Early photon tomography provides clearer picture of tumors in living animals

Who: The Centers for Disease Prevention and Control’s Injury Center is launching a new web resource that provides violence prevention data from 16 funded states. What: The new on-line tool, WISQARS(tm) NVDRS (Web-based Injury Statistics Query and Reporting System National Violent Death Reporting System) provides data on violent deaths from the National Violent Death Reporting

Full Post: CDC launches new on-line tool for violence prevention information

Fluorescent molecules - i.e. substances which can be stimulated to emit light - are extremely valuable tools in biological research and medical diagnosis.

Fluorescence can be used for instance to analyze the regulation and expression of genes, to locate proteins in cells and tissues, to follow metabolic pathways and to study the location and migration of cells. Of particular importance is the combination of fluorescence imaging with novel techniques that allow tomographic three-dimensional visualization of objects in living organisms. At the Helmholtz Zentrum M? - German Research Center for Environmental Health together with the Technische Universit?M? an own institute is concerned with the development and refinement of such new technologies: the Institute for Biological and Medical Imaging headed by Professor Vasilis Ntziachristos.

The quality of optical imaging in tissues is naturally limited, since beyond a penetration depth of a few hundred micrometers the photons are massively scattered due to interactions with cell membranes and organelles which results in blurred images. In the latest issue of the journal Proceedings of the National Academy of Sciences Prof. Ntziachristos and his team, together with colleagues from the Harvard Medical School and the Massachusetts General Hospital in Boston, USA, report on the use of the so-called early arriving photons together with tomographic principles. Early photons are the first photons that arrive onto a photon detector after illumination of tissue by an ultra-short photon pulse and undergo less scattering in comparison to photons arriving at later times. Compared to continuous illumination measurements a combination of these less scattered photons with 360-degree illumination-detection resulted in sharper and more accurate images of mice under investigation.

With this technique, called ‘Early Photon Tomography’ (EPT), the scientists imaged lung tumors in living mice. For this purpose they injected a substance into to the animals, which normally does not fluoresce, but becomes fluorescent after contact with certain cysteine proteases such as cathepsins. The amount of these proteases is enriched in lung tumors which allows fluorescence imaging of the tumor tissue. Comparison with conventional x-ray tomography showed, that EPT is not only a very sensitive technique for imaging of lung tumors in living organisms, but also has the potential to reveal biochemical changes that reflect the progression of the disease, which could not be detected by conventional X-ray imaging.

While early-photons are typically associated with reduced signal available for image formation, the authors demonstrated that due to the wide-field implementation, EPT operates with very small reduction in average signal strength as in conventional tomographic methods operating using continuous light illumination. In this respect EPT is a practical method for significantly improving the performance of fluorescence tomography in animals over existing implementations. At present EPT is practicable only with small animals, but - as stated by the authors of the paper - further development of the equipment can allow niche applications of the technique also with larger organisms including humans.



Researchers have developed a new type of imaging compound that allows them to visualize viable breast cancer cells that have spread to the lungs in mice. The compound binds to a protein called HER2, which is found on the surface of some breast cancer cells, and it glows, or fluoresces, only when taken inside

Full Post: Glowing imaging compound allows detection of viable cancer cells in mice

A study published in the scientific journal PLoS ONE highlights how the exploration of the ocean depths can benefit humankind. This is the story of a voyage of discovery, starting with marine animals that glow, the identification of the molecules responsible and their application as marker in living cells. Many marine organisms such as sea

Full Post: Biomedical research could benefit from deep sea

The monitoring and treatment of eye diseases that may cause blindness has taken a big leap forward, thanks to a new imaging technique that takes high quality colour photographs of the whole retina. Using the new technique called ‘TEFI’ (Topical Endoscopic Fundal Imaging), Professor Andrew Dick, David Copland and the team from the University

Full Post: New technique to watch for eye disease

Nikon Instruments, Inc. has introduced the AZ100 C1si, a macro confocal microscope system combining the best of stereo and compound microscopes into a single hybrid imaging system for dynamic imaging of single cells or whole specimens. This new macro confocal microscope system offers the highest resolution macro confocal imaging with rapid, real-time and high-accuracy unmixing

Full Post: Nikon Instruments introduces new confocal spectral imaging system

Researchers used a new imaging technique to take high quality color photographs of the clinical stages of ocular inflammation in mice, and the technology could help in the monitoring and treatment of diseases of the eye that may cause blindness. The study, “The Clinical Time-Course of Experimental Autoimmune Uveoretinitis Using Topical Endoscopic Fundal Imaging with

Full Post: New imaging technique captures clinical stages of ocular inflammation