JP2001061839A - Ultrasonograph and ultrasonic image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the quantity of data held in a three-dimensional image to be displayed using Doppler information, improving the usability and practicality of the three-dimensional image. SOLUTION: This ultrasonograph has an ultrasonic probe 11, a signal transmitter/receiver 13 for scanning a three-dimensional region inside a subject with ultrasonic waves by means of the probe 11, an ultrasonic 3D producing part 45 for producing power data of the blood flow in the three-dimensional region based on echo signals obtained by the scanning, producing power 3D image data from the power data, producing speed data of the blood flow in the three-dimensional region based on the echo signals and producing speed 3D image data from the speed data by the volume rendering process, an image synthesizing part 43 for synthesizing speed 3D image data in the power 3D image data to obtain power/speed 3D image data, and a CRT 47 for displaying the power/speed 3D image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power three-dimensional image expressing a three-dimensional structure of a blood flow by volume rendering from power data (angio power data) relating to the blood flow in a three-dimensional region in the subject. The present invention relates to an ultrasonic diagnostic apparatus and an ultrasonic image display apparatus that generate and display data.

[0002]

2. Description of the Related Art There are various medical applications of ultrasonic waves, and the mainstream is ultrasonic tomography of a soft tissue of a living body (B mode) using the ultrasonic pulse reflection method, and the tissue of one line. By arranging the images in parallel along the time axis, a so-called M-mode in which a morphological change over time of the heart, blood vessels, and the like can be observed in detail is generated.

[0003] Such an ultrasonic image diagnosis is performed by using other images such as an X-ray diagnostic apparatus, an X-ray computed tomography apparatus (X-ray CT), a magnetic resonance imaging apparatus (MRI), and a nuclear medicine diagnostic apparatus such as SPECT or PET. Compared with the device, it has the advantages that the movement of the heart and the fetus can be observed in real time with a simple operation of simply assigning an ultrasonic probe from the body surface, and that blood flow imaging is possible. In addition, there are various features such as harm to the living body is very small, and the test can be performed repeatedly. In addition, since the device is very small, the device can be moved to the bedside to perform the test. For this reason, its utilization range is wide in heart, abdomen, mammary gland, urology, obstetrics and gynecology, and the like.

In an X-ray computed tomography apparatus (CT scanner) or a magnetic resonance imaging apparatus (MRI),
A system for generating a very high-precision three-dimensional image from multi-slice images taken with these modalities has already been put into practical use. On the other hand, in the field of ultrasonic waves, this three-dimensional imaging technology is completely behind the CT scanner and MRI. The main reason for this was the low resolution of the ultrasound image, but the resolution has been increased due to the recent use of harmonic imaging (harmonic imaging), ultrasonic contrast agents, and the speeding up of processors. , To an extent that can withstand three-dimensional images.

In such a background, trial and error are repeated in an initial stage such as what kind of information is used and what kind of display mode is used in the ultrasonic three-dimensional display. At present, in the field of tissue structure images by harmonics and in the field of Doppler, power information (echo intensity from blood flow that can express blood vessel structure with relatively high accuracy due to less angular dependence) (Reflecting) to create a three-dimensional image is becoming mainstream.

However, the information provided by the three-dimensional image using the power information is limited to the structure of the blood vessel, and the accuracy of the three-dimensional image of the blood flow taken by the CT scanner or MRI described above alone is not sufficient. I couldn't compete at all,
Therefore, even the significance of three-dimensional ultrasound imaging is at stake.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultrasonic diagnostic apparatus and an ultrasonic image display apparatus capable of displaying a three-dimensional image using Doppler information. Increase the usefulness and practicality.

[0008]

(1) An ultrasonic diagnostic apparatus according to the present invention comprises: an ultrasonic probe; a means for scanning a three-dimensional region in a subject with ultrasonic waves via the ultrasonic probe; Means for generating power data relating to blood flow in the three-dimensional region based on an echo signal obtained by scanning, and generating power three-dimensional image data by volume rendering from the power data; and an echo signal obtained by scanning. Means for generating velocity data relating to blood flow in the three-dimensional region based on the velocity data, generating velocity three-dimensional image data from the velocity data by volume rendering processing, and obtaining power / velocity three-dimensional image data. Power 3D image data with the speed 3
Means for synthesizing two-dimensional image data;
Means for displaying two-dimensional image data.

