  Three-dimensional digital subtraction angiography (3D-DSA) is a widely
adopted technique for clinical evaluation of contrast-enhanced vasculatures.
The distribution of a contrast agent such as iodine is often estimated via
temporal subtraction. Advancements in spectral imaging technologies such as
photon counting detectors offer new opportunities to improve DSA image quality.
In this work, we propose a novel joint processing strategy to achieve an iodine
image using two-bin spectral measurements from a photon counting detector
acquired both the pre- and post-contrast injection. Simulation studies were
performed using a digital phantom with iodine-enhanced vessels. The proposed
method was compared with temporal subtraction and conventional spectral imaging
using just the post-contrast measurements. Imaging performance was evaluated in
terms of noise-resolution tradeoffs. Preliminary findings have shown measurably
improved image quality given by joint processing, reducing noise by 40% and 70%
compared to temporal subtraction and conventional spectral imaging,
respectively.
