Imaging Method Shows Promise for Evaluation of Cystic Fibrosis

An imaging method developed in part by researchers from Harvard Medical School and the University of Alabama at Birmingham is showing promise in the early diagnosis and evaluation of cystic fibrosis. The technique, based on optical coherence tomography, is able to provide high-resolution images of cilia lining the nasal pathways, as well as detailed features of the clearance of mucus, a significant impairment in people with cystic fibrosis.

The imaging catheter is about 2 mm in diameter with a resolution of about 1 µm — a 50th of the size of a human hair — and can be used to probe the nasal passages of patients without the need for sedatives.

The imaging catheter is inserted into the nose using live imaging guidance and can record data from various positions in the nasal cavity. Courtesy of B.R. McDonald et al. Science Translational Medicine (2019).

“We’ve done a lot of benchtop imaging with micro-OCT, but this is the first time we’ve been able to use it in people,” said co-principal investigator Guillermo Tearney, a pathologist and investigator for the department of pathology and the Wellman Center for Photomedicine at Massachusetts General Hospital (MGH) and professor of pathology at Harvard Medical School. “It’s unprecedented to see this pathophysiology dynamically in living patients. It will allow us to begin to understand things we never even knew were there.”

The researchers found that in patients with cystic fibrosis, mucus was dehydrated and contained far more inflammatory cells as compared with control subjects. Some more surprising information to the researchers was that with micro-OCT they were able to measure the reflective qualities of the mucus, and that patches of the patients cilia and epithelium were ablated.

“We thought they were there, but just not functioning well,” Tearney said, “but in places they were completely gone.”

The researchers expect that this technique will allow clinicians to diagnose diseases much earlier that affect the airways and will provide a higher level of information in monitoring progression and evaluating the effectiveness of drug therapies for individual patients.

“Visualizing mucus will be a powerful tool,” said co-principal investigator Steven M. Rowe, director of the Gregory Fleming James Cystic Fibrosis Research Center and a professor of medicine at the University of Alabama at Birmingham. “Now we’ll be able to see how various treatments affect the airway — not only agents intended to fix abnormal mucus, which is applicable to many diseases, but also treatments that repair the basic CF defect itself.”

Micro-OCT is expected to have many applications beyond cystic fibrosis, from diagnosing and treating respiratory ailments such as primary ciliary dyskinesia, chronic sinus disease, and chronic obstructive pulmonary disease (COPD), to screening the GI tract for diseases and imaging coronary artery cells. “The goal is to figure out who else it can be used to help, and make it more broadly available as a device,” Rowe said.

The research was published in Science Translational Medicine (https://doi.org/10.1126/scitranslmed.aav3505).