Non-Invasive Assessment of Mucociliary Clearance with Micron-Sized Iron Oxide Particles in Rat Lungs

Selina Bucher¹, Michael Neumaier¹, Sascha Koehler², Birgit Jung³, Detlef Stiller¹

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and mucus production. Because an excess of mucus triggers infections, an efficient mucociliary clearance (MCC) is important. To detect therapy-induced changes in MCC, non-invasive imaging techniques are needed. We used 2D radial MRI and micron-sized iron-oxide particles to evaluate MCC in the rat lung, where four different iron-oxide particles yielded an attenuated MR signal. Clearance of 4.5 m-sized particles occurred within one day, whereas smaller and larger particles were not cleared. Our results indicate a great potential for MRI with micron-sized iron-oxide particles to visualize and quantify MCC in patients.