Reducing reverberation artifacts in ultrasound images and associated devices, systems, and methods

Abstract

Various aspects of the present disclosure provide the following ultrasound systems and devices that reduce reverberation artifacts in ultrasound images by automatically changing imaging settings (e.g., PRI or transmit / receive configuration) based on an amount of reverberation detected in the ultrasound images. In an example embodiment, an apparatus includes a processor circuit in communication with an ultrasound probe. The processor circuit obtains a plurality of ultrasound images obtained using a plurality of different PRIs and / or pulse sequences, calculates an amount of reverberation artifacts in each of the plurality of ultrasound images, selects a pulse repetition interval and / or pulse sequence based on the amount of reverberation artifacts in each of the plurality of ultrasound images, and controls the ultrasound transducer to obtain a reduced-reverberation ultrasound image using the selected pulse repetition interval or pulse sequence. The reduced-reverberation ultrasound image is then output to a display.

Description

Technical Field

[0001] This disclosure relates generally to the acquisition and processing of ultrasound images, and particularly to systems and methods for reducing reverberation artifacts in ultrasound images obtained by ultrasound imaging equipment. Background Technology

[0002] Ultrasound imaging is frequently used to obtain images of a patient's internal anatomy. An ultrasound system typically includes an ultrasound transducer probe comprising an array of transducers coupled to a probe housing. The transducer array is activated to vibrate at ultrasound frequencies, thereby emitting ultrasound energy into the patient's anatomy. The ultrasound echoes reflected or backscattered by the patient's anatomy are then received to create an image. Such a transducer array can include various layers, including some with piezoelectric materials that vibrate in response to an applied voltage to generate the desired pressure waves. These transducers can be used to sequentially emit and receive several ultrasound pressure waves passing through various tissues of the body. The various ultrasound responses can be further processed by the ultrasound imaging system to visualize a wide range of structures and tissues of the body.

[0003] Ultrasonic transducer probes can be used to acquire ultrasound images in a variety of imaging modalities, including standard B-mode imaging, harmonic imaging, and contrast imaging. One challenge for clinicians in viewing and analyzing ultrasound images is distinguishing between portions of the image that represent artifacts or image clutter and portions that represent actual tissue structures. One type of artifact that can occur in ultrasound imaging is reverberation. Reverberation artifacts occur when vibrations of structures in the imaging field caused by previous emission events interfere with subsequent receive lines. This is because the time interval between emission events (called the pulse repetition interval (PRI)) is too short to allow the internal vibrations caused by previous pulses to dissipate or fade away. Some ultrasound imaging systems allow manual adjustment of the PRI. However, increasing the PRI (or conversely decreasing the pulse repetition frequency (PRF)) to reduce reverberation comes at the cost of a lower frame rate and increased blurring or clutter from tissue movement between pulses. Another technique for reducing reverberation is to introduce additional emission and / or receive events to sample and subtract the reverberation. This does not require changing the PRI but similarly reduces the frame rate by increasing the total number of emission / receive events per line. Therefore, there is a trade-off between reducing reverberation artifacts and maintaining high temporal resolution. Furthermore, while some systems allow for PRI adjustment, even trained clinicians are often unaware of PRI control or do not prefer to manipulate it. Summary of the Invention

[0004] Various aspects of this disclosure provide ultrasound systems and devices that reduce reverberation artifacts in ultrasound images by automatically adjusting imaging settings (e.g., PRI or transmit / receive configuration) based on the amount of reverberation detected in the ultrasound images. In an exemplary embodiment, an apparatus includes processor circuitry that communicates with an ultrasound probe and is configured to acquire multiple ultrasound images using multiple PRIs. The processor circuitry calculates and compares the amount of reverberation artifacts in each image to select the PRI that reduces reverberation artifacts, while also attempting to maintain the frame rate at an acceptable level. Automatically determining and / or adjusting imaging parameters (e.g., PRI) for the user advantageously improves workflow and increases physician confidence in the analysis of the acquired ultrasound images.

[0005] In another exemplary embodiment, an apparatus includes processor circuitry that communicates with an ultrasound probe and is configured to compare ultrasound images acquired using at least two different ultrasound pulse sequences, at least one of which is configured to reduce reverberation. The processor circuitry calculates and compares the degree of reverberation between the current pulse sequence and the pulse sequence configured to reduce reverberation, in order to select which sequence should be used to balance reverberation artifacts and frame rate loss. This automatically determines and / or adjusts imaging parameters for the user, advantageously improving workflow and increasing physician confidence in the analysis of the acquired ultrasound images.

[0006] In one embodiment, an apparatus for reducing reverberation artifacts in ultrasound images includes: a processor circuit in communication with an ultrasound transducer, wherein the processor circuit is configured to: control the ultrasound transducer, in communication with the processor circuit, to acquire multiple ultrasound images using corresponding multiple pulse repetition intervals; calculate the amount of reverberation artifact in each of the multiple ultrasound images; select a pulse repetition interval based on the amount of reverberation artifact in each of the multiple ultrasound images; in response to selecting the pulse repetition interval, control the ultrasound transducer to acquire a reverberation-reduced ultrasound image at the selected pulse repetition interval; and output the reverberation-reduced ultrasound image to a display in communication with the processor circuit.

[0007] In some embodiments, the processor circuitry is configured to: identify tissue portions and non-tissue portions of each of the plurality of ultrasound images; calculate an intensity value for the non-tissue portion of each of the plurality of ultrasound images; and determine the amount of reverberation artifact in each of the plurality of ultrasound images based on the calculated intensity value of the non-tissue portion of the plurality of ultrasound images. In some embodiments, the processor circuitry is configured to use a weighted algorithm to calculate the intensity value for the non-tissue portion of each of the plurality of ultrasound images, such that a first region of the corresponding ultrasound image closer to the focal point of the corresponding ultrasound image is assigned a greater weight than a second region of the corresponding ultrasound image farther from the focal point of the corresponding ultrasound image. In some embodiments, the processor circuitry is configured to: compare the amount of reverberation artifact in each of the plurality of ultrasound images with a threshold; and select the pulse repetition interval based on the comparison of the amount of reverberation artifact with the threshold. In some embodiments, the processor circuitry is configured to determine the threshold based on the amount of reverberation artifact in the ultrasound image associated with the maximum pulse repetition interval among the plurality of pulse repetition intervals. In some embodiments, the processor circuitry is configured to select the pulse repetition interval based on: a comparison of the amount of reverberation artifact with the threshold; and a predetermined maximum pulse repetition interval.

[0008] In some embodiments, the apparatus further includes the ultrasonic transducer. In some embodiments, the processor circuitry is configured to: control the ultrasonic transducer to acquire the multiple images by executing a multi-pulse sequence to obtain multiple receiver lines at a given location; perform incoherent summation on the multiple receiver lines; and determine the amount of reverberation artifact based on the incoherent summation of the multiple receiver lines. In some embodiments, the multiple receiver lines include a first receiver line and a second receiver line, and the processor circuitry is configured to perform incoherent summation on the multiple receiver lines by: calculating a first envelope for the first receiver line and a second envelope for the second receiver line; performing the following weighting: weighting the first envelope with a first summation weight and weighting the second envelope with a second summation weight; and performing incoherent summation on the weighted first envelope and the weighted second envelope. In some embodiments, the first receiving line corresponds to a first transmitting pulse having a first amplitude, the second receiving line corresponds to a second transmitting pulse having a second amplitude, and the first summation weight and the second summation weight are selected based on the ratio of the first amplitude of the first transmitting pulse to the second amplitude of the second transmitting pulse.

