Blood flow image display device, blood flow image display method, and program

Abstract

To preferably adjust brightness of a blood flow image without changing a display lower limit threshold of power of a blood flow signal relatively to a power value of the blood flow signal.SOLUTION: A blood flow image display device 100 includes change means 14 that changes a color gain of a blood flow signal and a power cut threshold used in cutting a brightness of a pixel with a power value of the blood flow signal less than a predetermined value when a blood flow image is generated and displayed in a display part 25. The blood flow image display device includes, as change means, a parameter input part 15a that inputs any parameter related to the blood flow signal, and a parameter application part 15b that applies the parameter input in the parameter input part to processing on the blood flow signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a blood flow image display device, a blood flow image display method, and a program. [Background technology]

[0002] Blood flow image display devices that display blood flow images are widely used in medical settings, etc. Blood flow image display devices create blood flow images by combining a tomographic image of a blood vessel with a power Doppler image in which the blood flow is colored. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-289235 Summary of the Invention [Problem to be solved by the invention]

[0004] As will be explained below, there is a demand for the prior art to suitably adjust the brightness of a blood flow image.

[0005] For example, blood flow image display devices are frequently required to brighten the brightness of a blood flow image to make areas that appear to be lesions easier to see, or conversely, to darken the brightness of a blood flow image to cut the brightness of areas that appear to be background noise. Thus, blood flow image display devices are required to adjust the brightness of a blood flow image. The brightness of a blood flow image is related to the color gain of the blood flow signal and the power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value.

[0006] Here, the principle of adjusting the brightness of a blood flow image in the conventional technology will be described with reference to Figs. 10 to 12. Fig. 10 is an explanatory diagram of the operation of the conventional technology. In Fig. 10, the horizontal axis represents the depth (reception time) of the blood flow signal in the living body, and the vertical axis represents the power of the blood flow signal. Fig. 11 is an explanatory diagram of the change in brightness of a blood flow image and the problems in the conventional technology. Fig. 12 is an explanatory diagram of the change in brightness of a blood flow image containing noise in the conventional technology and the problems.

[0007] In the example shown in Figure 10, the color gain of the blood flow signal 61 is increased or decreased to increase or decrease the power of the blood flow signal 61 (arrow 161). The excess blood flow signal 161a shown in Figure 10 is a region that is likely to be displayed as excess blood flow when a blood flow image is displayed, that is, a region that is likely to be displayed outside the blood vessels. In conventional technology, the power value of the blood flow signal 61 is calculated based on the color gain of the blood flow signal 61, and the brightness of pixels whose power value of this blood flow signal 61 is less than a power cut threshold 63 is cut to 0, and a blood flow image 271 (Figure 11) is created and displayed on a display unit.

[0008] When a user such as a doctor views a blood flow image 271 (FIG. 11) and wants to display the blood flow image darker, the user performs an operation to decrease the color gain. In response to this operation, the blood flow image display device of the prior art moves (attenuates) the blood flow signal 61 downward. The blood flow image display device of the prior art then displays a blood flow image 272 (FIG. 11). However, in this case, the lower display threshold of the power of the blood flow signal becomes relatively higher in the blood flow image 272 (FIG. 11) than the power value of the blood flow signal, which causes a problem that weak blood flow portions are not displayed. As a result, the user cannot clearly see the weak blood flow portions.

[0009] Furthermore, when a user views the blood flow image 271 (FIG. 11) and wishes to display the blood flow image brighter, the user performs an operation to increase the color gain. In response to this operation, the blood flow image display device of the prior art shifts (amplifies) the blood flow signal 61 upward. The blood flow image display device of the prior art then displays the blood flow image 273 (FIG. 11). However, in this case, the lower display threshold of the power of the blood flow signal rises relative to the power value of the blood flow signal in the blood flow image 273 (FIG. 11), which presents a problem in that a portion of the blood flow, corresponding to the excess blood flow signal 161a in FIG. 10, is displayed outside the blood vessels. As a result, the blood flow image display device cannot correctly display the blood flow portion within the blood vessels.

[0010] Furthermore, when a blood flow 283 and noise 284 (clutter noise) are included, as in the blood flow image 281 shown in FIG. 12, the user performs an operation to reduce the color gain in order to cut out the noise 284. In response to this operation, the blood flow image display device of the prior art moves (attenuates) the blood flow signal 61 downward. The blood flow image display device of the prior art then creates a blood flow image 282 (FIG. 12) based on the reduced color gain. At this time, the blood flow image display device cuts out the noise 284 in the blood flow image 282 (FIG. 12) by reducing the color gain. However, in the blood flow image 282 (FIG. 12), as the color gain decreases, the lower threshold for displaying the power of the blood flow signal increases relative to the power value of the blood flow signal, resulting in a problem in that most of the blood flow 283 is cut out. This makes it difficult for the user to clearly see the blood flow portion.

[0011] The present invention has been made in consideration of the problems of the above-mentioned conventional technology, and an object of the present invention is to provide a blood flow image display device, a blood flow image display method, and a program that suitably adjust the brightness of a blood flow image without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal. [Means for solving the problem]

[0012] The above-mentioned problems of the present invention can be solved by the following means.

[0013] (1) A blood flow image display device that, when generating a blood flow image and displaying it on a display unit, is equipped with a change means for changing both the color gain of the blood flow signal and a power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value.

[0014] (2) The blood flow image display device described in (1) above, comprising, as the change means, a parameter input unit for inputting any parameter related to the blood flow signal, and a parameter application unit for applying the parameter inputted by the parameter input unit to processing of the blood flow signal.

[0015] (3) The blood flow image display device according to (2) above, further comprising: a tomographic image creation unit that creates a tomographic image based on the blood flow signal; a blood flow signal analysis unit that analyzes the blood flow signal; a power image creation unit that creates a power image representing the blood flow that reflects the blood flow signal to which the parameter has been applied by the parameter application unit; an image synthesis unit that synthesizes the tomographic image and the power image to create a composite image; and a display control unit that selectively displays the tomographic image or the composite image.

[0016] (4) The blood flow image display device according to (1) above, further comprising a single operation unit for changing both the color gain and the power cut threshold.

[0017] (5) The blood flow image display device according to (4), wherein the operation unit is capable of changing only the color gain.

[0018] (6) A blood flow image display device according to (4) above, which is capable of selecting a first operation pattern and a second operation pattern, wherein the first operation pattern is a pattern in which both the color gain and the power cut threshold in the operation unit are changed in accordance with changes in parameters operated by the operation unit, and the second operation pattern is a pattern in which both the color gain and the power cut threshold inside the device are changed.

