摘要:
A method and an apparatus for improving the signal-to-noise ratio (SNR) and/or resolution in color flow ultrasound imaging by using complementary-coded excitation of the transducer array. The SNR is improved by transmitting a pair of Golay-coded pulse sequences in alternating sequence at the same transmit focal position over multiple firings and then partly decoding the beamsummed data. The partly decoded data is then vector summed and high pass filtered. The summed and high-pass-filtered data is optionally decimated by a factor of two. The decimated or undecimated data is then input to the parameter estimator, which provides imaging signals representing the flow in a scan plane. Those imaging signals are then displayed as color information on a display monitor.
摘要:
A color flow imaging technique uses coded excitation on transmit and pulse compression on receive. Coded excitation allows a long transmit pulse to be compressed on receive such that most energy is concentrated in a short interval. Multiple transmit firings of the same coded pulse sequence are focused at the same transmit focal position with the same transmit characteristics. The receive signals are compressed utilizing matched or mismatched filtering. These techniques can be used to maximize color flow sensitivity in deep-lying regions. Alternatively, for a given transmit acoustic burst length and dosage, the spatial resolution can be improved without compromising sensitivity.
摘要:
A method and an apparatus for increasing the spatial resolution and sensitivity of a color flow image while maintaining a desired acoustic frame rate. The ultrasound energy is concentrated at a more narrowly defined focal region, which allows for increased flow sensitivity and vessel filling. Better flow uniformity across the color region of interest is also achieved. The method uses multiple transmit focal zones, and transmit and receive apertures having low f-numbers. Using multiple focal zones with low f-numbers allows for tight focusing over a larger depth-of-field. Unique waveforms and unique gain curves are used for each focal zone. Each focal zone is fired on a separate acoustic frame. An adaptive frame averaging algorithm is used to blend together the in-focus data from each of these acoustic frames before the data is displayed.
摘要:
In performing flow imaging using coded excitation and wall filtering, a coded sequence of broadband pulses (centered at a fundamental frequency) is transmitted multiple times to a particular transmit focal position, each coded sequence constituting one firing. On receive, the receive signals acquired for each firing are supplied to a finite impulse response filter which both compresses and bandpass filters the receive pulses, e.g., to isolate a compressed pulse centered at the fundamental frequency. The compressed and isolated signals are then high pass filtered across firings using a wall filter. The wall-filtered signals are used to image blood flow and contrast agents.
摘要:
A method and an apparatus for three-dimensional imaging of ultrasound data by constructing projections of data from a volume of interest. An ultrasound scanner collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. A multi-row transducer array having a uniform elevation beamwidth is used to provide reduced slice thickness. The data from a respective region of interest for each of a multiplicity of stored slices is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that projects the data in the volume of interest onto a plurality of rotated image planes using a ray-casting technique. The data for each projection is stored in a separate frame in the cine memory. These reconstructed frames are then displayed selectively by the system operator. Segmentation of three-dimensional projection images is enhanced by decreasing the thickness and increasing the resolution (i.e., decreasing the point spread function) of the two-dimensional slices from which the projections are derived. The slice thickness is decreased by increasing the elevational focus of the beam. The two-dimensional resolution is increased by opening the aperture, i.e., decreasing the f-number, and by increasing the band-width.
摘要:
A method and system are provided for estimating velocity of flow within an ultrasound dataset. A sample volume gate is defined on a two-dimensional (2D) image. The 2D image is based on an ultrasonic dataset. Spectral Doppler velocity estimates of flow are detected within the sample volume gate in first and second dimensions that are orthogonal with respect to each other. A true velocity estimate of the flow within the sample volume gate is determined based on the Doppler velocity estimates.
摘要:
An ultrasound medical imaging system and non-ultrasound medical imaging system are combined and communicate via a suitable docking port, which is supported by the non-ultrasound medical imaging system and configured to receive the ultrasound medical imaging system. The systems can communicate directly, indirectly, and/or wirelessly. Each can also be configured for cross-imaging in the other modality, displaying medical imagery from the other modality on respective and/or combined displays, and/or control by a user interface of the other and/or a common user interface. Registry between patient imagery is possible, and improved workflow is provided.
摘要:
An ultrasound apparatus includes an ultrasound probe and a probe positioning device operably connected to the ultrasound probe. The probe positioning device is configured to provide one of an orientation and a position of the ultrasound probe during ultrasound imaging.
摘要:
In performing tissue-generated harmonic imaging using coded excitation, the transmit waveform for acquiring the N-th harmonic signal is biphase (1,−1) encoded using two code symbols of a code sequence, the portions (i.e., chips) of the transmit waveform encoded with the second code symbol each being phase-shifted by 180°/N relative to the chips encoded with the first code symbol. This is implemented by time shifting the portions (i.e., chips) of the transmit sequence which are encoded with the second code symbol by ½N fractional cycle at center frequency relative to the chips of the transmit sequence encoded with the first code symbol. During reception, the desired harmonic signal is isolated by a bandpass filter centered at twice the fundamental frequency and enhanced with decoding.
摘要:
A system for displaying accumulated ultrasound images of tissue structures. A set of N image frames is used to produce a peak image display. Multiple peak image displays are produced by discarding the oldest image frame in the set of N image frames and replacing the discarded image frame with another more recent image frame. The more recent image frame is added to the set of image frames to produce a new set of N image frames. The new set of N image frames is used to produce another peak display image. If there is an undesirable amount of distortion or blur in the peak display images due to tissue motion, then the number of image frames in the set of N image frames can be reduced.