[0009] In some embodiments, a method for reducing reverberation artifacts in ultrasound images includes: controlling an ultrasound transducer to acquire multiple ultrasound images using corresponding multiple pulse repetition intervals; calculating the amount of reverberation artifact in each of the multiple ultrasound images; selecting a pulse repetition interval based on the calculated amount of reverberation artifact in each of the multiple ultrasound images; in response to selecting the pulse repetition interval, controlling the ultrasound transducer to acquire a reverberation-reduced ultrasound image with the selected pulse repetition interval; and outputting the reverberation-reduced ultrasound image to a display.

[0010] In some embodiments, the method further includes: identifying tissue portions and non-tissue portions of each of the plurality of ultrasound images; calculating an intensity value for the non-tissue portion of each of the plurality of ultrasound images; and calculating the amount of reverberation artifact in each of the plurality of ultrasound images based on the calculated intensity value of the non-tissue portion of the plurality of ultrasound images. In some embodiments, calculating the intensity value for the non-tissue portion of each of the plurality of ultrasound images includes using a weighted algorithm to calculate the intensity value for the non-tissue portion of each of the plurality of ultrasound images, such that a first region of the corresponding ultrasound image closer to the focal point of the corresponding ultrasound image is assigned a greater weight than a second region of the corresponding ultrasound image farther from the focal point of the corresponding ultrasound image.

[0011] In some embodiments, the method further includes: comparing the amount of reverberation artifact in each of the plurality of ultrasound images with a threshold; and selecting the pulse repetition interval includes selecting the pulse repetition interval based on the comparison of the amount of reverberation artifact with the threshold. In some embodiments, the method further includes determining the threshold based on the amount of reverberation artifact in the ultrasound image associated with the largest pulse repetition interval among the plurality of pulse repetition intervals. In some embodiments, selecting the pulse repetition interval includes selecting the pulse repetition interval based on: the comparison of the amount of reverberation artifact with the threshold; and a predetermined maximum pulse repetition interval. In some embodiments, controlling the ultrasound transducer to acquire the plurality of ultrasound images includes: performing a multi-pulse sequence to obtain a plurality of receiver lines at a given location; performing an incoherent summation on the plurality of receiver lines; and determining the amount of reverberation artifact based on the incoherent summation of the plurality of receiver lines. In some embodiments, the plurality of receiving lines includes a first receiving line and a second receiving line, and the incoherent summation of the plurality of receiving lines includes: calculating a first envelope for the first receiving line and a second envelope for the second receiving line; performing the following weighting: weighting the first envelope with a first summation weight and weighting the second envelope with a second summation weight; and performing an incoherent summation of the weighted first envelope and the weighted second envelope. In some embodiments, the first receiving line corresponds to a first transmit pulse having a first amplitude, the second receiving line corresponds to a second transmit pulse having a second amplitude, and the first summation weight and the second summation weight are selected based on the ratio of the first amplitude of the first transmit pulse to the second amplitude of the second transmit pulse.

[0012] In another embodiment, an apparatus for selecting a pulse sequence associated with reducing reverberation artifacts includes: a processor circuit in communication with an ultrasonic transducer, wherein the processor circuit is configured to: control the ultrasonic transducer, in communication with the processor circuit, to use a first pulse sequence to acquire a first ultrasonic image; control the ultrasonic transducer to use a second pulse sequence to acquire a second ultrasonic image; calculate the amount of reverberation artifact in each of the first and second ultrasonic images; compare the amount of reverberation artifact in the first ultrasonic image with the amount of reverberation artifact in the second ultrasonic image; select a pulse sequence based on the comparison of the amount of reverberation artifact; control the ultrasonic transducer to use the selected pulse sequence to acquire a reverberation-reduced ultrasonic image; and output the reverberation-reduced ultrasonic image to a display in communication with the processor circuit.

[0013] Other aspects, features, and advantages of this disclosure will become apparent from the following detailed description. Attached Figure Description

[0014] Illustrative embodiments of this disclosure will be described with reference to the accompanying drawings, in which:

[0015] Figure 1 This is a schematic diagram of an ultrasound imaging system according to an embodiment of the present disclosure.

[0016] Figure 2 This is a schematic diagram of a processor circuit according to an embodiment of the present disclosure.

[0017] Figure 3 These are ultrasound images of a patient’s body regions according to various aspects of this disclosure, the ultrasound images including reverberation artifacts.

[0018] Figure 4 This is a flowchart illustrating a method for reducing reverberation artifacts in ultrasound images according to various aspects of this disclosure.

[0019] Figure 5 This is a flowchart illustrating a method for reducing reverberation artifacts in ultrasound images according to various aspects of this disclosure.

[0020] Figure 6 It is a set of ultrasound images obtained using multiple pulse repetition intervals according to various aspects of this disclosure.

[0021] Figure 7 Based on various aspects of this disclosure Figure 6 The figure shows a graph of quantized reverberation artifacts in ultrasound images obtained at multiple pulse repetition intervals.

[0022] Figure 8A These are raw ultrasound images of a patient’s body regions according to various aspects of this disclosure, the ultrasound images including reverberation artifacts.

[0023] Figure 8B These are reverberation-reduced ultrasound images of a patient's body region according to various aspects of this disclosure, the reverberation-reduced ultrasound images being obtained using PRI selected using methods for reducing reverberation artifacts.

[0024] Figure 9 This is a graphical view of the reverberation in an amplitude-modulated multipulse ultrasound imaging sequence according to various aspects of this disclosure.

[0025] Figure 10 This is a graphical view of reverberation in an amplitude-modulated pulse-inversion multipulse ultrasound imaging sequence according to various aspects of this disclosure.

[0026] Figure 11This is a graphical view of reverberation in a pulse-inverted multipulse ultrasound imaging sequence according to various aspects of this disclosure.

[0027] Figure 12 This is a flowchart illustrating a method for determining the amount of reverberation artifacts in an ultrasound image according to various aspects of this disclosure.

[0028] Figure 13 These are ultrasound images obtained using multi-pulse sequences and filtered to show quantified reverberation artifacts, according to various aspects of this disclosure.

[0029] Figure 14 This is a flowchart illustrating a method for reducing reverberation artifacts in ultrasound images according to various aspects of this disclosure. Detailed Implementation

[0030] To facilitate an understanding of the principles of this disclosure, reference will now be made to embodiments illustrated in the accompanying drawings, and these embodiments will be described using specific language. Nevertheless, it should be understood that this disclosure is not intended to limit its scope. Any changes and further modifications to the described devices, systems, and methods, as well as any further applications of the principles of this disclosure, are fully contemplated and included within this disclosure, as will commonly conceived by those skilled in the art to which this disclosure pertains. In particular, it is fully anticipated that features, components, and / or steps described with respect to one embodiment may be combined with features, components, and / or steps described with respect to other embodiments of this disclosure. However, for the sake of brevity, numerous iterations of these combinations will not be described separately.

