Scientists have developed a new technique that allows doctors to assess the effects of treatment on lung function in real time. This innovation could enable earlier detection of lung function decline in patients suffering from conditions such as asthma and chronic obstructive pulmonary disease (COPD), as well as for those who have had a lung transplant.

The new scanning technique, developed by a research team at Newcastle University which was funded by Rosetrees and the MRC, visualises how air moves in and out of the lungs during each breath. It utilises a gas called perfluoropropane which is visible on MRI scans and can be safely inhaled by patients. The scans reveal the distribution of the gas within the lungs, offering insights into lung ventilation.

A study by experts from Newcastle and Sheffield universities and NHS trusts showed that the scans worked effectively in patients with asthma and COPD. The scans can quantify ventilation improvement after patients use bronchodilators, providing valuable data for clinical trials of new lung disease treatments.

Pete Thelwall, Professor of Magnetic Resonance Physics and Director of the Centre for In Vivo Imaging at Newcastle University, said, “Our scans show where there is patchy ventilation in patients with lung disease, and show us which parts of the lung improve with treatment. For example, when we scan a patient as they use their asthma medication, we can see how much of their lungs and which parts of their lung are better able to move air in and out with each breath.”

Participants in the research study included those with asthma or COPD, and healthy controls. Conventional spirometry, proton MRI, and 19F-MRI were performed after inhalation of a gas mixture containing 79% perfluoropropane and 21% oxygen. Three-dimensional 19F-MRI scans were acquired during a single breath hold. For participants with asthma or COPD, spirometric and MRI measurements were repeated following administration of nebulized salbutamol. The ventilation defect percentage (VDP) was calculated from perfluoropropane distribution.

The results revealed that 19F-MRI derived VDP was significantly higher in participants with COPD and asthma compared to healthy participants. After bronchodilator administration, VDP decreased by 33% in participants with asthma and 14% in those with COPD.

The conclusion of the study was that 19F-MRI of inhaled perfluoropropane was sensitive to changes in regional ventilation properties associated with lung disease, and enabled quantification of changes following bronchodilator therapy.

The imaging technique was also tested on lung transplant recipients with chronic rejection, also known as lung allograft dysfunction (CLAD), a common complication characterized by irreversible damage to the lung graft. By the time CLAD is diagnosed using traditional pulmonary function tests, considerable damage may have occurred.

The researchers scanned the lungs of ten transplant recipients with chronic rejection (a common issue in transplant patients) and compared the images to those from people with normal lung function. In those with chronic rejection, the scans showed poorer movement of air to the edges of the lungs, most likely due to damage in the lung.

This suggests that 19F-MRI is a promising tool for the early detection of regional ventilation defects in CLAD before lung function declines. Further investigation with larger cohorts are needed to confirm these findings.

Andrew Fisher, Professor of Respiratory Transplant Medicine at Newcastle Hospitals NHS Foundation Trust and Newcastle University, and co-author of the study said; “We hope this new type of scan might allow us to see changes in the transplant lungs earlier and before signs of damage are present in the usual blowing tests. This would allow any treatment to be started earlier and help protect the transplanted lungs from further damage.”

By offering earlier detection of lung function decline, this innovative method could not only revolutionise how clinicians monitor and treat patients with respiratory diseases, thus reducing morbidity and mortality, but also help lower the economic burden of asthma and COPD on the NHS that is estimated at £3 billion and £1.9 billion, respectively.

 

References

1. Pippard BJ, Neal MA, Holland CW, et al. “Assessing Lung Ventilation and Bronchodilator Response in Asthma and Chronic Obstructive Pulmonary Disease with Fluorine 19 MRI.” Radiology. doi: https://doi.org/10.1148/radiol.240949 (live date: Dec 24).

2. Neal MA, Bos S, Holland CW, et al. “Dynamic 19F-MRI of pulmonary ventilation in lung transplant recipients with and without chronic lung allograft dysfunction.” JHLT Open. doi: https://www.jhltopen.org/article/S2950-1334(24)00116-2/fulltext.

3. NHS England. “Respiratory Disease.” https://www.england.nhs.uk/ourwork/clinical-policy/respiratory-disease/.