Gibbs ringing in diffusion MRI

Variability of perfusion dark rim artifacts due to Gibbs ringing

Methods Sub-pixel shifts were introduced in 5 in-vivo raw-data perfusion studies, where a DRA was visible. The shifts had a step of 1/8 of a pixel ranging from 0.125 to 0.875 of the in-plane pixel size. The unprocessed raw-data was phase-shifted using MATLAB before reconstructing it on the scanner using the same image processing as the original data. The original perfusion studies were done on ...

Gibbs-Ringing Artifact Removal Based on Local Subvoxel-shifts

PURPOSE To develop a fast and stable method for correcting the gibbs-ringing artifact. METHODS Gibbs-ringing is a well-known artifact which manifests itself as spurious oscillations in the vicinity of sharp image gradients at tissue boundaries. The origin can be seen in the truncation of k-space during MRI data-acquisition. Correction techniques like Gegenbauer reconstruction or extrapolation...

Diffusion MRI Diffusion Primer

Paul Berg’s book “Random Walks in Biology” (1), describes a useful thought experiment that illustrates the diffusion phenomenon. Imagine carefully introducing a drop of colored fluorescent dye into a jar of water. Initially, the dye remains concentrated at the point of release, but over time, it spreads radially, in a spherically symmetric distribution. This mixing process is taking place witho...

Prior Learning and Gibbs Reaction-Diffusion

Artifacts in Diffusion MRI

This chapter focuses on artifacts that are relevant for diffusion • imaging studies of the brain in a clinical research setting. For typical clinical studies, the most relevant sources of “physi • ological noise” artifacts are subject motion and cardiac pulsation, and the most common sources of “system-related artifacts” are eddy current distortions. Artifacts not only increase the variability...