via the input interface 3, a selection operation of selecting one point from the estimated points p3 and p5, and a selection operation of selecting one point from the estimated points p4 and p6. When the control function 451 receives the selection operation, the measurement function 454 executes a measurement process using the selected estimated point. Then, the control function 451 causes the display 2 to display the measurement result by the measurement function 454.

[0074] Note that the control function 451 can also display a cross-sectional image showing only the position of the estimated point. In such a case, for example, the image generation function 452 generates a plurality of cross-sectional images including the positions of the measurement points estimated by the estimation function 453 based on the reflected wave signals of the ultrasonic waves three-dimensionally transmitted to the subject. That is, the image generation function 452 generates a cross-sectional image including the estimated points p3 and p4, a cross-sectional image including the estimated points p3 and p6, a cross-sectional image including the estimated points p5 and p4, and a cross-sectional image including the estimated points p5 and p4. The control function 451 causes the display to display a display image showing the position of the estimated point for each of the generated cross-sectional images.

[0075] In the above-described modification 1, the case where the user selects one estimated point from a plurality of estimated points has been described. However, the embodiment is not limited to this, and one estimated point may be automatically selected from a plurality of estimated points. For example, the estimation function 453 estimates, as the three-dimensional position of the measurement point, the estimated point having the largest luminance difference among the estimated points whose luminance difference in the pixels within the region including the measurement point exceeds the threshold value. For example, the estimation function 453 selects the estimated point with the larger luminance difference between the estimated points p3 and p5. Also, the estimation function 453 selects the estimated point with the larger luminance difference between the estimated points p4 and p6.

[0076] Further, for example, the estimation function 453 can generate a histogram of the luminance values of the pixels included in the region, and select one estimation point from a plurality of estimation points based on the generated histogram. For example, the estimation function 453 estimates, as the three-dimensional position of the measurement point, an estimation point at which the histogram of the luminance values in the region becomes a predetermined state among the estimation points at which the luminance difference in the pixels within the region exceeds a threshold value. Here, examples of the above-described predetermined state include a state in which the distribution of the luminance values is biased toward the high-luminance side and the low-luminance side, respectively. That is, the estimation function 453 executes the selection process in a state where the smaller the intermediate luminance value, the better.

[0077] Further, for example, when a measurement point is set for a thick image MIP image, a slice image having a luminance value close to the luminance value at the set position may be selected. That is, the estimation function 453 estimates, as the three-dimensional position of the measurement point, an estimation point at which the luminance value at the estimation point is closest to the luminance value at the measurement point specified by the user among the estimation points at which the luminance difference in the pixels within the region exceeds a threshold value.

[0078] As described above, according to the first embodiment, the image generation function 452 generates a thick image based on the reflected wave signal of the ultrasonic wave transmitted to the subject. The estimation function 453 estimates the three-dimensional position of the measurement point based on the image information around the measurement point specified on the thick image. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can estimate the position in the thickness direction of the measurement point specified on the thick image, eliminate the deviation in the measurement on the thick image, and enable appropriate measurement in the thick image.

[0079] Further, according to the first embodiment, the estimation function 453 sets a region including the measurement point in the thick image, and estimates the position of the measurement point in the thickness direction based on the luminance information of the pixels included in the region at each position in the thickness direction of the thick image. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can accurately estimate the position in the thickness direction of the measurement point specified on the thick image.

[0080] Also, according to the first embodiment, the estimation function 453 calculates the luminance differences between the pixels in the region at each position in the thickness direction, and estimates the position of the measurement point in the thickness direction based on the calculated luminance differences. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can accurately estimate the three-dimensional position of the measurement point arranged at the position where there is a luminance gap on the thickness image.

[0081] Also, according to the first embodiment, the estimation function 453 estimates the position in the thickness direction where the luminance difference exceeds the threshold value as the position of the measurement point. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can easily estimate the position of the measurement point in the thickness direction.

[0082] Also, according to the first embodiment, the control function 451 causes a display image showing the three-dimensional position of the measurement point estimated by the estimation function 453 to be displayed. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can present the estimated three-dimensional position of the measurement point to the user.

