Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New phase-contrast microscopy developed at PSI enhances X-ray images.

10.05.2006


Innovations for society

Imaging techniques are increasingly at the forefront of progress in science and technology. The Paul Scherrer Institute (PSI) is among the leaders in this development. Imaging techniques turn objects visually inside out, allowing ever greater precision– for instance in medical diagnosis. They also contribute to a better understanding of the mechanisms of certain diseases, like Alzheimer’s or osteoporosis. Further applications occur in materials research, where imaging processes are a decisive factor in achieving results that ultimately – as with medical progress – benefit society.

The new phase-contrast microscopy developed at PSI enhances the sensitivity and contrast of classical X-ray images. Traditional techniques are based on the different X-ray absorbance of different materials, which enables the structure of dense body-matter like bones to be readily differentiated from that of lighter tissue. Low-absorbance materials, however, produce low-contrast images, which makes it difficult to visually reproduce fine details using conventional X-ray methods.

It has been discovered, however, that X-rays not only lose intensity when passing through a sample, they also undergo a phase shift, because the speed of light waves in matter differs from their speed in a vacuum. This phase shift is sensitive to the smallest changes in tissue, which means that phase signals can be used to substantially heighten the contrast of an X-ray picture.

Safer early diagnosis of breast cancer

Enhanced contrast enables the X-ray dose to be significantly reduced, which is particularly relevant to mammography techniques in screening for breast cancer. Phase-contrast microscopy is readily adaptable to existing X-ray equipment and could, therefore, trigger a major improvement in future X-ray diagnostic techniques.

Another aspect of medical technology currently at the top of PSI’s research programme is X-ray microtomography, a process that provides a detailed image of the interior of a sample. PSI results are of particularly high quality because the Swiss Light Source (SLS) particle accelerator generates X-rays of unparalleled intensity. The more intensive the X-ray beam, the better and faster the microtomography. Three dimensional images with a resolution of one thousandth of a millimeter (1 micrometer) can currently be produced within minutes.

Top quality 3D images

The PSI equipment can take snapshots of aluminum alloys, ceramics, and prehistoric embryos, as well as bones affected by osteoporosis. A joint research project of PSI, ETH Zurich, the University of Zurich and Novartis is looking for traces of Alzheimer’s disease in blood vessels. Scientists have recorded changes to blood vessels in the brains of young mice with Alzheimer’s disease. This might indicate that the -origins of the disease are connected with insufficient blood supply to the brain – in other words that the protein deposits typical of Alz-heimer’s might be caused by lack of oxygen. Achieving a resolution of 1–15 micrometers, PSI’s 3D imaging of mouse blood vessels is an important tool in researching this hypothesis.

PSI’s two neutron radiography instruments, NEUTRA and (since 2005) ICON, are basically no more than large-scale cameras. But they have special powers – they can see through objects without destroying them. So can X-ray devices; but the difference is that neutrons can do this with heavy metals like lead or uranium. And they have other advantages, too. For examining finely structured organic substances (and water) the neutron beam is definitely the instrument of choice.

Roman swords and dino vertebrae

The equipment is often used for routine jobs like the examination of welds and seams, or testing for corrosion, or for electro-chemical and geological research. But questions also come from archaeologists interested in Celtic coins or in the workmanship of Roman swords, from palaeontologists studying the cervical vertebrae of dinosaurs, and even from engineers testing bullet-proof vests.

Last year PSI spent almost SF 270 million not only on its in-house research projects, but also in academic training, and in its function as one of the top user laboratories worldwide. In 2005 a record number of more than 1400 scientists from 50 different countries used our large scale facilities for their experiments, and the number of user-visits was also substantially higher than in the previous year. The quality of PSI’s experimental facilities and equipment, as well as our advice and consultation services, is clearly a factor that attracts scientists in increasing numbers to Villigen.

Juanita Schlaepfer-Miller | alfa
Further information:
http://www.psi.ch/medien/medien_news_e.shtml

More articles from Medical Engineering:

nachricht Can radar replace stethoscopes?
14.08.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Novel PET imaging method could track and guide therapy for type 1 diabetes
03.08.2018 | Society of Nuclear Medicine and Molecular Imaging

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>