[0019] (7) A blood flow image display device as described in (4) above, wherein the operation pattern is set to a first operation pattern, and the first operation pattern is a pattern in which both the color gain and the power cut threshold in the operation unit are changed in accordance with changes in parameters operated in the operation unit.

[0020] (8) A blood flow image display device as described in (4) above, wherein the operation pattern is set to a second operation pattern, and the second operation pattern is a pattern that changes both the color gain and the power cut threshold value inside the device in accordance with changes in parameters operated by the operation unit.

[0021] (9) The blood flow image display device according to (4), wherein the operation unit has a first setting means for changing both the color gain and the power cut threshold.

[0022] (10) The blood flow image display device described in (9) above, wherein the operation unit specifies a first parameter to be operated by the first setting means, and changes the color gain and the power cut threshold according to the value of the first parameter.

[0023] (11) The blood flow image display device described in (10) above, wherein the operation unit has a second setting means for changing only a second parameter representing the color gain, and when an operation pattern for changing both the color gain and the power cut threshold within the device is executed, the color gain within the device is the combined value of the first parameter and the second parameter.

[0024] (12) The blood flow image display device described in (11) above, wherein the operation unit has a third setting means for changing only a third parameter representing the power cut threshold, and when an operation pattern for changing both the color gain and the power cut threshold within the device is executed, the power cut threshold within the device is the combined value of the first parameter and the third parameter.

[0025] (13) The blood flow image display device according to (12), wherein the operation unit changes the second parameter and the third parameter in conjunction with each other by the first setting means.

[0026] (14) The blood flow image display device according to (1) above, wherein the power cut threshold, which is changed together with the color gain, takes a value that varies depending on velocity and changes at the same ratio as the color gain.

[0027] (15) The blood flow image display device described in (1) above, wherein the changing means sets the power cut threshold low for low-velocity signal components of the blood flow signal and sets the power cut threshold high for high-velocity signal components of the blood flow signal.

[0028] (16) A blood flow image display device as described in (15) above, wherein the power cut threshold takes a different value for each velocity value of the blood flow signal, and the changing means changes the power cut threshold for each velocity value at the same ratio as the change in the color gain.

[0029] (17) A blood flow image display device as described in (1) above, wherein the power cut threshold is used to determine whether or not to create a composite image as the blood flow image by combining a tomographic image created based on the blood flow signal with a power Doppler image that displays blood flow in color according to the power value of the blood flow signal.

[0030] (18) The blood flow image display device described in (17) above, wherein the decision on whether to synthesize is made by determining whether to display the tomographic image or to superimpose the power Doppler image on the tomographic image for each pixel.

[0031] (19) A blood flow image display method, comprising a step of changing both the color gain of the blood flow signal and a power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value when generating a blood flow image and displaying it on a display unit.

[0032] (20) A program for causing a computer having a memory unit to execute a change procedure for changing both the color gain of a blood flow signal and a power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value when generating a blood flow image and displaying it on a display unit. [Effects of the Invention]

[0033] According to the present invention, the brightness of a blood flow image can be suitably adjusted without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a configuration diagram of a blood flow image display device according to an embodiment. [Figure 2] 10A and 10B are diagrams illustrating the operation of the blood flow image display device according to the embodiment. [Figure 3A] FIG. 1 is an explanatory diagram (1) of an example of changes in blood flow signals and power cut thresholds. [Figure 3B] FIG. 10 is an explanatory diagram (2) of an example of changes in the blood flow signal and the power cut threshold. [Figure 4] 10A and 10B are explanatory diagrams illustrating changes in brightness of a blood flow image in the blood flow image display device according to the embodiment. [Figure 5] 10A and 10B are explanatory diagrams illustrating changes in brightness of a blood flow image including noise in the blood flow image display device according to the embodiment. [Figure 6] FIG. 1 is an explanatory diagram of the operation unit. [Figure 7] FIG. 2 is an explanatory diagram of the operation unit. [Figure 8A] 1 is a diagram (1) illustrating the relationship between blood flow velocity and power cut threshold. [Figure 8B] FIG. 2 is an explanatory diagram (2) of the relationship between blood flow velocity and power cut threshold. [Figure 9] FIG. 10 is an explanatory diagram of how a composite image (blood flow image) is created. [Figure 10] FIG. 1 is an explanatory diagram of the operation of the prior art. [Figure 11]FIG. 1 is an explanatory diagram (1) of changes in brightness of blood flow images and problems in the prior art. [Figure 12] FIG. 10 is an explanatory diagram (2) of the change in brightness of a blood flow image containing noise in the prior art and the problems involved. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that each drawing is merely a schematic illustration to allow a sufficient understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. Furthermore, in each drawing, common or similar components are designated by the same reference numerals, and redundant explanations thereof will be omitted.

[0036] <Configuration of blood flow image display device> The configuration of a blood flow image display device 100 according to this embodiment will be described below with reference to Fig. 1. Fig. 1 is a configuration diagram of the blood flow image display device 100. In this embodiment, the blood flow image display device 100 is configured as an ultrasonic blood flow imaging device (ultrasound diagnostic device) that creates tomographic images and blood flow images based on ultrasonic echo signals.

[0037] As shown in FIG. 1, the blood flow image display device 100 according to this embodiment includes a control unit 10, an electronic scanning unit 11, a tomographic image creation unit 12, a blood flow signal analysis unit 13, a changing means 14, a power image creation unit 16, an image synthesis unit 17, a display control unit 18, a memory unit 20, and a display unit 25.

[0038] The control unit 10 controls the overall operation of the blood flow image display device 100. The electronic scanning unit 11 acquires an ultrasonic echo signal 31 from the probe 30 and outputs it to the tomographic image creation unit 12 and the blood flow signal analysis unit 13. The electronic scanning unit 11 also outputs a trigger signal, which is the starting point of the reception time of the ultrasonic echo signal 31, to the blood flow signal analysis unit 13.

[0039] The tomographic image creation unit 12 creates a tomographic image based on the ultrasonic echo signal 31 and outputs it to the image synthesis unit 17 and the display control unit 18. In this embodiment, it is assumed that a B-mode image 91 (FIG. 9) obtained by converting the amplitude of the echo signal into a brightness value is acquired as the tomographic image. The blood flow signal analysis unit 13 analyzes the ultrasonic echo signal 31, which is a blood flow signal.

[0040] The changing means 14 changes both the color gain of the blood flow signal and a power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value to 0, and changes the power cut threshold so that it is the same value relative to the power value of the blood flow signal. The changing means 14 includes a parameter input unit 15a and a parameter application unit 15b. The parameter input unit 15a inputs any parameter related to the blood flow signal. The parameter input unit 15a is electrically connected to the operation unit 40 via wire or wireless and acquires parameters such as power brightness 41, color gain 42, and power cut threshold 43 from the operation unit 40. The power brightness 41 is a parameter that adjusts the brightness of the blood flow portion of the power image created by the power image creation unit 16. The color gain 42 is a parameter that adjusts the degree of amplification (gain) of the blood flow signal. The power cut threshold 43 is a parameter used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value and is the lower limit threshold for displaying the power of the blood flow signal. The configuration of the operation unit 40 will be described later with reference to FIGS.

[0041] The parameter input unit 15a outputs the parameters acquired from the operation unit 40 to the image synthesis unit 17. The parameter application unit 15b applies the parameters input by the parameter input unit 15a to processing of the blood flow signal.

[0042] The power image creating unit 16 creates a power image. The power image is an image representing the blood flow that reflects the blood flow signal 61 to which parameters have been applied by the parameter applying unit 15b. In this embodiment, it is assumed that a power Doppler image 92 (FIG. 9) in which the blood flow is colored is created as the power image.

[0043] The image synthesis unit 17 synthesizes the tomographic image (B-mode image 91 (FIG. 9)) created by the tomographic image creation unit 12 and the power image (power Doppler image 92 (FIG. 9)) created by the power image creation unit 16 to create a synthesized image 93 (FIG. 9) as a blood flow image. The image synthesis unit 17 creates the synthesized image 93 (FIG. 9) by receiving parameters output from the parameter input unit 15a.

[0044] The display control unit 18 selectively displays a tomographic image (B-mode image 91 (FIG. 9)) and a composite image 93 (FIG. 9) on the display unit 25. When the composite image 93 (FIG. 9) has not been created, the display control unit 18 displays the B-mode image 91 (FIG. 9) on the display unit 25. When the composite image 93 (FIG. 9) has been created, the display control unit 18 displays the composite image 93 (FIG. 9) on the display unit 25.

[0045] The storage unit 20 stores various programs and data. In this embodiment, a program 51 stored in a storage medium 50 is installed in the storage unit 20 as the program 21. As a result, the blood flow image display device 100 has a configuration having functional means, for example, as shown in FIG. 1. In the example shown in FIG. 1, the blood flow image display device 100 is configured to include a scanning unit 10, an electronic scanning unit 11, a tomographic image creating unit 12, a blood flow signal analyzing unit 13, a changing unit 14, a power image creating unit 16, an image combining unit 17, and a display control unit 18. The display unit 25 is a liquid crystal display, an organic EL display, or the like, and displays any image.

[0046] The blood flow image display device 100 can be configured as a dedicated device specialized for displaying blood flow images, and includes a display unit 25, a probe 30, and an operation unit 40. The blood flow image display device 100 can also be configured by connecting the display unit 25, the probe 30, and the operation unit 40 to a personal computer.

[0047] <Configuration of blood flow image display device> Here, the principle of adjusting the brightness of a blood flow image in the blood flow image display device 100 will be explained with reference to Figs. 2 to 5. Fig. 2 is an explanatory diagram of the operation of the blood flow image display device 100. In Fig. 2, the horizontal axis represents the depth (reception time) of the blood flow signal 61 in the living body, and the vertical axis represents the power of the blood flow signal 61 (similar to Figs. 3A and 3B). Figs. 3A and 3B are explanatory diagrams of examples of changes in the blood flow signal 61 and the power cut threshold 63, respectively. Fig. 4 is an explanatory diagram of changes in the brightness of a blood flow image in the blood flow image display device 100. Fig. 5 is an explanatory diagram of changes in the brightness of a blood flow image containing noise in the blood flow image display device 100.

[0048] The blood flow image display device 100 displays a blood flow image in which the brightness of the blood flow portion is changed using a parameter that changes the strength of the blood flow while leaving the display range of the blood flow portion unchanged. Also, the blood flow image display device 100 internally changes both the color gain and the power cut threshold of the blood flow signal.

[0049] As shown in FIG. 2, the blood flow image display device 100 according to this embodiment differs from the prior art (FIG. 10) in the following respects. That is, in the conventional blood flow image display device, an operation to increase or decrease the color gain is performed. In response to this operation, the conventional blood flow image display device changes only the blood flow signal 61 in the up and down direction (the direction of the arrow 161) as shown in Fig. 10. In contrast, the blood flow image display device 100 according to this embodiment performs an operation to increase or decrease both the color gain and the power cut threshold 63. In response to this operation, as shown in Fig. 2, the blood flow image display device 100 according to this embodiment changes both the blood flow signal 61 and the power cut threshold 63 in the up and down directions (directions of arrows 161 and 163) at the same ratio.

[0050] The changes in the blood flow signal 61 and the power cut threshold 63 shown in Fig. 2 can be made such that the blood flow signal 61 and the power cut threshold 63 move in the same direction without changing the waveform of the blood flow signal 61, as shown in Fig. 3A. In the example shown in Fig. 3A, a blood flow signal 61a having the same waveform as the blood flow signal 61 moves upward, and the power cut threshold 63 moves upward as power cut threshold 63a. Also, a blood flow signal 61b having the same waveform as the blood flow signal 61 moves downward, and the power cut threshold 63 moves downward as power cut threshold 63b.

[0051] 2 can be changed by changing the waveform of the blood flow signal 61, as shown in FIG. 3B, so that the blood flow signal 61 and the power cut threshold 63 move in the same direction. In the example shown in FIG. 3B, a blood flow signal 61c having a waveform with a different amplitude in the vertical direction from that of the blood flow signal 61 moves upward, and the power cut threshold 63 moves upward as a power cut threshold 63c. Furthermore, a blood flow signal 61d having a waveform with a different amplitude in the vertical direction from that of the blood flow signal 61 moves downward, and the power cut threshold 63 moves downward as a power cut threshold 63d.