[0031] exist Figure 1The present invention illustrates, in block diagram form, an ultrasonic system 100 according to an embodiment of the present disclosure. An ultrasonic probe 10 has a transducer array 12 comprising a plurality of ultrasonic transducer elements or acoustic elements. In some instances, the array 12 may include any number of acoustic elements. For example, the array 12 is capable of including from 1 acoustic element to 100,000 acoustic elements, including, for example, 2 acoustic elements, 4 acoustic elements, 36 acoustic elements, 64 acoustic elements, 128 acoustic elements, 300 acoustic elements, 812 acoustic elements, 3,000 acoustic elements, 9,000 acoustic elements, 30,000 acoustic elements, 65,000 acoustic elements, and / or other more and fewer acoustic elements. In some instances, the acoustic elements of array 12 can be arranged in any suitable configuration, such as a linear array, planar array, curved array, zigzag array, circular array, ring array, phased array, matrix array, one-dimensional (1D) array, 1.x-dimensional array (e.g., 1.5D array), or two-dimensional (2D) array. The array of acoustic elements (e.g., one or more rows, one or more columns, and / or one or more orientations) can be uniformly or independently controlled and activated. Array 12 can be configured to acquire one-dimensional, two-dimensional, and / or three-dimensional images of the patient's anatomy.

[0032] While this disclosure refers to synthetic aperture external ultrasound imaging using an external ultrasound probe, it should be understood that one or more aspects of this disclosure can also be implemented in any suitable ultrasound imaging probe or system, including external ultrasound probes and intracavitary ultrasound probes. For example, various aspects of this disclosure can be implemented in an ultrasound imaging system using a mechanically scanning external ultrasound probe, an intracardiac (ICE) echocardiography catheter and / or a transesophageal echocardiography (TEE) probe, a rotating intravenous ultrasound (IVUS) probe, a phased array IVUS imaging catheter, a transthoracic echocardiography (TTE) imaging device, or any other suitable type of ultrasound imaging device.

[0033] Refer again Figure 1 The acoustic elements of array 12 may include one or more piezoelectric / piezoresistive elements, lead zirconate titanate (PZT), piezoelectric micromechanical ultrasonic transducer (PMUT) elements, capacitive micromechanical ultrasonic transducer (CMUT) elements, and / or any other suitable type of acoustic element. One or more acoustic elements of array 12 communicate (e.g., are electrically coupled) with electronic circuitry 14. In some embodiments (e.g., Figure 1In one embodiment, electronic circuitry 14 may include a microwave beamformer (μBF). In another embodiment, electronic circuitry includes a multiplexer circuit (MUX). Electronic circuitry 14 is located in probe 10 and communicatively coupled to transducer array 12. In some embodiments, one or more components of electronic circuitry 14 may be located in probe 10. In some embodiments, one or more components of electronic circuitry 14 may be located in computing device or processing system 28. Computing device 28 may be or include a processor, such as one or more processors communicating with memory. As further described below, computing device 28 may include... Figure 2 The processor circuitry is shown. In some aspects, some components of electronic circuitry 14 are located in probe 10, while other components of electronic circuitry 14 are located in computing device 28. Electronic circuitry 14 may include one or more electrical switches, transistors, programmable logic devices, or other electronic components configured to combine and / or continuously switch between multiple inputs to transmit signals from each of the multiple inputs on one or more common communication channels. Electronic circuitry 14 may be coupled to elements of array 12 via multiple communication channels. Electronic circuitry 14 is coupled to cable 16, which transmits signals including ultrasound imaging data to computing device 28.

[0034] In computing device 28, signals are digitized and coupled to channels of system beamformer 22, which appropriately delays each signal. The delayed signals are then combined to form a coherent steering-focusing receiving beam. The system beamformer may include electronic hardware components, software-controlled hardware, or a microprocessor running a beamforming algorithm. In this respect, beamformer 22 may be referred to as electronic circuitry. In some embodiments, beamformer 22 can be a system beamformer, for example, Figure 1The system beamformer 22, or beamformer 22 may be a beamformer implemented by circuitry within the ultrasonic probe 10. In some embodiments, the system beamformer 22 works in conjunction with a microwave beamformer (e.g., electronic circuitry 14) disposed within the probe 10. In some embodiments, beamformer 22 may be an analog beamformer, or in some embodiments, beamformer 22 may be a digital beamformer. In the case of a digital beamformer, the system includes an A / D converter that converts the analog signal from array 12 into sampled digital echo data. Beamformer 22 will typically include one or more microprocessors, shift registers, and / or digital or analog memories to process the echo data into coherent echo signal data. Delay is achieved by various means, such as the sampling time of the received signal, the write / read interval of data temporarily stored in memory, or by the length of the shift register or the clock rate, as described in U.S. Patent US4,173,007 to McKeighen et al., which is incorporated herein by reference in its entirety. Additionally, in some embodiments, the beamformer is capable of applying appropriate weights to each signal in the signal generated by array 12. The beamformed signals from the image field are processed by signal and image processor 24 to produce 2D or 3D images for display on image display 30. Signal and image processor 24 may include electronic hardware components, software-controlled hardware, or a microprocessor running image processing algorithms. It will also typically include dedicated hardware or software that processes the received echo data into image data for (e.g., a scan converter) a desired display format. In some embodiments, beamforming functions can be partitioned among different beamforming components. For example, in some embodiments, system 100 may include a microwave beamformer located within probe 10 and communicating with system beamformer 22. The microwave beamformer may perform preliminary beamforming and / or signal processing, which can reduce the number of communication channels required to transmit received signals to computing device 28.

[0035] Under the control of the system controller 26, which is coupled to the various modules of system 100, control is exercised over ultrasound system parameters (e.g., scanning modes (e.g., B-mode, M-mode), probe selection, beam control and focusing, and signal and image processing). The system controller 26 may be formed from application-specific integrated circuits (ASICs) or microprocessor circuits and software data storage devices (e.g., RAM, ROM, or disk drives). In the case of probe 10, some of this control information can be provided from computing device 28 to electronic circuitry 14 via cable 16, which is then adjusted according to the needs of a specific scanning procedure for operating the array. The user inputs these operating parameters via user interface device 20.

[0036] In some embodiments, image processor 24 is configured to generate images in different modes, which are then further analyzed or output to display 30. For example, in some embodiments, the image processor can be configured to compile B-mode images of the patient's anatomy, such as live B-mode images. In other embodiments, image processor 24 is configured to generate or compile M-mode images. M-mode images can be described as images showing the temporal changes of the imaged anatomy along a single scan line.

[0037] It should be understood that computing device 28 may include hardware circuitry (e.g., computer processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), capacitors, resistors, and / or other electronic devices), software, or a combination of hardware and software. In some embodiments, computing device 28 is a single computing device. In other embodiments, computing device 28 includes separate computer devices that communicate with each other.

[0038] Figure 2 This is a schematic diagram of a processor circuit 150 according to an embodiment of the present disclosure. The processor circuit 150 may be implemented in... Figure 1 The computing device 28, signal and image processor 24, controller 26, and / or probe 10 are included. As shown, the processor circuitry 150 may include a processor 160, a memory 164, and a communication module 168. These components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0039] Processor 160 may include a central processing unit (CPU), digital signal processor (DSP), ASIC, controller, FPGA, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein. Processor 160 may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor), multiple microprocessors, one or more microprocessors used in conjunction with a DSP core, or any other such configuration.

[0040] Memory 164 may include cache memory (e.g., cache memory of processor 160), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory devices, hard disk drives, other forms of volatile and non-volatile memory, or combinations of different types of memory. In embodiments, memory 164 includes a non-transient computer-readable medium. Memory 164 may store instructions 166. Instructions 166 may include instructions that, when executed by processor 160, cause processor 160 to perform actions referred herein to processor 28 and / or probe 10 (…). Figure 1 The operation described. Instruction 166 may also be referred to as code. The terms "instruction" and "code" should be interpreted broadly as including one or more computer-readable statements of any type. For example, the terms "instruction" and "code" can refer to one or more programs, routines, subroutines, functions, processes, etc. "Instruction" and "code" can include a single computer-readable statement or many computer-readable statements.

