TECHNICAL NOTE Pitfalls in Lactate Measurements at 3T

SUMMARY: In clinical MR spectroscopy at higher field strengths, lactate may show reduced or absent signal intensity at an echo time of 144 ms. Although this false-negative result may be predicted from theory, experimental verification and clinical impact have not been fully established. Using scanners from 3 major vendors, spectra from phantoms and patients demonstrate the lactate signal loss and potential error in interpretation. Strategies are discussed to overcome, or at least alleviate, this problem. Lactate is ametabolite that plays a pivotal role inmany brainpathologies such as tumors, stroke, cerebral ischemia, hyp-oxia, and several mitochondrial disorders.1 The lactate con-centration in healthy brain under normal conditions is ap-proximately 1 mmol/L. However, when oxygen availability is low because of metabolic stress, glucose molecules are no longer oxidized completely and pyruvate is produced. The pyruvate is converted to lactate, which can rise to concentra-tions10mmol/L. Lactate is, therefore, an important marker of anaerobic glycolysis taking place in the previously men