Role of Proton MR Spectroscopy in Differentiation of Benign and Malignant Breast Lesions

Aim: To determine the optimal cutoff value of choline (Cho) concentration in quantitative multivoxel magnetic resonance (MR) spectroscopic data to differentiate benign from malignant breast lesions. Material and Methods: The study was institutional review board approved, and informed consent was obtained from each patient. Between July 2012 and July 2013, multivoxel MR spectroscopy was performed in 40 consecutive patients with 40 breast lesions assessed as BIRADS 3 to 5 and larger than 1cm in diameter at mammography and US. Two-dimensional point-resolved spatially localized spectroscopy chemical shift imaging was first performed without signal suppression (TR/TE, 1450/30ms) as reference measurement and was performed subsequently with suppression of water and fat signals (1500/135) to detect Cho. Differences in mean and highest Cho concentration in the breast lesions were tested for significance by using the independent sample t-test. The final diagnosis was confirmed with pathologic findings. Results: Twenty four out of 40 breast lesions were malignant. The mean Cho concentration varied between 0.5 and 1.4mmol/L (0.94mmol/L±0.28 [standard deviation]) in benign lesions and between 1.4 and 8.5mmol/L (3.15mmol/L±1.5) in malignant lesions. The highest Cho concentrations in benign and malignant lesions were 0.6-1.7mmol/L (1.29mmol/L±0.33) and 1.8-10.6mmol/L (4.5mmol/L±1.99), respectively. Mean and highest Cho concentrations in benign and malignant breast lesions differed significantly (p 0.001 for both). Using the highest choline concentration cut off value of 1.7 resulted in 100% sensitivity, specificity and accuracy for differentiation of benign and malignant breast lesions. Conclusion: Quantitative single multivoxel MR spec-troscopy can be applied to differentiate benign from malignant breast lesions. The use of highest Cho concentration of 1.7mmol/L or lower as a cutoff. Further larger studies will be needed to confirm these results.