Figure 13a. Prolonged circulation time in a 78-year-old patient. (a) Early-phase dynamic subtraction MR angiogram shows enhancement of the proximal abdominal aorta (arrows). (b) Image from the next phase of dynamic subtraction MR angiography shows enhancement of the distal abdominal aorta (arrowheads). (c) Arterial image from dynamic subtraction MR angiography obtained by adding a and b shows the entire abdominal aorta and iliac arteries.