The tiny technology, presented at this year's meeting of the American Association of Physicists in Medicine in Anaheim, California, is being developed to image human breast tissue, laboratory animals, and cancer patients under radiotherapy treatment, and to irradiate cells with more control than previously possible with conventional X-ray tubes.
The X-ray machine used in a typical hospital today is powered by a "hot" vacuum tube that dates back to the beginning of the 20th century. Inside the tube, a tungsten metal filament -- similar to the one that creates light in an incandescent bulb -- is heated to a temperature of 1,000 degrees Celsius. The heat releases electrons, which accelerate in the X-ray tube and strike a piece of metal, the anode, creating X-rays.
Sha Chang, Otto Zhou, and colleagues that University of North Carolina have developed cold X-ray tubes that replace the tungsten filament with carbon nanotubes packed like blades of tiny grass. Electrons are instantly emitted from the sharp tips of the nanotubes when a voltage is applied. "Think of each nanotube as a lightning rod on top of a building. The high electric field at the tip of the lightning rod draws the electric current from the cloud. Carbon nanotubes emit electrons using a similar principle," said Chang.
The group used the nanotubes to build micro-sized scanners and image the interior anatomy of small laboratory animals. Existing X-ray technologies have difficulty compensating for the blur caused by the creature's breathing. Slow mechanical shutters that open and close to block and release the radiation are used to time X-ray pulses to correspond with breath, but their speed is inadequate for small animals because of the creatures' extremely fast breathing and cardiac motion. Chang and Zhou have demonstrated that their carbon nanotubes, which can be turned on and off instantaneously, are fairly easy to synch up to equipment that monitors small animal's breathing or heart rate.
The nanotube devices may also improve human cancer imaging and treatment. CT scanners currently in use check for breast cancer by swinging a single large X-ray source around the target to take a thousand pictures over the course of minutes. Using many nanotube X-ray sources lined up in an array instead, breast imaging can be done within few seconds by electronically turning on and off each of the X-ray sources without any physical motion. This fast "tomosynthesis" imaging improves patient comfort and boosts image quality by reducing motion blur. Using 25 simultaneous beams, the team produced images of growths in breast tissue at nearly twice the resolution of commercial scanners on the market.
This summer Chang's team will conduct a clinical test of a first generation nanotube-based imaging system for high-speed image-guided radiotherapy. The research image system is developed by Siemens and Xinray Inc., a joint venture between Siemens and a University of North Carolina startup company Xintech Inc.
The talk "Carbon Nanotube Field Emission Based Imaging and Irradiation Technology Development for Basic Cancer Research" will be at 10:55 a.m. on Tuesday, July 28 in Ballroom D.
Journalists are welcome to attend the conference free of charge. AAPM will grant complimentary registration to any full-time or freelance journalist working on assignment. The Press guidelines are posted at: http://www.aapm.org/meetings/09AM/VirtualPressRoom/.
If you are a reporter and would like to attend, or if you have questions about the meeting, contact Jason Bardi (email@example.com, 858-775-4080).
Main Meeting Web site: http://www.aapm.org/meetings/09AM/.
Search Meeting Abstracts: http://www.aapm.org/meetings/09AM/prsearch.asp?mid=42.
Meeting program: http://www.aapm.org/meetings/09AM/MeetingProgram.asp.
AAPM home page: http://www.aapm.org.
Background article about how medical physics has revolutionized medicine: http://www.newswise.com/articles/view/538208/.
ABOUT MEDICAL PHYSICISTS
If you ever had a mammogram, ultrasound, X-ray, MRI, PET scan, or known someone treated for cancer, chances are reasonable that a medical physicist was working behind the scenes to make sure the imaging procedure was as effective as possible. Medical physicists help to develop new imaging techniques, improve existing ones, and assure the safety of radiation used in medical procedures in radiology, radiation oncology and nuclear medicine. They collaborate with radiation oncologists to design cancer treatment plans. They provide routine quality assurance and quality control on radiation equipment and procedures to ensure that cancer patients receive the prescribed dose of radiation to the correct location. They also contribute to the development of physics intensive therapeutic techniques, such as the stereotactic radiosurgery and prostate seed implants for cancer to name a few. The annual AAPM meeting is a great resource, providing guidance to physicists to implement the latest and greatest technology in a community hospital close to you.
The American Association of Physicists in Medicine (AAPM) is a scientific, educational, and professional organization of more than 6,000 medical physicists. Headquarters are located at the American Center for Physics in College Park, MD. Publications include a scientific journal ("Medical Physics"), technical reports, and symposium proceedings. See: www.aapm.org.
Jason Bardi | EurekAlert!
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine