The iliac veins are the major veins that drain blood from the pelvis and lower extremities, formed by the union of the internal and external iliac veins and merging to form the inferior vena cava. While the iliac veins can be challenging to evaluate with ultrasound due to their deep pelvic location and overlying bowel gas, they are an important part of the venous system assessment. Iliac vein thrombosis is an extension of lower extremity deep vein thrombosis, and May-Thurner syndrome, compression of the left iliac vein by the overlying right iliac artery, is an increasingly recognized cause of left leg DVT.
Sonography Term