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Restricted field of view magnetic resonance imaging of a dynamic time series
Author(s) -
Pisani Laura,
Bammer Roland,
Glover Gary
Publication year - 2007
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.21115
Subject(s) - imaging phantom , multislice , nuclear magnetic resonance , magnetic resonance imaging , partial volume , materials science , image resolution , pulse sequence , signal (programming language) , volume (thermodynamics) , optics , physics , nuclear medicine , computer science , medicine , radiology , programming language , quantum mechanics
A restricted field of view (rFOV) approach for imaging a dynamic time series of volumes of limited spatial extent within a larger subject is described. The shorter readout with rFOV‐MRI can be exploited to either limit image artifacts or increase spatial resolution. To accomplish rFOV imaging of a multislice volume for a dynamic series, an outer volume suppression (OVS) preparation that saturates signal external to a cylinder through the subject is followed by slice‐selective excitation and a spiral readout. The pass‐ and stopband efficiencies of the OVS in an agar gel phantom were 97% (±1.5%) and 3% (±1%), respectively. Profiles of the temporal signal‐to‐noise ratio (SNR) were measured in a phantom and an adult brain. The rFOV sequence reduced distortions from off‐resonance signal and T 2 * ‐induced blurring compared to a conventional sequence. Sequence utility is demonstrated for high‐resolution rFOV functional MRI (fMRI) in the visual cortex. The rFOV sequence may prove to be useful for other multislice dynamic and high‐resolution imaging applications. Magn Reson Med 57:297–307, 2007. © 2007 Wiley‐Liss, Inc.