Dynamic Myocardial Ultrasound Localization Angiography.

Philippe Cormier,Jonathan Poree,Jean Provost,Chloe Bourquin

doi:10.1109/tmi.2021.3086115

Philippe Cormier, Jonathan Poree + Show 2 more

Open Access

https://doi.org/10.1109/tmi.2021.3086115

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Abstract

Dynamic Myocardial Ultrasound Localization Angiography (MULA) is an ultrasound-based imaging modality destined to enhance the diagnosis and treatment monitoring of coronary pathologies. Current diagnosis methods of coronary artery disease focus on the observation of vessel narrowing in the coronary vasculature to assess the organ's condition. However, we would strongly benefit from mapping and measuring flow from intramyocardial arterioles and capillaries as they are the direct vehicle of the myocardium blood income. With the advent of ultrafast ultrasound scanners, imaging modalities based on the localization and tracking of injected microbubbles allow for the subwavelength resolution imaging of an organ's vasculature. Yet, the application of these vascular imaging modalities relies on an accumulation of cine loops of a region of interest undergoing no or minimal tissue motion. This work introduces the MULA framework that combines 1) the mapping of the dynamics of the microvascular flow using an ultrasound sequence triggered by the electrocardiogram with a 2) novel Lagrangian beamformer based on non-rigid motion registration algorithm to form images directly in the myocardium's material coordinates and thus correcting for the large myocardial motion and deformation. Specifically, we show that this framework enables the non-invasive imaging of the angioarchitecture and dynamics of intramyocardial flow in vessels as small as a few tens of microns in the rat's beating heart in vivo.

Highlights

In patients with known or suspected coronary artery disease (CAD), cardiac imaging tests often constitute the first step in diagnosis and treatment planning
Since coronary angiography is often insufficient to prescribe a percutaneous coronary intervention, clinical practice relies on fractional flow reserve (FFR) [6] or coronary flow reserve (CFR) measurements to assess the myocardial ischemia risk
2) Dynamic angiography with motion correction on the microbubble positions As additional means of comparison, we proposed a second method for motion correction

Summary

Introduction

In patients with known or suspected coronary artery disease (CAD), cardiac imaging tests often constitute the first step in diagnosis and treatment planning. Since coronary angiography is often insufficient to prescribe a percutaneous coronary intervention, clinical practice relies on fractional flow reserve (FFR) [6] or coronary flow reserve (CFR) measurements to assess the myocardial ischemia risk. Multiple imaging approaches often based on large fixed infrastructure have been developed to obtain diagnostic and prognostic information non-invasively and through indirect measures. They often suffer from limitations in terms of sensitivity and specificity, which may lead, on the one side, to an unnecessary coronary angioplasty or, on the other side, to untreated life-threatening conditions.

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