[0041] The communication module 168 can include any electronic and / or logic circuitry to facilitate direct or indirect communication between the processor 28, the probe 10, and / or the display 30. In this respect, the communication module 168 can be an input / output (I / O) device. In some instances, the communication module 168 facilitates communication between the processor circuitry 150 and / or the processing system 160. Figure 2 Direct or indirect communication between the various components of a device.

[0042] As mentioned above, ultrasound images can include many undesirable artifacts, including reverberation artifacts. Reverberation artifacts are particularly undesirable in certain ultrasound imaging modalities (e.g., contrast imaging) where physicians aim to visualize blood flow below the skin layer. In many cases, it is desirable to operate at the fastest possible frame rate by minimizing the pulse repetition interval (PRI) and using as few pulses as possible in a multi-pulse sequence. One factor contributing to some reverberation artifacts in the images is insufficient PRI between pulses used to acquire the ultrasound image, causing echoes from deeper structures outside the imaging area to be received along with subsequent receive lines. Because it takes time for acoustic reverberation to dissipate in tissues and anatomical structures, short PRI maximizing the frame rate can cause artifacts that appear as uniformly spaced lines in the ultrasound image or diffuse noise appearing within the imaging area. One way to reduce these artifacts is simply to increase the PRI at the expense of the frame rate. While some systems allow PRI adjustment, adjusting the PRI can be too complex for some physicians who may not understand the physics behind reverberation and PRI. Therefore, some physicians may avoid adjusting the PRI. Without changing the PRI (Primary Intensity Level), physicians attempt to distinguish real structures from reverberation artifacts in ultrasound images, which can be difficult and inaccurate. Another way to reduce these artifacts is to modify the multi-pulse sequence for better sampling and reverberation elimination, typically achieved by introducing additional transmit and / or receive events at the expense of frame rate. Systems generally do not allow users to change the pulse configuration in response to reverberation; therefore, system designers can choose a preferred sequence to allow reverberation and maximize frame rate, or reduce reverberation and thus accept a lower frame rate.

[0043] Therefore, this disclosure provides apparatus, systems, and methods for automatically adjusting imaging settings (e.g., PRI and pulse sequence configuration) to reduce reverberation artifacts in ultrasound images. In this regard, the amount of reverberation artifacts in an image can be associated with the PRI or pulse configuration of an imaging sequence. Therefore, this application describes embodiments of systems and methods for automatically adjusting PRI and / or pulse configurations in a manner specifically designed to reduce reverberation artifacts. Automatic adjustment can be performed to maintain the frame rate of the imaging sequence at or above a certain level acceptable to the user. In this regard, embodiments of this disclosure relate to: identifying reverberation in one or more ultrasound images and automatically selecting a PRI and / or switching to an alternative pulse sequence based on the identification of reverberation artifacts. For example, apparatus, systems, and methods are provided that quantify reverberation artifacts in ultrasound images obtained using different PRIs, analyze the quantified reverberation artifacts for each image to select a PRI that reduces reverberation artifacts, and control an ultrasound probe to acquire images using the selected PRI to obtain reverberation-reduced ultrasound images.

[0044] Figure 3 These are ultrasound images obtained through an external ultrasound imaging system. Image 200 is obtained from an anatomical region of the patient's body and shows a skin region 210 and a reverberant region 220 at a deeper depth relative to that skin region. The skin region 210 may be associated with non-reverberant signals or true signals reflected from the skin and / or other tissue structures. In contrast, some or all of the reverberant region 220 may be associated with acoustic reverberation and therefore do not reflect the actual tissue structure within the anatomical structure. Artifacts and obfuscation in the reverberant region 220 can unintentionally impair a physician's ability to visualize anatomical structures and make diagnoses. Therefore, diagnostic confidence is reduced.

[0045] Figure 4 This is a flowchart illustrating a method 300 for reducing reverberation artifacts in ultrasound images according to an embodiment of the present disclosure. It should be understood that one or more steps of method 300 may be, for example, performed by… Figure 1 The ultrasound imaging system 100 and / or shown Figure 2 The processor circuit 150 shown is used to execute this. In step 310, the ultrasound transducer is controlled to acquire multiple ultrasound images using corresponding multiple pulse repetition intervals (PRI). In some embodiments, the ultrasound transducer includes an external ultrasound probe comprising an array of ultrasound transducer elements. However, other types of ultrasound transducers may also be used to perform method 300, including intravascular ultrasound (IVUS) devices, intracardiac echocardiography (ICE) catheters, transesophageal echocardiography (TEE) probes, transthoracic echocardiography (TTE) probes, or any other suitable ultrasound imaging device. In some embodiments, the system may include a user input device, such as a mouse, keyboard, touchscreen, and / or any other suitable user input device. Method 300 may be initiated by a user via a user input device. For example, in some embodiments, method 300 is initiated by a user pressing or selecting a button or icon (e.g., an icon on a touchscreen). In some embodiments, once initiated, method 300 automatically executes each step of method 300. In some embodiments, one or more steps of method 300 are performed in the background such that one or more steps of method 300 are not displayed on the screen. In some embodiments, one or more steps of the method are displayed on the screen so that a user or operator can monitor the progress of method 300.

[0046] In an exemplary embodiment, different PRIs are used to obtain each of the multiple ultrasound images. For example, the PRI may include a set of gradually varying PRIs. In step 310, any suitable number of ultrasound images and corresponding PRIs may be used, including the standard bidirectional propagation time (time of flight) of the sound waves in the imaging window plus 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 30, 50, or any other suitable (larger and smaller) number of microseconds. PRIs may be expressed or measured in time (e.g., μs, ms), depth or distance (e.g., mm), pixels, or any other suitable unit of measurement. In some embodiments, the PRI varies between a minimum PRI and a maximum PRI. In some embodiments, the minimum PRI is 0, such that there is virtually no gap or rest time between pulses, exceeding the standard bidirectional propagation time of the sound waves. In some embodiments, the minimum PRI is based on the hardware functionality of the ultrasound transducer's switching from receiving to transmitting. In some embodiments, the minimum PRI is predetermined by the processor circuitry and / or the ultrasound transducer manufacturer as representing the minimum amount of time allowed for vibration in the tissue and / or the minimum amount of time for the ultrasound transducer to dissipate before transmitting the next pulse. In some embodiments, a maximum PRI is predetermined, selected, or otherwise configured in the processor circuitry based on various imaging factors, including the specific scan sequence used (e.g., multi-pulse, pulse inversion, single-pulse, etc.), the desired imaging depth or focal zone, and / or the minimum frame rate. In some embodiments, the different PRIs used to acquire multiple ultrasound images vary in a constant increment. In other embodiments, the different PRIs vary in a non-constant or non-linear manner. In some embodiments, in step 310, only one ultrasound image is acquired for each PRI. In other embodiments, multiple images are acquired for each PRI.

[0047] In step 320, multiple ultrasound images are analyzed to calculate the amount of reverberation artifacts in each of the multiple ultrasound images. In the context of this disclosure, analyzing ultrasound images can refer to performing signal processing on electrical signals output from a transducer array and / or image processing on image data generated based on electrical signals output from the transducer array. In some embodiments, the amount of reverberation artifacts in an image can be quantified or inferred by removing or suppressing tissue in the image and summing the remaining signal or intensity in the image. The summed remaining signal can represent the amount of reverberation artifacts present in the image or related to it, and may also represent other artifacts. In some embodiments, a weighted algorithm is used to calculate the amount or intensity value of the intensity of non-tissue portions for each ultrasound image. The weighted algorithm can be applied such that specific regions of the ultrasound image are given greater weight than other regions. For example, in some embodiments, the non-tissue signal intensity in ultrasound image regions closer to the focal point of the ultrasound transducer is given greater weight than the non-tissue signal intensity in ultrasound image regions farther from the focal point.

