Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel technique for fluorescence tomography of tumors in living animals

10.12.2008
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 München – German Research Center for Environmental Health together with the Technische Universität München 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.

Michael van den Heuvel | alfa
Further information:
http://www.helmholtz-muenchen.de
http://www.helmholtz-muenchen.de/en/press/press/press-releases-2008/press-releases-2008-detail/article/11400/9/index.html

More articles from Medical Engineering:

nachricht Medical gamma-ray camera is now palm-sized
23.05.2017 | Waseda University

nachricht Computer accurately identifies and delineates breast cancers on digital tissue slides
11.05.2017 | Case Western Reserve University

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>