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!
Tracing aromatic molecules in the early universe
23.03.2017 | University of California - Riverside
New study maps space dust in 3-D
23.03.2017 | DOE/Lawrence Berkeley National Laboratory
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences