  Purpose: Conventional x-ray imaging and fluoroscopy have limitations in
quantitation due to several challenges, including scatter, beam hardening, and
overlapping tissues. In this work, we propose single-shot quantitative imaging
(SSQI) by combining the use of a primary modulator (PM) and dual-layer (DL)
detector, which enables motion-free dual-energy (DE) imaging with scatter
correction in a single shot.
  Methods: The SSQI algorithm allows simultaneous recovery of two
material-specific images and two scatter images using four sub-measurements
from the PM encoding. For validation, we set up SSQI on our tabletop system and
imaged acrylic and copper slabs with known thicknesses, estimated scatter with
our SSQI algorithm, and compared the material decomposition (MD) for different
combinations of the two materials with ground truth. Second, we imaged an
anthropomorphic chest phantom containing contrast in the coronary arteries and
compared the MD with and without SSQI. Lastly, to evaluate SSQI in dynamic
applications, we constructed a flow phantom that enabled dynamic imaging of
iodine contrast.
  Results: The root mean squared error (RMSE) of SSQI estimation was 0.13 cm
for acrylic and 0.04 mm for copper. For the anthropomorphic phantom, direct MD
resulted in incorrect interpretation of contrast and soft tissue, while SSQI
successfully distinguished them and reduced RMSE in material-specific images by
38% to 92%. For the flow phantom, SSQI was able to perform accurate dynamic
quantitative imaging, separating contrast from the background.
  Conclusions: We demonstrated the potential of SSQI for robust quantitative
x-ray imaging. The simplicity of SSQI may enable its widespread adoption,
including radiography and dynamic imaging such as real-time image guidance and
cone-beam CT.
