JP2013121453A - Ultrasonic diagnostic apparatus and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus and an image processor, capable of performing representation with an actual depth feeling when color-displaying velocity information of a three-dimensional blood flow.SOLUTION: In this ultrasonic diagnostic apparatus, a weighting processing part performs weighting corresponding to a distance from a viewpoint position when generating a three-dimensional image to each piece of power data calculated from each of reflected wave signals of an ultrasonic wave three-dimensionally transmitted to the subject, which are reflected by a fluid included in a subject. A normalization processing part performs prescribed normalization processing for each piece of the weighted power data. A multiplier multiples each piece of velocity data calculated from each of the reflected signals by the power data performed with the normalization processing of the same position. A first rendering processing part performs rendering processing on the velocity data performed with the multiplication processing, and performs coloring based on the velocity data to generate the three-dimensional image.

Description

  Embodiments described herein relate generally to an ultrasonic diagnostic apparatus and an image processing apparatus.

  Conventionally, an ultrasonic diagnostic apparatus transmits an ultrasonic wave from an ultrasonic probe and receives a reflected wave signal reflected from the internal tissue of the subject, thereby obtaining a tomographic image (B-mode image) of the tissue structure in the subject. Is generated and displayed. Furthermore, conventional ultrasound diagnostic devices can identify blood flow information such as blood flow velocity, dispersion, power, etc., by color using the Doppler effect of ultrasound and the range in which blood flow exists in the subject. A color Doppler image to be displayed is generated and displayed.

  In recent years, ultrasonic diagnostic apparatuses that collect three-dimensional volume data have been put to practical use in ultrasonic diagnostic apparatuses. Such an ultrasonic diagnostic apparatus creates a two-dimensional image reflecting three-dimensional information by performing volume rendering on the collected volume data, and displays the created two-dimensional image on a monitor. For example, the ultrasonic diagnostic apparatus generates and displays a B-mode image or a color Doppler image that reflects three-dimensional information.

  In recent years, a monitor that displays a stereoscopically viewable image by displaying multi-parallax images taken from a plurality of viewpoints has been put into practical use, and an observer stereoscopically recognizes the image displayed on the monitor. I was able to do it. However, in the conventional rendering process, it is difficult to express the three-dimensional blood flow velocity information with an actual sense of depth when displaying the color information in color.

JP 2002-136519 A

  The problem to be solved by the present invention is to provide an ultrasonic diagnostic apparatus and an image processing apparatus that can be expressed by an actual sense of depth when color information of three-dimensional blood flow velocity information is displayed.

  The ultrasonic diagnostic apparatus according to the embodiment includes weighting means, normalization means, multiplication means, and first rendering processing means. The weighting means is a three-dimensional image for each power data calculated from each reflected wave signal in which the ultrasonic wave transmitted three-dimensionally to the subject is reflected by the fluid contained in the subject. Is weighted in accordance with the distance from the viewpoint position when generating. The normalizing means performs a predetermined normalization process on each weighted power data. The multiplying unit multiplies each velocity data calculated from each reflected wave signal by the normalized power data at the same position. The first rendering processing unit generates the three-dimensional image by performing rendering processing on the speed data that has been subjected to multiplication processing, and coloring the speed data.

FIG. 1 is a diagram for explaining the overall configuration of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2A is a first diagram for explaining a problem according to the related art. FIG. 2B is a second diagram for explaining a problem according to the related art. FIG. 2C is a third diagram for explaining the problem according to the related art. FIG. 3 is a diagram illustrating an example of the configuration of the image generation unit according to the first embodiment. FIG. 4 is a diagram for explaining processing by the weighting processing unit according to the first embodiment. FIG. 5 is a diagram for explaining an example of processing by the normalization processing unit according to the first embodiment. FIG. 6 is a diagram illustrating an example of a color Doppler image generated by the first rendering processing unit according to the first embodiment. FIG. 7 is a flowchart illustrating a processing procedure performed by the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 8 is a diagram illustrating an example of the configuration of the image generation unit according to the second embodiment. FIG. 9A is a diagram for explaining general blood flow characteristics. FIG. 9B is a diagram for explaining an example of processing by the MIP processing unit according to the second embodiment. FIG. 10 is a flowchart illustrating a processing procedure performed by the ultrasonic diagnostic apparatus according to the second embodiment.

(First embodiment)
First, the configuration of the ultrasonic diagnostic apparatus according to the present embodiment will be described. FIG. 1 is a diagram for explaining a configuration of an ultrasonic diagnostic apparatus 1 according to the present embodiment. As shown in FIG. 1, the ultrasonic diagnostic apparatus 1 according to the first embodiment includes an ultrasonic probe 11, an input apparatus 12, a monitor 13, and an apparatus main body 100.

