Health & Medicine, UK (Commonwealth Union) – A global team of researchers who partnered with the University of St Andrews have made a significant step forward for a key from of light imaging, optical coherence tomography (OCT), that can revolutionise the utilization of ophthalmology, dermatology, cardiology, as well as earlier diagnosis of cancer.
A recent research study, appearing this month in Science Advances, was led by an international team of experts from the University of Adelaide in Australia, the Technical University of Denmark (DTU), the Aerospace Corp in the USA, and academics from the School of Physics and Astronomy at the University of St Andrews. This groundbreaking research has the potential to enhance the diagnosis of various diseases.
In recent years, there have been remarkable advancements in light imaging technology. Its application in biomedical imaging has made significant strides, offering a unique combination of simplicity, user-friendliness, high-resolution image recovery, and versatility. However, certain obstacles still continue, particularly in obtaining information from deeper layers. This obstacle comes up due to the scattering of light within tissues, which obscures information beyond the surface.
Optical Coherence Tomography (OCT) relies on the backscattering of light within the sample, occurring when light passes through different layers of cells, for instance. This phenomenon is similar to the way light is scattered in a fog, where water droplets with a different refractive index than the surrounding air disrupt visibility. The scattering of light by cells, including membranes and smaller components, in biological tissues poses a challenge for imaging. In fact, obtaining a clear signal from depths beyond 1 mm is extremely difficult due to various factors, including signal interference from intervening tissue.
Traditionally, it has been widely believed that the signal obtained through OCT primarily arises from light that has experienced a single backscattering event. Conversely, light that undergoes multiple scattering events is considered detrimental to the formation of clear images. However, the research team uncovered a different perspective. They found that selectively collecting the multiply scattered light can actually enhance image contrast, particularly in samples with high levels of scattering.
Significantly, the researchers demonstrated a straightforward implementation of this approach with minimal additional optics. By modifying the paths for light delivery and collection, they achieved improved image contrast at depth. This innovative technique offers a promising avenue for enhancing OCT imaging in highly scattering samples without the need for complex optical setups.
Gavrielle Untracht, the DTU 1st author of the paper indicated that the findings of the study may be the initial point of a new method of looking at OCT imaging. She further indicated that she was excited to contribute to such a technological step forward in the well-established field of OCT.
University of St Andrews, Professor Kishan Dholakia, of the School of Physics and Astronomy says “Our study breaks norms in optical imaging and I believe heralds a new path to recovering information at depth. OCT is a world established method to gain useful information on human health – our approach can enhance this even further.”
DTUs Dr Peter Andersen, co-corresponding author, says “The unique configuration, supported by our modelling, should redefine our view on OCT signal formation – and we can now use this insight to extract more information and to improve diagnosis of disease.”
The team is confident that their groundbreaking discovery has the potential to challenge conventional practices and bring about a significant advancement in the recovery of images from deep within samples. They are particularly encouraged by their intellectual property, which has been both granted and filed in this field, and they are eager to witness its translation into practical applications.
With the current Optical Coherence Tomography (OCT) market valued at $1.3 billion in 2021, it is projected to triple in size by the end of the decade. This growth trajectory further gives reason for the team to be enthusiastic for the impact their breakthrough could have in revolutionizing the field of OCT imaging.
