title: Prostate cancer metabolite quantification relative to water in 1H-MRSI in vivo at 3 Tesla.
abstract: (1)H magnetic resonance spectroscopic imaging was performed on 16 men with suspected prostate cancer using an 8-channel external receive coil at 3 T. Choline and citrate (Cit) signals were measured in prostate lesions and normal-appearing peripheral zone as identified on T(2)-weighted images. Metabolites were quantified relative to unsuppressed water from a separately acquired magnetic resonance spectroscopic imaging dataset using LCModel. Validation experiments were also performed in a phantom containing physiological concentrations of choline, Cit, and creatine. In vitro, fair agreement between measured and true concentrations was observed, with the greatest discrepancy being a 35% underestimation of Cit. In vivo, one dataset was rejected for failure to meet the quality criterion of linewidth <15 Hz, and in 6 of 15 subjects, insufficient normal-appearing peripheral zone tissue was identified for study. Lesions were found to have higher choline and choline/Cit, and lower Cit, than normal-appearing peripheral zone. The smaller skew of data obtained using water normalization in comparison with metabolite ratios suggests potential usefulness in longitudinal tumor monitoring and in studies of treatment effects.
authors.affiliation: Cancer Research UK Cambridge Research Institute, Li Ka Shing Centre, Cambridge, United Kingdom. mary.mclean@cancer.org.uk
authors.forename: Mary A
authors.initials: MA
authors.lastname: McLean
authors.forename: Tristan
authors.initials: T
authors.lastname: Barrett
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Gnanapragasam
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Priest
authors.forename: Ilse
authors.initials: I
authors.lastname: Joubert
authors.forename: David J
authors.initials: DJ
authors.lastname: Lomas
authors.forename: David E
authors.initials: DE
authors.lastname: Neal
authors.forename: John R
authors.initials: JR
authors.lastname: Griffiths
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001834:Body Water / Q000378:metabolism*; D003198:Computer Simulation; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D011522:Protons