C5 2v curvilinear array

Channel echo data were collected from in vivo liver and fetal targets in accordance with IRB-approved protocols at the Duke University Medical Center. Data were acquired using the Verasonics Vantage 256 research scanner and a C5-2v curvilinear array. Pulse inversion harmonic imaging sequences were used with a 2.4 MHz transmit frequency, a 4.8 MHz receive frequency, and a 60 element transmit and receive aperture. Channel I/Q data were collected, time-delayed, and processed using conventional B-Mode, receive spatial compounding (3 apertures, 50% overlap) [33 (link)]–[35 ], SLSC (Q=5%, 1λ axial kernel) [3 ], and MIST (1λ axial kernel). Correlation curves were calculated for a speckle-generating region at the transmit focus. The lag at which the correlation reached approximately zero was used to inform the effective transmitting aperture size when constructing the covariance models for the MIST estimator.

The Verasonics Vantage scanner and a C5-2v curvilinear array (128 elements, 508 μm pitch) were used to collect RF echo data from the liver of a healthy male volunteer, in a protocol approved by the Duke University Institutional Review Board. A pulse-inversion harmonic sequence was used with a 2.36 MHz transmit center frequency and a 4.72 MHz receive center frequency. The transmit focus was 85 mm. Three sets of images were formed: (1) MIST using ROI widths of (0.1 – 2) and axial averaging of (0, 1, 2)λ, (2) spatial compounding, and (3) frequency compounding.