[0052] The difference between the example shown in Fig. 3A and the example shown in Fig. 3B is as follows: For example, when the power image creating unit 16 creates a power image, it performs a log compression process based on the following equation (1). log(ax)=(log a+log x) …(1) Here, Color Gain: a Blood flow signal power: x Pixel brightness: log(ax)

[0053] In this case, if the parameters input from the parameter input unit 15a are applied after the Log compression process, the result will be as shown in the example in FIG. 3A. On the other hand, if the parameters input from the parameter input unit 15a are applied before the Log compression process, the result will be as shown in the example in FIG. 3B. In the example shown in FIG. 3A, changes in the color gain and power cut threshold are applied to the power signal after the Log compression. In this case, the changes in the color gain and power cut threshold are applied by addition or subtraction. In contrast, in the example shown in FIG. 3B, changes in the color gain and power cut threshold are applied to the power signal before the Log compression. In this case, the changes in the color gain and power cut threshold are applied by multiplication, not by addition or subtraction.

[0054] 2, the excess blood flow signal 161a is a region that is likely to be displayed as an excess blood flow portion when a blood flow image is displayed, that is, a region that is likely to be displayed outside the blood vessel. The blood flow image display device 100 calculates the power value of the blood flow signal 61 based on the color gain of the blood flow signal 61, cuts the brightness of pixels whose power value of the blood flow signal 61 is less than the power cut threshold 63 to 0, and creates a blood flow image 71 (FIG. 4) to display on the display unit 25.

[0055] When a user such as a doctor views a blood flow image 71 (FIG. 4) and wishes to display the blood flow image darker, the user performs an operation to decrease the color gain and the power cut threshold 63 (FIG. 2). In response to this operation, the blood flow image display device 100 shifts (attenuates) the blood flow signal 61 (FIG. 2) downward and decreases the power cut threshold 63 (FIG. 2). The blood flow image display device 100 then displays a blood flow image 72 (FIG. 4). A blood flow image 272 (FIG. 11) created by a conventional blood flow image display device has the problem that weak blood flow portions are not displayed. As a result, the user cannot clearly view the weak blood flow portions. In contrast, in the blood flow image 72 (FIG. 4) created by the blood flow image display device 100 according to this embodiment, the power cut threshold 63 is relatively constant with respect to the power value of the blood flow signal, so the weak blood flow portions are also displayed. As a result, the user can clearly view the weak blood flow portions.

[0056] Furthermore, if a user wants to display the blood flow image 71 (FIG. 4) brighter, the user increases the color gain and the power cut threshold 63 (FIG. 2). In response to this operation, the blood flow image display device 100 shifts (amplifies) the blood flow signal 61 (FIG. 2) upward and increases the power cut threshold 63 (FIG. 2). The blood flow image display device 100 then creates a blood flow image 73 (FIG. 4). The blood flow image 273 (FIG. 11) created by a conventional blood flow image display device has the problem that a portion of the blood flow corresponding to the excess blood flow signal 161a (FIG. 10) is displayed outside the blood vessel. Therefore, the conventional blood flow image display device cannot accurately display the blood flow portion within the blood vessel. Therefore, the user cannot clearly see the blood flow portion. In contrast, in the blood flow image 73 (FIG. 4) created by the blood flow image display device 100 according to this embodiment, the power cut threshold 63 is relatively constant relative to the power value of the blood flow signal. Therefore, in the blood flow image 73 (FIG. 4), the portion corresponding to the excess blood flow signal 161a (FIG. 2), which is a part of the blood flow, is displayed so as not to protrude from the blood vessel. Therefore, the blood flow image display device 100 according to this embodiment can correctly display the blood flow portion within the blood vessel. Therefore, the user can clearly visually recognize the blood flow portion.

[0057] Furthermore, when a blood flow 83 and noise 84 (clutter noise) are included, as in the blood flow image 81 shown in FIG. 5, the user performs an operation to reduce the color gain and power cut threshold 63 (FIG. 2) to cut out the noise 84. In response to this operation, the blood flow image display device 100 shifts (attenuates) the blood flow signal 61 (FIG. 2) downward and reduces the power cut threshold 63 (FIG. 2). The blood flow image display device 100 then creates a blood flow image 82 (FIG. 5) based on the reduced color gain. In a blood flow image 282 (FIG. 11) created by a blood flow image display device of the prior art, the lower limit threshold for displaying the power of the blood flow signal increases relative to the power value of the blood flow signal as the color gain decreases, resulting in the problem of most of the blood flow 283 being cut out. As a result, the user is unable to clearly view the blood flow portion. In contrast, in the blood flow image 82 (FIG. 5) created by the blood flow image display device 100 according to this embodiment, the power cut threshold 63 is relatively constant with respect to the power value of the blood flow signal, so most of the blood flow 83 is not cut off, and the image is displayed so that noise 84 is cut off. In other words, the blood flow image 82 (FIG. 5) is configured so that the blood flow 83 is left in a moderate amount, while the noise 84 (clutter noise) is darkened to make it less noticeable. This allows the user to clearly see the blood flow portion.

[0058] If only the power cut threshold 63 is lowered, the weak blood flow will be emphasized and displayed outside the blood vessels, while maintaining the same brightness, as in the blood flow image 281 (FIG. 12) created using conventional technology. This prevents the user from clearly viewing the blood flow portion. If only the power cut threshold 63 is raised, the weak blood flow will disappear, while maintaining the same brightness, as in the blood flow image 282 (FIG. 12) created using conventional technology. This prevents the user from clearly viewing the blood flow portion. In contrast, the blood flow image display device 100 according to this embodiment changes both the color gain and the power cut threshold 63 (FIG. 2). This prevents the blood flow image from generating this phenomenon and allows the user to appropriately adjust the brightness of the blood flow image without changing the power cut threshold 63 relative to the power value of the blood flow signal. This allows the user to clearly view the blood flow portion.

[0059] In addition, the above-mentioned Patent Document 1 describes that the power masking threshold is changed in response to a change in the gain of TGC (Time Gain Control) in order to cut background noise. However, the technology described in Patent Document 1 is not for adjusting the brightness of the blood flow image, so it is difficult to conceive of the blood flow image display device 100 according to this embodiment.

[0060] <Configuration of the operation section> Here, the configuration of the operation unit 40 will be described with reference to FIGS. 6 and 7. FIGS. 6 and 7 are explanatory diagrams of the operation unit 40, respectively. The operation unit 40 allows selection between a first operation pattern and a second operation pattern. The first operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 inside the device are changed in response to changes in parameters operated on the operation unit 40 (FIG. 6). The second operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 on the operation unit 40 are changed (FIG. 7). In the example shown in FIG. 6, the operation unit 40 is configured to display the numerical value of each parameter. On the other hand, in the example shown in FIG. 7, the operation unit 40 is configured so that, of the parameters, only the power brightness 41 is not displayed as a numerical value.

