JP2002000607A - Ultrasonic image display through combining the flow imaging enforced by b mode and color flow mode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means of displaying an image of a subject by combining the data from a gray scale operating mode and the data from a color flow operating mode. SOLUTION: Receiving signals in response to echo ultrasonics received from a subject (S) are produced by a transducer (10) of an ultrasonic system (1) and the gray scale data indicating various in vivo movements of a subject (the blood flow, the blood or the motion of a contrast medium in the tissue) are generated in a gray scale receiving channel (8G) and the color flow data (for example, either the power data or the speed data) also indicating various movements of a subject are created in a color flow receiving channel (9C). The results to be obtained by a processor (30) that combines the gray scale flow data and the color flow data are displayed on a monitor screen (19), when the movements of a subject are displayed in colored gray scale images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates generally to ultrasonic imaging of human anatomy for medical diagnostic purposes. Specifically, the present invention transmits an ultrasonic wave to a moving body fluid or tissue in the human body, and then detects an ultrasonic echo reflected from the body fluid, thereby imaging the moving body fluid or tissue (contrast agent). (May or may not be used)
Method and apparatus.

[0002]

BACKGROUND OF THE INVENTION US patent application Ser. No. 09 / 065,212 filed on Apr. 23, 1998 by Richard Chao et al. And assigned to the present applicant, entitled "B
In "Methods and Apparatus for Enhanced Flow Imaging in Modal Ultrasound", Applicants use a gray scale data to enable a new visualization of flow hemodynamics and tissue motion in B-mode. The method (hereinafter referred to as “gray scale flow”) is described. This modification B
The modal method provides fine resolution and high frame rate imaging by subtracting successive B-mode-like firings (for high resolution) and displaying changes over time (movement or flow). However, sensitivity is limited because of the wider bandwidth and fewer firings compared to color flow imaging. In addition, signals from stationary tissue and signals from the stream are processed equally and displayed using the B-mode display, thus limiting the possibility of image segmentation between the stationary and flowing regions. The present invention addresses such a problem and provides a solution.

[0003]

SUMMARY OF THE INVENTION The preferred embodiment is useful in an ultrasound system that acquires data representing a two-dimensional image of blood flow and tissue motion using both a gray scale mode of operation and a color flow mode of operation. An image of the subject is displayed by combining the data from the gray scale mode of operation with the data from the color flow mode of operation.

[0004] More specifically, a plurality of ultrasonic beams are transmitted into a subject, and echo ultrasonic waves are received from the subject in response to the transmitted ultrasonic waves. The echo ultrasound is converted to a corresponding received signal. Transmission, reception and conversion are preferably performed by an ultrasonic transducer. The transducer is pulsed along a one of the beams for a first predetermined number of times in a gray scale mode of operation, such that the transducer transmits a first ultrasonic wave and responds to the first ultrasonic wave. Then, a first reception signal is generated in response to the received echo ultrasonic wave. In the color flow mode of operation, the transducer is pulsed a second predetermined number of times along one of the beams so that the transducer transmits a second ultrasonic wave and is responsive to the second ultrasonic wave. The second reception signal is generated in response to the received echo ultrasonic wave. Gray scale flow data and color flow data are generated that represent the motion of each part of the subject. These data are preferably generated on a first receiving channel and on a second receiving channel, respectively. At least a portion of the gray scale flow data and at least a portion of the color flow data are preferably combined by a processor. An image corresponding to the combined data is preferably displayed by a display device. As a result, the movement of each part of the subject is represented by a color-enhanced gray scale image.

Using the above approach, while retaining the time and resolution advantages of gray scale data,
Along with increased sensitivity, the distinction between flow and tissue regions can be clarified through the addition of color data.

