Ans CMR Spectroscopy of Prostate - Principal among the identifiable metabolite is citrate, found in relatively high concentration in the glandular tissue of a healthy prostate. The normal MRI spectrum of the prostate reveals a prominent citrate peak, which often appears as a doublet if the shim is good enough. Other are those of creatinine and choline. Choline is a composite peak made up of phospholipid membrane components. It is elevated in many malignant tumors, including prostate cancer