Partial field-of-view spiral phase-contrast imaging using complex difference processing

Accelerated phase contrast imaging using compressed sensing with complex difference sparsity

Methods Figure 1 shows the proposed CS reconstruction with CD sparsity for phase contrast MR. The objective function J = ‖FΩmi-yi‖2+l‖Ψmi‖1‖+lCD‖m1-m2‖1, where mi=1,2 are the two bipolar encoding acquisitions and |m1-m2| is the corresponding CD image, is used in the reconstruction. The reconstruction performs iteratively between two bipolar images. Every iteration, the recon of m1 makes the int...

Quantitative phase imaging and complex field reconstruction by pupil modulation differential phase contrast.

Differential phase contrast (DPC) is a non-interferometric quantitative phase imaging method achieved by using an asymmetric imaging procedure. We report a pupil modulation differential phase contrast (PMDPC) imaging method by filtering a sample's Fourier domain with half-circle pupils. A phase gradient image is captured with each half-circle pupil, and a quantitative high resolution phase imag...

High resolution , large field of view x - ray differential phase contrast imaging on a compact setup

Subnanoradian X-ray phase-contrast imaging using a far-field interferometer of nanometric phase gratings

Hard X-ray phase-contrast imaging characterizes the electron density distribution in an object without the need for radiation absorption. The power of phase contrast to resolve subtle changes, such as those in soft tissue structures, lies in its ability to detect minute refractive bending of X-rays. Here we report a far-field, two-arm interferometer based on the new nanometric phase gratings, w...

Dynamic Susceptibility Contrast Imaging using a multi-echo spiral sequence

Introduction To characterize microvasculature, one can perform a DCE-MRI experiment (a first injection of contrast agent (CA) to estimate the vessel wall permeability) followed by a DSC-MRI experiment (a second injection of CA to estimate relative blood volume (rCBV), relative blood flow, etc.) [1]. The DSC experiment can even yield information on vessel size if a gradient echo and a spin echo ...