[0006]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, an ultrasound imaging system 1 formed in accordance with a preferred embodiment of the present invention comprises a transducer having a plurality of transducer elements 12 which are separately driven. Array 1
0, and each of the transducer elements, when energized by a pulse waveform generated by the transmitter 14, generates a unit burst of ultrasonic energy. The ultrasonic energy reflected from the subject (S) and returned to the transducer array 10 is converted into an electric signal by each of the receiving transducer elements 12, and is converted via a pair of transmission / reception (T / R) switches 18. Applied separately to receiver 16. The T / R switch is typically a diode that protects the receiving electronics from the high voltage generated by the transmitting electronics. Depending on the transmitted signal, the diode blocks or limits the signal to the receiver. The transmitter 14 and the receiver 16 operate under the control of the master controller 20 in response to commands from the operator. One complete scan is performed when the transmitter 14 is momentarily gated on and each transducer element 12
, And subsequently by acquiring a series of echoes, such that the echo signal generated by each transducer element 12 is applied to a receiver 16. One channel may start receiving while the other channel is still transmitting. The receiver 16 combines the separate echo received signals from each transducer element to generate a single echo signal, and uses this single echo signal to create a single line of the image on a display monitor 19. Form.

[0007] Under the direction of master controller 20, transmitter 14 drives transducer array 10 such that the ultrasonic energy is transmitted as a directional, focused beam. To accomplish this, the transmit beamformer 26 applies a respective time delay to the plurality of pulsars 24. The master controller 20 determines the conditions under which the sound pulse is transmitted. With this information, transmit beamformer 26 determines the timing and amplitude for each of the transmit pulses to be generated by pulser 24. The amplitude of each transmit pulse is
It is generated by an apodization generation circuit 36 which is a high-voltage controller or the like for setting a power supply voltage to each pulser. The pulsar 24 is then operated by the transducer
T / R switch 1 for each of elements 12 of array 10
Send a transmission pulse via 8. The T / R switch 18
It protects the time gain control (TGC) amplifier 28 from high voltages that may be present in the transducer array. The weight is generated inside the apodization generation circuit 36. Apodization generation circuit 36
May include a set of digital-to-analog converters that obtain weighted data from transmit beamformer 26 and apply this data to pulser 24. By appropriately adjusting the transmission focusing time delay in a conventional manner and adjusting the transmission apodization weight, the ultrasound beam can be directed and focused to form a transmission beam.

An echo signal is generated by each unit burst of the ultrasonic energy wave reflected from the object in the subject S located in a continuous range along each transmission beam. The echo signal is transmitted to each transducer element 12
And a sample of the magnitude (ie, amplitude) of the echo signal at a particular point in time represents the amount of reflection that has occurred in a particular range. Since there is a difference in the propagation path between the reflection point and each transducer element 12, the echo reception signals are not detected at the same time, and the amplitudes of the echo reception signals are not equal.
The receiver 16 amplifies a separate echo signal via a respective TGC amplifier 28 provided for each receiving channel. The amount of amplification provided by the TGC amplifier is controlled through a control path (not shown) driven by a TGC circuit (not shown).
The GC circuit is set by manual operation of a master controller and a potentiometer. Next, the amplified echo signal is supplied to the reception beam former 30. Each receive channel of the receive beamformer is coupled to a respective transducer element 12 by a respective TGC amplifier 28.

Under the direction of the master controller 20, the receive beamformer 30 tracks the direction of the transmitted beam. The receive beamformer 30 applies the appropriate time delay and receive apodization weight to each amplified echo signal, sums these signals and places them in a particular range along one ultrasonic beam. An echo receive signal is formed that accurately indicates the total ultrasonic energy reflected from the point. The receive convergence time delay is calculated in real time using specialized hardware or read from a look-up table. The receiving channel also
It has circuit components (circuitry) for filtering received pulses.

[0010] The transmitter 14 has two modes of operation. In the gray scale mode, the transducer 10 is pulsed two to four times along each ultrasonic beam. In the color flow mode, the transducer 10 is pulsed 6 to 16 times along each ultrasonic beam. The details of the pulses used are different between the two modes,
Compared to flow firing, gray scale firing generally uses higher frequencies, wider bands, and possibly coded pulses.
Alternatively, the two modes can use the same set of firings, so that each mode processes the same data set in some different way.

