Gadolinium containing contrast agents for pulmonary ventilation magnetic resonance imaging: preliminary results

Five gadolinium containing contrast media (gadopentetate dimeglumine [Magnevist; Berlex Imaging, Montville, NJ, USA], gadobutrol [Gadovist; Schering, Järfälla, Sweden], gadoteridol [ProHance; Bracco-Byk Gulden, Konstanz, Germany], gadobenate dimeglumine [MultiHance; Bracco-Byk Gulden, Konstanz, Germany], and gadopentetate dimeglumine added with mannitol and a surface active detergent) were evaluated for their efficacy in magnetic resonance depiction of lung ventilation.

All contrast agent aerosols were generated by a jet nebulizer. Twelve intubated domestic pigs were mechanically ventilated with the respective aerosolized contrast agent and studied on a 1.5 T MR imager. T1-weighted TSE images using respiratory gating were obtained before and after a 10-minute ventilation period. Pulmonary signal intensity (SI) and signal-to-noise (SNR) changes were measured for both lungs.

Mean SI increases ranged between 13.5% and 45.8% (right lung) and 14% and 39.8% (left lung). SNR changes ranged from +14.7% to +46.8% and from +13.1% to +40.5% for the right and left lung, respectively. The highest SI and SNR increases were observed in the gadoteridol group.

The use of gadolinium for MR ventilation imaging is primarily hindered by its viscosity properties and thus, its capability of aerosolization. Of the five agents tested, the medium with the lowest viscosity at room temperature (gadoteridol) showed the most promising enhancement results. The results reaffirm the potential of gadolinium-based contrast agents as a pulmonary imaging alternative. With a reduction of ventilation duration down to ten minutes, the method appears tolerable in a clinical setting.