Proton (1H) MR spectroscopy of the breast.

Proton (hydrogen 1) [1H]) magnetic resonance (MR) spectroscopy provides biochemical information about the tissue under investigation. Its diagnostic value in cancer is typically based on the detection of elevated levels of choline compounds, choline being a marker of active tumor. The two main potential clinical applications of 1H MR spectroscopy are (a) as an adjunct to breast MR imaging to improve specificity in differentiating benign from malignant lesions, and (b) for monitoring or even predicting response to treatment in patients undergoing neoadjuvant chemotherapy. Preliminary data are promising, with study results suggesting that 1H MR spectroscopy may decrease the number of benign biopsies recommended on the basis of MR imaging findings and may help predict response as early as 24 hours after the first dose of neoadjuvant chemotherapy. Although several limitations currently exist that make the technique premature for clinical use, further evaluation with larger, preferably multicenter trials is certainly warranted.