Noninvasive functional lung imaging with hyperpolarized xenon Breakthrough for diagnostics?

Background Magnetic resonance imaging (MRI) is a noninvasive technique that provides excellent contrast for soft tissue organs. However, due to the low density of protons and many air-tissue junctions, its application in the lung is limited. Thus, X-ray-based methods are often used here (with the well-known disadvantages of ionizing radiation). Objectives In this review, we discuss pulmonary MRI with hyperpolarized xenon-129 (Xe-MRI). Xe-MRI provides unique valuable insights into lung microstructure and function, including gas exchange with red blood cells-parameters not accessible by any standard clinical methods. Methods By magnetic labelling, i.e. hyperpolarization, the signal from xenon-129 is amplified by up to 100,000 times. In this process, electrons from rubidium are first polarized to 100% using laser light and then transferred to xenon by collisions. Then the hyperpolarized gas is brought to the patient in a bag and inhaled shortly before the MRI scan. Results Using special programming (sequences) of the MRI, the ventilation, microstructure, or gas exchange of the lungs, can be displayed in 3D. This allows, for example, quantitative visualization of ventilation defects, alveolar size, tissue gas uptake and gas transfer to the blood. Conclusions Xe-MRI provides unique information about the state of the lung-noninvasively, in vivo and in less than a minute.

Automated summary

This review discusses the use of hyperpolarized xenon-129 (Xe-MRI) for pulmonary MRI and its unique insights into lung microstructure and function.