Figure 8b. Pulmonary embolism. (a, b) Contrast-enhanced CT scans of the thorax obtained 4 days after UAE (b obtained at a higher level than a) show a discrete filling defect (arrow) in a pulmonary artery branch to the right lower lobe. (c) Three-dimensional multiplanar reformatted image from contrast-enhanced CT data shows the filling defect expanding a pulmonary artery that supplies the right lower lobe (arrow), a finding that is diagnostic for a pulmonary embolus.