title: Design of cosine modulated very selective suppression pulses for MR spectroscopic imaging at 3T.
abstract: The advantages of using a 3 Tesla (T) scanner for MR spectroscopic imaging (MRSI) of brain tissue include improved spectral resolution and increased sensitivity. Very selective saturation (VSS) pulses are important for maximizing selectivity for PRESS MRSI and minimizing chemical shift misregistration by saturating signals from outside the selected region. Although three-dimensional (3D) PRESS MRSI is able to provide excellent quality metabolic data for patients with brain tumors and has been shown to be important for defining tumor burden, the method is currently limited by how much of the anatomic lesion can be covered within a single examination. In this study we designed and implemented cosine modulated VSS pulses that were optimized for 3T MRSI acquisitions. This provided improved coverage and suppression of unwanted lipid signals with a smaller number of pulses. The use of the improved pulse sequence was validated in volunteer studies, and in clinical 3D MRSI exams of brain tumors.
authors.affiliation: UCSF/UCB Joint Graduate Group in Bioengineering, San Francisco, California 94158-2532, USA. joseph.osorio@radiology.ucsf.edu
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Osorio
authors.forename: Duan
authors.initials: D
authors.lastname: Xu
authors.forename: Charles H
authors.initials: CH
authors.lastname: Cunningham
authors.forename: Albert
authors.initials: A
authors.lastname: Chen
authors.forename: Adam B
authors.initials: AB
authors.lastname: Kerr
authors.forename: John M
authors.initials: JM
authors.lastname: Pauly
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Nelson
mesh_terms: D000465:Algorithms; D014408:Biomarkers, Tumor / Q000032:analysis*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D014408:Biomarkers, Tumor