Courtesy of Prof Edwin van Beek, this CT perfusion image of a patient who was treated for pulmonary embolism, but had incomplete resolution of the embolus, shows a colour map of where the contrast material is distributed. Filling defects (blue wedge shaped areas) indicate where the pulmonary arteries are still blocked.

This was a study supported by the Chest Heart Stroke Scotland charity and carried out in collaboration with Toshiba Medical Systems.