The contribution of research platforms to the pathway from off-line to real-time high-frame-rate imaging

Abstract

Ultrasound research platforms are characterized by a great flexibility of parameters that are usually fixed on clinical scanners. They allow the transmission of arbitrary waveforms in arbitrary scan sequences, and to test novel methods by processing off-line the raw radiofrequency channel data received after each transmission (TX) event. In particular, the availability of research platforms has boosted the development of high-frame-rate (HFR) imaging methods. These are typically based on the TX of multi-line focused beams, plane waves or diverging waves, which can be optimally produced by linear power amplifiers. The echoes received after each TX event should thus be beamformed along multiple lines in parallel, which is feasible, on line, only when high processing power is available. In this talk, the characteristics of “hardware-based” research platforms, like the ULA-OP 256, are discussed. The presence of powerful FPGA devices, on board such systems, allows implementing efficient parallel beamforming methods, which is the key-requirement for HFR imaging. Sample results obtained in real-time at rates of hundreds frames/s will be presented for both multi-line and plane wave compounding scan sequences. Finally, the main challenges to be faced to extend such modalities to volumetric (3-D) imaging will be discussed.