Dual-band water and lipid suppression for MR spectroscopic imaging at 3 Tesla.
A dual-band water and lipid suppression sequence was developed for multislice sensitivity-encoded proton MR spectroscopic imaging of the human brain. The presaturation scheme consisted of five dual-band frequency-modulated radiofrequency pulses based on hypergeometric functions integrated with eight outer volume suppression (OVS) pulses. The flip angles of the dual-band pulses were optimized through computer simulations to maximize suppression factors over a range of transmitter amplitude of radiofrequency field and water and lipid T(1) values. The resulting hypergeometric dual band with OVS (HGDB + OVS) sequence was implemented at 3 T in a multislice sensitivity-encoded proton MR spectroscopic imaging experiment and compared to a conventional water suppression scheme (variable pulse power and optimized relaxation delays (VAPOR)) with OVS. The HGDB sequence was significantly shorter than the VAPOR sequence (230 versus 728 msec). Both HGDB + OVS and VAPOR + OVS produced good water suppression, while lipid suppression with the HGDB + OVS sequence was far superior. In sensitivity-encoded proton MR spectroscopic imaging data, artifacts from extracranial lipid signals were significantly lower with HGDB + OVS. The shorter duration of HGDB compared to VAPOR also allows reduced pulse repetition time values in the multislice acquisition.
Zhu
He
H
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland 21287, USA.
Ouwerkerk
Ronald
R
Barker
Peter B
PB
D001921:Brain / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008055:Lipids; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019047:Phantoms, Imaging; D011859:Radiography; D014867:Water
D008055:Lipids; D014867:Water