[0048] Therefore, in some embodiments, multiple ultrasound images are analyzed to distinguish between tissue and non-tissue portions in each of the multiple ultrasound images. Each ultrasound image can then be analyzed to calculate the remaining overall intensity value. The amount of reverberation artifact for each ultrasound image can be determined based on the calculated intensity value. In other embodiments, a reverberation detection algorithm can be used to distinguish the contribution of reverberation artifacts and other factors to the image. Since the ultrasound images are obtained using different PRIs, it can be expected that the amount of reverberation artifact varies based on the PRI associated with a particular image.

[0049] In step 330, the amount of reverberation artifact in each of the multiple ultrasound images is analyzed to select a PRI. In some embodiments, analyzing the amount of reverberation artifact includes comparing the amount of reverberation artifact. For example, the amount of reverberation artifact in each image can be compared to a threshold. As further explained below, the threshold can be determined based on the minimum intensity image and / or the maximum PRI image. In other embodiments, the amount of reverberation artifact in each image is compared to the amount of reverberation artifact in other images. Based on this comparison and / or analysis, a PRI associated with reduced reverberation artifact is selected. For example, the selected PRI could be the PRI closest to but not exceeding the threshold. In other embodiments, the selected PRI is determined based on the mean, median, statistical distribution (e.g., Gaussian), or any other statistically significant value determined by comparing the intensity values ​​of the multiple images. In some embodiments, the PRI can be selected such that it does not exceed a predetermined maximum PRI. The predetermined maximum PRI can be determined by the manufacturer such that the frame rate of the ultrasound images does not fall below a lower limit. In some embodiments, the predetermined maximum PRI may vary based on the imaging modality used, imaging depth, and / or other imaging parameters.

[0050] In many instances, the selected PRI associated with reduced reverberation artifacts can be higher than the initially used PRI, which can lead to a decrease in frame rate. However, while reverberation artifacts decrease as PRI increases, it is undesirable to select an excessively high PRI that results in an unsatisfactory frame rate. As mentioned above, in some cases, physicians may prefer to maintain the frame rate above a certain level, even if some reverberation artifacts remain. Therefore, the PRI can be selected in a way that balances the benefits of reducing reverberation artifacts with the benefits of maintaining a high frame rate. For example, in some aspects, the system can be configured to select only the PRI at or below a predetermined maximum PRI. Additionally, the system can be configured to establish or determine a threshold based on the minimum reverberation detected across multiple images, allowing a satisfactory level of reverberation to maintain a sufficiently high frame rate for imaging applications.

[0051] In step 340, in response to selecting the PRI, the ultrasound transducer is controlled to obtain a reverberation-reduced ultrasound image at the selected PRI. In step 350, the reverberation-reduced ultrasound image is output to a display. It should be understood that the steps of method 300 can be repeated to generate and display a live view or live stream of the reverberation-reduced ultrasound image. Additionally, in some embodiments, the user can stop method 300 by selecting user input on a user input device. For example, if a particular imaging application or modality is unlikely to produce reverberation, the user can terminate method 300 to return the PRI to its default or initial value.

[0052] Figure 5 This is a flowchart illustrating a method 400 for reducing reverberation artifacts in ultrasound images according to an embodiment of the present disclosure. It should be understood that one or more steps of method 400 may be performed by… Figure 1 The ultrasound imaging system 100 and / or shown Figure 2 The processor circuit 150 shown is used to execute this. In some aspects, one or more steps of method 400 can be used to execute... Figure 4 Method 300 is shown. In step 410, the processor circuitry or processing system controls the ultrasound transducer to acquire multiple ultrasound images of tissue suppression using corresponding multiple PRIs. In some aspects, the processor circuitry may be configured to suppress tissue in the ultrasound images using image processing techniques. In some aspects, the processor circuitry may receive user input to initiate a tissue suppression protocol via a user input device. In some embodiments, the tissue suppression protocol is automatically activated as part of a reverberation reduction protocol. In this regard, in some embodiments, method 400 is initiated by user input and continues to execute each step of method 400 automatically. In some embodiments, one or more steps of method 400 are executed in the background such that one or more steps of method 400 are not displayed on the screen.

[0053] Figure 6 This includes multiple ultrasound images acquired during step 410 of method 400. In this regard, each of the multiple tissue-suppressed ultrasound images 412a-412f is obtained using corresponding PRI 414a-414f. The corresponding PRI 414a-414f is illustrated as the time interval between successive emission pulses. Figure 6 In one embodiment, each PRI 414 is illustrated as the spacing between the beginnings of successive transmit pulses. However, in other embodiments, PRI 414 may be defined, for example, by the distance between the centers or ends of successive transmit pulses. Figure 6 As can be seen, with the increase of PRI414, the overall intensity or bright portion of the ultrasound image 412 decreases. Since tissue has already been suppressed in ultrasound image 412, it can be inferred that the remaining portion is likely due to image clutter (e.g., reverberation artifacts). Therefore, by increasing PRI, more time is allowed for reverberation in the anatomical structures to dissipate, and fewer reverberation artifacts are visible. Thus, ultrasound image 412f obtained using the maximum PRI 414f has the least amount of residual reverberation artifacts.

[0054] Refer again Figure 5In step 420, the processor circuit sums the residual intensity values ​​of the ultrasound images with tissue suppression and normalizes the summed intensity values ​​for each ultrasound image. The processor circuit is configured to normalize the summed intensity values ​​based on the minimum intensity value of the minimum intensity image among multiple ultrasound images. However, in other embodiments, the processor circuit is configured to normalize for other values ​​(e.g., the maximum intensity value image, the average summed intensity value, or a predetermined intensity value). In step 430, a threshold is selected or determined based on the summed intensity values ​​of the ultrasound images. For example, the threshold may be selected based on the ultrasound image containing the minimum reverberation. For example, referring to... Figure 6 The threshold can be selected based on the ultrasound image 412f that includes the lowest amount of reverberation artifacts and / or the lowest amount of residual image intensity. In other embodiments, the threshold 432 is selected based on the ultrasound image associated with the maximum PRI.

[0055] In step 440, the normalized intensity value calculated in step 420 for each ultrasound image is compared with a threshold to select the desired PRI. In this regard, Figure 7 This is a graphic 500 illustrating aspects of steps 420-440. For example, the graphic or plot 500 shows the summed normalized intensity values ​​422a-422f of tissue inhibition images 412a-412f relative to a threshold 432, with PRI as the x-axis. Figure 7 In this context, additional PRI increments are represented by depth in millimeters. However, other units of measurement can also be used for PRI, including units of time, pixels, or any other suitable type of measurement. It can be seen that in... Figure 7 In this context, PRI represents the additional delay beyond the minimum bidirectional acoustic propagation time, and is associated with normalized intensity values ​​422a-422f of ultrasound images ranging from 0 mm to 250 mm (in increments of 50 mm). In other words, referencing... Figure 7 A PRI of 0mm indicates a minimum PRI, which has no additional delay or buffering beyond the bidirectional acoustic propagation time associated with the acoustic pulse. In other embodiments, such as Figure 7 As shown, the intervals between the multiple PRIs are not gradual and uniform. For example, in some embodiments, the PRIs vary by varying amounts (e.g., 10 mm, 20 mm, 25 mm, 30 mm, 100 mm and / or any other suitable (larger or smaller) increments).

