The evaluation of human breast lesions with magnetic resonance imaging andproton magnetic resonance spectroscopy

Purpose. MR spectroscopy (MRS) assists in lesion characterization and diagn osis when combined with magnetic resonance imaging (MRI). Cancerous lesions demonstrate elevated composite choline levels arising from increased cellu lar proliferation. Our study investigated if MR spectroscopy of the breast would be useful for characterizing benign and malignant lesions. Materials and methods. Single voxel proton MR spectroscopy (MRS) was acquir ed as part of an MR imaging protocol in 38 patients referred upon surgical consultation. The MR spectra were read independently in a blinded fashion w ithout the MR images by three spectroscopists. The MRI exam was interpreted in two settings: (a) as a clinical exam with detailed histories and result s from previous imaging studies such as mammography or ultrasound included and (b) as a blinded study without prior histories or imaging results. Results. Elevated choline levels were demonstrated by MRS in 19 of the 23 c onfirmed cancer patients. The sensitivity and specificity for determining m alignancy from benign breast disease with MRS alone were 83 and 87%, respec tively, while a blinded MRI review reported 95 and 86%, respectively. Conclusions. Proton MR spectroscopy provides a noninvasive, biochemical mea sure of metabolism. The technique can be performed in less than 10 min as p art of an MRI examination. MRI in combination with MRS may improve the spec ificity of breast MR and thereby, influence patient treatment options. This may be particularly true with less experienced breast MRI readers. In exam s where MRI and MRS agree, the additional confidence measure provided by MR S may influence the course of treatment.