Ultrasound microvasculature imaging with entropy-based radiality super-resolution (ERSR)

Abstract

Objective: Microvasculature is highly relevant to the occurrence and development of pathologies such as cancer and diabetes. Ultrasound localization microscopy (ULM) has bypassed the diffraction limit and demonstrated its great potential to provide new imaging modality and establish new diagnostic criteria in clinical application. However, sparse microbubble distribution can be a significant bottleneck for improving temporal resolution, even for further clinical translation. Other important challenges for ULM to tackle in clinic also include high microbubble concentration and low frame rate. Approach: As part of the efforts to facilitate clinical translation, this paper focused on the low frame rate and the high microbubble distribution issue and proposed a new super-resolution imaging strategy called entropy-based radiality super-resolution (ERSR). The feasibility of ERSR is validated with simulations, phantom experiment and contrast-enhanced ultrasound scan of rabbit sciatic nerve with clinical accessible ultrasound system. Main results: ERSR can achieve 10 times improvement in spatial resolution compared to conventional ultrasound imaging, higher temporal resolution (∼10 times higher) and contrast-to-noise ratio under high-density microbubbles, compared with ULM under low-density microbubbles. Significance: We conclude ERSR could be a valuable imaging tool with high spatio-temporal resolution for clinical diagnosis and assessment of diseases potentially.

Nanodroplet-Based Super-Resolution Ultrasound Localization Microscopy

“…Tang and his team developed nanodroplet-based AWSALM and fast-AWSALM and further verified the ability to visualize microvasculature in vivo and in vitro, respectively, which opens up the possibilities for super-resolution molecular imaging. ,, Nevertheless, there are a few challenges to be conquered to speed up the clinical translation of ULM. Out-of-plane motion, long acquisition time, and low frame rates are the major challenges faced by the clinical translation of ULM. ,− A previous study has attempted to overcome out-of-plane motion by implementing a 3D imaging technique . The microbubble-based ULM results in a long image acquisition time due to differentiation of individual microbubble signals.…”