Lung perfusion demonstrated by contrast-enhanced dynamic magnetic resonance imaging. Application to unilateral lung transplantation.

RATIONALE AND OBJECTIVES: The authors evaluate the use of magnetic resonance (MR) to image pulmonary perfusion in healthy controls and to detect pulmonary defects in patients with unilateral lung transplantation, using dynamic images after contrast administration. METHODS: Five patients with right lung transplantation and nine healthy volunteers underwent MR imaging. Twenty-five subsecond contrast-enhanced MR images (turbo-fast low-angle shot [FLASH]) were obtained at the level of the pulmonary arteries after a single injection of gadopentetate dimeglumine (0.1 mmol/kg) in an antecubital vein. Perfusion lung scintigraphy was done within 24 hours after the MR imaging examination in the transplanted patients. RESULTS: Before administration of contrast material, MR images showed both lungs to be homogeneous and of low signal intensity in healthy controls and in patients with lung transplantation. After contrast administration in controls, the mean signal intensity of the dependent lung increased markedly to 171 +/- 24% above baseline, whereas the nondependent signal intensity lung increased by only 105 +/- 17%; these changes were significantly different. In all patients with lung transplantation, a clear perfusion defect was demonstrated in the native lung. This defect was confirmed in all cases by perfusion nuclear scintigraphy, which showed that the majority of lung perfusion is directed to the transplanted allograft, compared with the native contralateral lung. CONCLUSIONS: Our results suggest that dynamic contrast-enhanced MR imaging is a potential method for detecting pulmonary perfusion defects in patients with lung transplantation.