Detecting blood oxygen level-dependent (BOLD) contrast in the breast.

PURPOSE To develop a robust technique for detecting blood oxygenation level-dependent (BOLD) contrast in the human breast and to evaluate the signal in healthy and malignant breast. MATERIALS AND METHODS The design of this study focused on determining the optimal pulse sequence and stimulus for detecting BOLD contrast in the breast. For this study a single-shot fast spin echo (SSFSE) sequence was compared to a gradient echo (GRE) pulse sequence. Also, several hyperoxic stimuli were tested on 15 healthy volunteers to determine the best stimulus for inducing BOLD contrast in the breast: air interleaved with carbogen (95% O(2), 5% CO(2)), air interleaved with oxygen, and oxygen interleaved with carbogen. The stimulus with the most consistent results among the healthy population was tested on three breast cancer patients. RESULTS An SSFSE pulse sequence produced improved BOLD contrast results in the breast compared to a GRE pulse sequence. Oxygen interleaved with carbogen yielded the most consistent results in the healthy population. BOLD contrast in healthy glandular breast tissue positively correlates with carbogen and malignant tissue mostly negatively correlates to carbogen. CONCLUSION BOLD contrast can consistently be detected in the breast using a robust protocol. This methodology may be used in the future as a noninvasive method for evaluating tumor oxygenation.