In my PhD, I make multispectral cameras for detecting early cancer and pre-cancerous disease in Barrett’s Oesophagus.
Barrett’s Oesophagus is a largely benign condition impacting up to 1 in 15 people. Barrett’s occurs when repeated stomach acid reflux causes the usually smooth lining of the lower food-pipe becomes bumpy with protruding columnar cells, similar to that of the intestine. When a healthy cell type grows in the wrong place like this, we call it “Metaplasia”.
Sometimes Barrett’s Metaplasia can become “dysplasia”, meaning the mutated cells are no longer healthy but have become warped. Barrett’s can progress to cancer, and the likelihood is strongly linked to the degree of dysplasia; the probability of developing oesophageal cancer within one year is <0.3% for metaplasia, 5-10% for low grade dysplasia and over 20% for high grade dysplasia[1]. Surgical removal of dysplasia can prevent cancer []… but to remove all the benign Barrett’s would be overtreatment, and risks doing more harm than good. It is therefore essential to be able to tell apart the different forms.
Doctors use endoscopes (cameras on tubes passed down the throat) to inspect Barrett’s, and can conduct minor surgery via the tube. Sadly, conventional endoscope cameras often struggle to distinguish early dysplasia from metaplastic Barrett’s, missing 50% of cases.
The problem is that standard colour cameras image only three broadband colours – red, green and blue – to imitate human vision, and these are unable to tell apart the subtle spectral differences between Barrett’s stages. In our lab we are designing “multispectral” endoscope cameras which take images at a greater number of narrow wavelength bands, targeted to maximise the detection of dysplasia and excess blood vessels (another indicator of early cancer). We achieve this by patterning tiny filters (a few microns wide, a few nanometres thick!) over monochrome endoscope cameras, for which we are developing custom image processing algorithms to enable real-time dynamic imaging. Meanwhile, we are evaluating the efficacy of multispectral endoscopy in vivo in patients using a pre-existing monochrome endoscope and colour-changing illumination.
NanoDTC Associate, a2022