Pulmonary ventilation: dynamic MRI with inhalation of molecular oxygen

We have recently demonstrated a non-invasive technique to visualize pulmona ry ventilation in humans with inhalation of molecular oxygen as a paramagne tic contrast agent. In the current study, T1 shortening of lung tissue by i nhalation of oxygen was observed (P<0.001). The T1 values of lung tissue we re also correlated with arterial blood oxygen pressure (PaO2) in a pig, res ulting in excellent correlation (r(2) = 0.997). Dynamic wash-in and wash-ou t MR ventilation images as well as dynamic wash-in wash-out signal intensit y versus time curves were obtained. The mean wash-in decay constants were 2 6.8 +/- 10.5 s in the right lung, and 26.3 +/- 9.5 s in the left lung. The mean wash-out decay constants were 23.3 +/- 11.3 s in the right lung, and 2 0.8 +/- 10.5 s in the left lung. Dynamic assessment of pulmonary ventilatio n is feasible using oxygen-enhanced MR imaging, which could provide dynamic MR ventilation-perfusion imaging in combination with recently developed MR perfusion imaging technique, and thus a robust tool for the study of pulmo nary physiology and pathophysiology. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.