CT with Nanotubes for People and Baggage Scans

Feb 02, 2010

Researchers from Siemens are investigating the use of small, fast X-ray sources based on nanotubes.

In combination with a computer tomograph (CT) scanner, these could serve to generate high-quality images of rapid processes within the human body, such as the dispersion of a contrast medium. The radiation would be reduced without any sacrifice of image quality compared to the equipment in use today. The use of fast X-ray sources is also attractive for applications requiring a fast throughput. These include scanning systems for luggage and passengers in airports. Siemens is developing these sources together with the U.S. company Xintek in a joint venture by the name of XinRay Systems.

are generated when accelerated electrons strike an electrode. Today's conventional source for such electrons is a hot filament inside a . However, this type of system consumes a lot of energy, is reacts relatively slow, gets hot, and can only be miniaturized to a certain degree. Therefore, researchers look for "cold" electron sources which emit electrons under high voltage from a metal formed into tiny spikes or sharp edges.

Nanotubes made of carbon are ideal as so-called field emitters, since they are as conductive as metal and also very thin, with a diameter of a few . They can be activated in less than a millionth of a second, whereas it takes several hundredths of a second to trigger a conventional X-ray source. The researchers at Siemens, Xintek and XinRay first apply to a metal substrate and then control these individually in order to create an array of mini electron sources. The technology stems from research by a team at the University of North Carolina and is now being developed into a commercial solution by Siemens.

In the most powerful CT scanners currently available from Siemens, two X-ray tubes revolve around the patient at more than three times per second. In the future, hundreds of mini X-ray sources could be permanently installed in a fixed circle and triggered in sequence. This would generate ten high-quality images per second — fast enough to enable observation of processes such as the destruction of tumor tissue during radiation therapy. It will take several years before such X-ray sources can be used in series-produced medical devices. However, their market readiness for use in industrial environments or to scan baggage in airports could come much sooner.

Explore further: Simpler process to grow germanium nanowires could improve lithium ion batteries

add to favorites email to friend print save as pdf

Related Stories

Teeny-tiny X-ray vision

Jul 28, 2009

The tubes that power X-ray machines are shrinking, improving the clarity and detail of their Superman-like vision. A team of nanomaterial scientists, medical physicists, and cancer biologists at the University of North Carolina ...

Space saving approach to satellite communications

Dec 05, 2005

Ken Teo and his team at the University of Cambridge have come up with a much more efficient and compact way to send signals from satellites. They have managed to use an array of carbon nanotubes to create a ...

New X-ray microscope for science and industry

Jul 03, 2006

Australian researchers have taken X-ray technology to a new level, developing and using high-powered microscopes to see inside objects and capture high-resolution images of their subsurface structures.

Recommended for you

User comments : 0