Abstract
In vivo magnetic resonance spectroscopy (MRS) is a sensitive technique for metabolic evaluation of normal, benign and malignant tissues and is rapidly evolving as a clinical tool for diagnosis, characterization and monitoring the therapeutic response of tumor. The proton (1H) MR spectra of normal breast tissues are characterized by high fat content while tumor tissues have higher water content. From the respective peak areas, the water–fat (W–F) ratio can be calculated. The in vivo1H MR spectrum obtained with water and fat suppression from malignant breast tissues are characterized by a peak at 3.2 ppm corresponding to choline-containing metabolites (tCho) and has been shown as a reliable biochemical marker of malignancy. With developments in MR methodology, it is possible to determine the in vivo absolute quantification of tCho that provide an opportunity to have cut-off values for the discrimination of normal, benign and malignant breast tissues. Both W–F ratio and the concentration of tCho have been demonstrated to be useful in monitoring the effect of therapy in breast cancer patients. In patients receiving chemotherapy, reduction of W–F ratio and the concentration of tCho were observed in association with the reduction of the primary tumor size indicating its use as non-invasive indicators of favorable clinical outcome of therapy. Studies showed that addition of MRS investigation increases the specificity of MRI. This article reviews some salient features of in vivo MRS and its role in the diagnosis and treatment management of breast cancer patients.