PULMONARY PERFUSION - QUALITATIVE ASSESSMENT WITH DYNAMIC CONTRAST-ENHANCED MRI USING ULTRA-SHORT TE AND INVERSION-RECOVERY TURBO FLASH

The accurate assessment of pulmonary perfusion is especially important in the evaluation of patients with suspected pulmonary embolism, a co mmon and potentially lethal disorder that can be treated by aggressive anticoagulation. In this study, we demonstrate for the first time the use of MR to image pulmonary perfusion in humans by using dynamic ima ging after contrast administration, The technique, which uses an inver sion recovery turbo FLASH sequence with ultra short TE (1.4 ms) and 1- s temporal resolution, was tested in a series of eight healthy subject s and in a porcine model of pulmonary embolism. After the administrati on of gadopentetate dimeglumine in humans and animal models, there was serial enhancement of the systemic veins, right atrium, right ventric le, and pulmonary arteries. The pulmonary arterial tree was visualized beyond the segmental branches, followed by a gradual diffuse increase in signal intensity of the lung parenchyma over a period of 4.0-7.0 s . Pulmonary circulation times ranged from 3.03.4 s. Whereas a high dos e (20 or 40 ml) of contrast agent tended to produce the most intense p arenchymal enhancement, a low dose (5 ml) was best for showing recircu lation, In the animal model, a perfusion defect due to a pulmonary emb olus was clearly shown and confirmed by cine angiography, It is conclu ded that MRI of lung perfusion is feasible, With further development, perfusion MRI could eventually have a significant clinical role in the diagnostic evaluation of pulmonary embolism.