[0083] Also, according to the first embodiment, the control function 451 causes a comparative display of the three-dimensional position of the measurement point estimated by the estimation function 453 and the position of the measurement point specified on the thickness image. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can present more understandable information to the user.

[0084] Also, according to the first embodiment, the measurement function 454 executes a measurement process based on the three-dimensional position of the measurement point estimated by the estimation function 453. The control function 451 causes the result of the measurement process to be displayed. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment can display an appropriate result.

[0085] Further, according to the first embodiment, the image generation function 452 generates a cross-sectional image or a three-dimensional image including the positions of the measurement points estimated by the estimation function 453 based on the reflected wave signals of the ultrasonic waves. The control function 451 causes a display image showing the three-dimensional positions of the measurement points to be displayed on the cross-sectional image or the three-dimensional image. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment enables the display of a display image that makes it easy to observe the three-dimensional positions of the measurement points.

[0086] Also, according to Modification 1, when there are a plurality of positions in the thickness direction where the luminance difference exceeds the threshold value, the control function 451 accepts a selection operation from the user. Therefore, the ultrasonic diagnostic apparatus 10 according to the first embodiment enables the more accurate determination of the three-dimensional positions of the measurement points.

[0087] (Second Embodiment) In the above-described first embodiment, the processing for measuring the distance was explained. In the second embodiment, the processing for measuring the area will be explained. In the second embodiment, the content of the measurement processing by the measurement function 454 is different from that in the first embodiment. Hereinafter, the explanation will focus on this point.

[0088] FIG. 7 is a diagram for explaining an example of the measurement processing according to the second embodiment. Here, in FIG. 7, an example of measuring the area of the right ventricle of the heart is shown. For example, in the measurement of the heart, the area of the right ventricle in the systolic phase and the area in the diastolic phase may be measured respectively. In this case, there are cases where a thickened image is used so that the wall of the right ventricle can be clearly observed.

[0089] In such a case, first, the control function 451 collects the reflected wave signals obtained by three-dimensionally scanning the heart over time, thereby collecting three-dimensional B-mode data of the heart in the systolic phase and three-dimensional B-mode data of the heart in the diastolic phase. Then, the image generation function 452 generates, from each B-mode data, a thickened image in the systolic phase and a thickened image in the diastolic phase in which the right ventricle is depicted as shown in FIG. 7. The control function 451 displays the thickened image in the systolic phase and the thickened image in the diastolic phase, and accepts an input operation of a curve L1 for designating the position of the right ventricle with respect to each thickened image. Note that, in FIG. 7, the curve L1 is used to designate the right ventricle, but the embodiment is not limited thereto, and it may be the case where it is designated at a plurality of points.

[0090] The estimation function 453 estimates the position of the inner wall of the right ventricle in the systolic phase by estimating the position in the thickness direction for each position on the curve L1 designated for the right ventricle in the systolic phase as described in the first embodiment. Further, the estimation function 453 estimates the position of the inner wall of the right ventricle in the diastolic phase by estimating the position in the thickness direction for each position on the curve L1 designated for the right ventricle in the diastolic phase as described in the first embodiment.

[0091] The measurement function 454 measures the area of the right ventricle in the systolic phase using the position of the inner wall of the right ventricle in the systolic phase estimated by the estimation function 453. Further, the measurement function 454 measures the area of the right ventricle in the diastolic phase using the position of the inner wall of the right ventricle in the diastolic phase estimated by the estimation function 453. Note that, similar to the first embodiment, the control function 451 can display a display image showing the position of the inner wall of the right ventricle estimated by the estimation function 453.

[0092] In addition, as a case of measuring an area using a thickness image, for example, the case of calculating the stenosis rate of the carotid artery can be mentioned. FIG. 8 is a diagram for explaining an example of the measurement process according to the second embodiment. Here, in FIG. 8, an example of the case of measuring the area of the carotid artery is shown. For example, when observing the carotid artery, it is useful to use a thickness image in order to search for the most stenotic part. Therefore, as shown in FIG. 8, a thickness imaging region is set for the carotid artery, and a thickness image is generated.