  The ultrasonic probe 11 includes a plurality of piezoelectric vibrators, and the plurality of piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from a transmission / reception unit 110 included in the apparatus main body 100 described later. The ultrasonic probe 11 receives a reflected wave from the subject P and converts it into an electrical signal. The ultrasonic probe 11 includes a matching layer provided in the piezoelectric vibrator, a backing material that prevents propagation of ultrasonic waves from the piezoelectric vibrator to the rear, and the like. The ultrasonic probe 11 is detachably connected to the apparatus main body 100.

  When ultrasonic waves are transmitted from the ultrasonic probe 11 to the subject P, the transmitted ultrasonic waves are reflected one after another at the discontinuous surface of the acoustic impedance in the body tissue of the subject P, and the ultrasonic probe is used as a reflected wave signal. 11 is received by a plurality of piezoelectric vibrators. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic wave is reflected. Note that the reflected wave signal when the transmitted ultrasonic pulse is reflected on the moving blood flow or the surface of the heart wall depends on the velocity component of the moving body in the ultrasonic transmission direction due to the Doppler effect. And undergoes a frequency shift.

  Here, in the present embodiment, an ultrasonic probe 11 that mechanically swings a plurality of piezoelectric vibrators of a one-dimensional ultrasonic probe and a two-dimensional ultrasonic wave in which a plurality of piezoelectric vibrators are two-dimensionally arranged in a lattice shape. The subject P is scanned three-dimensionally by the ultrasonic probe 11 which is a probe.

  The input device 12 is connected to the device main body 100 and includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, and the like. The input device 12 receives various setting requests from the operator of the ultrasonic diagnostic apparatus 1 and transfers the received various setting requests to the apparatus main body 100. For example, the input device 12 receives a region of interest (ROI) setting request, a color gain setting request, and a viewpoint position setting request when performing volume rendering processing from the operator.

  The monitor 13 displays a GUI (Graphical User Interface) for an operator of the ultrasonic diagnostic apparatus 1 to input various setting requests using the input device 12, and displays an ultrasonic image generated in the apparatus main body 100. Or display. Specifically, the monitor 13 displays in-vivo morphological information and blood flow information as an image based on a video signal input from the image generation unit 130 described later.

  The monitor 13 may be a monitor such as a liquid crystal display (LCD), a cathode ray tube (CRT), plasma, an organic light emitting diode (OLED), and a light emitting diode (LED). The monitor 13 may be a stereoscopic display monitor that allows a viewer to stereoscopically view a multi-parallax image such as a 9-parallax image with the naked eye by using a light beam controller such as a lenticular lens. Further, the monitor 13 may be a stereoscopic display monitor that enables stereoscopic viewing with binocular parallax by displaying a two-parallax image. For example, the two-parallax monitor includes a stereoscopic display monitor that performs stereoscopic display by a shutter method, a device that performs stereoscopic display by a polarizing glasses method, a device that performs stereoscopic display by a parallax barrier method, and the like.

  The apparatus main body 100 is an apparatus that generates an ultrasonic image based on the reflected wave received by the ultrasonic probe 11. As shown in FIG. 1, the apparatus main body 100 includes a transmission / reception unit 110, a signal processing unit 120, an image generation unit 130, an image memory 140, an internal storage unit 150, and a control unit 160.

  The transmission / reception unit 110 includes a trigger generation circuit, a delay circuit, a pulsar circuit, and the like, and supplies a drive signal to the ultrasonic probe 11. The pulsar circuit repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency. The delay circuit also sets the delay time for each piezoelectric vibrator necessary for determining the transmission directivity by focusing the ultrasonic wave generated from the ultrasonic probe 11 into a beam shape, and for each rate pulse generated by the pulser circuit. Give to. The trigger generation circuit applies a drive signal (drive pulse) to the ultrasonic probe 11 at a timing based on the rate pulse. In other words, the delay circuit arbitrarily adjusts the transmission direction from the piezoelectric vibrator surface by changing the delay time given to each rate pulse.

  Note that the transmission / reception unit 110 has a function capable of instantaneously changing a transmission frequency, a transmission drive voltage, and the like in order to execute a predetermined scan sequence based on an instruction from the control unit 160 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.

