title: High speed 1H spectroscopic imaging in human brain by echo planar spatial-spectral encoding.
abstract: We introduce a fast and robust spatial-spectral encoding method, which enables acquisition of high resolution short echo time (13 ms) proton spectroscopic images from human brain with acquisition times as short as 64 s when using surface coils. The encoding scheme, which was implemented on a clinical 1.5 Tesla whole body scanner, is a modification of an echo-planar spectroscopic imaging method originally proposed by Mansfield Magn. Reson. Med. 1, 370-386 (1984), and utilizes a series of read-out gradients to simultaneously encode spatial and spectral information. Superficial lipid signals are suppressed by a novel double outer volume suppression along the contours of the brain. The spectral resolution and the signal-to-noise per unit time and unit volume from resonances such as N-acetyl aspartate, choline, creatine, and inositol are comparable with those obtained with conventional methods. The short encoding time of this technique enhances the flexibility of in vivo spectroscopic imaging by reducing motion artifacts and allowing acquisition of multiple data sets with different parameter settings.
authors.affiliation: Diagnostic Radiology Department, Warren Grant Magnuson Clinical Center.
authors.forename: S
authors.initials: S
authors.lastname: Posse
authors.forename: G
authors.initials: G
authors.lastname: Tedeschi
authors.forename: R
authors.initials: R
authors.lastname: Risinger
authors.forename: R
authors.initials: R
authors.lastname: Ogg
authors.forename: D
authors.initials: D
authors.lastname: Le Bihan
mesh_terms: D016477:Artifacts; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001921:Brain / Q000033:anatomy & histology* / Q000378:metabolism; D001923:Brain Chemistry; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013997:Time Factors
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate