The exploration of flow pattern in the superior vena cava of healthy adults: A 4D flow magnetic resonance imaging study

Abstract

Our study sought to investigate the blood flow pattern in the superior vena cava (SVC) of healthy adults and to describe the development and characteristics of the flow pattern using 4D flow magnetic resonance imaging (MRI). 4D flow MRI data with full coverage of SVC and brachiocephalic veins (BVs) were acquired with a 3-Testa MRI in thirty healthy adults (age: 28.70 ​± ​9.09). Hemodynamic parameters in the SVC, including velocity, velocity vector, flow visualization (pathlines, streamlines), flow waveform and energy loss, were obtained with specialized commercial post-processing software based on 4D flow MRI data. This study found that: (1) The SVC has a pulsating flow waveform with double peaks. (2) Based on BVs flow of the SVC pathline visualization, flow patterns could be divided into three development types: twining (n ​= ​14), untwining (n ​= ​9) and no helical flow (n ​= ​7). (3) With the decreasing blood velocity, helical flow areas tended to gradually extend. (4) There were no significant differences in most hemodynamic parameters among the three types. The exploration of the blood flow characteristics of normal SVC may be the first step for capturing pathogenic features before the patients develop symptoms with a certain positive significance. The potential physiological significance of these phenomena deserves more exploration in future studies.

Keywords

• Superior vena cava
• 4D flow magnetic resonance imaging
• Blood flow
• Circulation