  The transmission / reception unit 110 includes an amplifier circuit, an A / D converter, an adder, and the like, and performs various processes on the reflected wave signal received by the ultrasonic probe 11 to generate reflected wave data. The amplifier circuit amplifies the reflected wave signal for each channel and performs gain correction processing. The A / D converter performs A / D conversion on the gain-corrected reflected wave signal and gives a delay time necessary for determining reception directivity to the digital data. The adder performs an addition process of the reflected wave signal processed by the A / D converter to generate reflected wave data. By the addition processing of the adder, the reflection component from the direction corresponding to the reception directivity of the reflected wave signal is emphasized.

  The signal processing unit 120 receives reflected wave data, which is a processed reflected wave signal subjected to gain correction processing, A / D conversion processing, and addition processing, from the transmission / reception unit 110. Then, the signal processing unit 120 performs logarithmic amplification, envelope detection processing, and the like, and generates data (B mode data) in which the signal intensity is expressed by brightness.

  Further, the signal processing unit 120 performs frequency analysis on velocity information from the reflected wave data received from the transmission / reception unit 110, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, and moves average velocity, dispersion, power, and the like. Data (Doppler data) obtained by extracting body information for multiple points is generated.

  More specifically, the signal processing unit 120 is a processing unit that can execute a tissue Doppler method (TDI: Tissue Doppler Imaging) and a color Doppler method (CDI: Color Doppler Imaging). That is, the signal processing unit 120 is a processing unit that acquires tissue motion information (tissue motion information) within a scanning range and generates tissue Doppler data for generating a tissue Doppler image indicating tissue dynamics. . In addition, the signal processing unit 120 obtains motion information (blood flow motion information) of blood flow within the scanning range, and generates color Doppler data for generating a color Doppler image indicating the blood flow dynamics. Part.

 Note that the signal processing unit 120 according to the first embodiment can process both two-dimensional reflected wave data and three-dimensional reflected wave data. That is, the signal processing unit 120 according to the first embodiment can generate three-dimensional B-mode data from the three-dimensional reflected wave data. Further, the signal processing unit 120 according to the first embodiment can generate three-dimensional Doppler data from the three-dimensional reflected wave data.

  The image generation unit 130 generates an ultrasonic image from the data generated by the signal processing unit 120. That is, the image generation unit 130 generates a B-mode image in which the intensity of the reflected wave is represented by luminance from the B-mode data generated by the signal processing unit 120. The image generation unit 130 can also generate a three-dimensional B-mode image from the three-dimensional B-mode data generated by the signal processing unit 120.

  Further, the image generation unit 130 generates a color Doppler image as an average velocity image, a dispersed image, a power image, or a combination image representing moving body information from the Doppler data generated by the signal processing unit 120. Note that the image generation unit 130 can also generate a three-dimensional color Doppler image from the three-dimensional Doppler data generated by the signal processing unit 120. The image generation unit 130 can also generate a composite image in which character information, scales, body marks, and the like of various parameters are combined with the ultrasonic image.

  Here, the image generation unit 130 generally converts (scan converts) a scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence of a video format typified by a television or the like, and serves as a display image. Generate an ultrasound image. Specifically, the image generation unit 130 generates an ultrasonic image as a display image by performing coordinate conversion or interpolation processing according to the ultrasonic scanning mode by the ultrasonic probe 11. In addition to the scan conversion, the image generation unit 130 may perform various image processing, such as image processing (smoothing processing) for regenerating an average luminance image using a plurality of image frames after scan conversion, Image processing (edge enhancement processing) using a differential filter is performed in the image.

  The image memory 140 is a memory that stores the ultrasonic image generated by the image generation unit 130. The image memory 140 can also store data generated by the signal processing unit 120. The image memory 140 stores the processing result of the image generation unit 130.

  The internal storage unit 150 stores various data such as a control program for performing ultrasonic transmission / reception, image processing and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), diagnostic protocol, and various body marks. To do. The internal storage unit 150 is also used for storing images stored in the image memory 140 as necessary.

  Furthermore, the internal storage unit 150 is also used for storing various medical images transferred from an external device. Specifically, the internal storage unit 150 stores image data transferred from an external device. For example, the internal storage unit 150 stores image data generated by another ultrasonic diagnostic apparatus. The data stored in the internal storage unit 150 can be transferred to an external peripheral device (external device) via the interface.

  In this embodiment, the image data desired by the operator is transmitted via a storage medium such as a flexible disk (FD), a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto Optical), and a DVD (Digital Versatile Disk). Thus, the present invention is applicable even when stored in the internal storage unit 150. Further, the present embodiment is applicable even when a storage device that stores image data desired by the operator is installed other than the internal storage unit 150.

