Figure 15a. Iliac artery aneurysm. (a) Dynamic subtraction MR angiogram obtained with three separate injections of gadopentetate dimeglumine shows an aneurysm of the right common iliac artery (arrows) and distal abdominal aorta (arrowhead). Note the irregular lumen of the bilateral femoral arteries. (b) Coronal source image shows both the patent lumen and a mural thrombus of the aneurysm (arrowheads). (c) Conventional angiogram show only the lumen of the aneurysm.