The time-delayed received signal is processed by receiver 16 in both a gray scale mode and a color flow mode to process two channels for processing, ie, gray scale flow data. And a color flow channel 9C for processing color flow data. The outputs of channels 9G and 9C are sent to a conventional scan converter 15 which prepares the signal for display by a conventional display monitor 19. In the gray scale mode (for example, the B mode), the envelope of the signal is detected by performing some additional processing such as edge enhancement and logarithmic compression. Scan converter 15
It receives data from channels 9G and 9C and converts these data into an image desired for display. In particular,
The scan converter 15 converts the sound image data from polar coordinate (R-θ) sector format to display pixel data in video rate appropriately scaled Cartesian coordinates. Then, the sound data obtained by the scan conversion (scan conversion) is supplied to be displayed on the display monitor 19, and is supplied to the display monitor 19.
Image data from gray scale mode and data from color flow mode as a colored gray scale image. For each transmit beam,
Each scan line is displayed.

Continuing with reference to FIG. 1, in the gray scale mode, each transducer element 12 in the transmit aperture has the same waveform by providing each pulser with a transmit sequence 38 N times. Are pulsed N times. The pulser 24 drives the elements 12 of the transducer array 10 such that the generated ultrasonic energy is steered, ie, steered, as a beam for each transmission firing. To achieve this, for each pulse waveform generated by the pulser in response to the transmission sequence 38, a transmission focusing time delay 37
Is given. By appropriately adjusting the transmission focusing time delay in a conventional manner, the ultrasound beam can be focused to a desired transmission focal position.

For each transmission in the gray scale mode, the echo received signal from transducer element 12 is transmitted to a respective receive channel 40 of the receive beamformer.
Supplied to Under the command of the master controller 20,
The receive beamformer tracks the direction of the transmitted beam. The receive beamformer applies the appropriate receive focus time delay 42 to the received echo signals and adds these echo signals to accurately determine the total ultrasonic energy reflected from a particular location along the transmit beam. Is formed. The time-delayed reception signal is added in the reception adder 44 for each of N transmission firings focused on a specific transmission focal position. Each of the reception signals after the addition for the continuous transmission firing is supplied to the wall filter 46, and the wall filter 4
6 supplies the signal after the filter processing to the B-mode intermediate processor 8G after performing the filter processing over N transmission firings, and outputs the signal to the B-mode intermediate processor 8G.
Forms the envelope of the filtered signal from filing to firing. After post-processing (including edge enhancement and logarithmic compression) and scan conversion, the display monitor 19 displays a single scan line. This procedure is repeated for all focal zone positions on each scan line that make up the resulting image.

According to a preferred embodiment of the present invention, filter 46 includes a FIR filter 48 having an input coupled to the output of receive adder 44, and an input and gray scale B-mode filter coupled to FIR filter 48. Unit 8G
And a vector adder 50 having an output coupled thereto. Adder 50 responds to the received signal obtained from transducer 10 pulsing along the beam in gray scale mode from the same range point straddling an adjacent firing received at its input. Is effectively subtracted. The FIR filter can be used to perform bandwidth shaping or decoding of the encoded pulse, and for each transmission firing, use M filter filters to receive a respective set of M filter coefficients. With a tap. The filter coefficients for the n-th transmission firing are a _{n
c 0, a n c 1,} ...., is a _n c _M-1, here, a _n is the scalar weighting for the transmit firing of the n-th, n = 0,1, ... ., N-1 and c ₀ ,
c ₁ ,..., c _M-1 are encoded such that FIR filter 48 passes most of the desired fundamental frequency or desired high (or low) harmonic frequency in the received signal. A set of filter coefficients that have been selected to effectively decode the resulting waveform. Scalar weights a ₀ , a ₁ , ...., a
_N-1 forms a "wall" filter that spans a firing that selectively passes signals from reflectors moving at a speed faster than a predetermined threshold. Filter coefficients _{a n c 0, a n c} 1, ..., a n c M-1 , for each transmit firing, supplied from the filter coefficient memory 52 to the filter by the master controller. For example, for the first transmission firing,
The set of filter coefficients a ₀ c ₀ , a ₁ c ₁ ,..., A ₀ c _M−1 is F
Supplied to the IR filter, and for the second transmission firing, a set of filter coefficients a ₁ c ₀ , a ₁ c ₁ ,.
a ₁ c _M−1 is supplied to the FIR filter, and so on. The filter coefficients are programmable according to the diagnostic application. The various sets of filter coefficients can be stored in a look-up table in the memory of the master controller so that the desired set of coefficients can be selected by the system operator. For applications where the number of transmit firings, N = 2, a pair of filter coefficient sets is stored in memory and one set of filter coefficients of the selected pair is used for the first transmit firing. Before F
Transferred to the IR filter, the other set of filter coefficients of the selected pair are transferred to the FIR filter after the first transmission firing and before the second transmission firing. Similarly, the number of transmission firings N = 3
For some applications, two or three sets of filter coefficients are stored in memory for use in filtering the received signal resulting from the first through third firings. A similar procedure is followed for applications where the number of transmission firings N> 3. Successive FIR filter output signals for N transmission firings are stored in vector adder 50. The output signal of the vector adder is then subjected to conventional gray scale B-mode processing, followed by scan conversion and display.