  The control unit 160 is a control processor (CPU: Central Processing Unit) that realizes a function as an information processing apparatus (computer), and controls the entire processing of the ultrasonic diagnostic apparatus 1. Specifically, the control unit 160 is based on various setting requests input from the operator via the input device 12, various control programs and various data read from the internal storage unit 150, and the transmission / reception unit 110, signal processing The processing of the unit 120 and the image generation unit 130 is controlled. The control unit 160 also includes an ultrasonic image stored in the image memory 140, various images stored in the internal storage unit 150, a GUI for performing processing by the image generation unit 130, a processing result of the image generation unit 130, and the like. Is displayed on the monitor 13. Further, the control unit 160 controls the image data received from the operator via the input device 12 to be transferred from the external device to the internal storage unit 150 via the network and the interface.

  The overall configuration of the ultrasonic diagnostic apparatus according to the first embodiment has been described above. With such a configuration, the ultrasonic diagnostic apparatus according to the first embodiment performs an actual display when color information of three-dimensional blood flow velocity information is displayed by the processing of the image generation unit 130 described in detail below. An ultrasonic diagnostic apparatus and an image processing apparatus that can be expressed with a sense of depth can be provided.

  Here, first, it will be described with reference to FIGS. 2A to 2C that it is difficult to express the velocity information of the three-dimensional blood flow in color in the conventional technique with an actual sense of depth. FIG. 2A is a first diagram for explaining a problem according to the related art. In FIG. 2A, when the blood flow velocity is displayed in color, the blood flow flowing in the direction approaching the ultrasonic probe is shown in red, and the blood flow flowing in the direction away from the ultrasonic probe is shown in blue. A three-dimensional color Doppler image expressed with higher luminance as the flow velocity increases is shown. For example, in the prior art, since the brightness of the color is changed depending on the blood flow velocity, as shown by the arrow 21 blood flow and the arrow 22 blood flow in FIG. It is located in front and it is not clear which blood flow is located behind, and the sense of depth is not expressed.

  FIG. 2B is a second diagram for explaining a problem according to the related art. In FIG. 2B, the figure of ADF (Advanced Dynamic Flow) which colored the power image of the blood flow in the blood flow direction is shown. For example, in the prior art, as shown in FIG. 2B, since the color is colored in the direction of blood flow, the color of the same color system is not shaded and the depth of the color image is not expressed.

  FIG. 2C is a third diagram for explaining the problem according to the related art. In FIG. 2C, two blood flows having the same blood flow velocity displayed in color by the prior art are shown. For example, in the prior art, when the blood flow velocity is approximately the same, as shown in FIG. 2C, the sense of depth of the image is not expressed, and therefore, the positional relationship between the blood flow 23 and the blood flow 24 is relative to each other. I can't figure out what it is.

  As described above, in the prior art, even when a color image is displayed three-dimensionally and viewed stereoscopically, there is no color change in the depth direction, so that a sense of depth cannot be expressed, so-called writing The splitting phenomenon will occur. For example, this also occurs when a monitor that displays a stereoscopically viewable image is displayed by displaying multi-parallax images taken from a plurality of viewpoints. Referring to FIG. 2C, the cracking phenomenon will be described with reference to FIG. 2C. As a positional relationship between the blood flow 23 and the blood flow 24, a part where the blood flow 23 is in front of the blood flow 24 and a part in the back are mixed. Despite being present, the blood flow 23 and the blood flow 24 appear to be located on the same plane or on different planes.

  Therefore, in the present embodiment, an ultrasonic diagnostic apparatus capable of expressing the three-dimensional blood flow velocity information with an actual sense of depth when performing color display of the three-dimensional blood flow velocity information by the processing of the image generation unit 130 described in detail below. And an image processing apparatus can be provided.

  FIG. 3 is a diagram illustrating an example of the configuration of the image generation unit 130 according to the first embodiment. As illustrated in FIG. 3, the image generation unit 130 includes a rendering processing unit 131. As illustrated in FIG. 3, the rendering processing unit 131 includes a weighting processing unit 131a, a normalization processing unit 131b, a multiplier 131c, and a first rendering processing unit 131d.

  The weighting processing unit 131a transmits ultrasonic waves three-dimensionally to the subject, and three-dimensionally applies to each power data calculated from each reflected wave signal reflected by the fluid contained in the subject. Weighting is performed according to the distance from the viewpoint position when generating an image. Specifically, as shown in FIG. 3, the weighting processing unit 131a weights the power data in the depth direction by weighting the power data calculated by the signal processing unit 120 according to the distance from the viewpoint position. Reflect the information.

