Proton MR spectroscopy of the breast

Magnetic resonance imaging (MRI) of the breast has emerged as a highly sensitive modality. In addition to morphologic and kinetic analysis obtained from contrast-enhanced breast MRI, functional information has been needed for diagnosis of breast disease. In vivo proton (hydrogen 1 [¹H]) MR spectroscopy of the breast has demonstrated that choline (Cho) can be detected in breast cancers, whereas Cho is generally undetectable in normal breast tissue. Thus, breast MR spectroscopy has shown great promise as a way to differentiate between benign and malignant lesions and to gauge the effect of chemotherapeutic agents in patients with locally advanced breast cancer. Prior studies performed on 1.5-T MR imagers have reported sensitivities of 70–100% (average 89%; 149/168) and specificity of 67–100% (average 87%; 97/112) for breast MR spectroscopy. Moreover, the presence of a Cho peak in breast cancer may reflect the increased cell proliferation, with a decrease in this peak after treatment reflecting decreased viability of the tumor. With further development and the assessment of Cho quantity in the tumor, breast MR spectroscopy may be helpful in the elucidation of the biology of breast cancer.