JUNE 25, 2009--MIT professor and optical coherence tomography (OCT) pioneer James Fujimoto became the fifth annual Hounsfield memorial lecturer at the UK's Imperial College London Imaging Sciences Centre earlier this month. The annual event, designed to recognize the contribution of Sir Godfrey Hounsfield to medical imaging, is meant to showcase a world-leading researcher and review developments in imaging science. As part of the event, Fujimoto was presented with the 2009 Hounsfield medal.
Sir Roy Anderson, Rector of Imperial College London, presided over the meeting of more than 200. He introduced Prof. Fujimoto as a man passionate about teaching, a model advocate of interdisciplinary collaboration, and one who has the motivation to make a difference in the world.
This is supported by a range of posters produced by imaging related research groups in Imperial which demonstrate the scope and depth of research going on at the College.
In his talk, titled "Biomedical Imaging and Optical Biopsy with Optical Coherence Tomography (OCT)," Prof. Fujimoto, charted the ups and downs of OCT from the 1990s, which he said nearly died through lack of commercial opportunity. However by 2006, there were over 6,000 systems being used in the ophthalmic field from Carl Zeiss alone with their Stratus system. Retinal imaging, identification of glaucoma and macular degeneration are all now well established applications for OCT, which can generate high-resolution, cross-sectional and three-dimensional images of microstructure in biological systems. Imaging is performed by measuring the echo time delay of light backscattering in tissue. OCT can perform "optical biopsy" enabling the in situ, real time visualization of tissue pathology.
OCT utilizes advances in photonics and fiber optics such as femtosecond broadband lasers, high speed wavelength swept lasers and line scan camera technologies. Three dimensional volumetric imaging with extremely high voxel density is now possible, enabling microstructure and pathology to be visualized and rendered in a manner analogous to magnetic resonance imaging. OCT is rapidly becoming a clinical standard in ophthalmology, where it can image retinal pathology with unprecedented resolutions. OCT is also being developed for other applications ranging from cancer detection in endoscopy to intravascular imaging in cardiology.
Fujimoto made clear that the technology is developing quickly as both software and hardware improvements coupled to laser developments have increased sensitivity of measurement while greatly reducing the time taken for the measurement. At this time, OCT is being used as a fast diagnosis tool based mainly on the observations of the user, e.g. the ophthalmologist. Looking to the future, the use of pattern recognition software may well be applied as it has started to become accepted in the field of digital pathology.
Screening and early stage diagnosis of cancers is another area of growth for the use of OCT. Work using an endoscopic probe has been reported where OCT may prove helpful in the early diagnosis of Barrett's esophagus, where refluxing acid from the stomach can damage cells. This in turn may lead to esophageal cancer, the UK's 9th most common cancer with around 7800 cases being diagnosed each year.
Not all applications are biomedical in nature. Fujimoto discussed examples in which OCT has been used for art conservation, and to demonstrate the technique's power he used a 16th century painting. As the technique enables imaging of sections, it may be applied to the different processes of a painting. For example, the surface is likely to be a varnish. Below this will be the paints/pigments and then below that may be the original charcoal sketches of the artist before the painting proper commenced.
The success of OCT may also be measured through observing the number of papers now being published in the field. The last 2-3 years has seen an explosion in publications with over 7,000 currently reported with around half being ophthalmic in origin. To put this into perspective with other microscopies, OCT is chasing after confocal microscopy (29,000). While growth will continue in medical areas, new applications will develop in areas such as metrology and other areas of imaging below a surface.
The meeting provided the opportunity for imaging related research groups to demonstrate the scope and depth of research at Imperial through poster presentations. The top award went to Andrew Chan from the Department of Chemical Engineering. His work, "Fourier transform infra red spectroscopy imaging of live cells and healing wounds" was rewarded with a prize of £500. The poster illustrated the power of imaging and chemistry being applied in tandem.
In closing the presentation and proposing the vote of thanks, Prof. Maggie Dallman, Principal of the Faculty of Natural Sciences at Imperial, presented Fujimoto with the 2009 Hounsfield medal.
The 2009 Hounsfield lecture was sponsored by CORDA, the pioneering charity dedicated to preventing heart diseases and stroke, by Michelson Diagnostics, the UK's leaders in OCT instrumentation and technology and the Clinical Imaging Centre.