venograms

Venograms, or venography, are radiographic studies of the veins performed after the injection of a radiopaque contrast agent. The imaging is typically done with fluoroscopy to capture sequential images as the contrast fills the venous system. The term phlebography is often used for peripheral venography.

A range of venographic techniques exists. Peripheral venography assesses the limbs to visualize deep and superficial veins. Cerebral venography images the cerebral venous system. Central venography targets thoracic and abdominal veins, often performed via central venous access. Venography can be used selectively during interventional procedures to map venous anatomy or guide treatment.

Common indications include evaluation of suspected deep vein thrombosis, assessment of venous reflux and insufficiency in chronic venous disease, visualization of central venous obstruction from tumor or prior interventions, and preoperative planning for arteriovenous fistula creation or venous reconstruction. Venography may also be used to delineate venous anatomy before transplantation or complex endovascular procedures.

Procedure and technology details: Access is gained by cannulating a suitable vein, such as a dorsal foot or antecubital vein for peripheral studies, or via central venous access for thoracic/central venography. A radiopaque contrast agent is injected under fluoroscopic control, and serial X-ray images are obtained to outline venous structures. In some cases, carbon dioxide may be used as a non-iodinated alternative to reduce iodine exposure.

Risks and limitations: Adverse reactions to iodinated contrast, nephrotoxicity, venous injury or infection, and radiation exposure are potential concerns. Venography is more invasive than noninvasive imaging and has largely been superseded for many indications by duplex ultrasound, CT venography, and MR venography, though it remains useful in select cases where other modalities are inconclusive or unavailable.