  FIG. 4 is a diagram for explaining processing by the weighting processing unit 131a according to the first embodiment. FIG. 4 shows three-dimensional data 200 acquired by three-dimensionally scanning a subject with ultrasonic waves. A point 30 in FIG. 4 indicates a viewpoint position when generating a three-dimensional image. Further, points 31 and 32 in FIG. 4 indicate sample points that are positions where the reflected wave signals are obtained.

  For example, the weighting processing unit 131a weights the power data of the sample point 31 according to the distance 31a. In addition, the weighting processing unit 131a weights the power data of the sample point 32 according to the distance 32a. Similarly, the weighting processing unit 131a weights the power data of all sample points included in the three-dimensional data 200 according to the distance from the viewpoint position 30.

  Returning to FIG. 3, the normalization processing unit 131b performs arbitrary normalization processing on each weighted power data. FIG. 5 is a diagram for explaining an example of processing performed by the normalization processing unit 131b according to the first embodiment. FIG. 5 shows normalization when the minimum value of the distance from the viewpoint position is 0 and the maximum value is 1. For example, the normalization processing unit 131b performs linear conversion on each weighted power data as indicated by a straight line 33 in FIG. Or the normalization process part 131b performs the conversion process which becomes S character shape with respect to each power data by which weighting was performed, as shown in the curve 34 of FIG.

  Returning to FIG. 3, the multiplier 131 c multiplies each velocity data calculated from each reflected wave signal by power data that has been normalized by each reflected wave signal. Specifically, as shown in FIG. 3, the multiplier 131c superimposes the power data of the same sample point normalized by the normalization processing unit 131b on the speed data calculated by the signal processing unit 120.

  For example, the multiplier 131c superimposes the power data after normalization of the sample point 31 on the velocity data of the sample point 31 shown in FIG. Similarly, the multiplier 131c superimposes the normalized power data on the velocity data for all sample points included in the three-dimensional data 200, respectively.

  The first rendering processing unit 131d generates a three-dimensional image that is colored based on the speed data multiplied by the power data. Specifically, as illustrated in FIG. 3, the first rendering processing unit 131 d performs a rendering process using the speed data multiplied by the power data by the multiplier 131 c, thereby generating a color Doppler image. Here, the first rendering processor 131d performs MIP (Maximum Intensity Projection) processing or volume rendering processing as rendering processing.

  Note that MIP processing is a rendering method that uses the maximum value for each value on the line of sight emitted radially from the viewpoint position in three-dimensional data. Volume rendering processing is based on the calculation of opacity and shading value based on each voxel value in consideration of attenuation and shading when light rays from the viewpoint pass through each voxel. Is a rendering method that continuously performs the multiplication operation in the projection direction from the viewpoint to generate a two-dimensional image of the projection plane reflecting the three-dimensional information.

  That is, the first rendering processing unit 131d executes one of the processes of the following formula (1) or formula (2). In the following expression, V (d) represents speed data, P (d) represents power data, Wt (d) represents weighting, and d represents depth. VR represents volume rendering processing, and MIP represents MIP processing.

[V (d) × | P (d) × Wt (d) |] _VR (1)

[V (d) × | P (d) × Wt (d) |] _MIP (2)

  As shown in Expression (1), the first rendering processing unit 131d applies “P (d) × Wt (d)” obtained by multiplying the power data “P (d)” by the weight “Wt (d)”. The color Doppler data [V (d) × | P (d) × Wt (d) obtained by multiplying the velocity data “V (d)” by the normalized “| P (d) × Wt (d) |” ) Perform volume rendering processing for |].

  Alternatively, as shown in the equation (2), the first rendering processing unit 131d has “P (d) × Wt (d)” obtained by multiplying the power data “P (d)” by the weight “Wt (d)”. Color Doppler data [V (d) × | P (d) × Wt] obtained by multiplying velocity data “V (d)” by “| P (d) × Wt (d) |” normalized to (D) MIP processing is executed for |].

  Here, the first rendering processing unit 131d performs the rendering process and performs coloring based on the speed data on which the power data reflecting the information in the depth direction is superimposed. Here, the first rendering processing unit 131d performs coloring by using the speed map of the speed data reflecting the depth information. That is, the first rendering processing unit 131d performs coloring using a color assigned in advance to the value of the speed data on which the power data is superimposed. For example, the first rendering processing unit 131d performs coloring using a speed map that is expressed brighter as the distance from the viewpoint position is shorter and darker as the distance from the viewpoint position is longer.

