Microsoft PowerPoint - 20140708_NCKU_MRS_.pptx•
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• 3.5 ppm
– : ppm (freq shift / ) – 3.5 ppm (3T:440 Hz 1.5T:220Hz)
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• splittingsplitting
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PPM
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PPM
In vivo NMR spectroscopy : principle and techniques, R.A. de Graff. 2nd ed. 2007

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– Choline (Cho)
Glutamine (Gln)
1010In vivo NMR spectroscopy : principle and techniques, R.A. de Graff. 2nd ed. 2007
? (Glu Gln)?  (Glu, Gln)
11 Hz PPM
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MEGA PRESS for GABAMEGA PRESS for GABA
• Spectral editing scheme for detection of in vivo GABA in PNAS 1993 by Rothman DL.
• Implement in PRESS sequence in NMR Bio 1998 by M Mescher and M Garwood (MEGA PRESS)
Edit on Partial saturated
by M. Mescher and M. Garwood (MEGA-PRESS)Pulse 30x30x30 mm3, 256 measurements
Edit on – Edit off
1H1H 
• (mM) ~ (SNR) • (1 ~ 4 ppm) ~ (1 4 ppm)
S Q• MRS Quality – (SNR) (FWHM)( ) ( ) – voxel size
(shimming)– (shimming)
– TR = 2.0 sec ~ 4
• Voxel size : 20x20x20 mm3~ 8 ml. fMRI 4 4 5 3 0 08 l– fMRI : 4x4x5 mm3 ~ 0.08 ml.
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Average:64  SNR:33
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–SNR
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3T vs 7T MRS3T vs 7T MRS
2020In vivo NMR spectroscopy : principle and techniques, R.A. de Graff. 2nd ed. 2007
MRSMRS
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M ( l/l)– mM (mmol/l) – : (Cre)
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MRS:MRS: 
• Localized MRS in hippocampus by 15x20x10 pp p y mm3 box
• Reduced Glx in IBS patients G• Glx has negative correlation with state anxiety
AJG 2010, D. Niddam et. al.

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– fMRI MRS – Focus on neurotransmitters such as GluGABA
• Functional MRS (fMRS) – Dynamic metabolic change during stimuli – MRS with brain activity (BOLDEEGMEG)MRS with brain activity (BOLD EEG MEG) – MRS with resting state fMRI
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Visual fMRS experimentVisual fMRS experiment
JCBFM2007 S M i t l• JCBFM2007, S. Mangia et. al.
• Localized MRS in visual cortex by 20x22x20  mm3 box at 7T 
• Block design with 5.3 min. visual stimuli  • Glu and Lac increase with stimulusGlu and Lac increase with stimulus • Glc and Asp decrease with stimulus ???
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Motor fMRS experimentMotor fMRS experiment
• NeuroImage2014, B. Schaller et. al.
• Localized MRS covering motor and somatosensory 3area by 17x20x17 mm3 box  at 7T
• Block design with 5 min. finger tapping in both hand  • Glu and Lac increase with stimulus
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EEG or MEG activity– EEG or MEG activity •
– Glu GABA ? – Glu GABA ?Glu GABA ?
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MRS and brain activityMRS and brain activity
• Resting state GABA level in visual cortex predicted the HRF, EEG and MEG activity during visual stimuli
• PNAS2009, S. Muthukumaraswamya et. al • J Neurosci2009 R Edden et al• J Neurosci2009, R. Edden et. al • HBM2012, S. Muthukumaraswamya et. al
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MRS and brain activityMRS and brain activity
• Resting state Glu level in dorsal anterior cingulate cortex (dACC) predicted the individual BOLD response to auditory cognitive control task (PNAS2012 Lauditory cognitive control task (PNAS2012, L. Falkenberg et. al.)
• Resting state Gaba and Glu level in ventromedial prefrontal cortex (vmPFC) predicted the individual p e o a co e ( C) p ed c ed e d dua behavioral performance in reward guided decision making task (Nat Neurosci2012, G. Jocham et. al.)
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MRS and resting state fMRIMRS and resting state fMRI
• Resting state Glu and GABA level in posterior medial cortex (PMC) predict the individual functional connectivity of default mode network (Neuroimage2013connectivity of default mode network (Neuroimage2013, D. Kapogiannis et. al.)
• Resting state Glu level in medial prefrontal cortex (mPFC) di h i di id l f i l i i fpredict the individual functional connectivity of a
subcortical network (PLOSOne2013, NW. Duncan et. al.)
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Magnetic Resonance Spectroscopic Imaging  (MRSI)
• Combine MRS and MRI to acquire metabolite information from whole slice – Metabolite maps – Cover multiple regions of interest
• Limitation in traditional MRSILimitation in traditional MRSI – Limited spatial coverage – Long acquisition timeLong acquisition time – Low spatial resolution
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fast MRSI technique: (P t ) E h Pl
Five metabolite maps in 8 minutes (PEPSI) versus 1 hour (traditional MRSI)
(Proton) Echo Planar Spectroscopic Imaging “(P)EPSI”
• Combine EPI and MRS to reduce scan time proposed by Dr. P. Mansfield in 1984
• Automatic analysis tool for absolute metabolite y concentrations (Neuroimage 2012; J Neuroimaging 13)
PEPSI in sagittal and transverse plane
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Application : metabolites along medial wall • Patients with pain syndrome : Myofascial pain syndrome• Patients with pain syndrome : Myofascial pain syndrome,
Irritable bowel syndrome, headache etc.. • Develop voxel based analysis (VBM) method for group
l i i MRSIanalysis in MRSI
• Normalized metabolites maps from 24 subjects using statisticalNormalized metabolites maps from 24 subjects using statistical nonparametric mapping algorithm
• Age effect (>31 yrs. and < 31 yrs.) in right and left dorsal anterior cingulate, left  posterior cingulate
• Hemispheric asymmetry in mid 
tCr
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3D PEPSI for whole brain coverage Technique and Automatic analysis tool developed by research group of• Technique and Automatic analysis tool developed by research group of A. A. Maudsley (NMRBio2006; MRM2009; NMRBio2009; MRM2010; NMRBio2011; MRM2014)
• 26 minutes for 18 slices, spatial resolution around 5.6x5.6x10 mm3
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