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Comparison of optimized soft‐tissue suppression schemes for ultrashort echo time MRI
Author(s) -
Li Cheng,
Magland Jeremy F.,
Rad Hamidreza Saligheh,
Song Hee Kwon,
Wehrli Felix W.
Publication year - 2012
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.23267
Subject(s) - physics , nuclear magnetic resonance , microsecond , millisecond , contrast to noise ratio , subtraction , echo time , adiabatic process , materials science , optics , image quality , computer science , magnetic resonance imaging , mathematics , arithmetic , astronomy , artificial intelligence , image (mathematics) , thermodynamics , medicine , radiology
Ultrashort echo time (UTE) imaging with soft‐tissue suppression reveals short‐ T 2 components (typically hundreds of microseconds to milliseconds) ordinarily not captured or obscured by long‐ T 2 tissue signals on the order of tens of milliseconds or longer. Therefore, the technique enables visualization and quantification of short‐ T 2 proton signals such as those in highly collagenated connective tissues. This work compares the performance of the three most commonly used long‐ T 2 suppression UTE sequences, i.e., echo subtraction (dual‐echo UTE), saturation via dual‐band saturation pulses (dual‐band UTE), and inversion by adiabatic inversion pulses (IR‐UTE) at 3 T, via Bloch simulations and experimentally in vivo in the lower extremities of test subjects. For unbiased performance comparison, the acquisition parameters are optimized individually for each sequence to maximize short‐ T 2 signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) between short‐ and long‐ T 2 components. Results show excellent short‐ T 2 contrast which is achieved with these optimized sequences. A combination of dual‐band UTE with dual‐echo UTE provides good short‐ T 2 SNR and CNR with less sensitivity to B 1 homogeneity. IR‐UTE has the lowest short‐ T 2 SNR efficiency but provides highly uniform short‐ T 2 contrast and is well suited for imaging short‐ T 2 species with relatively short T 1 such as bone water. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.