  FIG. 6 is a diagram illustrating an example of a color Doppler image generated by the first rendering processing unit 131d according to the first embodiment. FIG. 6 shows a case where the same color Doppler image as in FIG. 2C is generated using this method. As shown in FIG. 6, the color Doppler image generated by the first rendering processing unit 131 d has an improved sense of depth in the image, and the positional relationship between the blood flow 23 and the blood flow 24 can be grasped. For example, the right side of FIG. 6 represents that the blood flow 24 is positioned in front of the blood flow 23. On the other hand, the left side of FIG. 6 represents that the blood flow 24 is located behind the blood flow 23.

  As shown in FIG. 3, the first rendering processing unit 131d can perform rendering processing using tissue data and generate a three-dimensional B-mode image. That is, the first rendering processing unit 131d can display a three-dimensional color Doppler image that reflects the information in the depth direction described above on a three-dimensional B-mode image. The generation of the color Doppler image reflecting the information in the depth direction described above can be arbitrarily executed by the operator of the ultrasonic diagnostic apparatus 1. For example, the depth addition mode is set as a mode for generating a color Doppler image reflecting information in the depth direction, and the operator can freely switch the mode by turning the depth addition mode on and off.

  Next, processing of the ultrasonic diagnostic apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 7 is a flowchart illustrating a processing procedure performed by the ultrasound diagnostic apparatus 1 according to the first embodiment. FIG. 7 shows processing after color Doppler data such as speed data and power data is calculated by the signal processing unit 120.

  As shown in FIG. 7, in the ultrasonic diagnostic apparatus 1 according to the first embodiment, when the depth addition mode is ON (Yes in step S101), the weighting processing unit 131a is calculated by the signal processing unit 120. A weighting process is executed on the power data for each sample point in accordance with the distance from the viewpoint position when generating a three-dimensional color Doppler image (step S102).

  Then, the normalization processing unit 131b performs normalization processing on the power data for each sample point on which the weighting processing is executed by the weighting processing unit 131a (step S103). Thereafter, the multiplier 131c multiplies the speed data for each sample point calculated by the signal processing unit 120 by the power data after the normalization process (step S104).

  Then, the first rendering processing unit 131d performs volume rendering processing and coloring processing using the speed data multiplied by the power data (step S105), and ends the processing. When the depth addition mode is OFF (No at Step S101), the ultrasound diagnostic apparatus 1 executes volume rendering processing and coloring processing using speed data that is not multiplied by power data (Step S106).

  As described above, according to the first embodiment, the weighting processing unit 131a reflects the reflected wave signal in which the ultrasonic wave transmitted three-dimensionally to the subject is reflected by the fluid contained in the subject. Each power data calculated from each is weighted according to the distance from the viewpoint position when generating a three-dimensional image, which is a two-dimensional image reflecting three-dimensional information. Then, the normalization processing unit 131b performs a predetermined normalization process on each weighted power data. The multiplier 131c multiplies each velocity data calculated from each reflected wave signal by the normalized power data at the same position. Then, the first rendering processing unit 131d performs a rendering process on the speed data that has been multiplied, and generates a three-dimensional image by coloring the speed data. Accordingly, the ultrasonic diagnostic apparatus 1 according to the first embodiment can reflect information in the depth direction on the three-dimensional color image, and when displaying the three-dimensional blood flow velocity information in color, Enables expression with a sense of depth.

(Second Embodiment)
In the first embodiment described above, the case where the volume rendering process or the MIP process is executed after the speed data and the power data are superimposed by the multiplier 131c has been described. In the second embodiment, a case will be described in which volume rendering processing or MIP processing is performed on each of the speed data and the power data before the multiplier 131c superimposes the speed data and the power data.

  First, an example of the configuration of the image generation unit 130a according to the second embodiment will be described. FIG. 8 is a diagram illustrating an example of the configuration of the image generation unit 130a according to the second embodiment. As illustrated in FIG. 8, the image generation unit 130a newly includes a second rendering processing unit 132a, a MIP processing unit 132b, and a coloring processing unit 132c, as compared with the image generation unit 130 according to the first embodiment. There are different points. Hereinafter, these will be mainly described.

  Here, the outline of the second embodiment will be described first. In the second embodiment, a case will be described in which the depth perception of a color image is improved in consideration of blood flow characteristics in a blood vessel. FIG. 9A is a diagram for explaining general blood flow characteristics. In FIG. 9A, the flow rate of one blood vessel and blood in the blood vessel is shown. Arrows 35 and 36 indicate the blood flow rate in the blood vessel. That is, the longer the arrow, the faster the flow rate.

