Short-lag spatial coherence imaging on matrix arrays, Part II: Phantom and in vivo experiments

Abstract

In Part I of the paper, we demonstrated through simulation the potential of volumetric Short-lag Spatial Coherence (SLSC) imaging to improve visualization of hypoechoic targets in three dimensions. Here, we demonstrate the application of volumetric SLSC imaging in phantom and in vivo experiments using a clinical 3-D ultrasound scanner and matrix array. Using a custom single-channel acquisition tool, we collected partially beamformed channel data from the fully sampled matrix array at high speeds and created matched B-mode and SLSC volumes of a vessel phantom and in vivo liver vasculature. 2-D and 3-D images rendered from the SLSC volumes display reduced clutter and improved visibility of the vessels when compared to their B-mode counterparts. We use concurrently acquired color Doppler volumes to confirm the presence of the vessels of interest and to define the regions inside the vessels used in contrast and CNR calculations. SLSC volumes show higher CNR values than their matched B-mode volumes while the contrast values appear to be similar between the two imaging methods.

Robust Short-Lag Spatial Coherence Imaging

“…SLSC imaging has since demonstrated remarkable improvements over traditional ultrasound B-mode imaging when visualizing liver tissue[8], endocardial borders[9], fetal anatomical features[10], and point-like targets in the presence of noise[11]. A suite of traditional ultrasound transducer arrays (i.e., linear[7], curvilinear[8], phased[9], and 2D matrix[12], [13] arrays) were demonstrated to be compatible with SLSC imaging. This new imaging method was additionally extended to photoacoustic imaging to improve the visibility of prostate brachytherapy seeds[14], to improve signal contrast when imaging with low-energy, pulsed laser diodes[15] and to potentially guide minimally invasive surgeries [16].…”

Short-lag spatial coherence imaging on matrix arrays, Part 1: Beamforming methods and simulation studies

“…Performance is also measured as a function of simulated clutter levels by modulating the channel SNR with spatially incoherent noise. In Part II, we implement SLSC imaging using a 2-D transducer on a clinical scanner and present imaging results from phantoms and in vivo liver [15]. …”

Blocked Elements in 1-D and 2-D Arrays—Part I: Detection and Basic Compensation on Simulated and In Vivo Targets

“…The complex data of the individual channels were collected using a full-synthetic receive sequence, as implemented in [17]. In this method, the full aperture was used to transmit focused waves while parallel receive beamforming was used to collect signals on 30 channels per transmit event.…”