Methods for complete lower extremity phlebography are based on experience with over 600 examinations. A tilting table with undercouch tube and television monitoring is used. Tourniquets at the ankle and lower thigh are placed initially, and 50 to 100 ml of iothalamate meglumine injection are administered through a 20-gauge needle placed in a dorsal vein of the foot. Usually the iliac veins and inferior vena cava are demonstrable with the assistance of a Valsalva maneuver, calf compression, and rapid injection into the foot; but, if unsuccessful, direct femoral vein or pertrochanteric injections are made. Special complications include phlebothrombosis (preventable by flushing the veins with saline) or local sepsis. Pulmonary embolism secondary to calf compression has not been seen. Interpretation depends heavily upon identification of thrombus as a cylindrical or round translucency in the opacified vein. A completely occluded vein may be totally blocked or bypassed by collaterals. Common causes for artifacts are underfilling, dilution, or streamlining.
Thomas ML. Phlebography. Arch Surg. 1972;104(2):145-151. doi:10.1001/archsurg.1972.04180020025005