  As shown in FIG. 9A, the flow rate of blood in a blood vessel is generally faster at the center of the blood vessel and slower as it is closer to the blood vessel wall. This is because friction between the blood and the blood vessel wall occurs when the blood flows in the blood vessel. Then, when diagnosing the blood flow velocity and hemodynamics using a color Doppler image, a doctor or the like makes a diagnosis by using an image of a portion having a high flow velocity at the center of the blood vessel.

  Therefore, in the second embodiment, a case will be described in which the depth sensation of a color image using velocity data of a portion having a high flow velocity in a blood vessel is improved. The second rendering processing unit 132a performs the rendering process using the power data weighted according to the distance from the viewpoint position. Specifically, the second rendering processing unit 132a performs volume rendering processing or MIP processing on the power data weighted by the weighting processing unit 131a.

  The normalization processing unit 131b performs the normalization process on the value after the rendering process calculated by the second rendering processing unit 132a, although the processing content is the same as in the first embodiment.

  The MIP processing unit 132b performs a rendering process using the speed data. Specifically, the MIP processing unit 132b performs MIP processing using the speed data. FIG. 9B is a diagram for explaining an example of processing by the MIP processing unit 132b according to the second embodiment. FIG. 9B shows three-dimensional data 200 acquired by three-dimensionally scanning a subject with ultrasonic waves. Moreover, the arrow of FIG. 9B shows a gaze.

  For example, as illustrated in FIG. 9B, the MIP processing unit 132b performs the MIP processing for each arbitrary range on the line of sight. As an example, the MIP processing unit 132b executes MIP processing using the velocity data of the sample points included in the range 37a shown in FIG. 9B. Further, the MIP processing unit 132b executes the MIP process using the velocity data of the sample points included in the range 37b on the line of sight. Similarly, the MIP processing unit 132b performs MIP processing for each arbitrary range on the line of sight. As a result, speed data having a high flow speed on the line of sight is extracted. The range on the line of sight is arbitrarily set by the operator.

  Returning to FIG. 8, the multiplier 131c multiplies each speed data subjected to the MIP process by the power data subjected to the normalization process. That is, the value after the rendering process of the speed data is multiplied by the value after the rendering process of the power data reflecting the information in the depth direction. The coloring processing unit 132c performs coloring processing based on the value after processing by the multiplier 131c.

  The rendering processing unit 132 according to the second embodiment described above executes one of the processes of the following formula (3) or formula (4).

[V (d)] _MIP × | [P (d) × Wt (d)] _MIP | (3)

[V (d)] _MIP × | [P (d) × Wt (d)] _VR | (4)

That is, as shown in Expression (3), the rendering processing unit 132 multiplies the power data “P (d)” by the weight “Wt (d)” and performs MIP processing on the value after the multiplication “[ P (d) × Wt (d)] _MIP ”. Then, the rendering processing unit 132 normalizes the value after MIP processing “| [P (d) × Wt (d)] _MIP |”, and uses the normalized value as velocity data “[V (d )] _MIP ".

Alternatively, as shown in Expression (4), the rendering processing unit 132 multiplies the power data “P (d)” by the weight “Wt (d)” and performs VR processing on the value after the multiplication “[ P (d) × Wt (d)] _VR ”. Then, the rendering processing unit 132 normalizes “| [P (d) × Wt (d)] _VR |” after the VR processing, and uses the normalized value as velocity data “[V (d )] _MIP ".

  Next, processing of the ultrasonic diagnostic apparatus 1 according to the second embodiment will be described with reference to FIG. FIG. 10 is a flowchart illustrating a processing procedure performed by the ultrasonic diagnostic apparatus 1 according to the second embodiment. Note that FIG. 10 shows processing after color Doppler data such as speed data and power data is calculated by the signal processing unit 120.

  As shown in FIG. 10, in the ultrasonic diagnostic apparatus 1 according to the second embodiment, when the depth addition mode is ON (Yes at Step S201), the weighting processing unit 131a is calculated by the signal processing unit 120. A weighting process is executed on the power data for each sample point in accordance with the distance from the viewpoint position when generating a three-dimensional color Doppler image (step S202).

  Then, the second rendering processing unit 132a performs MIP processing or volume rendering processing on the power data on which the weighting processing has been executed (step S203). Thereafter, the normalization processing unit 131b performs normalization processing on the power data after the MIP processing or volume rendering processing by the second rendering processing unit 132a (step S204).

