Imaging technologies are crucial to contemporary medicine and early-stage diagnosis, potentially enhancing patient outcomes.
The image illustrates the novel Bijective Illumination Collection Imaging (BICI) concept using metasurfaces. Image Credit: Queen’s University
Microscopic imaging enables scientists and experts to observe cells directly, making it feasible to picture processes and structures that were once undetectable. However, a significant limitation of existing technology is that high-resolution microscopic imaging is restricted to two-dimensional (2D) images acquired in microscope slides, while tissue structures are three-dimensional (3D).
For several years, researchers have been seeking a method to resolve this challenge and attain 3D microscopic images.
An article published in the journal Nature Photonics co-authored by Majid Pahlevani (Electrical and Computer Engineering) and colleagues at Harvard University describes a new method that can improve advanced microscopes, facilitating a boost in image resolution and simultaneously making 3D microscopic imaging conceivable.
One of the key challenges of imaging on a microscopic scale is managing diffraction — the quick dispersion of tightly focused light — as the occurrence obstructs the accomplishment of high-resolution images.
In the research, the scientists demonstrate that a specific disposition of light and a path formed by an ultra-thin optical component made up of a collection of nanocolumns on a glass surface can break the boundaries otherwise forced by diffraction, thus cracking the issue. An optical lens with this organization could be developed into the advanced version of microscopic imaging devices.
This method, named bijective illumination collection imaging (BICI), can extend the range of high-resolution imaging by over 12-fold compared to the state-of-the-art imaging techniques. Unlike conventional imaging techniques, in BICI, the light which illuminates the target and the light collected from the target are distributed along the depth using the nanostructures, making it possible to preserve high-resolution imaging along a large depth into the tissue.
Dr. Majid Pahlevani, Study Co-Author, department of Electrical and Computer Engineering, Queen’s University
Dr. Pahlevani is also a member of the Queen’s Centre for Energy and Power Electronics Research (ePOWER).
Three-dimensional microscopic imaging allows many clinical and biological applications, such as offering insight into the intercellular mechanisms, and facilitating in vivo (in the body) instantaneous diagnosis and cancer cell detection.
Another core benefit of the new technique is how rapidly it can be processed.
Computationally intensive techniques result in slow imaging, which is not suitable for in vivo imaging. Organs in live patients are not stationary and move, which give rise to artifacts in imaging. Therefore, in vivo imaging requires fast techniques.
Dr. Majid Pahlevani, Study Co-Author, department of Electrical and Computer Engineering, Queen’s University
As the newly proposed method is an optical solution for boosting microscopic imaging resolution, it does not need extra computational capacity.
The article in Nature Photonics underlines cancer diagnoses as one of the key applications for the new technique: “Pathological changes in the early stages of diseases like cancer are often very subtle and can be easily overlooked. In vivo high-resolution imaging maintained in a large depth range has the potential to enable early and accurate detection and diagnosis”.
Dr. Pahlevani is confident in the fact that BICI can be applied to numerous existing imaging methods.
Journal Reference:
Pahlevaninezhad, M., et al. (2022) Metasurface-based bijective illumination collection imaging provides high-resolution tomography in three dimensions. Nature Photonics. doi.org/10.1038/s41566-022-00956-6.