Yueh Z. Lee PhD, Presenter: Nothing to Disclose

Jian Zhang PhD, Abstract Co-Author: Nothing to Disclose

Guang Yang, Abstract Co-Author: Nothing to Disclose

Dan Chalothorn, Abstract Co-Author: Nothing to Disclose

Jianping Lu, Abstract Co-Author: Nothing to Disclose

Otto Zhou PhD, Abstract Co-Author: Nothing to Disclose

James Faber, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Carbon nanotubes (CNT) have been demonstrated as a useful replacement for tungsten filaments in cold cathode based x-ray production. Utilizing field emission, these CNT sources offer precise x-ray pulse control as well as the potential for multiple focal spots in close proximity. Our goal was to demonstrate the use of a multi-beam x-ray source for applications in small animal and biological imaging.

A multi-beam x-ray source was implemented using multiple CNT cathodes and a molybdenum target, all within a single vacuum chamber. Five cathodes, corresponding to distinct 5 focal spots, were spaced 1 cm apart. Maximum acceleration voltage was 40kV with a current range of 0 to 100 microamps. A Hamamatsu C7921 detector was fixed opposite the x-ray sources. Both normal mice and a mouse model of vascular-genesis were imaged. Mice with popliteal artery ligation were sacrificed at multiple time points after surgery, allowing the growth of new arteries. Each mouse was perfused with fixative and arterially filled with barium sulfate. Mice were imaged with the multi-beam system and a commercial Faxitron system for comparison.

Five sets of images from the multi-beam x-ray source were obtained for each time point. Images were realigned for visualization and demonstrated the ability to achieve multiple perspectives from a single x-ray “tube” (vacuum chamber). Resolution of the system was estimated to be 200 micron.

CNT based x-ray sources offer unique advantages over traditional tungsten based x-ray tubes. Amongst the advantages includes the ability to readily place multiple focal spots in close proximity, allowing rapid image acquisition from multiple viewpoints. This technique requires no movement of the subject or x-ray source, ensuring a fixed geometry and precise alignment. Multi-place cine type images may be rapidly acquired in synchronization with a physiological signal. Further work on increasing the number of focal spots, reducing focal spot size, and developing new applications are ongoing.

J.L.,O.Z.: Author is employed by Xintek which partially funded this study.

Lee, Y, Zhang, J, Yang, G, Chalothorn, D, Lu, J, Zhou, O, Faber, J, et al, , Biological Applications of a Carbon Nanotube-based Multi-beam X-ray Source.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4408579.html