[0061] 6 and 7, the operation unit 40 is configured to have a first setting means 40a, a second setting means 40b, and a third setting means 40c, which respectively set the first to third parameters. The first setting means 40a sets power brightness 41 as the first parameter. The second setting means 40b sets color gain 42 as the second parameter. The third setting means 40c sets power cut threshold 43 as the third parameter. Each setting means has a "+" button to increase the value and a "-" button to decrease the value.

[0062] As shown in FIG. 6, in the first operation pattern, the combined value of the setting value of the power brightness 41 and the setting value of the color gain 42 becomes the gain (internal color gain) that is applied internally. I is a value calculated based on the following equation (2) in the case of dB (log scale), for example. G I =(G C +B) …(2) Here, Log scale internal color gain: G I Log scale color gain: G C Log scale power brightness: B

[0063] In the first operation pattern, the sum of the set value of the power brightness 41 and the set value of the power cut threshold 43 becomes the internally applied threshold (internal power cut threshold). I is a value calculated based on the following equation (3) in the case of dB (log scale), for example. C I =(C C +B P ) …(3) Here, Log-scale internal power cut threshold: C I Log scale power cut threshold: C C Log scale power brightness: B P

[0064] Note that the above-mentioned formulas (2) and (3) are examples for the case of dB (log scale), and are calculated by adding two parameters. However, in the case of a linear scale, the above-mentioned formulas (2) and (3) are calculated by multiplying the two parameters. In other words, in the case of a linear scale, the above-mentioned formulas (2) and (3) become the following formulas (4) and (5). G I2 =(G C2 ×B2) …(4) Here, Linear scale internal color gain: G I2 Linear scale color gain: G C2 Linear scale power brightness: B2 C I2 =(C C2 ×B P2 ) …(5) Here, Linear scale internal power cut threshold: C I2 Linear scale power cut threshold: C C2 Linear scale power brightness: B P2

[0065] The parameter application unit 15b (FIG. 1) of the blood flow image display device 100 adjusts (changes) the blood flow signal 61 in the vertical direction (direction of arrow 161) according to the change in the internal color gain. At the same time, the parameter application unit 15b (FIG. 1) of the blood flow image display device 100 adjusts (changes) the power cut threshold 63 in the vertical direction (direction of arrow 163) according to the change in the internal power cut threshold. As a result, the blood flow image display device 100 creates blood flow images 72, 73 as shown in FIG. 4 or a blood flow image 82 as shown in FIG. 5.

[0066] The user can change only the value of the second parameter (color gain) by operating the second setting means 40b. In this case, the color gain within the device is calculated as a combined value of the first parameter (power brightness operated by the first setting means 40a) and the second parameter (color gain operated by the second setting means 40b). The blood flow image display device 100 configured in this manner can appropriately adjust the brightness of the blood flow portion by changing the color gain within the device.

[0067] Furthermore, the user can change only the value of the third parameter (power cut threshold) by operating the third setting means 40c. In this case, the power cut threshold in the device is calculated as a combined value of the first parameter (power brightness operated by the first setting means 40a) and the third parameter (power cut threshold operated by the third setting means 40c). The blood flow image display device 100 configured in this way can suitably adjust the brightness of the blood flow portion by changing the power cut threshold in the device.

[0068] 7, in the second operation pattern, the color gain 42 and the power cut threshold 43 change in response to a change in the setting value of the power brightness 41 by the first setting means 40a. The parameter application unit 15b (FIG. 1) of the blood flow image display device 100 adjusts (changes) the blood flow signal 61 in the vertical direction (direction of arrow 161) in response to a change in the color gain 42. At the same time, the parameter application unit 15b (FIG. 1) of the blood flow image display device 100 adjusts (changes) the power cut threshold 63 in the vertical direction (direction of arrow 163) in response to a change in the power cut threshold 43. As a result, the blood flow image display device 100 creates blood flow images 72 and 73 as shown in FIG. 4 or a blood flow image 82 as shown in FIG. 5.

[0069] <Relationship between blood flow velocity and power cut threshold> The relationship between blood flow velocity and power cut threshold 63 will be explained below with reference to Fig. 8A and Fig. 8B. Fig. 8A and Fig. 8B are explanatory diagrams of the relationship between blood flow velocity and power cut threshold 63. The blood flow image display device 100 sets a different power cut threshold 63 for each blood flow velocity. In Fig. 8A and Fig. 8B, the horizontal axis represents velocity, which is the speed of the blood flow signal, and the vertical axis represents the power of the blood flow signal.

[0070] For example, slow blood flow is minute and has a relatively weak signal intensity. Such slow blood flow may have its brightness cut off in the low-velocity range of blood flow velocity, causing it to disappear from the blood flow image. Therefore, the blood flow image display device 100 may set the power cut threshold 63 low in the low-velocity range of the absolute value of blood flow velocity to prevent the brightness of slow blood flow from being cut off.

[0071] Furthermore, fast blood flows have relatively strong signal strength. Such fast blood flows may be displayed outside the blood vessels in the high-velocity blood flow range. Therefore, in order to prevent the blood flow image display device 100 from being displayed outside the blood vessels, it is recommended that the power cut threshold 63 be set relatively high in the high-velocity absolute value range of the blood flow velocity.

[0072] Therefore, as shown in Fig. 8A, in the case of a linear scale, the parameter application unit 15b (Fig. 1) of the blood flow image display device 100 changes the power cut threshold 63 at the same ratio in the low-velocity range and the high-velocity range when the power brightness 41 is changed. Also, the parameter application unit 15b (Fig. 1) of the blood flow image display device 100 changes the color gain at the same ratio in the low-velocity range and the high-velocity range.

[0073] 8B, in the case of dB (log scale), the parameter application unit 15b (FIG. 1) of the blood flow image display device 100 changes the power cut threshold 63 by adding or subtracting the same amount in the low-speed range and the high-speed range when the power brightness 41 is changed. Also, the parameter application unit 15b (FIG. 1) of the blood flow image display device 100 changes the power cut threshold 63 by adding or subtracting the same amount in the color gain in the low-speed range and the high-speed range.

