Name
Title | ||
|---|---|---|
Accounting for signal loss due to dephasing in the correction of distortions in gradient-echo EPI via nonrigid registration. |
Abstract | ||
|---|---|---|
Gradient-echo (GE) echo planar imaging (EPI) is susceptible to both geometric distortions and signal loss. This paper presents a retrospective correction approach based on nonrigid image registration. A new physics-based intensity correction factor derived to compensate for intravoxel dephasing in GE EPI images is incorporated into a previously reported nonrigid registration algorithm. Intravoxel dephasing causes signal loss and thus intensity attenuation in the images. The new rephasing factor we introduce, which changes the intensity of a voxel in images during the registration, is used to improve the accuracy of the intensity-based nonrigid registration method and mitigate the intensity attenuation effect. Simulation-based experiments are first used to evaluate the method. A magnetic resonance (MR) simulator and a real field map are used to generate a realistic GE EPI image. The geometric distortion computed from the field map is used as the ground truth to which the estimated nonrigid deformation is compared. We then apply the algorithm to a set of real human brain images. The results show that, after registration, alignment between EPI and multi-shot, spin-echo images, which have relatively long acquisition times but negligible distortion, is improved and that signal loss caused by dephasing can be recovered. |
Year | DOI | Venue |
|---|---|---|
2007 | 10.1109/TMI.2007.901987 | IEEE Trans. Med. Imaging |
Keywords | Field | DocType |
gradient echo (ge) echo planar imaging (epi),estimated nonrigid deformation,distortion correction,human brain images,retrospective correction approach,neurophysiology,simulation-based experiments,ge epi images,magnetic resonance simulator,nonrigid image registration algorithm,intravoxel dephasing,physics-based intensity correction factor,biomedical mri,intensity attenuation effect,nonrigid registration,computed geometric distortion,gradient-echo echo planar imaging,brain,rephasing factor,image registration,intensity-based nonrigid registration method,medical image processing,ground truth,magnetic resonance,error correction,biomedical imaging,new physics,spin echo | Voxel,Computer vision,Dephasing,Medical imaging,Computer science,Error detection and correction,Ground truth,Artificial intelligence,Attenuation,Distortion,Image registration | Journal |
Volume | Issue | ISSN |
26 | 12 | 0278-0062 |
Citations | PageRank | References |
1 | 0.90 | 11 |
Authors | ||
6 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Yong Li | 1 | 14 | 2.67 |
| Ning Xu | 2 | 8 | 3.45 |
| J. Michael Fitzpatrick | 3 | 598 | 133.90 |
| Victoria L. Morgan | 4 | 34 | 6.21 |
| David R. Pickens | 5 | 17 | 3.38 |
| Benoit M. Dawant | 6 | 1388 | 223.11 |