Pulmonary embolism: detection with MR perfusion imaging of lung--a feasibility study

To evaluate the feasibility of magnetic resonance (MR) perfusion imaging in the human lung to help detect perfusion defects distal to suspected pulmonary embolism.

Seven patients suspected of having pulmonary embolism first underwent ventilation-perfusion lung scintigraphy followed by MR perfusion imaging with rapid acquisition of two sets of dynamic images in the coronal and transaxial planes. A bolus of 0.05 mmol per kilogram of body weight gadopentetate dimeglumine or gadodiamide was administered. Single images obtained in each section that showed peak signal intensity from the first passage of contrast material were evaluated visually. An analysis of change in signal intensity over time was performed both on a pixel-by-pixel basis and in selected regions of interest.

In the seven patients, a total of 18 regions of lung tissue with perfusion defects were shown on the ventilation-perfusion scans. In 16 of these regions, MR perfusion images showed a reduced peak signal intensity during first passage of the contrast agent. Perfusion defects could be detected in both the coronal and the transaxial planes on MR perfusion images.

MR perfusion imaging was feasible for detection of perfusion defects distal to a pulmonary embolism.