According to one preferred embodiment of the present invention, it consists of N identical or coded (in this case, not identical) broadband pulses centered on the fundamental frequency of the corresponding transducer array. One sequence is transmitted by the array to a particular transmit focal position. During reception, a bandpass filter centered on the desired receive frequency substantially isolates the desired receive component. A wall filter then extracts the flow signal over N transmissions. A flow filter as shown in FIG. 5 may include two stages. That is, a first stage 54 extracts most of the fundamental components, and a second stage 56 comprises a high-pass wall
The stationary fundamental component is substantially suppressed by the filter. The same type of processing can be performed to effectively extract the high (low) harmonic flow signal, specifically to image the contrast agent.

Both stages of the basic flow filter are embodied in the FIR filter 48 shown in FIG. A set of filter coefficients c ₀ , c, so that the M-tap FIR filter 48 passes most of the fundamental frequency in the received signal.
_{c 1, ...., c M-} 1 is selected. In addition, when the respective output signals of the FIR filters for a given transmit focal position are added, a ₀ , so that the fundamental signal is high-pass filtered across firing.
The wall filter weights 56 of a ₁ ,..., a _N−1 are selected. The summed signal is then gray scale B-mode processed in a conventional manner, ie, envelope detection,
Logarithmic compression is performed.

According to the above preferred embodiment of the present invention, the gray scale B-mode flow image is colorized according to the color flow data of channel 9C. In addition, some stationary components of the B-mode image can be provided through the wall filter, allowing the diagnostician to observe blood flow to known anatomical landmarks during medical diagnosis. The feed-through of this B-mode image is one of the wall filter weights.
This is achieved by adding a perturbation to one. For example, FIG.
As shown in the flowchart, the weight a ₀ for the first transmission firing can be perturbed by an amount α. The B-mode passing supply enables a colorized flow image to be displayed superimposed on a conventional B-mode image.

Referring again to FIG. 1, in the color flow mode of operation, the transducer 10 is pulsed six to sixteen times along each ultrasonic beam. Thus, receiver 30 generates separate received signals for the gray scale and color flow modes of operation, and these signals are processed separately in channels 9G and 9C.

Continuing with the description of FIG.
0 adds the delayed channel data and outputs a beam summed signal that is demodulated by a demodulator (not shown) into in-phase and quadrature (I / Q) signal components. You. The B-mode I and Q outputs from the demodulator are transmitted to an intermediate processor 8G for gray scale B-mode processing, and the I and Q outputs of the color flow from the demodulator are output to an intermediate processor for color processing. 8
Sent to C.

FIG. 2 shows an intermediate processor 8C for the color flow channel 9C. The I / Q signal components from the demodulator buffer the data from the possibly interleaved firings and convert the data as a vector of points across each firing in a given range of cells. It is stored in the corner turner memory 117 for output. The data is received in a "fast time" manner, i.e., in each firing, in descending range (along the vector) in descending order. The output of the corner-turner memory is rearranged in a "slow time" manner, that is, rearranged in firing order for each range cell. The resulting "slow time" I / Q signal samples pass through a wall filter 119, which removes any clutter corresponding to stationary or very slow moving tissue. Then, the output after filtering is
Provided to the parameter estimator 111, the parameter estimator 111 converts the range cell information into intermediate autocorrelation parameters N, D and R (0). N and D are the numerator and denominator of the autocorrelation equation and are given as:

[0021]

(Equation 1)

Here, I _i and Q _i are demodulated basebanded input data for firing i, and M is the number of firings in the packet. R (0) is approximated as a finite sum over the number of firings in the packet, as follows:

[0023]

(Equation 2)

The processor sets N and D to each range
Convert to cell size and phase. The equation used is as follows:

| R (T) | = (N ² + D ² ) ^1/2 (5) φ (R (T)) = tan ⁻¹ (N / D) (6)

The parameter estimator processes the magnitude and phase values into signals having values representing power, velocity, and turbulence or variance estimates, respectively.
A, 111B and 111C. The phase is used to calculate the average Doppler frequency, which is proportional to velocity, as will be shown. Also, R (0)
And | R (T) | (magnitude) are used to estimate turbulence.

The average Doppler frequency in hertz is obtained from the N and D phases and the pulse repetition time T.

[0028]

(Equation 3)

The average speed is calculated using the following Doppler shift equation. Since the angle θ between the flow direction and the sampling direction is unknown, cos θ is 1.0
It is assumed that

[0030]

(Equation 4)

Preferably, the parameter estimator does not calculate the average Doppler frequency as an intermediate output,
Use a look-up table to directly read the phase output of the processor.

[0032]

[Outside 1]

Turbulence can be calculated in the time domain as a second-order series expansion of the variance of the average Doppler frequency.
The time domain representation of turbulence involves calculating the autocorrelation functions R (0) and R (T) with zero delay and one stage delay, respectively. The exact autocorrelation function is approximated by a finite sum over the known data within the number of firings in the packet.

Σ ² = [2 / (2πT) ² ] [1- (| R (T) | / R (0))] (9).

The average signal φ (R (T)) is an estimate of the average Doppler frequency shift of the flowing reflector and is proportional to the average blood flow velocity. The dispersion signal σ ² indicates the spread of the frequency of the flow signal component of the baseband echo signal. This value is indicative of flow turbulence since turbulence is a mixture of many velocities while laminar flow has a very narrow range of velocities. To indicate the strength of the signal from the flowing reflector, signal R (0) indicates the amount of return power in the Doppler shifted flow signal.

The signal power on conductor 111A passes through data compression module 113 to output path 113A. Module 113 compresses data according to a plurality of groups of data compression curves. Different groups of curves can be provided for different scanning applications. For example, one group of curves may be prepared for a kidney scan while another group of curves may be prepared for a carotid scan. Typically, about 3 per group
Curve exists. The dynamic range of the signal varies according to the curve used for data compression. The curves within each group are arranged in order of increasing dynamic range. When the user selects a scanning application, the controller 20 sets a predefined curve. The dynamic range controls the range of the intensity or lumen formed on the display 19.

Referring to FIG. 3, the gray-scale B-mode intermediate processor 8G for the gray-scale channel 9G is beam-summed by calculating the quantity (I ² + Q ² ) ^1/2 . An envelope detector 110 for forming an envelope of the received signal is included. The signal envelope is subjected to some additional B-mode processing such as logarithmic compression (block 112 in FIG. 3) to form display data representing a two-dimensional image and output to scan converter 15 (FIG. 1).

Referring again to FIG. 1, when the color flow estimate and the B flow gray scale display data are sent to the scan converter 15, the scan
Converter 15 converts the data into a two-dimensional XY format for video display. The scan-converted frame is passed to the video processor 17 and the video processor 1
7 basically maps the video data to a combined color map and gray scale image frame for display for video display. The image frames are then sent to video monitor 19 for display. Typically, for a colored gray scale image, either speed or power is displayed in gray scale. System control is centralized in a host computer (not shown), which receives operator input via an operator interface (eg, a keyboard) and controls various subsystems.

Generally, for a B-flow gray scale image, the display data is
5 is converted to an XY format for video display. The scan-converted frame is output to the video processor 17.
The video processor 17 maps the video data as gray scale or gray mapping for video display. The gray scale image frames are then sent to video monitor 19 for display.