[0056] refer to Figure 5-7 The threshold 432 can be determined based on the ultrasound image with minimum tissue suppression (e.g., 412f). The threshold 432 can also be determined based on the percentage of the normalized sum of the intensity of the minimum intensity ultrasound image (e.g., 412f). For example, in... Figure 7In one embodiment, the threshold 432 can be determined by adding 3% of the normalized summation intensity of the ultrasound image 412f. In other embodiments, the threshold 432 is determined by adding 1%, 2%, 5%, 10%, or any other suitable (larger and smaller) percentage of the normalized summation intensity of the ultrasound image. The desired PRI is selected by identifying the PRI associated with the normalized intensity value that is closest to but does not exceed the threshold 432. Figure 7 In this embodiment, the desired or selected PRI is 150 mm, which is associated with the normalized intensity value 422d. In other embodiments, the desired PRI is selected by identifying the PRI associated with the normalized intensity value closest to the threshold 432, regardless of whether the corresponding PRI exceeds the threshold 432. In some embodiments, the desired PRI is determined based on interpolation between two or more PRIs. In some embodiments, the desired PRI is selected by calculating the best-fit line or curve of two or more normalized intensity values ​​in the normalized intensity values ​​422 and determining the intersection point between the threshold 432 and the best-fit line or curve.

[0057] In step 450, the ultrasound transducer is controlled, set, or configured to acquire one or more reverberation-reduced ultrasound images at a selected PRI. In some embodiments, method 400 further includes configuring the system to retain tissue features previously reduced, suppressed, or discarded in step 410. In some embodiments, this involves disabling tissue suppression features. In some embodiments, tissue suppression features may include a protocol or set of instructions stored in memory as part of an image processing sequence or computer program. In some embodiments, tissue suppression features are automatically disabled, and the ultrasound transducer is automatically configured using the selected PRI in response to selection. In some embodiments, the operator disables the tissue suppression features. In step 460, one or more reverberation-reduced ultrasound images are output to a display.

[0058] Figure 8A and Figure 8B The diagram illustrates the reverberation reduction effect of method 300 and / or method 400 in the ultrasound imaging process. In this respect, Figure 8A Image 402 is shown before the application of reverberation reduction techniques. In this regard, either the default PRI or the initial PRI can be used. Figure 8A Image 402. For image 402, the initial PRI can be compared to... Figure 8B The significantly shorter PRI used results in substantial reverberation artifacts in region 442 of image 402. As mentioned above, these reverberation artifacts are particularly undesirable in contrast imaging procedures used to indicate and / or quantify blood flow in region 442. Figure 8BAn ultrasound image 452 obtained using the reverberation techniques described above with respect to methods 300 and / or 400 is shown. In this respect, Figure 8B Image 452 includes with Figure 8A Image 402 shown has the same image features and imaging area, but it was acquired using an adjusted PRI that was automatically selected and set according to methods 300 and / or 400 described above. Therefore, in region 462 of image 452, reverberation artifacts are significantly reduced or eliminated, while tissue features remain.

[0059] Some ultrasound imaging modalities that rely on pulse-to-pulse cancellation (e.g., contrast imaging and tissue harmonics) are particularly susceptible to reverberation artifacts. Figure 9-11 These are graphical views of various multi-pulse ultrasound imaging sequences 610, 620, and 630 (with reverberation present). Specifically, Figure 9 An amplitude-modulated multipulse sequence 610 is shown. Figure 10 An amplitude modulation pulse inversion (AMPI) multipulse sequence 620 is shown, and Figure 11 A pulse inversion sequence 620 is shown. In each sequence, multiple transmit pulses are used for a given position (e.g., position -1, position 0, position 1). The transmit pulses vary in amplitude and / or phase. For example, Figure 9 The amplitude modulation sequence 610 shown includes three transmit pulses for each position, where the first and third pulses are weighted at 0.5, and the second pulse is weighted at 1.0. When the individual echoes of the pulses are summed in amplitude modulation, the linear frequency components of the echo signal are canceled out, while the nonlinear components are preserved. However, referring again... Figure 9 The reverberation 612 caused by a pulse in sequence 610 at a given location can spill over into other receiver lines at the same location or into receiver lines at subsequent locations. Therefore, a standard 3-pulse amplitude modulation implementation can effectively cancel a fixed linear signal, but may not be able to cancel the signal caused by reverberation. (See reference...) Figure 10 and Figure 11 Other multi-pulse sequences (e.g., AMPI 620 sequence and pulse inversion 630 sequence) can more effectively cancel some artifacts caused by reverberation 622, 632, but cannot cancel all artifacts caused by reverberation 622, 632. For example, in AMPI 620 and pulse inversion 630, if (1) the inter-pulse interval and intra-pulse interval are different, causing the reverberation instances to shift relative to each other; (2) a three-pulse inversion scheme is used to deal with motion “flickering” artifacts; or (3) when differential harmonics are used in pulse inversion to generate two sets of data (e.g., (pulse 1 + pulse 2) and (pulse 1 - pulse 2)), then reverberation artifacts may be present in the resulting image.

[0060] Although multi-pulse sequences can produce reverberation artifacts, reverberation techniques can also be used to detect reverberation in the resulting image by weighted summation of individual pulses in the sequence. In this respect, Figure 12 This is a flowchart of a method 700 for detecting reverberation in a multi-pulse sequence. It should be understood that one or more steps of method 700 can be, for example, performed by... Figure 1 The ultrasound imaging system 100 and / or shown Figure 2 The processor circuit 150 shown is used to execute this. In some aspects, one or more steps of method 400 can be used to execute... Figure 4 Method 300 is shown. For example, in some aspects, the steps of method 700 can be used to perform steps 310 and / or 320 of method 300. In step 710, the processor circuitry or processing system controls the ultrasonic transducer to execute a multi-pulse sequence to obtain multiple receive lines at a given location. These receive lines include echo signals caused by corresponding transmit pulses of the sequence. In some embodiments, the transmit pulses of the multi-pulse sequence can be weighted differently, including weights of 0.5, 1.0, -0.5, 1.0, 0.33, or any other suitable larger and smaller weights. For example, a pulse with a weight of -1.0 can represent the reciprocal of the waveform form of a pulse with a weight of 1.0.

[0061] In step 720, the processor circuitry calculates the envelope of each receive line in the receive lines. In some aspects, calculating the envelope of a receive line may include applying analog and / or digital functions or operations to the receive lines. For example, in some embodiments, calculating the envelope may include applying a Hilbert transform to the signal lines. In some aspects, calculating the envelope of a receive line may include sampling and / or digitizing the receive line signals. In some aspects, the receive line signals may be digitized before calculating the envelope.

[0062] In step 730, summation weights are applied to the first and second computed envelopes. In step 740, the weighted envelopes are incoherently summed to produce a summed receiver line. It should be understood that incoherent summation refers to summing the envelopes that have lost phase information, rather than coherent summing the receiver lines that have phase information in the summation. In some embodiments, the summation weights are applied to the envelopes in step 730 such that the non-reverberant portion of the envelope (e.g., tissue signal) is canceled out, while the reverberant portion of the envelope is still preserved. For example, in some embodiments, a first summation weight of -1.0 is applied to the first envelope, and a second summation weight of 1.0 is applied to the second envelope. Summation weights with opposite signs but equal amplitudes enable the common signal portion for each envelope to be canceled out, while the difference signal portion between the first and second envelopes is still preserved.

