New scanning method observes lung function in real time

A new method of scanning lungs has enabled UK researchers to observe the effects of treatment on lung function in real time, as well as to assess the functioning of transplanted lungs. This could enable medics to better identify any decline in lung function.

The method utilises a special gas, called perfluoropropane, which can be seen on an MRI scanner. The gas can be safely breathed in and out by patients, and then scans taken to look at where in the lungs the gas has reached.

Using the new scanning method, the team are able to reveal the parts of the lung that air doesn’t reach properly during breathing. By measuring how much of the lung is well-ventilated and how much is poorly ventilated, experts can make an assessment of the effects of a patient’s respiratory disease, and they can locate and visualise the lung regions with ventilation defects.

Demonstrating that the scans work in patients with asthma or chronic obstructive pulmonary disease (COPD), the team used the technique to quantify the degree of improvement in ventilation when patients used an inhaler (or ‘bronchodilator’) known as salbutamol. Their study, published in the journal Radiology, showed that the imaging method could be valuable in clinical trials of new treatments of lung disease.

“Our scans show where there is patchy ventilation in patients with lung disease, and show us which parts of the lung improve with treatment,” said project lead Professor Pete Thelwall, Director of the Centre for In Vivo Imaging at Newcastle University. “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.”

In a second study, published in JHLT Open, the team further developed the imaging method to provide lung function measurements which could be used to better support lung transplant recipients in the future. The sensitivity of the measurement means medics can spot early changes in lung function, allowing them to identify lung problems sooner.

Lung function MRI showing measurements in lung transplant recipients.

The team scanned transplant recipients’ lungs over multiple breaths in and out, collecting MRI pictures that show how the air containing the gas reached different areas of the lung. The team scanned those who either had normal lung function or who were experiencing chronic rejection after lung transplant, which is a common issue. 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’s airways in the lung — a feature known as chronic lung allograft dysfunction.

“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,” said study co-author Professor Andrew Fisher, from Newcastle Hospitals NHS Foundation Trust and Newcastle University. “This would allow any treatment to be started earlier and help protect the transplanted lungs from further damage.”

The team say there is potential for their method to be used in the clinical management of lung transplant recipients and other lung diseases in the future, spotting early changes in lung function and enabling better management of these conditions.

Top image: A radiographer preparing their patient for a scan.