Mechanical delivery of aerosolized gadolinium-DTPA for pulmonary ventilation assessment in MR imaging

RATIONALE AND OBJECTIVES. TO evaluate a new technique with mechanical admin istration of aerosolized gadolinium (Gd)-DTPA for MR visualization of lung ventilation, METHODS, Ten experimental procedures were performed in six domestic pigs, G d-DTPA was aerosolized by a small-particle generator. The intubated animals were mechanically aerosolized with the nebulized contrast agent and studie d on a 1.5-T MR imager, Respiratory gated T1-weighted turbo spin-echo image s were obtained before, during, and after contrast administration. Pulmonar y signal intensity (SD changes were calculated for corresponding regions of both lungs. Homogeneity of aerosol distribution was graded independently b y two radiologists, RESULTS, TO achieve a comparable SI increase as attained in previous trials that used manual aerosol ventilation, a ventilation period of 20 minutes ( formerly 30 minutes) was sufficient. Mean SI changes of 116% were observed after that duration. Contrast delivery was rated evenly distributed in all cases by the reviewers. CONCLUSIONS, The feasibility of applying Gd-DTPA as a contrast agent to dem onstrate pulmonary ventilation in large animals has been described before, The results of this refined technique substantiate the potential of Gd-base d ventilation MR imaging by improving aerosol distribution and shortening t he nebulization duration in the healthy lung.