  Further, the MIP processing unit 132b performs MIP processing on the velocity data for each sample point calculated by the signal processing unit 120 (step S205). Thereafter, the multiplier 131c multiplies the speed data after the MIP process by the power data after the normalization process (step S206).

  Then, the coloring processing unit 132c executes coloring processing based on the speed data on which the power data is superimposed (Step S207), and ends the processing. When the depth addition mode is OFF (No at Step S201), the ultrasound diagnostic apparatus 1 performs volume rendering processing and coloring processing using speed data that is not multiplied by power data (Step S208). In the above-described processing procedure, the case where the MIP processing of the speed data is executed after the normalization processing has been described. However, the embodiment is not limited to this, and the MIP processing for the speed data is performed first. Alternatively, the processing for power data and the processing for speed data may be performed in parallel.

  As described above, according to the second embodiment, the second rendering processing unit 132a performs volume rendering processing or MIP processing on each power data weighted according to the distance from the viewpoint position. Then, the MIP processing unit 132b performs MIP processing on the speed data. Then, the normalization processing unit 131b performs arbitrary normalization processing on each power data subjected to MIP processing or volume rendering processing as rendering processing. Then, the multiplier 131c multiplies each speed data subjected to the MIP process as the rendering process by the power data that has been normalized at the same position. Therefore, the ultrasonic diagnostic apparatus 1 according to the second embodiment can extract speed data having a high flow velocity in the blood in the same blood vessel, and a color image using the speed data of a portion having a high flow velocity in the blood vessel. It makes it possible to improve the sense of depth.

(Third embodiment)
Although the first and second embodiments have been described so far, the present invention may be implemented in various different forms other than the first and second embodiments described above.

  In the first and second embodiments described above, the case where a color image is generated by the ultrasonic diagnostic apparatus has been described. However, the embodiment is not limited to this. For example, an image processing apparatus such as a workstation may generate a color image. In such a case, the image processing apparatus includes the image generation unit 130 and stores the three-dimensional data collected by the ultrasonic diagnostic apparatus (for example, the ultrasonic diagnostic apparatus, the image storage apparatus, the storage apparatus included in the own apparatus, etc.) ) And a color image is generated using the read three-dimensional data. Alternatively, a medical image diagnostic apparatus (for example, an X-ray CT apparatus or an MRI apparatus) other than the ultrasonic diagnostic apparatus includes the image generation unit 130 and generates a color image from three-dimensional data collected by the ultrasonic diagnostic apparatus. There may be.

  As described above, according to the first embodiment, the second embodiment, and the third embodiment, the ultrasonic diagnostic apparatus and the image processing apparatus of the present embodiment improve the sense of depth of a three-dimensional color image. Make it possible.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit 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 the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Ultrasonic diagnostic apparatus 130 Image generation part 131 Rendering process part 131a Weighting process part 131b Normalization process part 131c Multiplier 131d 1st rendering process part

Claims (3)

When generating a three-dimensional image for each power data calculated from each reflected wave signal in which an ultrasonic wave transmitted three-dimensionally to a subject is reflected by a fluid contained in the subject Weighting means for weighting according to the distance from the viewpoint position;
Normalization means for performing a predetermined normalization process on each weighted power data;
Multiplying means for multiplying each velocity data calculated from each of the reflected wave signals by normalized power data at the same position;
A first rendering processing means for generating the three-dimensional image by performing rendering processing on the multiplied speed data and coloring the speed data;
An ultrasonic diagnostic apparatus comprising: A second rendering processing unit that performs rendering processing on each of the power data weighted according to the speed data and the distance from the viewpoint position;
The normalization means performs a predetermined normalization process on each power data subjected to the maximum value projection process or the volume rendering process as the rendering process,
The ultrasonic diagnostic apparatus according to claim 1, wherein the multiplication unit multiplies each velocity data subjected to the maximum value projection processing as the rendering processing by power data that has been normalized at the same position. When generating a three-dimensional image for each power data calculated from each reflected wave signal in which an ultrasonic wave transmitted three-dimensionally to a subject is reflected by a fluid contained in the subject Weighting means for weighting according to the distance from the viewpoint position;
Normalization means for performing a predetermined normalization process on each weighted power data;
Multiplying means for multiplying each velocity data calculated from each of the reflected wave signals by normalized power data at the same position;
A first rendering processing means for generating the three-dimensional image by performing rendering processing on the multiplied speed data and coloring the speed data;
An image processing apparatus comprising:

Images