摘要:
A composition for cell tracking and molecular imaging containing perfluorocarbon (“PFC”) droplets having a liquid PFC core enclosed within a stabilizing shell and embedded with solid nanoparticles. The solid nanoparticles act as nucleating agents for reducing the activation pressure of the liquid PFC core required to transition the liquid PFC core to a gaseous microbubble thereby permitting the use of more body-temperature stable longer chain PFCs in the liquid PFC core. The improved stability of the PFC droplets with a reduced or limited increase in the activation pressure required due to the nucleating nanoparticles improves the efficacy of using the PFC droplets as phase-change contrast agents.
摘要:
An apparatus can be used to generate acoustic imaging pulse sequences and receive corresponding echoes elicited by the acoustic imaging pulse sequences. An acoustic radiation force (ARF) pulse sequence can be generated to agitate a contrast medium in a tissue region between the acoustic imaging pulse sequences. A decorrelation between images corresponding to the received echoes can be determined. A weighting map can be applied to an image to weight a region of the image corresponding to a spatial location of the contrast medium using the determined decorrelation. In an example, the receiving of corresponding echoes elicited by the acoustic imaging pulse sequences can include receiving acoustic energy having a range of frequencies offset from a fundamental frequency associated with the acoustic imaging pulse sequences. An acoustic imaging pulse sequence can include a pulse having an inverted amplitude envelope with respect to another pulse included in the sequence.
摘要:
An ultrasound system and method that can include: a receive beamformer configured to receive signals from a transducer; a processor coupled to the receive beamformer, the processor configured to: analyze echo data reflected from a region of interest, the echo data elicited by a transmitted pulse sequence; using the echo data, determine a central tendency of a signal magnitude from regions of adherent microbubbles over time within the region of interest; determine a time series of the signal magnitude; using the time series, determine an initial signal magnitude parameter; obtain a saturated signal parameter and a residual signal parameter using the time series; and determine a relative indication of information indicative of the residual signal magnitude versus the saturated signal magnitude.
摘要:
Backing substrates for reducing parasitic echoes produced within a ultrasonic transducer are provided comprising a polymeric material, for example, an epoxy having a glass transition temperature (Tg) ranging from about 10 to 50° C.; or an epoxy having an acoustical attenuation that increases by at least about 2 dB/mm at 5 MHz in a temperature range of about 5° C. to 40° C. Transducer assemblies comprising the backing substrates and methods for producing the assemblies are also provided.
摘要:
An improved device and method for collecting data used for ultrasonic imaging. The data is gathered over numerous transmit and echo receive cycles, or iterations and combined into a synthetic acquisition representing a complete echo characteristic acquisition. At each iteration, only a portion, or subset, of the echo characteristic is sampled and stored. During the iterations, the portion of the echo characteristic that is measured and sampled is varied by changing the relative sampling instants. That is, the time offset from the transmission to the respective sampling instant is varied. The sample sets representative of the entire echo characteristic are then compiled from the multiple subsets of the ultrasonic transmissions.
摘要:
A medical diagnostic ultrasound imaging system aligns substantially co-planar two-dimensional images to form an extended field of view using improved methods that speed the alignment, use Doppler processors to alert the user when transducer motion relative to the imaged region is excessive, and provide a longitudinal sectional view of a blood vessel and surrounding tissue.
摘要:
A hand held ultrasonic instrument (10) is provided in a portable unit that performs C-Mode imaging and collects 3D image data. In a preferred embodiment a transducer array (60), display unit (20), beamformer (40), power system, and image processor are integrated in one enclosure weighing less than three pounds. In operation, the portable unit is scanned across a target and the displayed image is conveniently presented to the operator whereby the displayed image corresponds exactly to the target, or a scaled fashion if desired.
摘要:
An electrostatic transducer circuit and method of tuning the same, in which a balancing circuit is inserted into the electrostatic transducer circuit, is described. The electrostatic transducer circuit generally includes transmit circuitry, receive circuitry, a capacitive electrostatic transducer and the balancing circuit. The balancing circuit can include, either singly or in combination, an inductance and a negative capacitance. The balancing inductance is tuned to counteract the negative reactance of the capacitive electrostatic transducer at a desired operating frequency and can be inserted into the transmit circuitry and/or the receive circuitry. The balancing negative capacitance is tuned to counteract the capacitance of the capacitive electrostatic transducer and can be inserted into the receive circuitry and/or the transmit circuitry. The transmit circuitry can be isolated from the receive circuitry, and vice versa, once the balancing circuit has been inserted. Isolation can be achieved by switching the electrostatic transducer circuit between transmit and receive modes of operation, or by providing separate transmit and receive electrode subsets.
摘要:
An ultrasound system and related method for forming 2D C-scan images and/or collecting 3D image data from 2D transducer arrays. The system including in part a 2D transducer array of elements, transmit voltage generation means for each element, a memory buffer with or part of channels for each element, and a receive beamformer. On a time serial or sequential basis, several times for each line of firing, the contents of the per element memory buffer are read into the beamformer with different focusing values for each buffer reading cycle. In this way, the beamformer can calculate beamformed image values for multiple points per line firing cycle—or per each line of signals between the transducer array and receive beamformer.
摘要:
An electrostatic transducer circuit and method of tuning the same, in which a balancing inductance is inserted into the electrostatic transducer circuit is described. The electrostatic transducer circuit generally includes transmit circuitry, receive circuitry and a capacitive electrostatic transducer. The balancing inductance is tuned to counteract the negative reactance of the capacitive electrostatic transducer at a desired operating frequency during the transmit mode. The balancing inductance is inserted into the transmit circuitry and is then isolated from the remaining parts of the electrostatic transducer circuit. Isolation is achieved by switching the electrostatic transducer circuit between transmit and receive modes of operation. Further, a receive circuit balancing reactance can also be included. The method provides a balancing inductance that is used to counteract negative reactance of the capacitive electrostatic transducer at a desired operating frequency during transmit mode.