Venous Imaging

Introduction

“As, year by year there is an increase in the number of patients operated upon in a more rational matter, so the demands upon X-ray examination of these patients have also risen. Under these circumstances it seems to be of great importance that a method of phlebography be worked out that would be as far as possible informative and reliable and, at the same time, simple of performance.”1 Today these words remain as true as when they were first written in 1960 by the “godfather” of venography, Gunnar Bauer. The modalities available to image the venous system are abundant: conventional direct venography (CV), duplex ultrasound (DUS), intravascular ultrasound (IVUS), magnetic resonance (MRV) venography, and computed tomography (CTV) venography. Both MRV and CTV have revolutionized the way we look at the venous system as they readily and reliably demonstrate the structures in question. Both allow for large fields-of-view (FOV), with cross-sectional images that provide superb soft tissue detail and levels of contrast that permit clear delineation between veins and adjacent structures. This is very valuable in identifying extra- or intraluminal filling defects that impact venous structures. Their usefulness becomes even more evident as vascular interventionalists continue to implant more and more devices in the venous system. We start to understand that sizing and visualization of these devices is as important in the venous system as it is in the arterial. The impact of respiration, cardiac function, and Valsalva on the central venous structures is quite pronounced and can profoundly affect the interpretation of venous anatomy. One must be cognizant of this fact when interpreting a diagnostic study. As much as possible, the aim should be in the direction of less-invasive imaging. This can be successfully achieved with MRV, CTV, and DUS, but each modality has its strengths and weaknesses. We will discuss the relevance of these studies as they apply to the most important clinical applications for venous disease.