[0093] Here, as shown in the central diagram of FIG. 8, a short-axis cross-sectional image is used as the thickness image for observing the carotid artery. That is, the user displays a thickness image in which the short-axis cross-section of the carotid artery is clearly drawn, and arranges measurement points for measuring the area using the input interface 3. For example, as shown in the central diagram of FIG. 8, the user arranges a plurality of measurement points p7 on the vascular part excluding the plaque with respect to the thickness image showing the short-axis cross-section of the carotid artery.

[0094] The estimation function 453 estimates the estimated points p8 corresponding to each of the measurement points p7 by estimating the positions in the thickness direction for each of the plurality of measurement points p7 as described in the first embodiment. Then, the control function 451 displays a display image showing the estimated points p8.

[0095] The measurement function 454 measures the area of the carotid artery using the estimated points p8 estimated by the estimation function 453. Here, in the thickness image, the most stenotic cross-section is shown. Therefore, the area measured using the estimated points estimated by the above-described process is the area of the most stenotic cross-section. The measurement function 454 calculates the stenosis rate by calculating the area of the entire blood vessel and the area of the blood vessel part excluding the plaque in the above-described cross-section.

[0096] As described above, according to the second embodiment, the ultrasonic diagnostic apparatus 10 can perform appropriate measurement even when measuring an area in a thickness image.

[0097] (Third Embodiment) In the above-described first and second embodiments, the case where the thickened image generated based on the straight cross-section is targeted has been described. In the third embodiment, the case where the thickened image generated based on the curved cross-section is targeted will be described. In the third embodiment, the thickened image to be measured is different from that in the first and second embodiments. Hereinafter, the description will focus on this point.

[0098] As a case of measurement using a thickened image based on a curved cross-section (for example, a thickened CPR image based on the curved surface of a CPR image), for example, the case of measuring the length of the backbone of a fetus can be mentioned. FIG. 9 is a diagram for explaining an example of the measurement process according to the third embodiment. Here, in FIG. 9, an example of the case of measuring the length of the backbone of a fetus is shown.

[0099] The user displays a thickened CPR image in which the backbone of the fetus is clearly depicted, and arranges measurement points for measuring the length using the input interface 3. For example, as shown in FIG. 9, the user arranges measurement points p11 to p16 along the curve of the backbone of the fetus (curve L2).

[0100] The estimation function 453 estimates the corresponding estimated points for the measurement points p11 to p16 by estimating the positions in the thickness direction for the measurement points p11 to p16 as described in the first embodiment. Here, the estimation function 453 estimates the estimated points corresponding to the measurement points p11 to p16 for a plurality of curved cross-sections used for generating the thickened CPR image. That is, the estimation function 453 sets regions for the measurement points p11 to p16 respectively, and when acquiring the luminance information of the set regions, it acquires them respectively from a plurality of curved cross-sections used for generating the thickened CPR image. Then, the estimation function 453 estimates the estimated points corresponding to the measurement points p11 to p16 based on the acquired luminance information.

[0101] The measurement function 454 measures the length of the backbone of the fetus using the measurement points estimated by the estimation function 453. Note that the control function 451 can display a display image showing the estimated points estimated by the estimation function 453, as in the first embodiment.

[0102] As described above, according to the third embodiment, the ultrasonic diagnostic apparatus 10 can perform appropriate measurement even in a thickness-added image based on a curved cross-section.

[0103] (Other Embodiments) In the above-described embodiment, the case where the estimation function 453 performs processing using luminance information for each region of the slice image (the cross-section where the thickness-added image is generated) has been described. However, the embodiment is not limited to this. For example, processing using luminance information may be performed for a three-dimensional region including the measurement point specified by the user. For example, the luminance difference between a plurality of pixels included in the three-dimensional region may be calculated, and the estimated point may be estimated based on the calculated luminance difference.

[0104] Also, in the above-described embodiment, the case where the estimation process is performed using the luminance information of the pixel including the measurement point has been described. However, the embodiment is not limited to this, and any data may be used as long as it is image information. That is, the estimation process may be performed using a reflected wave signal, reflected wave data, B-mode data, or the like.

