Figure 12b. Patent ductus arteriosus in a 46-year-old woman with a heart murmur. (a) Gadolinium-enhanced MR angiographic image shows a patent ductus (arrow) connecting the proximal descending aorta (dAo) to the left pulmonary artery (LPA), just beyond the pulmonary arterial bifurcation. Note the focal dilatation of the aorta at the site of ductal attachment. (b, c) Axial (b) and oblique (c) MR angiographic images also depict the ductus (arrow). aAo = ascending aorta. (Courtesy of Ruth Carlos, MD, Department of Radiology, University of Michigan, Ann Arbor)