Faculty Collaboration Database

Accelerating sequences in the presence of metal by exploiting the spatial distribution of off-resonance. Magn Reson Med 2014 Dec;72(6):1658-67

Date

01/17/2014

Pubmed ID

24431210

Pubmed Central ID

PMC4099324

DOI

10.1002/mrm.25087

Scopus ID

2-s2.0-84911990134 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

PURPOSE: To demonstrate feasibility of exploiting the spatial distribution of off-resonance surrounding metallic implants for accelerating multispectral imaging techniques.

THEORY AND METHODS: Multispectral imaging (MSI) techniques perform time-consuming independent three-dimensional acquisitions with varying radio frequency offsets to address the extreme off-resonance from metallic implants. Each off-resonance bin provides a unique spatial sensitivity that is analogous to the sensitivity of a receiver coil and, therefore, provides a unique opportunity for acceleration. Fully sampled MSI was performed to demonstrate retrospective acceleration. A uniform sampling pattern across off-resonance bins was compared with several adaptive sampling strategies using a total hip replacement phantom. Monte Carlo simulations were performed to compare noise propagation of two of these strategies. With a total knee replacement phantom, positive and negative off-resonance bins were strategically sampled with respect to the B0 field to minimize aliasing. Reconstructions were performed with a parallel imaging framework to demonstrate retrospective acceleration.

RESULTS: An adaptive sampling scheme dramatically improved reconstruction quality, which was supported by the noise propagation analysis. Independent acceleration of negative and positive off-resonance bins demonstrated reduced overlapping of aliased signal to improve the reconstruction.

CONCLUSION: This work presents the feasibility of acceleration in the presence of metal by exploiting the spatial sensitivities of off-resonance bins.

Author List

Smith MR, Artz NS, Koch KM, Samsonov A, Reeder SB

Author

Kevin M. Koch PhD Adjunct Professor in the Radiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Algorithms
Hip Joint
Humans
Image Enhancement
Image Interpretation, Computer-Assisted
Knee Joint
Knee Prosthesis
Magnetic Resonance Imaging
Metals
Phantoms, Imaging
Reproducibility of Results
Sensitivity and Specificity
Signal Processing, Computer-Assisted