Published online by Cambridge University Press: 04 August 2010
MRS of the breast is more technically demanding than that in the brain.
Cho levels have been reported to be higher in malignant breast cancer than in benign lesions and normal breast tissue.
Early decreases in Cho signal intensity may be seen in lesions that respond to treatment.
MRS is limited by sensitivity to lesions at least 1 cm3.
Inadequate sensitivity may lead to false negatives, and both false positives and negatives may arise due to insufficient water and lipid suppression, or other artifacts.
Introduction: MRS of breast tissues
Although the vast majority of magnetic resonance spectroscopy (MRS) studies in humans have been performed to date in the central nervous system, there is growing interest in the application of MRS to other organ systems in the body. This is particularly true for areas such as breast cancer, where conventional diagnostic techniques have relatively limited sensitivity and/or specificity. MRS of the breast presents a number of technical challenges (described in detail later in this chapter) which are gradually being overcome, allowing clinical research studies to be performed. Early MRS studies of human breast cancer focused on the phosphorus (31P) nucleus, since localized, water-suppressed proton spectroscopy was not available at that time. However, with the development of improved gradient hardware, spatial localization, and water suppression techniques, 31P spectroscopy has largely been replaced by proton (1H) MRS. The much higher sensitivity of the proton nucleus allows spectra with higher signal-to-noise ratios (SNR) to be recorded from smaller volumes of tissue compared to 31P.