3D localized in vivo 1H spectroscopy of human brain by using a hybrid of 1D-Hadamard with 2D-chemical shift imaging.
We report acquisition of 3D image-guided localized proton spectroscopy (1H-MRS) in the human brain on a standard clinical imager. 3D coverage is achieved with a hybrid of chemical shift imaging (CSI) and transverse Hadamard spectroscopic imaging (HSI). 16 x 16 x 4 arrays of 3.5 and 1 ml voxels were obtained in 27 min. The spatially selective HSI 90 degrees pulses incorporate naturally into a PRESS double spin-echo sequence to subdivide the VOI into four partitions along its short axis. 2D CSI (16 x 16) is performed along the other long axes. Because the hybrid excites the spins in the entire VOI, a square-root-N signal-to-noise-ratio (SNR) gain per given examination time is realized compared with sequentially interleaving N 2D slices. A two-fold gain in sensitivity is demonstrated in the brain for N = 4.
Gonen
O
O
Department of NMR and Medical Spectroscopy, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Arias-Mendoza
F
F
Goelman
G
G
D000328:Adult; D001921:Brain / Q000033:anatomy & histology*; D001923:Brain Chemistry; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*