A Meta Matching Layer to Image Behind Calcified Plaques

Cardiovascular diseases (CADs) are the number one cause of death worldwide. In addition to preventive measures, which serve as the first line of defense against CADs, monitoring is crucial for timely intervention. Recently, ultrasound particle image velocimetry (echoPIV) using contrast agents has been utilized to monitor blood flow in arteries. This approach provides vector fields of blood flow over time, allowing physicians to identify features such as vortices and stagnation points around plaques or within vascular aneurysms. However, when a plaque is calcified, it casts a shadow in the ultrasound image, impeding the analysis of blood flow. This study reports the design, fabrication, and testing of a meta matching layer (MML) aimed at reducing reflections from a plaque model (aberrating layer) while improving transmission. The results show that the MML decreases reflections (represented by a ratio defined in this paper) by at least 28% and up to 80% over the range of 3-6 MHz; however, attenuation and shadowing remain challenges. Future work will focus on tacking the attenuation effect.