Quantitative proton MRS assessment of citrate heterogeneity in normal prostate

Water-suppressed proton spectra of the two major anatomical regions of the normal prostate were acquired with a commercial phased-array multicoil. The spectra demonstrated excellent signal-to-noise ratio and spectral resolution allowing identification of peaks from choline, creatine, and amino acids, as well as a major peak from citrate. Quantification of the citrate peak using tissue water as an internal concentration reference revealed a marked variability among different volunteers. In each case, citrate was consistently twofold to threefold greater in the peripheral zone than in the central gland. The results demonstrate heterogeneity of citrate within the prostate and suggest significant differences in the cytology and hormonal control of citrate synthesis among individuals.