The following case is a great example demonstrating the benefits of dual energy CT, in an earlier time scans that produce lower Hounsfied units over the pulmonary artery would require repeating until the scan was satisfactory.

Although this scan is borderline adequate, utilizing the monochromatic data set of 50 KeV has better demonstrated the contrast filled structures. The monochromatic energy is closer to the K-edge of iodine, and therefore iodine-enhanced structures will display better attenuation values.

Not every failed CTPA can be 'saved' using this method, yet it should be considered before re-scanning ^1,2.