The degree of the inflammation so far has been determined primarily by means of samples from patients’ airways or lungs. To this end, either coughing is induced for sputum collection (induced sputum) or bronchoscopy is performed to collect cells from the lungs by means of brush biopsies or lung lavage. Performance of these examinations can be perfectly safe and they provide important information about cellular composition and cell activation status in the airways and lungs; however, they also put a certain strain on test subjects, so that methods involving no invasive examinations or challenge tests represent a valuable complementary option for efficacy testing of medicinal products.
Magnetic resonance imaging is one such non-invasive method, used to generate images of the human lung. The aim of current research activities is to improve the imaging technology, so as to enable visualization not only of the lung’s structure, but also of inflammatory processes. Airway inflammation involves an influx of liquid into the lung tissue, reduced local ventilation and blood flow, and diminished gas exchange in the lung tissue. By further development of the traditional MRI technology, these processes can be visualized by magnetic resonance imaging. In addition to the classical proton-based sequences, functional examination sequences are used in particular. Furthermore, methods are being developed that enable contrast enhancement in the lungs by means of a gaseous contrast agent, instead of using the traditional proton-based MRI technology.