Work

Real‐time motion and B 0 corrected single voxel spectroscopy using volumetric navigators

Year: 2011

Type: article

Abstract: In population groups where head pose cannot be assumed to be constant during a magnetic resonance spectroscopy examination or in difficult-to-shim regions of the brain, real-time volume of interest, frequency, and shim optimization may be necessary. We investigate the effect of pose change on the B0 homogeneity of a (2 cm)3 volume and observe typical first-order shim changes of 1 μT/m per 1° rotation (chin down to up) in four different volumes of interest in a single volunteer. An echo planar imaging volume navigator was constructed to measure and apply in real-time within each pulse repetition time: volume of interest positioning, frequency adjustment, and first-order shim adjustment. This volume navigator is demonstrated in six healthy volunteers and achieved a mean linewidth of 4.4 Hz, similar to that obtained by manual shim adjustment of 4.9 Hz. Furthermore, this linewidth is maintained by the volume navigator at 4.9 Hz in the presence of pose change. By comparison, a mean linewidth of 7.5 Hz was observed, when no correction was applied.

Source: Magnetic Resonance in Medicine

DOI: 10.1002/mrm.22805

Authors: Aaron T. Hess, M. Dylan Tisdall, Ovidiu C. Andronesi, Ernesta M. Meintjes, André J. W. van der Kouwe

Institutions: University of Cape Town, Harvard University, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

Open Access status: bronze