Application of 4D flow MRI for exploring factors affecting haemodynamics of iliac veins in asymptomatic population

BACKGROUND: Haemodynamics plays an important role in the development of vascular disease. There is currently a lack of studies evaluating the characteristics and affecting factors of the iliac vein haemodynamics in clinical practice. OBJECTIVE: The goal of this study was to use 4D flow MRI to explore the haemodynamic characteristics of iliac veins and its affecting factors in an asymptomatic population. METHODS: Thirty consecutive volunteers without venous-related symptoms or signs underwent four-dimensional postprocessing of their MRI images. Relevant parameters, the demographic data, common iliac vein-inferior vena cava angle, iliac vein area, tortuosity, iliac vein mean flow, mean velocity was computed and analysed. T tests and Spearman's tests were used for analysing. A P value of 0.05 or less was considered significant. RESULTS: Height and iliac vein area were positively correlated with flow, while degree of stenosis, and common iliacinferior vena cava angle were negatively correlated with that. Degree of stenosis was positively correlated with velocity, but the common iliac-inferior vena cava angle and iliac vein tortuosity were negatively correlated with that. The mean flow and velocity of iliac veins in females were lower than males. The mean flow and velocity of the left iliac veins were lower than those of the right. CONCLUSION: The height, gender, tortuosity, degree of stenosis, common iliac vein-inferior vena cava angle of the iliac vein are important factors that affect flow and velocity of the iliac veins. There were differences in haemodynamic parameters of the bilateral iliac veins.