PHELINET · Polarized Helium Lung Imaging Network

Final Activity Report Summary - PHELINET (Polarized Helium Lung Imaging NETwork)

Respiratory diseases are among the most prevalent diseases for morbidity and mortality. The top five respiratory diseases account for 17.4% of all deaths and 13.3% of disability life years. Chronic obstructive pulmonary diseases have become the fourth cause of death worldwide whereas lung cancer, respiratory infections and tuberculosis are among the 10 leading causes. Asthma affects about 150 million people worldwide and is the most prevalent chronic disease in childhood. Furthermore, the impact for health of pulmonary diseases is increasing in contrast for instance to cardiovascular diseases. Diagnosis of lung diseases traditionally relied on imaging techniques like chest radiography, high resolution computed tomography (CT) or lung scintigraphy. Inherent patient exposure to ionising radiation limits the extensive use of these techniques, and excludes repeated use for accurate follow-up of the evolution of the disease (especially in case of young patients) and of the response to treatment or surgery. The PHELINET research network focused on the use of Magnetic Resonance Imaging (MRI) for lung diagnosis as an alternative to ionizing imaging techniques. The network places special emphasis on the use of helium gas as an inhaled imaging agent. In order to image the ventilation of the lungs with this inhaled gas, a non-radioactive isotope of helium (known as Helium-3) is required. Furthermore, the helium gas undergoes beforehand an operation called polarisation (or hyperpolarisation) based on optical pumping devices. Beside the use of Helium-3 gas, the network investigated as well the potential of MRI for imaging the lung tissue. The PHELINET network includes 17 academic and industrial partners from 9 European countries. It recruited 17 young scientist and implemented collaborative research objectives and network-wide training schools for the researchers new in the field. Four scientific objectives were explored during the 4-years duration of the network. The first objective is related to the polarisation techniques needed for imaging the helium-3 gas. The physicists involved here demonstrated that the polarisation of the helium-3 gas can be improved in certain experimental conditions. These scientists developed more compact and more powerful polarising apparatus for the production of hyperpolarised gases. Importantly, they designed and implemented a recycling system to recover and re-use the Helium-3 gas for new experiments. This point is crucial considering the scarcity and the price of helium-3 gas. The second objective concerned the implementation of imaging protocols using the helium3 gas. Indeed, MRI of helium-3 gas requires specific hardware and image analysis software. The engineers, physicists and computing scientists from the network developed new radiofrequency probes to image the inhaled gas. They validated new concepts for the diagnostic of lung diseases based for instance on the diffusion of gas in the lung or on the elasticity of lung tissue. In a third research workpackage, the scientists (physicists, radiologists and clinicians) applied the gas ventilation and lung tissue imaging techniques for the diagnostic of lung diseases in patients. Young patients (children and adolescents) with cystic fibrosis diseases underwent Helium-3 MRI to visualise the ventilation defects induced by this genetic disorder. Adult patients with emphysema (destruction of lung tissue) were imaged using Helium-3 in order to determine the severity and the progression of the disease. The ventilation technique was applied as well to help planning surgical intervention in patients with lung cancer. The last objective concerned the application of gas and lung tissue MRI in animal models of lung diseases. MR physicists and biologists worked together for the application of lung MRI for grading and monitoring disease progression in animals with the overall objective of validating the efficacy of treatment and drugs therapy.

Data: CORDIS, © European Union