Ultrafast ultrasound for super­resolution imaging: The effect of pulse inversion and harmonic­ or SVD­filtering on microbubble detection

Background/purpose: The mapping of microvasculature requires a high­resolution imaging method. Super­resolution ultrasound­imaging can provide such high resolution by detecting individual microbub­ bles (MBs) in a flow circuit. This method relies on the dynamic appearance of MBs, which appear as point scatterers on the US image, mixed with...

Combining ultrafast ultrasound and high-density EMG to assess local electromechanical muscle dynamics: a feasibility study

Skeletal muscles generate force, enabling movement through a series of fast electro-mechanical activations coordinated by the central nervous system. Understanding the underlying mechanism of such fast muscle dynamics is essential in neuromuscular diagnostics, rehabilitation medicine and sports biomechanics. The unique combination of...

Two-Dimensional Blood Flow Estimation in the Brain with Ultrafast Ultrasound

Detailed imaging of blood flow may improve the understanding of brain functions. The state-of-the-art non-invasive flow imaging of the brain is limited to a one-dimensional Doppler setting. We propose a method to estimate the two-dimensional flow vector in the fine vascular network of the brain by using a speckle tracking technique. The...

4-D Echo-Particle Image Velocimetry in a Left Ventricular Phantom

Left ventricular (LV) blood flow is an inherently complex time-varying 3-D phenomenon, where 2-D quantification often ignores the effect of out-of-plane motion. In this study, we describe high frame rate 4-D echocardiographic particle image velocimetry (echo-PIV) using a prototype matrix transesophageal transducer and a dynamic LV phantom for...

Tracking Electromechanical Muscle Dynamics using Ultrafast Ultrasound and High-density EMG

Muscles generate force and enable movement. After excitation of a muscle the muscle fibers contract. Methods to assess muscle contraction in vivo are scarce. Electromechanical delay (EMD), defined as the time lag between muscle excitation and contraction onset, has been proposed as a measure for contraction efficiency, but provides limited...