venogram

A venogram, or venography, is a radiographic imaging technique used to visualize veins by injecting radiopaque contrast material and capturing X-ray images. It can be performed as a conventional catheter-based procedure or via noninvasive imaging modalities such as computed tomography (CT) or magnetic resonance (MR) venography.

Conventional venography involves introducing contrast into a vein, often through a peripheral or central access point, and imaging the venous lumen during different phases of circulation. This allows direct assessment of venous patency, collateral networks, valve function, and obstructions. CT venography and MR venography provide alternatives that visualize the venous system noninvasively and rapidly, sometimes with greater patient comfort and without arterial catheterization.

Indications for venography include suspected deep vein thrombosis or venous obstruction, evaluation of venous insufficiency or reflux, assessment of central venous obstructions (such as after trauma or in patients with indwelling catheters), preoperative mapping for reconstructive procedures, and investigation of vascular malformations or dural venous sinus thrombosis in the brain.

Advantages of venography include detailed visualization of the venous lumen and collateral pathways and, in some cases, the ability to perform pressure measurements or interventions. Limitations include invasiveness, exposure to ionizing radiation, and risks related to contrast administration, such as allergic reactions or nephrotoxicity. Because of these considerations, noninvasive imaging modalities are often preferred when feasible, with venography reserved for cases requiring detailed lumenal assessment or interventional treatment.