Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

French, Swiss Research Groups Demonstrate New "Phase" in Biological Imaging

10.08.2005


The Beginnings of a New Phase in Medical Imaging? Phase-Contrast Imaging Device Provides 3-Dimensional Views of Hard-to-Image Biological Objects



In a development that could help usher in a new kind of medical imaging for clinics and hospitals, researchers have demonstrated a practical x-ray device that provides 2- and 3-dimensional images of features in soft biological tissue that are ordinarily hard to discern with conventional x-ray imaging. Performed by researchers at the Paul Scherrer Institut in Switzerland and the European Synchrotron Radiation Facility in France, this work may help make practical new medical applications, such as the ability to detect cancerous breast tissue directly, rather than the hard-tissue calcifications that are produced in later stages of the disease. The new x-ray demonstration appears in the 8 August issue of Optics Express, an open-access journal published by the Optical Society of America.

X-rays excel at imaging hard tissue--such as teeth--as well as the differences between hard and soft tissue--such as bones and skin in the human hand. However, x-rays are not good at distinguishing between different types of soft tissue, such as normal and cancerous cells in the breast. While x-ray mammography detects the hard “calcifications” that are the byproducts of breast tumors, researchers wish to be able to detect the tumor cells directly-potentially leading to better and earlier diagnosis of breast cancer.


This is just one of the potential biomedical applications of an emerging technique called phase-sensitive x-ray imaging. Normal x-ray pictures, such as those at dental offices, are “absorption-based” images: they rely upon the fact that the teeth absorb many more x-rays than the rest of the mouth. However, soft tissue does not absorb x-rays very well, making absorption imaging unsuited to the task of capturing the details of soft structures in such organs as the breast and kidney.

Optics researchers have long known that x-rays have the potential to make detailed images of soft biological tissue through a technique known as “phase” imaging. X-rays, a form of electromagnetic wave like light, can be visualized as a series of peaks and valleys like a water wave. When an x-ray encounters the boundary of two types of material, such as normal tissue and cancerous tissue, it will undergo a “phase shift”: the peak of the wave will move backward by a small amount relative to the position where it would be if there were no sample in the beam. By measuring the phase shifts as x-rays pass through the boundaries of different kinds of tissue, researchers can obtain detailed pictures of soft biological tissue.

In a demonstration that could bring this approach much closer to medical applications, a new phase-based imaging device combines three desirable attributes-compact size (only a few centimeters in length), large field of view (up to 20x20 cm^2), and the ability to use x-rays over a broad spectrum of energies. Crucially, the design uses a pair of gratings-each a thin slab of material with narrow, closely spaced parallel lines etched deeply into them, like little slits carved into the inch marks of a ruler.

In the setup, a stream of x-rays passes through the object to be imaged and it undergoes a series of phase shifts, which distorts the stream in a precise way. The distorted x-ray stream then passes through the first grating and is diffracted; the grating slices the x-ray stream into multiple waves that combine and interfere to produce a series of fringes (bright and dark stripes). The second grating extracts from this pattern precise information on the inner details of the object (see accompanying article for more information).

Using this technique, the researchers imaged a small spider, revealing internal structures that would be difficult to image with any other method. The researchers believe that the modest requirements of this technique, both in terms of x-ray source, laboratory space, and materials, may make phase-based imaging practical for a wide range of biological and medical applications.

| alfa
Further information:
http://www.opticsexpress.org

More articles from Physics and Astronomy:

nachricht Astrophysicists measure precise rotation pattern of sun-like stars for the first time
21.09.2018 | NYU Abu Dhabi

nachricht Halfway mark for NOEMA, the super-telescope under construction
20.09.2018 | Max-Planck-Institut für Radioastronomie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells

21.09.2018 | Life Sciences

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>