'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
Recently, an all-optical ultrasound imaging system was presented that was capable of real-time, video-rate 2D pulse-echo imaging. This was achieved through the use of rapid scanning optics and a centimetre-scale optical ultrasound generator, which allowed for the synthesis of 1D source arrays of arbitrary geometry. Back-scattered ultrasound was recorded using a highly sensitive fibre-optic ultrasound detector. Here, a modification to this system is presented that enabled the synthesis of arbitrary 2D source array geometries. This extension allowed for the implementation of 1.5D arrays, which we demonstrated to yield improved elevational resolution (1.1 mm for 1D arrays versus 0.9 mm for 1.5D arrays)at the expense of a decrease (-3.4 dB)in signal-to-clutter level. The axial (115 μm)and lateral (320 μm)resolutions, as well as the acquisition time, remained unchanged, as was shown using phantoms and ex vivo tissue samples. In addition, the 1.5D source array geometry enabled 3D out-of-plane tracking (0.7 mm resolution across a range of ±1.5 mm)while performing high-quality 2D imaging. The presented ability to synthesise arbitrary, two-dimensional source array geometries will greatly improve and facilitate ultrasound imaging and guidance of interventional procedures