[0074] <Creating composite images> Creation of a composite image will be described below with reference to Fig. 9. Fig. 9 is an explanatory diagram of creation of a composite image 93 as a blood flow image. The image composition unit 17 (Fig. 1) of the blood flow image display device 100 creates the composite image 93 by combining a B-mode image 91 and a power Doppler image 92. Combining is performed by superimposing the power Doppler image 92 on the B-mode image 91 for each pixel. At that time, the image composition unit 17 (Fig. 1) determines the conditions for each pixel and determines whether or not to display the power Doppler image 92 superimposed on the B-mode image 91.

[0075] The condition for displaying a power Doppler image 92 superimposed on a B-mode image 91 is that the following formulas (6) and (7) are both satisfied. P P ≧ P T …(6) Here, Power value of power Doppler image: P P Power Doppler image threshold: P T B0< B T …(7) Here, Brightness value of B-mode image: B0 B-mode image threshold: B T Here, the threshold value P of the power Doppler image T and the threshold value B for the B-mode image T is a threshold value that is arbitrarily determined in advance.

[0076] The image synthesis unit 17 (FIG. 1) determines for each pixel whether the above-described formula (6) and formula (7) are compatible, and if they are compatible, displays a power Doppler image 92 superimposed on a B-mode image 91. The display may be such that the power Doppler image 92 is made semi-transparent. Note that if the above-described formula (6) and formula (7) are not compatible, the image synthesis unit 17 (FIG. 1) does not superimpose a power Doppler image on the pixel, and displays the B-mode image 91 created by the tomographic image creation unit 12 on the display unit 25.

[0077] <Main features of the blood flow image display device, blood flow image display method, and program> The blood flow image display device 100 according to this embodiment has the following main features. (1) As shown in FIG. 1, the blood flow image display device 100 according to this embodiment includes a change means 14 that changes both the color gain 42 of the blood flow signal 61 and the power cut threshold 43 used to cut the brightness of pixels whose power value of the blood flow signal 61 is less than a predetermined value when generating a blood flow image and displaying it on the display unit 25.

[0078] The user changes both the color gain 42 and the power cut threshold 43 of the blood flow signal 61, and changes the power cut threshold 43 so that it is at the same position relative to the power value of the blood flow signal 61. This allows the blood flow image display device 100 of this embodiment to suitably adjust the brightness of the blood flow portion. Therefore, the blood flow image display device 100 of this embodiment can suitably adjust the brightness of the blood flow image without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal.

[0079] (2) As shown in FIG. 1, the blood flow image display device 100 having the configuration (1) according to this embodiment includes, as the change means 14, a parameter input unit 15a for inputting any parameter related to the blood flow signal 61, and a parameter application unit 15b for applying the parameter inputted by the parameter input unit 15a to processing of the blood flow signal 61.

[0080] The blood flow image display device 100 according to this embodiment can apply the parameters inputted by the parameter input unit 15a to the processing of the blood flow signal 61 by the parameter application unit 15b. The blood flow image display device 100 according to this embodiment can suitably adjust the brightness of the blood flow image.

[0081] (3) As shown in FIG. 1, the blood flow image display device 100 according to this embodiment, configured as described in (2) above, further includes a tomographic image creating unit 12, a blood flow signal analyzing unit 13, a power image creating unit 16, an image combining unit 17, and a display control unit 18. The tomographic image creating unit 12 is a component that creates a tomographic image based on a blood flow signal 61. The blood flow signal analyzing unit 13 is a component that analyzes the blood flow signal 61. The power image creating unit 16 is a component that creates a power image representing blood flow that reflects the blood flow signal 61 to which parameters have been applied by the parameter applying unit 15b. The image combining unit 17 is a component that combines a tomographic image and a power image to create a combined image. The display control unit 18 is a component that selectively displays a tomographic image or a combined image.

[0082] According to the blood flow image display device 100 of this embodiment, the user can suitably adjust the brightness of the blood flow portion simply by operating the operation unit 40.

[0083] (4) As shown in Figure 6 or Figure 7, the blood flow image display device 100 of this embodiment having the configuration (1) above is equipped with a single operation unit 40 that changes both the color gain 42 and the power cut threshold 43.

[0084] The user can change both the color gain 42 and the power cut threshold 43 simply by operating the single operation unit 40. Therefore, the blood flow image display device 100 having this configuration can suitably adjust the brightness of the blood flow portion.

[0085] (5) As shown in FIG. 7, in the blood flow image display device 100 having the configuration of (4) above according to this embodiment, the operation unit 40 is capable of changing only the color gain 42.

[0086] The color gain 42 is a parameter that is naturally used in various devices, including those of the prior art. The blood flow image display device 100 according to this embodiment can also be operated in the same way as a conventional device. The user can choose between changing both the color gain 42 and the power cut threshold 43, or changing only the color gain 42. Therefore, the blood flow image display device 100 having this configuration can change the display pattern of the blood flow image depending on the operation, making the blood flow image easier to view.

[0087] (6) As shown in Fig. 6 or 7, the blood flow image display device 100 having the configuration (4) according to this embodiment can select a first operation pattern and a second operation pattern. As shown in Fig. 6, the first operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 inside the device are changed in response to changes in parameters operated by the operation unit 40. As shown in Fig. 7, the second operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 in the operation unit 40 are changed.

[0088] The user can select either the first operation pattern or the second operation pattern depending on the operation. Therefore, the blood flow image display device 100 having this configuration can change the display pattern of the blood flow image depending on the operation, making the blood flow image easier to view.

[0089] (7) In the blood flow image display device 100 having the configuration described in (4) above according to this embodiment, the operation pattern may be set to a first operation pattern. As shown in Fig. 7, the first operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 in the operation unit 40 are changed in response to changes in parameters operated by the operation unit 40.

[0090] The blood flow image display device 100 having this configuration can change both the color gain 42 and the power cut threshold 43 in the operation unit 40 in response to changes in the parameters operated by the operation unit 40.

[0091] (8) In the blood flow image display device 100 having the configuration described in (4) above according to this embodiment, the operation pattern may be set to a second operation pattern. As shown in Fig. 6, the second operation pattern is a pattern in which both the color gain 42 and the power cut threshold 43 inside the device are changed in response to changes in parameters operated by the operation unit 40.

[0092] The blood flow image display device 100 having this configuration can change both the color gain 42 and the power cut threshold 43 inside the device according to parameters operated by the operation unit 40.

