Flow Dynamics in Clinical Imaging – A Practical Review of Manifestations, Exploitations, and Specific Interrogations

Fluid dynamics plays a central role in several physiologic and pathophysiologic processes throughout the body, across multiple spatial and temporal scales. From the earliest applications of catheter angiography, medical imaging has at least qualitatively interrogated hemodynamics to improve diagnosis, and recent decades have seen dramatic advances in our ability to depict and quantitatively understand flow in-vivo. These advances have afforded a better understanding of imaging findings, improved diagnostics, a deeper comprehension of normal and disordered hemodynamics and their sequela, and importantly, have allowed the refinement of existing and creation of new therapeutics.

Cardiovascular flow and its effects are evident in most forms of clinical imaging. This talk will present key clinical examples where flow dynamics 1) manifest in anatomic imaging (not targeted to flow measurement), revealing features of locoregional hemodynamics, 2) cause imaging features that are exploited for either image formation or imaging interpretation, and 3) are directly interrogated for diagnosis of both flow-mediated and end-organ pathology in different vascular territories. The bulk of examples will concern computed tomography, magnetic resonance, and ultrasound imaging techniques that are in routine clinical use, introducing flow phenomena of prime clinical relevance and setting the stage for more detailed discussions on specific modern techniques for direct flow imaging.