Sunday, December 21, 2008

3D Cancer Detection

Biomedical engineers and cancer specialists at Duke have long been collaborating to discover ways to detect and treat cancer at all its stages. One of the recent major breakthroughs is the ability to observe and examine a live body tissue in three dimensions using a technique called Multi-photon microscopy.

According to researchers, more than 50% of all detected cancers arise in squamous epithelium, and if detected in a pre-invasive or pre-cancerous state, it can be treated relatively well.

The team led by Dr. Nirmala Ramanujam, Associate Professor of BME at Duke, has been studying optical spectroscopy, optical sectioning microscopy and photon migration techniques, and attempting to use them for characterizing and detecting biochemical and structural properties of various human tissues. According to Dr.Ramanujam, the multi-photon fluorescence microscopy—a technique enables doctors to "peer into the individual cells in a very non-invasive way to see how things change as early cancer progresses."

A multiphoton fluorescence microscope uses pulsed long wavelength laser light to excite fluorophores within a specimen. The fluorophore absorbs the energy from two long-wavelength photons that must arrive simultaneously in order to excite an electron into a higher energy state, from which it can decay, emitting a signal.

Another technique being explored by Ramanujam's group is called Ultraviolet-visible optical spectroscopy (UV-VIS). It is similar to fluorescence spectroscopy, in a way that fluorescence involves transitions from the excited state to the ground state, while absorption deals with electron transitions from the ground state to the excited state.

Dr. Ramanujam's current focus is on further researching and developing broad and effective techniques for clinical detection of cancer.