(2) An ultrasonic image processing apparatus according to the present invention comprises: means for generating power three-dimensional image data by volume rendering from power data relating to blood flow in a three-dimensional region in a subject; Means for generating velocity three-dimensional image data by volume rendering processing from velocity data relating to blood flow in the inside;
In order to obtain speed three-dimensional image data, the power three-dimensional image data is combined with the power three-dimensional image data, and the power / speed three-dimensional image data is displayed. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an ultrasonic diagnostic apparatus according to the present embodiment. The ultrasonic diagnostic apparatus includes an ultrasonic diagnostic apparatus main body that acquires an ultrasonic image,
And an ultrasonic image processing device that generates a useful three-dimensional image from the ultrasonic image acquired by the ultrasonic diagnostic device main body. The ultrasonic diagnostic apparatus main body includes an ultrasonic probe 11, a transmitter / receiver (Transmitter / Receiver) 13, and an ultrasonic image generating apparatus 15, while the ultrasonic image processing apparatus includes a mouse 21 and a keyboard 23.
, An input unit 25, a large-capacity disk device 31, a memory 41, an image synthesis processing unit 43, an ultrasonic 3D (three-dimensional)
It comprises a creating unit 45, a CRT 47, and an image data extracting unit 49.

In order to scan a three-dimensional region inside a subject with ultrasonic waves (three-dimensional scanning), a plurality of transducers for mutually converting an electric signal and an acoustic signal are used as the ultrasonic probe 11. A so-called two-dimensional array probe which is two-dimensionally arranged is desirable. This two-dimensional array probe can electronically scan a three-dimensional area at high speed. However, since the above-described three-dimensional scanning can be realized by a conventional method such as manually or mechanically moving or mechanically moving a so-called one-dimensional array probe in which a plurality of transducers are arranged one-dimensionally, The acoustic probe 11 may be a one-dimensional array probe.

The transceiver 13 includes a transmission system and a reception system. The transmission system includes a clock generator, a frequency divider, a transmission delay circuit, and a pulser. On the other hand, the reception system includes a preamplifier and an analog-to-digital converter. And a digital beamformer unit.

The clock pulse generated by the clock generator in the transmission system is reduced to a rate pulse of, for example, about 6 KHz by a frequency divider, and this rate pulse is applied to a pulser through a transmission delay circuit to generate a high-frequency voltage pulse. The child is driven, that is, mechanically vibrated. The ultrasonic wave generated in this manner is reflected at the boundary of the acoustic impedance in the subject, returns to the ultrasonic probe 1, and mechanically vibrates the vibrator. As a result, the electric signals individually generated in the respective vibrators are amplified by a receiving system preamplifier, converted into digital signals, sent to a digital beamformer unit, and subjected to phasing and addition.

The ultrasonic image generating device 15 has a B-mode processing system, a spectrum Doppler processing system, and a color Doppler processing system. The B-mode processing system and the spectrum Doppler processing system generate a B-mode image (tissue tomographic image) and a distribution (spectrum) of Doppler frequency (blood flow velocity), respectively. Is not directly related to the description, and a description thereof will be omitted.

On the other hand, the color Doppler processing system includes a mixer,
Low-pass filter, analog-to-digital converter, MT
It is composed of an I filter (clutter filter), an autocorrelator, and a calculation unit. The mixer and the low-pass filter constitute a quadrature phase detection circuit. The reference signal having the same center frequency as the transmission frequency and the reference signal shifted by 90 ° from the reference signal are individually multiplied with the echo signal, and the multiplication is performed. By removing the high-frequency component from each signal obtained by the low-pass filter, the shifted frequency component shifted by the Doppler effect when reflected by a moving body such as a blood flow or a heart wall is extracted, and this is used as a Doppler signal. Output. The Doppler signal mainly includes a high-frequency component subjected to frequency shift due to reflection from a fast moving body such as blood cells and a low-frequency component mainly subject to frequency shift due to reflection from a slow moving body such as a heart wall. And are included.

