4D Flow MRI of the Thoracic Aorta.

Four-dimensional (4D) flow MRI has emerged as a versatile technique for the three-dimensional evaluation of blood flow dynamics, offering the ability to visualize flow patterns qualitatively and allow for the retrospective quantification of standard and advanced hemodynamic parameters. Recent advancements in 4D flow MRI technology, including optimized acquisition protocols and improved hemodynamic analysis workflow efficiency, have facilitated its integration into standard clinical practice, enhancing the accessibility and applicability of this innovative imaging modality. A growing body of studies have demonstrated its clinical value for monitoring and informing the management of aortic pathologies, cementing its role in modern cardiovascular care. In this review, the authors provide a concise overview of data acquisition techniques and hemodynamics analysis methods for 4D flow MRI, with a specific focus on the thoracic aorta. The core of this article explores the clinical applications of aortic 4D flow MRI in patients with aortic valve disease, aortopathy, coarctation, dissection, connective tissue disorders, and age-related changes. Furthermore, the authors discuss the emerging role of artificial intelligence on improving 4D flow MRI acquisition and processing efficiencies. Keywords: Aorta, MR-Imaging, Vascular, Aortic Valve, 4D Flow MRI, Phase-Contrast, Hemodynamics, Clinical Applications © RSNA, 2025.