[0093] (9) As shown in Figure 6 or Figure 7, in the blood flow image display device 100 having the configuration (4) above according to this embodiment, the operation unit 40 has a first setting means 40a that changes both the color gain 42 and the power cut threshold 43.

[0094] By simply operating the first setting means 40a, the user can change both the color gain 42 and the power cut threshold 43. Therefore, the blood flow image display device 100 having this configuration can suitably adjust the brightness of the blood flow portion without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal.

[0095] (10) As shown in Figure 6 or Figure 7, in the blood flow image display device 100 having the configuration of (9) above according to this embodiment, the operation unit 40 defines a first parameter (power brightness 41) operated by the first setting means 40a, and is configured to change the color gain 42 and power cut threshold 43 according to the value of the first parameter.

[0096] The user can change both the color gain 42 and the power cut threshold 43 by operating the first setting means 40a to change the value of the first parameter (power brightness 41). Therefore, the blood flow image display device 100 configured as described above can suitably adjust the brightness of the blood flow portion.

[0097] (11) As shown in Fig. 6, in the blood flow image display device 100 having the configuration of (10) according to this embodiment, the operation unit 40 has a second setting means 40b that changes only the second parameter representing the color gain 42. When an operation pattern that changes both the color gain and the power cut threshold value within the device is executed, the color gain within the device is calculated as a value obtained by adding the first parameter and the second parameter.

[0098] The user can change only the value of the second parameter (color gain) by operating the second setting means 40b. In this case, the color gain within the device is calculated as a combined value of the first parameter (power brightness operated by the first setting means 40a) and the second parameter (color gain operated by the second setting means 40b). The blood flow image display device 100 configured in this way can suitably adjust the brightness of the blood flow portion by changing the color gain within the device.

[0099] (12) As shown in Fig. 6, in the blood flow image display device 100 having the configuration of (11) according to this embodiment, the operation unit 40 has a third setting means 40c that changes only the third parameter that represents the power cut threshold 43. When an operation pattern that changes both the color gain and the power cut threshold within the device is executed, the power cut threshold within the device is calculated as a value obtained by adding the first parameter and the third parameter.

[0100] The user can change only the value of the third parameter (power cut threshold) by operating the third setting means 40c. In this case, the power cut threshold in the device is calculated as the sum of the first parameter (power brightness operated by the first setting means 40a) and the third parameter (power cut threshold operated by the third setting means 40c). The blood flow image display device 100 configured in this way can suitably adjust the brightness of the blood flow portion by changing the power cut threshold in the device.

[0101] (13) As shown in Figure 6 or Figure 7, in the blood flow image display device 100 having the configuration of (12) above according to this embodiment, the operation unit 40 is configured to change the second parameter and the third parameter in conjunction with each other using the first setting means 40a.

[0102] The user can change the value of the first parameter (power brightness 41) by operating the first setting means 40a, thereby changing the second parameter (color gain 42) and the third parameter (power cut threshold 43) in conjunction with each other. Therefore, the blood flow image display device 100 configured as described above can suitably adjust the brightness of the blood flow portion.

[0103] (14) As shown in Figure 8A or 8B, in the blood flow image display device 100 having the configuration (1) above according to this embodiment, the power cut threshold 43 takes a variable value depending on the velocity and changes at the same ratio as the color gain 42.

[0104] The blood flow image display device 100 according to this embodiment can change the power cut threshold 43 at the same ratio as the color gain 42. Therefore, the blood flow image display device 100 having this configuration can suitably adjust the brightness of the blood flow portion.

[0105] (15) In the blood flow image display device 100 having the configuration (1) according to this embodiment, the change means 14 is configured to set the power cut threshold 43 low for the low-velocity signal components of the blood flow signal 61. The change means 14 is also configured to set the power cut threshold 43 high for the high-velocity signal components of the blood flow signal 61.

[0106] Slow blood flows are minute and have relatively weak signal strength. Such slow blood flows may be cut off in the low blood flow velocity range and disappear from the blood flow image. Therefore, the blood flow image display device 100 sets the power cut threshold 63 low in the low absolute value range of blood flow velocity to prevent the cutting of slow blood flows. On the other hand, fast blood flows have relatively strong signal strength. Such fast blood flows may be displayed protruding from the blood vessels in the high blood flow velocity range. Therefore, the blood flow image display device 100 sets the power cut threshold 63 high in the high absolute value range of blood flow velocity to prevent the protruding from the blood vessels. The blood flow image display device 100 with this configuration can appropriately set the power cut threshold 63, thereby appropriately adjusting the brightness of the blood flow portion.

[0107] (16) In the blood flow image display device 100 having the configuration described in (15) above according to this embodiment, the power cut threshold 43 takes a different value for each velocity value of the blood flow signal 61. The changing means 14 is configured to change the power cut threshold 43 for each velocity value at approximately the same ratio as the change in the color gain 42.

[0108] The changing means 14 changes the power cut threshold 43 for each velocity value at approximately the same ratio as the change in the color gain 42. The blood flow image display device 100 configured in this manner can suitably set the power cut threshold 63. Therefore, the blood flow image display device 100 can suitably adjust the brightness of the blood flow portion without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal.

[0109] (17) As shown in Fig. 9, in the blood flow image display device 100 having the configuration of (1) above according to this embodiment, the power cut threshold 43 is used to determine whether to synthesize a B-mode image 91 (tomographic image) and a power Doppler image 92 to create a synthetic image 93 as a blood flow image. The B-mode image 91 (tomographic image) is an image created based on a blood flow signal 61. The power Doppler image 92 is an image in which blood flow is colored according to the power value of the blood flow signal 61.

[0110] The blood flow image display device 100 having this configuration can use the power cut threshold 43 to determine whether or not to create a composite image 93.

[0111] (18) In the blood flow image display device 100 having the configuration described in (17) above according to this embodiment, the decision as to whether to perform synthesis is made by determining whether to display the B-mode image 91 (tomographic image) or to display the power Doppler image 92 superimposed on the tomographic image for each pixel.

[0112] The blood flow image display device 100 configured in this manner can use the power cut threshold 43 to determine whether to display a B-mode image 91 (tomographic image) or to display a power Doppler image 92 superimposed on the tomographic image for each pixel.

