Multilayer X-Ray Transmission Grating Array for Phase-Contrast Imaging and Tomography

Classical X-ray Computed Tomography (CT) and radiography are based on X-ray absorption and cannot show soft tissue structures as well as Magnetic Resonance Imaging (MRI). Detecting the phase delay/advance of X-rays that travel through the body could enhance soft tissue contrast 10 - 100 times. Submicron-period X-ray transmission gratings for medical x-ray energies can substantially enhance the phase detection sensitivity, but fabrication is a great challenge. This invention includes a method to fabricate multilayer transmission gratings of large areas. The design uses multilayer deposition of alternating materials on a staircase substrate to form micro grating arrays of extremely small periods and high aspect ratio in large areas. This invention should substantially improve the visibility of soft tissue structures and reduce radiation dose to patients.

Potential Commercial Applications: Competitive Advantages:
  • X-ray diagnostic imaging
  • X-ray non-destructive materials testing
  • X-ray security screening
  • X-ray lithography of nanostructures
  • Also applies to neutron beam or proton beam imaging
  • Gratings of ultra-high aspect ratio and small period allow phase-contrast imaging at high x-ray energies which are suitable for human body CT, and provide better soft tissue contrast in radiography and CT
  • Reduces radiation exposure to patient
  • Large area gratings enable full field imaging without raster or line scanning

Development Stage:
  • Pre-clinical
  • Early-stage


Han Wen (NHLBI)  ➽ more inventions...

Intellectual Property:
US Pat: - issued -
PCT Application No. PCT/US13/020561 filed on 2013-01-07

Lynch SK, et al. Multilayer-coated micro-grating array for x-ray phase-contrast imaging. Proc. SPIE 8076, 80760F (2011)

Collaboration Opportunity:

The Imaging Physics Lab, Biophysics and Biochemistry Center, NHLBI/NIH, is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate or commercialize multilayer-coated gratings for phase-contrast CT. For collaboration opportunities, please contact Dr. Han Wen at

Licensing Contact:
Admin. Licensing Specialist (ALS),

OTT Reference No: E-207-2011-0
Updated: Sep 9, 2015