The image displayed by video monitor 19 is formed from an image frame of data such that each data indicates the intensity or brightness of a respective pixel of the display. The image frame is, for example, 2
It is composed of a 56 × 256 data array, etc.
Each intensity data in the array is an 8-bit binary number indicating the brightness of the pixel. The brightness of each pixel on the display monitor 19 is constantly updated by reading the value of the corresponding element in the data array in a known manner. Each pixel has an intensity value, which is a function of the cross-section of the backscatterer in each sample space in response to the interrogated ultrasonic pulse and the gray map used. Has become.

Referring to FIG. 4, system control is centralized in a host computer or processor 126, which receives operator input via an operator interface (not shown). Control various subsystems. Processor 126
It also generates system timing and control signals and includes a central processing unit (CPU) 130 and a random access memory 132. Keyboard 12
9 to input data to the CPU 130. CPU1
30 incorporates a read-only memory that stores the routines used to construct the gray and color maps based on the acquired raw data.

The scan converter 15 includes a polar memory 122 and an XY memory 124. Memory 1
The gray scale B-mode flow data and color flow intensity data stored at 22 in polar (R-.theta.) Sector format are converted to appropriately scaled Cartesian coordinate pixel display data, and X
It is stored in the Y memory 124. The color flow velocity data is stored in memory location 122CV, the color flow power data is stored in memory location 122CP,
Gray scale B-mode flow data is stored in memory location 122G. The color flow velocity data is also stored in memory location 124CV,
Flow power data is stored at memory location 124CP, and B flow gray scale data is stored at memory location 124G. The scan-converted frames are passed to video processor 17, which maps the data to a colored gray map for video display. The color flow data is essentially the correct B-mode flow data to be colorized.
Used as a tool to identify pixels. The colored gray scale image frames are then sent to a video monitor for display.

Successive frames of sound sample data are stored in cine memory 128 on a first-in first-out basis. The color speed frame is stored in memory location 128CV and the color power frame is stored in memory location 128CV.
The P flow and B flow gray scale frames are stored at memory location 128G. In the color region of interest, for each word of color velocity data and color power data corresponding to a display pixel, there is a corresponding word of B-flow gray scale data corresponding to that pixel. . The cine memory is like a cyclical image buffer running in the background, constantly capturing sound sample data and displaying it to the user in real time. When the user freezes the system, the user has the ability to view the sound sample data previously captured in the cine memory.

The CPU 130 has a system control bus 134
, A polar coordinate memory 122, an XY memory 124, and a cine memory 128 are controlled. Specifically, the CPU 13
0 indicates the flow of data from the polar coordinate memory 122 to the XY memory 124,
7 to the cine memory 128 and the video processor 17 and the CPU 12 from the cine memory.
6 controls the flow of data to itself. The CPU also converts the gray map, the color map, and the combination of the gray scale map and the color map to a video map.
Load into processor.

The image frames are collected in the cine memory 128 in a continuous manner. Cine memory 128 provides resident digital image storage for single image viewing and multiple image loop viewing, as well as various control functions. The region of interest displayed at the time of cine reproduction of a single image is the region used at the time of acquiring the image. The cine memory also serves as a buffer for transferring images via the processor 126 to a digital storage device (not shown).

The preferred embodiment combines color flow data (speed or power) with gray scale data, as shown by the block diagram in FIG. The data paths for each of channels 9G and 9C are separately processed and then combined, and the results are sent to display 19. The correct processing and combining algorithm 11 will vary depending on the desired result. For example, gray scale flow
The data and the color flow data may be simply added and displayed. In this case, it is necessary to adjust the size and the dynamic range of the gray scale data and the color flow data so that the characteristics of both imaging modes appear in the combined image. There is. Alternatively, the color flow data can be used as a threshold that the system later uses to determine whether to colorize the gray scale flow pixels. Other colorization methods will be apparent to those skilled in the art.

In addition, the combining algorithm is designed such that once both the color flow data and the gray scale flow data have been generated (after 8C and 8G in FIG. 1), any combination within a single path is possible. It may be embodied at a location (eg, any location within the receiving channels 9C and 9G). For example, color flow data and gray scale data
After each of the data has been converted to a display format and interpolated (ie, scan converted), the memory 124CV
And 124G or from memory 124CP and 124G
The color flow data and the gray scale data from the data can be combined on a pixel-by-pixel basis. The same data combination is performed using the memories 128CV, 128CP and 128C.
It can also be performed on data from G. Also, from the memories 122CV and 124G, or from the memories 122CV and 124G.
Color flow data and gray scale flow data from P and 122G may be combined. From the combined data, a combined signal is obtained that allows the formation of a colored gray scale image on the display 19.

The location of the combination of the gray scale flow and the color flow is controlled by a color flow region of interest (CROI) 160 (FIG. 7) that determines where the color flow data is being acquired. Is done. By adjusting the size and position of the color flow ROI 160,
In the composition mode, a part of the field of view or the entire field of view can be displayed. Areas outside the ROI 160 are processed using only gray scale data and displayed in the area 150 of the display 19.

FIG. 7 illustrates the combined color flow and gray scale images acquired using system 1 in ROI 160. The image shows the artery wall 162
166 shows a branch region 166 of the carotid artery having the following. In this case, a pixel-based combining algorithm 11 was used. The color flow data processing was similar to conventional power Doppler imaging, but the power values were converted to color pixels using a specialized color map. Gray generated according to system 1
Scale data was processed without correction. Memory 124
The data from the CP and 124G was combined according to the algorithm in the gray map generator 136. More specifically, gray scale and color flow PDI
Pixels were combined by adding their respective red, green, blue (RGB) values and displaying the result in ROI 160. Reducing the dynamic range and intensity of the color map displayed on the left side of the image made it possible to see the gray scale dynamics after combining the data, avoiding saturation and loss of contrast. Color·
Flow PDI and gray scale are mixed with color
CF ROI 16 displaying a gray scale image
Restricted to the area defined by 0. The remaining image area 150 was displayed using only gray scale data generated by channel 9G.

Those skilled in the art will appreciate that preferred embodiments can be changed and modified without departing from the spirit and scope of the invention as defined by the appended claims.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a preferred form of an ultrasound imaging system formed in accordance with the present invention.

FIG. 2 is a schematic block diagram of a portion of the color flow receive channel shown in FIG.

FIG. 3 is a schematic block diagram of a portion of the gray scale receive channel shown in FIG.

FIG. 4 is a schematic block diagram showing further details of each part of the system shown in FIG. 1;

FIG. 5 is a flow chart illustrating B-mode (basic) flow filtering with B-mode feed-through according to a preferred embodiment of the present invention.

FIG. 6 is a schematic block diagram illustrating a preferred mode of combining gray scale data and color flow data in accordance with the present invention.

FIG. 7 is a schematic diagram of an example of a form of display according to a preferred embodiment;

[Explanation of symbols]

 1 Ultrasound Imaging System 8C, 8G Intermediate Processor 9C Color Flow Channel 9G Gray Scale Channel 10 Transducer Array 12 Transducer Element 14 Transmitter 15 Scan Converter 16 Receiver 26 Transmit Beamformer 28 Time Gain Control (TGC) ) Amplifier 30 Receive beamformer 46 Wall filter 126 Host computer 150 Gray scale image region 160 Color flow region of interest 162, 164 Arterial wall 166 Carotid artery branch region

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seed Omar Ishraq, United States, Wisconsin, Fox Point, North Beach Drive, No. 8035 (72) Inventor Gary E. MacLeod, United States, Meno, Wisconsin Monney Falls, Old Hickory Road, N51.17,000 (72) Inventor Michelle G. Angle, United States, Wisconsin, Muskegow, Fairfield Court, Es 76. Anne Lindsay Hall West Top-O-Hill Drive, New Berlin, Wisconsin, United States, 16015 (72) James David Hamilton Five Fields Load Number 2, N.W.23708, Pea Walky, Wisconsin, United States of America Inventor Stephen Sea Miller Inventor, United States of America, Waukesha, Aspen, Wisconsin Wood Lane, W 226, N 2572 F term (reference) 4C301 AA02 CC02 DD01 DD06 EE01 EE20 HH01 HH17 JB23 JB35 JC13 KK02 KK03 KK12

Claims (20)