[0113] (19) The blood flow image display method according to this embodiment includes a step of changing both the color gain 42 of the blood flow signal 61 and the power cut threshold 43 used to cut the brightness of pixels whose power value of the blood flow signal 61 is less than a predetermined value when generating a blood flow image and displaying it on the display unit 25. In this blood flow image display method according to this embodiment, the blood flow image display device 100 can suitably adjust the brightness of the blood flow image without changing the lower display threshold of the power of the blood flow signal relative to the power value of the blood flow signal.

[0114] (20) The program 51 according to this embodiment is configured to cause a computer having a storage unit 20 to execute a procedure for changing both the color gain 42 of the blood flow signal 61 and the power cut threshold 43 used to cut the brightness of pixels whose power value of the blood flow signal 61 is less than a predetermined value when generating a blood flow image and displaying it on the display unit 25. The program 51 according to this embodiment can realize the blood flow image display device 100 according to this embodiment on a computer.

[0115] The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit of the present invention.

[0116] For example, the above-described embodiment has been described in detail to clearly explain the gist of the present invention. Therefore, the present invention is not necessarily limited to an embodiment including all of the components described. Furthermore, the present invention may include some components by adding other components to them, or by replacing some components with other components. Furthermore, the present invention may also include some components by deleting them. [Explanation of symbols]

[0117] 10 Control Unit 11 Electronic scanning unit 12 Tomography section 13 Blood flow signal analysis section 14 Means of change 15a Parameter input section 15b Parameter application section 16 Power Image Creation Department 17 Image synthesis unit 18 Display control unit 20 Memory section 21 Programs 25 Display section 30 probes 31 Ultrasound echo signal (blood flow signal) 40 Control section 40a First setting means 40b Second setting means 40c Third setting means 41 Power Brightness (first parameter) 42 Color Gain (2nd parameter) 43 Power cut threshold (third parameter) 50 Storage medium 51 Programs 61,61a,61b,61c,61d Blood flow signal 63, 63a, 63b, 63c, 63d Power cut threshold (threshold) 71,271 blood flow images 72,272 blood flow images 73,273 blood flow images 81,281 blood flow images 82,282 blood flow images 83,283 Blood flow 84,284 noise 91 B-mode image (tomographic image) 92 Power Doppler images 93 Composite image (blood flow image) 100 Blood flow image display device 161a Excess blood flow signal 161,163 arrows

Claims

1. a change unit for changing both the color gain of the blood flow signal and a power cut threshold used to cut the luminance of pixels whose power value of the blood flow signal is less than a predetermined value when generating a blood flow image and displaying it on a display unit; Blood flow image display device.

2. The changing means includes: a parameter input unit for inputting any parameter related to the blood flow signal; a parameter application unit that applies the parameters input by the parameter input unit to processing of the blood flow signal. The blood flow image display device according to claim 1 .

3. a tomographic image creating unit that creates a tomographic image based on the blood flow signal; a blood flow signal analysis unit that analyzes the blood flow signal; a power image creating unit that creates a power image representing a blood flow that reflects the blood flow signal to which the parameters have been applied by the parameter applying unit; an image synthesis unit that synthesizes the tomographic image and the power image to create a synthetic image; a display control unit that selectively displays the tomographic image or the composite image, The blood flow image display device according to claim 2 .

4. a single operating unit for changing both the color gain and the power cut threshold; The blood flow image display device according to claim 1 .

5. The operation unit is capable of changing only the color gain.

5. The blood flow image display device according to claim 4.

6. A first operation pattern and a second operation pattern can be selected, the first operation pattern is a pattern in which both the color gain and the power cut threshold in the operation unit are changed in accordance with a change in a parameter operated by the operation unit, the second operation pattern is a pattern in which both the color gain and the power cut threshold value are changed inside the device; 5. The blood flow image display device according to claim 4.

7. The operation pattern is set to the first operation pattern, the first operation pattern is a pattern in which both the color gain and the power cut threshold in the operation unit are changed in response to a change in a parameter operated by the operation unit; 5. The blood flow image display device according to claim 4.

8. The operation pattern is set to the second operation pattern, the second operation pattern is a pattern in which both the color gain and the power cut threshold value in the device are changed in response to a change in a parameter operated by the operation unit.

5. The blood flow image display device according to claim 4.

9. the operation unit has a first setting means for changing both the color gain and the power cut threshold value; 5. The blood flow image display device according to claim 4.

10. the operation unit defines a first parameter operated by the first setting means, and changes the color gain and the power cut threshold value according to the value of the first parameter; The blood flow image display device according to claim 9 .

11. the operation unit has a second setting means for changing only a second parameter representing the color gain, when an operation pattern is executed that changes both the color gain and the power cut threshold value within the device, the color gain within the device is a sum of the first parameter and the second parameter; The blood flow image display device according to claim 10.

12. the operation unit has a third setting means for changing only a third parameter representing the power cut threshold value, when an operation pattern for changing both the color gain and the power cut threshold value within the device is executed, the power cut threshold value within the device is a sum of the first parameter and the third parameter; The blood flow image display device according to claim 11.

13. the operation unit changes the second parameter and the third parameter in conjunction with each other by the first setting means; The blood flow image display device according to claim 12.

14. the power cut threshold, which is changed together with the color gain, takes a value that is variable depending on velocity and changes at the same ratio as the color gain; The blood flow image display device according to claim 1 .

15. The changing means is setting the power cut threshold low for a low-velocity signal component of the blood flow signal; setting the power cut threshold high for high-velocity signal components of the blood flow signal; The blood flow image display device according to claim 1 .

16. the power cut threshold takes a different value for each velocity value of the blood flow signal; the changing means changes the power cut threshold for each speed value at the same ratio as the change in the color gain; The blood flow image display device according to claim 15.

17. the power cut threshold is used to determine whether or not to synthesize a tomographic image created based on the blood flow signal with a power Doppler image that displays blood flow in a color according to the power value of the blood flow signal to create a composite image as the blood flow image. The blood flow image display device according to claim 1 .

18. The determination of whether to combine the images includes determining whether to display the tomographic image or to superimpose the power Doppler image on the tomographic image for each pixel. The blood flow image display device according to claim 17.

19. a step of varying both a color gain of the blood flow signal and a power cut threshold used to cut brightness of pixels whose power value of the blood flow signal is less than a predetermined value when generating a blood flow image and displaying it on a display unit; Blood flow image display method.

20. A program for causing a computer having a memory unit to execute a change procedure for changing both the color gain of the blood flow signal and the power cut threshold used to cut the brightness of pixels whose power value of the blood flow signal is less than a predetermined value when generating a blood flow image and displaying it on a display unit.

Images