Virtual real-time: a new US operating modality

High frame rate (HFR) imaging methods are increasingly popular but impose severe requirements to ultrasound scanners. Real-time HFR imaging is such a challenging task that, conventional scanners merely elaborate the echo-data in post-processing. Real-time acquisition and data post-processing are usually well separated: the former needs to be guided by a standard B-Mode display that is interrupted when the raw data are transferred to, e.g., a GPU board for off-line processing. In this paper we describe a different approach, called "virtual real-time" mode, implemented on the ULA-OP 256 scanner, in which the two phases are tightly interleaved: raw data that are continuously stored in RAM during a real-time elaboration can be immediately re-processed at a different rate. This enables not only to display in slow-motion possible fast recorded events, but also to facilitate the achievement of optimal conditions for US acquisition and the extraction of additional information from the echo data.