Julio Garcia

By Patrick Geeraert, Hansuk Kim, Safia Ihsan Ali, Ashifa Hudani, Shirin Aliabadi, Monisha Ghosh Srabanti, Hourieh Jamalidinan and Julio Garcia

Blood flow through the heart and great vessels moves in three dimensions (3D) throughout time. However, the assessment of its 3D nature has been limited in the human body. Recent advances in magnetic resonance imaging (MRI) allow for the comprehensive visualization and quantification of in-vivo flow dynamics using four-dimensional (4D) flow MRI. In addition, this technique provides the opportunity to obtain advanced hemodynamic biomarkers such as vorticity, helicity, wall shear stress (WSS), pressure gradients, viscous energy loss (EL), and turbulent kinetic energy (TKE). This chapter will introduce 4D flow MRI which is currently used for blood flow visualization and advanced quantification of cardiac hemodynamic biomarkers. We will discuss its advantages relative to other in-vivo flow imaging techniques and describe its potential clinical applications in cardiology.

Part of the book: Blood

By Mankarman Ghuman, Hansuk Kim, Hana Sheitt and Julio Garcia

Atrial fibrillation (AF) patients can be referred to cardiac magnetic resonance imaging (MRI) for an accurate assessment of cardiac function and left atrial structure. Cardiac MRI is the gold standard for the quantification of heart volumes and allows the noninvasive tissue characterization of the heart. In addition, advanced flow assessment can be achieved using 4D-flow MRI to elegantly depict the hemodynamic efficiency of the left atrium (LA) and left ventricle (LV) throughout the cardiac cycle. Patients with AF may have occult LV disease and thrombus formation. Biomarkers based on 4D-flow MRI may unmask the presence of LA/LV disease by quantifying 3D stasis, flow distribution, and vortex formation. These biomarkers have proved to characterize AF stages, to complement standard risk scores, and bring new insights on heart hemodynamic performance. This chapter aims to present a standard cardiac MRI protocol for atrial fibrillation and the innovative usefulness of advanced flow imaging in clinical settings.

Part of the book: Atrial Fibrillation