Nano X-ray Tubes: Faster and Cheaper

Evolving nano technology has come a long way in improving a wide range of medical technology.  Scientists have been using nanostructures on the surface of X-ray tubes to improve their efficiency in converting power to radiation, making X-ray tubes faster and longer lasting while delivering better resolution. 

The carbon nano-coating allows the tube to be energized with a fraction of electrical energy and can be turned on and off instantaneously, which results in less heat produced, permitting a smaller, faster device.  The current X-ray tube design has historically not been very efficient in transforming electricity to radiation.  As a result, only 1% of the electrical energy is converted into a usable X-ray and the rest is heat.  Because of this, designs are larger and mechanical shutters are required to help control the radiation from the tube.  This limits the speed in which a tube can be switched on and off.

One prime advantage of increased speed and energy conversion is that multiple X-ray sources can be used simultaneously.  Prototypes using up 25 simultaneous beams produced images of twice the resolution in breast tissue when compared to existing CT technology.  Current nanotube designs also allow the technology to produce a spot size of approximately 80 um.  These improvements allow the technology to focus on breast, lung, and cardiovascular imaging, studies where movement is a major issue.   

I spoke to Dr. Otto Zhou, one of the original thought leaders of the technology, and he said, “The properties of the technology allow the X-ray source to be very efficient in converting energy and to be turned off and on instantly.  Now, we can produce a very clear tomosynthesis image.”

But, it doesn’t stop with improved imaging and longer lasting tubes.  The next step is miniature X-ray tubes, which will really change how we use X-rays.

Safety and Quality, a Low Dose Skeletal Study in 3D

Just think: a 3D study that exposes patients to a fraction of the radiation dose as a CT or X-ray.  FDA approved in 2011, the sterEOS system is designed to provide unique weight bearing images of the hip, knee, and spine.  CT technology has been the gold standard for hard tissue imaging since it first appeared in the 70s.  It has become so effective that each year there are over 62 million CT scans prescribed in the U.S.  Although a proven tool, its radiation exposure to patients has made the routine use of the technology a concern.

The sterEOS is a X-ray-based biplane system with a 3D workstation.  Along with the ability to provide 1:1 3D images of a patient’s skeletal system, its xenon gas detector delivers less than 10% of the radiation as existing film X-ray technology and up to 1,000 times less than a CT scan.  This makes it very attractive for younger patients. 

I asked Dr. Michael R. Terk, M.D., professor of Radiology, division director of Musculoskeletal Radiology, and director of Musculoskeletal Imaging at Emory University School of Medicine in Atlanta, GA, about the advantages of 3D.  He said, “The advantage of a 3D image over a 2D image is it gives you a greater ability to conceptualize the complex anatomy in space.  When you are only looking at an X-ray, you are looking at three dimensions compressed into two and this is a problem.  I think the 3D imaging is particularly useful for certain places like the pelvis, the head and neck, and in the spine where there is growing interest.  The spine is a complex structure and I admire our surgical colleagues who are able to do as good of a job as they do now”. 

Clinical trials also support the advantages of the technology.  When comparing existing computed radiography to the EOS system, the average dose was reduced from six to nine times when viewing the spine.  Physicians also reported improved image quality.

With the growth of the computer-assisted surgery market, the need for 3D images will continue to increase.  Although EOS technology has just recently hit the U.S. market, you have got to be pretty excited about a technology that can deliver on both safety and quality.  Combine this with what appears to be lower costs and it is likely to be very attractive for orthopedic imaging applications.