학술논문

Reduced field-of-view imaging for single-shot MRI with an amplitude-modulated chirp pulse excitation and Fourier transform reconstruction.
Document Type
Article
Source
Magnetic Resonance Imaging (0730725X). Jun2015, Vol. 33 Issue 5, p503-515. 13p.
Subject
*MAGNETIC resonance imaging
*AMPLITUDE modulation
*FOURIER transform nuclear magnetic resonance spectroscopy
*COMPUTER simulation
*CHIRPED pulse amplification
Language
ISSN
0730-725X
Abstract
Purpose We employ an amplitude-modulated chirp pulse to selectively excite spins in one or more regions of interest (ROIs) to realize reduced field-of-view (rFOV) imaging based on single-shot spatiotemporally encoded (SPEN) sequence and Fourier transform reconstruction. Materials and Methods The proposed rFOV imaging method was theoretically analyzed and illustrated with numerical simulation and tested with phantom experiments and in vivo rat experiments. In addition, point spread function was applied to demonstrate the feasibility of the proposed method. To evaluate the proposed method, the rFOV results were compared with those obtained using the EPI method with orthogonal RF excitation. Results The simulation and experimental results show that the proposed method can image one or two separated ROIs along the SPEN dimension in a single shot with higher spatial resolution, less sensitive to field inhomogeneity, and practically no aliasing artifacts. In addition, the proposed method may produce rFOV images with comparable signal-to-noise ratio to the rFOV EPI images. Conclusion The proposed method is promising for the applications under severe susceptibility heterogeneities and for imaging separate ROIs simultaneously. [ABSTRACT FROM AUTHOR]