X-ray scatter may significantly degrade imaging performance in x-ray radiography applications, including flatpanel
detector-based x-ray imaging, tomosynthesis, and cone-beam CT (CBCT), primarily due to their large projection
field sizes. It results in soft tissue contrast reduction, potentially severe image artifacts, and increased patient dose.
Several different approaches have been developed to reject the scatter contributions, including analytical calculation,
empirical algorithms, Monte-Carlo simulation, blocker based measurement, and slot scan technique. We recently
developed a new x-ray scatter rejection method based on nanotechnology-enabled frequency division multiplexing x-ray
(FDMX) imaging technique. The key enabling technology is the carbon nanotube (CNT)-based multi-beam field
emission x-ray (MBFEX) source technology. The proposed FDMX imaging system has a MBFEX source with an array
of x-ray tubes. The x-ray radiation from each individual x-ray tube is modulated at a certain given frequency. The
collimated x-ray beams passed through the object and were captured by a high speed x-ray detector. A demultiplexing
algorithm was applied to reject the scatter radiation from the primary radiation based on their different modulation
frequencies. The x-ray images generated by the FDMX imaging technique clearly demonstrated improved imaging
quality in terms of lower scatter-to-primary-ratio (SPR) and higher contrast-to-noise-ratio (CNR). It shows great
potential of improving x-ray imaging performance and reducing patient dose.