[Claims] 1. An ultrasonic system (1) comprising:
An apparatus for displaying an image of a subject (S) by combining data from a scale operation mode and data from a color flow operation mode, comprising: transmitting an ultrasonic beam into the subject; A transducer (10) adapted to receive echo ultrasound from the subject generated in response to the transmitted ultrasound and convert the echo ultrasound to a corresponding received signal; In a scale operation mode, the transducer transmits a first ultrasonic wave and generates a first received signal in response to an echo ultrasonic wave received in response to the first ultrasonic wave. Pulsing the transducer (10) a first predetermined number of times along each of said beams and in the color flow mode of operation, Transmitting a second ultrasonic wave and generating a second received signal in response to an echo ultrasonic wave received in response to the second ultrasonic wave. A transmitter (14) connected to pulse the transducer (10) a second predetermined number of times along with gray scale data representing motion of each portion of the subject in two dimensions. A first receiving channel (9G) responsive to the first received signal to generate; and a second received signal to generate color flow data representing motion of each portion of the subject. A responsive second receive channel (9C), configured to combine at least a portion of the gray scale data and at least a portion of the color flow data to generate a combined signal. And A processor (126), and a display (19) for displaying an image in response to the combined signal, such that movement of each part of the subject is represented by a colored gray scale image. Equipment equipped. 2. The apparatus of claim 1, wherein the gray scale mode of operation comprises a B mode of operation modified to allow visualization of the motion. 3. The apparatus of claim 2, wherein said color flow mode of operation comprises a color flow power mode of operation. 4. The apparatus of claim 2, wherein said color flow mode of operation comprises a color flow speed mode of operation. 5. The apparatus of claim 1, wherein the first received signal defines an amplitude value, and wherein the first received channel subtracts at least some of the amplitude values. 6. The apparatus of claim 1, wherein said first predetermined number is in a range of two to four. 7. The apparatus according to claim 5, wherein the first receiving channel (9G) comprises a wall filter. 8. The color flow data according to claim 2, wherein
4. The apparatus according to claim 3, wherein the power of the received signal is represented by: 9. The apparatus of claim 4, wherein said color flow data is representative of a velocity of each portion of said subject. 10. The apparatus of claim 6, wherein said second predetermined number is in the range of 6-16. 11. A method for displaying an image of a subject (S) by combining data from a gray scale mode of operation and data from a color flow mode of operation in an ultrasound system (1). Transmitting a beam of ultrasound into the subject (S) a first predetermined number of times along each of the plurality of ultrasound beams in the gray scale mode of operation; A first signal from the subject generated in response to the transmitted ultrasound.
Receiving the echo ultrasound waves of the following; converting the first echo ultrasound waves into a corresponding first received signal; and, in the color flow mode of operation, performing a second step along each of the plurality of ultrasonic beams. Transmitting a beam of ultrasound into the subject a predetermined number of times; and in the color flow mode of operation, a second beam from the subject generated in response to the transmitted ultrasound. Receiving the echo ultrasonic wave; converting the second echo ultrasonic wave to a corresponding second reception signal; and responding to the first reception signal in two dimensions to each part of the subject. Generating gray scale data representative of motion; generating color flow data representative of motion of each portion of the subject in response to the second received signal; appear Combining at least a portion of the gray scale data with at least a portion of the color flow data, wherein movement of each portion of the subject is represented by a colored gray scale image Displaying an image in response to the combined signal. 12. The gray scale mode of operation comprises:
The method of claim 11, including a B mode of operation modified to allow visualization of the movement. 13. The color flow operation mode includes a color flow power operation mode.
3. The method according to 2. 14. The method of claim 12, wherein the color flow mode of operation comprises a color flow speed mode of operation. 15. The method according to claim 11, wherein the first received signal defines an amplitude value, and generating gray scale data includes subtracting at least some of the amplitude values. The method described in. 16. The method of claim 11, wherein said first predetermined number is in the range of two to four. 17. The method of claim 15, wherein generating gray scale data comprises wall filtering the first received signal. 18. The method of claim 13, wherein said color flow data represents a power of a second received signal. 19. The method of claim 14, wherein said color flow data is representative of a velocity of each portion of said subject. 20. The method of claim 16, wherein said second predetermined number is in the range of 6-16.