TY - JOUR
T1 - Implementation of two-dimensional L-COSY at 7 Tesla
T2 - An investigation of reproducibility in human brain
AU - Verma, Gaurav
AU - Hariharan, Hari
AU - Nagarajan, Rajakumar
AU - Nanga, Ravi P.R.
AU - Delikatny, Edward J.
AU - Thomas, M. Albert
AU - Poptani, Harish
N1 - Publisher Copyright:
© 2013 Wiley Periodicals, Inc.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Materials and Methods: The 2D L-COSY sequence was implemented at 7T and its reliability was assessed by test-retest studies of a metabolite phantom and a healthy volunteer. L-COSY data were acquired from the occipital lobe of healthy subjects (n=6; all male; age, 30-72 years) to assess intersubject variability. Additionally, two subjects underwent scans from the parieto-occipital region, basal ganglia, frontal lobe or dorsolateral prefrontal cortex to test the versatility of L-COSY in studying differing anatomy. Integral/volume measurements of L-COSY spectra were used to estimate normalized metabolite-to-creatine concentrations.Purpose: To evaluate the utility of two-dimensional (2D) Localized Correlated Spectroscopy (L-COSY) in metabolic profiling of the human brain at 7 Tesla (T).Results: Phantom test-retest studies revealed coefficients of variation (CVs) of 3-20% for most metabolites. Human 2D L-COSY spectra permitted detection of several metabolite resonances from multiple locations and intersubject variation studies demonstrated CVs of 4-26%. Cross-peaks from gamma-aminobutyric acid (GABA), isoleucine (Ile), lysine (Lys) and Ethanolamine (Eth) were quantified, which are not readily resolvable with conventional one-dimensional (1D) MR spectroscopy.Conclusion: 2D L-COSY at 7T demonstrated improved sensitivity in detecting additional metabolites with reliability comparable to established techniques at lower fields, which may aid in the metabolic assessment of diseased states.
AB - Materials and Methods: The 2D L-COSY sequence was implemented at 7T and its reliability was assessed by test-retest studies of a metabolite phantom and a healthy volunteer. L-COSY data were acquired from the occipital lobe of healthy subjects (n=6; all male; age, 30-72 years) to assess intersubject variability. Additionally, two subjects underwent scans from the parieto-occipital region, basal ganglia, frontal lobe or dorsolateral prefrontal cortex to test the versatility of L-COSY in studying differing anatomy. Integral/volume measurements of L-COSY spectra were used to estimate normalized metabolite-to-creatine concentrations.Purpose: To evaluate the utility of two-dimensional (2D) Localized Correlated Spectroscopy (L-COSY) in metabolic profiling of the human brain at 7 Tesla (T).Results: Phantom test-retest studies revealed coefficients of variation (CVs) of 3-20% for most metabolites. Human 2D L-COSY spectra permitted detection of several metabolite resonances from multiple locations and intersubject variation studies demonstrated CVs of 4-26%. Cross-peaks from gamma-aminobutyric acid (GABA), isoleucine (Ile), lysine (Lys) and Ethanolamine (Eth) were quantified, which are not readily resolvable with conventional one-dimensional (1D) MR spectroscopy.Conclusion: 2D L-COSY at 7T demonstrated improved sensitivity in detecting additional metabolites with reliability comparable to established techniques at lower fields, which may aid in the metabolic assessment of diseased states.
KW - 7T
KW - Isoleucine
KW - L-COSY
KW - Localized Correlated Spectroscopy
KW - Lysine
KW - Magnetic resonance spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84910018076&partnerID=8YFLogxK
U2 - 10.1002/jmri.24510
DO - 10.1002/jmri.24510
M3 - Article
C2 - 24273136
AN - SCOPUS:84910018076
SN - 1053-1807
VL - 40
SP - 1319
EP - 1327
JO - Journal of Magnetic Resonance Imaging
JF - Journal of Magnetic Resonance Imaging
IS - 6
ER -