Imaging of pulmonary pathologies: focus on magnetic resonance imaging

Magnetic resonance imaging (MRI) of the lung has shown tremendous progress in recent years. This includes parallel imaging, new contrast agents and mechanisms, ultrafast imaging, and respiratory gating. With these improvements in speed and image quality, MRI is now ready for routine clinical use. The main advantage for MRI of the lung is its unique combination of structural and functional assessment within a single imaging examination. This comprehensive imaging assessment is an asset when compared with computed tomography, which is complemented by the fact that MRI does not carry any exposure to ionizing radiation, making it especially advantageous in children, young adults, and for follow-up examinations either in disease surveillance or therapy monitoring. Clinical indications for MRI are: pulmonary vascular disease, especially pulmonary hypertension, airway diseases, especially cystic fibrosis; neoplastic disease, including staging of lung cancer as an alternative imaging modality; all pediatric indications (e.g., congenital anomalies); as well as follow-up examinations. Under investigation is the application of MRI for chronic obstructive pulmonary disease as well as asthma. In this regard the additional benefit from MRI using hyperpolarized gases has to be determined.