Although the use of balloon dilation for treatment of native and recurrent coarctation of the aorta (coA) has become widespread, the optimal balloon size and postdilation vessel wall changes remain undetermined. Intravascular ultrasound (IVUS) imaging has emerged as a an important adjunct in the treatment and follow-up of patients with coronary artery and peripheral vascular lesions, and has been used for evaluation in a limited number of patients with CoA. We used a combination of balloon dilation/ultrasound imaging catheter in animals with experimentally-induced CoA. We used a combination balloon dilation/ultrasound imaging catheter in animals with experimentally-induced CoA . This technique provided real-time data regarding aortic wall morphology and luminal diameter during balloon angioplasty of the CoA. In humans, we used IVUS to study CoA before and after both transcatheter and surgical therapy. IVUS was more sensitive than angiography in the detection of intimal tears post-balloon dilation and in the evaluation of vessel wall changes and remodelling observed at follow-up after relief of CoA. IVUS may provide valuable information regarding vascular wall changes that predict aneurysm format ion, restenosis, or a successful result after balloon dilation.