A 55-year-old woman became increasingly breathless over a 9-month period. Systolic pulmonary artery pressure was estimated at 50 mm Hg by echocardiography. CT pulmonary angiography was performed using a dual energy technique whereby datasets are simultaneously acquired at 80 kV and 140 kV. Differential absorption of these energy spectra by iodine molecules in intravenous contrast medium is exploited to generate a map of parenchymal perfusion in addition to standard grey-scale images.1

Multiple laminated thrombi and web stenoses were …