Clinical Applications of MRA 4D-Flow

Abstract

Purpose of review: Four-dimensional (4D)-Flow cardiovascular magnetic resonance (CMR) is three-dimensional, time-resolved, three-directional velocity-encoded magnetic resonance that provides flow velocity data within a volumetric region across the cardiac cycle (CC). The goals of this paper are to review the current clinical applications of this technique; provide an overview of the general physics; discuss key points from the expert consensus document; and present recent advances in the field. The advantages and disadvantages of 4D-Flow CMR in comparison with the standard and gold standard methods are summarized.

Recent findings: 4D-Flow CMR offers unique insights into cardiac and circulatory physiology with an ability to quantify advanced hemodynamic parameters in a variety of pathologic entities including aortic and pulmonary artery diseases, valvular heart disease, complex congenital heart disease, and extra-thoracic cardiovascular diseases. Recent large cohort studies highlight how it provides information that has clinical impact beyond a better understanding of the disease and that will permit better and more timely management and prognosis. 4D-Flow CMR provides unique qualitative and quantitative flow dynamics information and its impact on cardiac chambers, vessel walls, and myocardium. As scan acquisition and post-processing of 4D-Flow CMR become faster and simpler, the investigational and clinical opportunities will expand dramatically.

Keywords: 4D; 4D-Flow; Aorta; Blood flow; CMR; Flow; MRA; Magnetic resonance; Phase contrast.