[0105] Note that the term "processor" used in the above description means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a circuit such as an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The processor realizes its functions by reading and executing a program stored in a memory. Note that instead of storing the program in the memory, the program may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading and executing the program incorporated into the circuit. Note that each processor of the present embodiment is not limited to being configured as a single circuit for each processor, and a plurality of independent circuits may be combined to be configured as one processor to realize its functions.

[0106] Note that each component of each device illustrated in the description of the above embodiment is conceptually functional, and does not necessarily have to be physically configured as illustrated. That is, the specific form of the distribution and integration of each device is not limited to that illustrated, and all or part of it can be functionally or physically distributed and integrated in any unit according to various loads, usage situations, etc. Furthermore, each processing function performed by each device can be realized in whole or in any part by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware by wired logic.

[0107] Also, the method described in the above-described embodiments can be realized by executing a pre-prepared program on a computer such as a personal computer or a workstation. This program can be distributed via a network such as the Internet. Further, this program is recorded on a non-transitory computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, a DVD, a USB memory, and a Flash memory such as an SD card memory, and can also be executed by being read from the non-transitory recording medium by a computer.

[0108] As described above, according to the embodiment, appropriate measurement is enabled in the thickness image.

[0109] Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations of the embodiments can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0110] 10 Ultrasonic diagnostic apparatus 451 Control function 452 Image generation function 453 Estimation function 454 Measurement function

Claims

1. A generation unit that generates a thickness image based on a reflected wave signal of ultrasonic waves transmitted to a subject; An estimation unit that estimates a three-dimensional position of the measurement point based on image information around the measurement point specified on the thickness image; An ultrasonic diagnostic apparatus comprising:

2. The estimation unit sets a region including the measurement point in the thickness image, and estimates the position of the measurement point in the thickness direction based on the luminance information of the pixels included in the region at each position in the thickness direction of the thickness image. The ultrasonic diagnostic apparatus according to claim 1.

3. The estimation unit calculates the luminance difference between the pixels in the region at each position in the thickness direction, and estimates the position of the measurement point in the thickness direction based on the calculated luminance difference. The ultrasonic diagnostic apparatus according to claim 2.

4. The estimation unit estimates the position in the thickness direction where the luminance difference exceeds a threshold value as the position of the measurement point. The ultrasonic diagnostic apparatus according to claim 3.

5. The ultrasonic diagnostic apparatus according to claim 4, further comprising a reception unit that receives a selection operation from a user when there are a plurality of positions in the thickness direction where the luminance difference exceeds a threshold value.

6. The ultrasonic diagnostic apparatus according to any one of claims 1 to 5, further comprising a display control unit that displays a display image showing the three-dimensional position of the measurement point estimated by the estimation unit.

7. The display control unit compares and displays the three-dimensional position of the measurement point estimated by the estimation unit and the position of the measurement point specified on the thickness image. The ultrasonic diagnostic apparatus according to claim 6.

8. The ultrasonic diagnostic apparatus according to claim 6, further comprising a measurement unit that executes a measurement process based on the three-dimensional position of the measurement point estimated by the estimation unit, The display control unit displays the result of the measurement process.

9. The generation unit generates a cross-sectional image or a three-dimensional image including the position of the measurement point estimated by the estimation unit based on the reflected wave signal of the ultrasonic waves, The display control unit displays a display image showing the three-dimensional position of the measurement point on the cross-sectional image or the three-dimensional image. The ultrasonic diagnostic apparatus according to claim 6.

10. Generates a thickness image based on the reflected wave signal of ultrasonic waves transmitted to the subject, Estimates the three-dimensional position of the measurement point based on the image information around the measurement point specified on the thickness image. A method including the following.

11. Generating a thickness image based on a reflected wave signal of ultrasonic waves transmitted to a subject, Estimating a three-dimensional position of a measurement point based on image information around the measurement point specified on the thickness image, A program for causing a computer to execute each process.

Images