[0063] In some respects, steps 720-740 can be performed to generate a summed receiver line representing the reverberation at a given location using a three-pulse sequence according to the following formula:

[0064] Reverberation = Weighted sum of weight 1 (envelope (R receiver line 1)) + Weighted sum of weight 2 (envelope (receiver line 2)) + Weighted sum of weight 3 (envelope (receiver line 3))

[0065] Wherein, summation weight 1, summation weight 2, and summation weight 3 are the summation weights for the first envelope, second envelope, and third envelope of the corresponding weighted reception line, respectively. The above formula calculates the intensity and depth of reverberation at a given location or scan line. In step 750, by calculating for each location in the ultrasound image (e.g., Figure 9-11 The amount of reverberation in an ultrasound image or field of view is determined, calculated, estimated, and / or mapped using the position (-1, 0, 1) or the reverberation of each scan line. Figure 13 This is a mapping or image 800 that shows only reverberation artifacts in the ultrasound image after filtering using the method 700 and formula described above. It can be observed that the reverberation is stronger or more intense in the deeper parts of the image. In some embodiments, in the method (e.g., Figure 4 In embodiment 300, the amount of reverberation quantified by method 700 can be used to automatically control the PRI or select the pulse sequence or configuration of the ultrasonic transducer to reduce the amount of reverberation artifacts in the image. In other embodiments, method 700 can be used to identify the location and amount of reverberation artifacts in the image, so that reverberation artifacts can be subtracted or removed from the image regardless of whether the PRI is adjusted or the pulse sequence is changed.

[0066] It should be understood that similar formulas can be used for other multi-pulse sequences (e.g., pulse inversion) that use fewer or more pulses at a given location. For example, the above formula can be modified to include a third receiver line and a third summation weight to calculate the amount of reverberation at a given location. (The remaining text appears to be incomplete and requires further context.) Figure 9-11 The multi-pulse sequences 610, 620, and 630 shown use the methods 700 and / or formulas discussed above. For example, for... Figure 9 The amplitude-modulated multipulse sequence 610 shown (which includes a first receive line, a second receive line, and a third receive line corresponding to the first transmit pulse, the second transmit pulse, and the third transmit pulse) can have the above formula applied to the first envelope, the second envelope, and the third envelope respectively using summation weights (0, -1, 2), such that only the second and third envelopes of the weighted receive lines are considered. Alternatively, a similar result can be obtained using summation weights (1, -1, 1). Figure 10 The AMPI sequence 620 shown can be applied using the above formula with summation weights (0, -1, 2), as shown in the amplitude modulation sequence 610. For Figure 11 The PI sequence 630 shown can be applied using summation weights (1, -1) to apply the above formula. Therefore, the summation weights applied to each receive line in the multi-pulse sequence can be selected or configured based on the type of the applied multi-pulse sequence and the transmit weights applied to the corresponding transmit pulses. In some embodiments, the applied summation weights can be based on the ratio of the amplitudes of different receive lines. For example, in two pulse sequences (where a first transmit pulse includes a first amplitude and a second transmit pulse includes a second amplitude), a first summation weight is determined or selected based on the ratio of the second amplitude to the first amplitude, and a second summation weight is determined based on the ratio of the first amplitude to the second amplitude. Additionally, in some embodiments, different weight sets can be combined to generate more robust reverberation calculation results, such as the average or geometric mean of different metrics. In some embodiments, different receive weights can be applied to the receive lines before or after calculating the envelope. For example, different combinations of receive weights and / or summation weights can be selected and used to adapt to different types of multi-pulse sequences.

[0067] Figure 14 This is a flowchart of a method 900 for controlling an ultrasound transducer to reduce reverberation artifacts in ultrasound images by selecting between different ultrasound pulse sequences or configurations. In step 910, the processor circuitry controls the ultrasound transducer to acquire an ultrasound image using a first pulse sequence and to acquire another ultrasound image using a second pulse sequence. The first and second pulse sequences are different and may include one or more of a single-pulse sequence, amplitude modulation, pulse inversion, AMPI, or any other suitable pulse sequence. In some embodiments, step 910 may include: acquiring a first ultrasound image having a single pulse or standard imaging sequence, and acquiring a second ultrasound image using a multi-pulse sequence configured to automatically reduce reverberation artifacts. In step 920, the processor circuitry uses, for example, image processing and analysis techniques to analyze the acquired ultrasound images to calculate normalized intensity values ​​for the first ultrasound image acquired using the first pulse sequence and the second ultrasound image acquired using the second pulse sequence. In some embodiments, calculating the normalized intensity values ​​includes using the tissue suppression techniques described above with respect to method 400. In some embodiments, instead of calculating normalized intensity values ​​or as a supplement to calculating normalized intensity values, the steps of method 700 can be used to calculate the amount of reverberation artifacts in each ultrasound image.

[0068] In step 930, the intensity values ​​of the first and second images are compared to select a pulse sequence or configuration. In some embodiments, the pulse sequence associated with the lowest amount of reverberation artifact or normalized intensity is selected. In some embodiments, comparing intensity values ​​includes comparing the intensity or reverberation artifact value with a threshold. For example, in some embodiments, the threshold is selected, for example, according to the steps of method 400, and the pulse sequence or configuration is selected based on the comparison with the threshold. In some aspects, the threshold may represent the degree of reverberation artifact variation from the current pulse sequence or the first pulse sequence. If the reverberation artifact variation caused by the second pulse sequence does not exceed the threshold, the processor circuitry can select the current pulse sequence or the first pulse sequence, even if a reduction in reverberation artifact occurs under the second pulse sequence. In other embodiments, the processor circuitry can select the second pulse sequence if the second pulse sequence causes any reduction in reverberation artifact.

[0069] In step 940, the processor circuitry controls the ultrasonic transducer to use the selected pulse sequence or configuration to obtain a reverberation-reduced ultrasonic image. In step 950, the processor circuitry outputs the reverberation-reduced ultrasonic image to a display. It should be understood that in some embodiments, the processor circuitry may automatically execute the steps of method 900 with little or no user input. For example, in some embodiments, a user initiates the method using a user input device (e.g., keyboard, mouse, trackball, touchscreen, etc.), and the processor circuitry runs computer program code to execute the steps of method 900. In some embodiments, the user may not see the execution of individual steps of method 900 (i.e., the output to the display) before the reverberation-reduced image is displayed. In other embodiments, the processor circuitry may generate one or more graphical representations indicating individual steps of method 900. In some embodiments, additional pulse sequences are executed to obtain additional ultrasonic images for selecting a multi-pulse sequence. For example, two, three, four, five, ten, or more sequences of different types and / or with different configurations and parameters may be used to select the pulse sequence and / or configuration associated with reverberation artifact reduction.

[0070] It should be understood that one or more steps in methods 300, 400, 700, and 900 described above (e.g., controlling the array to use multiple PRIs, pulse sequences, and / or configurations to acquire ultrasound images, calculating the amount of reverberation artifacts in each ultrasound image, selecting PRIs, pulse sequences, and / or configurations, and any other steps) can be performed by one or more components of the ultrasound imaging system (e.g., the system's processor or processor circuitry, multiplexer, beamformer, signal processing unit, image processing unit, or any other suitable component). For example, one or more of the above steps can be performed by... Figure 2The processor circuit 150 performs the operation. The system's processing components can be integrated into the ultrasound imaging device, contained in an external console, or can be a separate component.