The Doppler signal is sampled by an analog-to-digital converter according to a predetermined sampling frequency corresponding to, for example, 0.5 mm intervals for one scanning line, converted into a digital signal, and then sent to an MTI filter. . The MTI filter functions as a high-pass filter, passes only high-frequency components (blood flow components) that have undergone frequency shift due to reflection from a fast moving body such as blood cells, and is mainly used for a slow moving body such as a heart wall. And has a function of removing a low-frequency component (clutter component) that has undergone a frequency shift due to reflection of light. Then, the Doppler signal including only the blood flow component is subjected to frequency analysis by an autocorrelator. Based on this analysis result, the calculation unit calculates the average velocity of blood flow, its variance,
The power (also called color angio) representing the intensity of the echo from the blood flow (reflecting the blood flow) together with the blood flow direction,
Calculate for each sample point.

Here, by changing the transmission / reception delay pattern little by little every several times (number of averages) transmission and reception, 1
The cross section can be scanned two-dimensionally, and a Doppler image (average speed image, dispersion image, color angio image (power image)) of the cross section can be obtained. further,
By changing the transmission / reception delay pattern little by little in the direction perpendicular to the cross section for each frame, a Doppler image having a slightly different two-dimensional scanning plane is collected as a so-called multi-slice. By performing such an operation as moving the scanning plane, a three-dimensional area inside the subject can be scanned by ultrasonic waves, and this scanning is generally called a three-dimensional scanning, a so-called volume scan. It is.

The multi-slice Doppler image data generated by the ultrasonic image generating device 15 is sent to the large-capacity disk device 31 and stored therein. The ultrasonic image processing device has a function of using the multi-slice Doppler image data to create three-dimensional image data with a much richer amount of information than before. This function will be described below with reference to FIG. 2 while additionally describing the configuration of the ultrasonic image processing device.

First, color angiographic image data and velocity image data for the same part are respectively collected in multi-slices by the ultrasonic diagnostic apparatus main body, and are stored in the large-capacity disk device 31 of the ultrasonic image processing apparatus. S1, S2). Note that it is generally impossible to simultaneously perform scanning for collecting color angiographic image data and scanning for collecting velocity image data, and therefore, they are separately performed.

Next, the ultrasonic 3D creating section 45 arbitrarily designates multi-slice color angio image data (volume data) through interpolation between slices, and further through an input section such as the mouse 21 and the keyboard 23. By performing rendering, shading, projection processing, and the like in accordance with the visual line direction, power 3D image data mainly representing a blood vessel structure as shown in FIG. 3 is created (S3).
3). The power 3D image data is stored in the memory 4
1 (S4).

Similarly, the ultrasonic 3D creation unit 45 arbitrarily designates multi-slice velocity image data (volume data) through interpolation between slices, and further through an input unit such as the mouse 21 and the keyboard 23. By performing rendering, shading, projection processing, and the like according to the same line-of-sight direction as S3, velocity 3D image data representing a blood flow velocity distribution as shown in FIG. 4 is created (S5). The speed 3D image data is similarly temporarily stored in the memory 41 (S6).

The image synthesizing processing section 43 synthesizes the power 3D image data created in this way with the speed 3D image data, thereby obtaining synthesized image data (power / speed 3D).
Image data) is generated (S7). This power / speed 3
The D image data is sent to the CRT 47 and displayed as shown in FIG. 5 (S8).

As a display mode of the power / speed 3D image data, for example, as shown in FIG. 6, red is assigned to the forward flow and blue is assigned to the backward flow, and the brightness is changed according to the power level and the speed is changed according to the speed. The green is mixed to change the hue from red to yellow in the forward flow and from blue to green in the reverse flow.

When the power / speed 3D image data is displayed, a command to change the synthesis rate (green mixing rate in the example of FIG. 6) is issued via input devices such as the mouse 21 and the keyboard 23 (FIG. 6). S9) When the combination rate is input (S9)
10) The speed 3D image data is synthesized again with the power 3D image data according to the input synthesis rate (S).
7). Although not shown, when displaying the power / speed 3D image data, the mouse 21 and the keyboard 2 are displayed.
When the viewpoint or the line of sight is changed via an input device such as the 3, the power 3D is changed according to the changed viewpoint or line of sight.
Image data and speed 3D image data are created (S
3, S5).

As described above, according to the present embodiment, since the three-dimensional velocity image data is synthesized with the three-dimensional power image data, the blood vessel structure is observed simultaneously with the blood flow velocity distribution and at the same position between the two. can do. Therefore, there is a possibility that a lesion that is likely to be overlooked only by the vascular structure due to power can be found without overlooking by judging the vascular structure in combination with the velocity distribution. In addition, by changing the synthesis rate as needed, it is possible to emphasize one of the structure and the velocity distribution for observation. It is also possible to observe a 3D image while freely changing the viewpoint and the line of sight. By the above action, the diagnostic ability of the doctor is remarkably improved.

It is needless to say that the present invention is not limited to the above-described embodiment, but can be implemented in various modifications.

[0027]

According to the present invention, by synthesizing speed 3D image data with power 3D image data, not only blood vessel structure but also speed information unique to ultrasonic diagnosis can be grasped. The combined effect of observing the blood vessel structure and the blood flow velocity at the same time and aligning the positions between them can be obtained by observing the blood vessel structure and the blood flow velocity separately on the screen or by switching between them. There is nothing special.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a diagram illustrating a power 3 created by the ultrasound 3D creating unit in FIG.
The figure which shows an example of a two-dimensional image.

FIG. 4 is a diagram showing an example of a three-dimensional velocity image created by the ultrasound 3D creating unit in FIG. 1;

FIG. 5 is a view showing an example of a three-dimensional power / speed image created by the image synthesis processing unit in FIG. 1;

FIG. 6 is a diagram showing coloring of power / speed 3D image data in the embodiment.

[Description of Signs] 11 ... Ultrasonic probe, 13 ... Transceiver, 15 ... Ultrasonic image generator, 21 ... Mouse, 23 ... Keyboard, 25 ... Input unit, 31 ... Large capacity disk device, 41 ... Memory, 43 ... Image rigidity processing unit, 45: Ultrasonic 3D creation unit, 47: CRT, 49: Image data extraction unit.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C301 AA02 BB05 BB13 BB22 BB28 BB29 CC02 DD01 DD02 EE20 GB03 GB09 HH33 HH54 HH60 JB03 JB28 JB29 JB36 JB38 JC01 JC14 KK02 KK09 KK12 KK17 CB20 CE5

Claims (2)

[Claims] 1. An ultrasonic probe, means for scanning a three-dimensional region in a subject with ultrasonic waves via the ultrasonic probe, and blood in the three-dimensional region based on an echo signal obtained by the scanning. Means for generating power data relating to flow, and generating power three-dimensional image data by volume rendering from the power data; and generating velocity data relating to blood flow in the three-dimensional region based on echo signals obtained by the scanning. Means for generating speed three-dimensional image data from the speed data by volume rendering processing; means for synthesizing the power three-dimensional image data with the power three-dimensional image data to obtain power / speed three-dimensional image data And a means for displaying the power / speed three-dimensional image data. Apparatus. 2. A means for generating power three-dimensional image data by volume rendering processing from power data on a blood flow in a three-dimensional region in a subject, and volume rendering processing from velocity data on a blood flow in the three-dimensional region. Means for generating speed / three-dimensional image data by means of: means for synthesizing the power / speed three-dimensional image data with the power / speed three-dimensional image data to obtain power / speed three-dimensional image data; An ultrasonic image processing apparatus comprising: means for displaying data.