Three-Dimensional Blood Flow Dynamics: Spiral/Helical Laminar Flow

Introduction

Recent work in cardiac and peripheral vascular blood flow has shown evidence for an elegant complexity to flow within the heart and in the large to medium arteries. Blood flow is normally described as laminar in that the blood travels smoothly or in regular paths. The velocity, pressure, and other flow properties at each point in the fluid remain constant, all parallel to each other. Our understanding has revolved around a two-dimensional representation of flow within three-dimensional (3-D) blood vessels. However, MRI and color Doppler flow imaging techniques have demonstrated that there is a spiral/helical/rotational property to laminar blood flow. (In this article, this blood flow profile will be termed spiral laminar flow though all are equally valid terms.) The column of blood turns on a central axis as it passes along the major arteries (Figure 1).