[0071] Those skilled in the art will recognize that the above-described apparatus, system, and method can be modified in various ways. Therefore, those skilled in the art will realize that the embodiments covered by this disclosure are not limited to the specific exemplary embodiments described above. In this regard, although illustrative embodiments have been shown and described, various modifications, alterations, and substitutions are contemplated in the foregoing disclosure. It should be understood that such changes can be made to the foregoing without departing from the scope of this disclosure. Therefore, the claims should be interpreted broadly in accordance with this disclosure.

Claims

1. An apparatus for reducing reverberation artifacts in ultrasound images, comprising: A processor circuit that communicates with an ultrasonic transducer, wherein the processor circuit is configured to: The ultrasonic transducer is controlled to use corresponding multiple pulse repetition intervals to obtain multiple ultrasonic images; Calculate the amount of reverberation artifact in each of the multiple ultrasound images; The pulse repetition interval is selected based on the amount of reverberation artifact in each of the multiple ultrasound images. In response to selecting the pulse repetition interval, the ultrasonic transducer is controlled to obtain a reverberation-reduced ultrasonic image at the selected pulse repetition interval; and The reverberation-reduced ultrasonic image is output to a display that communicates with the processor circuitry.

2. The apparatus according to claim 1, wherein, The processor circuit is configured as follows: Identify the tissue portion and non-tissue portion of each of the multiple ultrasound images; Calculate the intensity value of the non-tissue portion for each of the multiple ultrasound images; and The amount of reverberation artifact in each of the multiple ultrasound images is determined based on the calculated intensity values ​​of the non-tissue portions of the multiple ultrasound images.

3. The apparatus according to claim 2, wherein, The processor circuitry is configured to use a weighted algorithm to calculate the intensity value of the non-tissue portion of each of the plurality of ultrasound images, such that a first region of the corresponding ultrasound image that is closer to the focal point of the corresponding ultrasound image is assigned a greater weight than a second region of the corresponding ultrasound image that is farther from the focal point of the corresponding ultrasound image.

4. The apparatus according to claim 1, wherein, The processor circuit is configured as follows: The amount of reverberation artifact in each of the multiple ultrasound images is compared with a threshold; and The pulse repetition interval is selected based on the comparison between the amount of reverberation artifact and the threshold.

5. The apparatus according to claim 4, wherein, The processor circuitry is configured to determine the threshold based on the amount of reverberation artifact in the ultrasound image associated with the largest pulse repetition interval among the plurality of pulse repetition intervals.

6. The apparatus according to claim 4, wherein, The processor circuit is configured to select the pulse repetition interval based on the following: The comparison between the amount of the reverberation artifact and the threshold; and The predetermined maximum pulse repetition interval.

7. The apparatus according to claim 1, further comprising the ultrasonic transducer.

8. The apparatus according to claim 1, wherein, The processor circuit is configured as follows: The ultrasonic transducer is controlled to obtain the multiple images by executing a multi-pulse sequence to obtain multiple receiving lines at a given location; Perform incoherent summation on the multiple receiving lines; and The amount of reverberation artifact is determined based on the incoherent summation of the multiple receiving lines.

9. The apparatus according to claim 8, wherein, The plurality of receiving lines includes a first receiving line and a second receiving line, and wherein the processor circuit is configured to perform an incoherent summation on the plurality of receiving lines by means of the following operation: Calculate the following: For the first envelope of the first receiving line, and For the second envelope of the second receiving line; Perform the following weighting: The first envelope is weighted using the first summation weight, and The second envelope is weighted using the second summation weight; and Perform incoherent summation on the weighted first envelope and the weighted second envelope.

10. The apparatus according to claim 9, wherein: The first receiving line corresponds to a first transmitting pulse having a first amplitude. The second receiving line corresponds to a second transmitting pulse with a second amplitude, and The first summation weight and the second summation weight are selected based on the ratio of the first amplitude of the first transmitted pulse to the second amplitude of the second transmitted pulse.

11. The apparatus according to claim 1, wherein, The processor circuit is also configured to: The ultrasonic transducer is controlled to use a first pulse sequence to obtain a first ultrasonic image; The ultrasonic transducer is controlled to use a second pulse sequence to obtain a second ultrasonic image; Calculate the amount of reverberation artifact in each of the first and second ultrasound images; The amount of reverberation artifact in the first ultrasound image is compared with the amount of reverberation artifact in the second ultrasound image; The pulse sequence is selected based on the comparison of the amount of the reverberation artifact; The ultrasonic transducer is controlled to further use the selected pulse sequence to obtain the reverberation-reduced ultrasonic image.

12. A method for reducing reverberation artifacts in ultrasound images, comprising: The ultrasonic transducer is controlled to use corresponding multiple pulse repetition intervals to obtain multiple ultrasonic images; Calculate the amount of reverberation artifact in each of the multiple ultrasound images; The pulse repetition interval is selected based on the amount of reverberation artifact in each of the multiple ultrasound images calculated. In response to selecting the pulse repetition interval, the ultrasonic transducer is controlled to obtain a reverberation-reduced ultrasonic image at the selected pulse repetition interval; and The reverberation-reduced ultrasound image is output to a display.

13. The method of claim 12, further comprising: Identify the tissue portion and non-tissue portion of each of the multiple ultrasound images; Calculate the intensity value of the non-tissue portion for each of the multiple ultrasound images; and The amount of reverberation artifact in each of the multiple ultrasound images is calculated based on the intensity value of the non-tissue portion of the calculated multiple ultrasound images.

14. The method according to claim 13, wherein, Calculating the intensity value for the non-tissue portion of each of the plurality of ultrasound images includes using a weighted algorithm to calculate the intensity value for the non-tissue portion of each of the plurality of ultrasound images, such that a first region of the corresponding ultrasound image that is closer to the focal point of the corresponding ultrasound image is assigned a greater weight than a second region of the corresponding ultrasound image that is farther from the focal point of the corresponding ultrasound image.

15. The method of claim 12, further comprising: The amount of reverberation artifact in each of the multiple ultrasound images is compared with a threshold. and Selecting the pulse repetition interval includes selecting the pulse repetition interval based on the comparison between the amount of the reverberation artifact and the threshold.

16. The method of claim 15, further comprising determining the threshold based on the amount of reverberation artifact in the ultrasound image associated with the largest pulse repetition interval among the plurality of ultrasound images.

17. The method according to claim 15, wherein, The selection of the pulse repetition interval includes selecting the pulse repetition interval based on the following criteria: The comparison between the amount of the reverberation artifact and the threshold; and The predetermined maximum pulse repetition interval.

18. The method according to claim 12, wherein, Controlling the ultrasonic transducer to obtain the multiple ultrasonic images includes: Perform a multi-pulse sequence to obtain multiple receive lines at a given location; Perform incoherent summation on the multiple receiving lines; and The amount of reverberation artifact is determined based on the incoherent summation of the multiple receiving lines.

19. The method according to claim 18, wherein, The plurality of receiving lines includes a first receiving line and a second receiving line, and wherein, performing incoherent summation on the plurality of receiving lines includes: Calculate the following: For the first envelope of the first receiving line, and For the second envelope of the second receiving line; Perform the following weighting: The first envelope is weighted using the first summation weight, and The second envelope is weighted using the second summation weight; and Perform incoherent summation on the weighted first envelope and the weighted second envelope.

20. The method of claim 19, wherein: The first receiving line corresponds to a first transmitting pulse having a first amplitude. The second receiving line corresponds to a second transmitting pulse with a second amplitude, and The first summation weight and the second summation weight are selected based on the ratio of the first amplitude of the first transmitted pulse to the second amplitude of the second transmitted pulse.

Images