In vivo MR spectroscopic imaging of polyunsaturated fatty acids (PUFA) in healthy and cancerous breast tissues by selective multiple-quantum coherence transfer (Sel-MQC): a preliminary study.

The spatial distribution of polyunsaturated fatty acids (PUFA) in healthy and cancerous human breast tissues was measured in vivo with a selective multiple-quantum coherence transfer (Sel-MQC) technique. This method selectively detected the olefinic methylene protons (-CH = CH-) of PUFA at 5.3 ppm that were coupled with allylic methylene protons (-CH(2)-CH(2)-CH=) of unsaturated acyl chain at 2.8 ppm. Unwanted lipid coherences and tissue water signal were dephased in a single scan. Breast PUFA were mapped at 1 cm(3) voxel resolution in sagittal slices of nine breasts in six healthy female volunteers that were compared to invasive ductal carcinoma (IDC) in one breast cancer patient. The healthy breast tissue displayed continuous PUFA distribution. In some individuals, PUFA appeared throughout the breast tissue; in others they were only located in the central breast area. Decreased PUFA levels were detected in the IDC of the breast cancer patient. The magnetic resonance spectroscopic imaging (MRSI) measurement was consistent with the histological findings, ultrasound, and mammography images. PUFA patterns are sensitive to abnormal breast tissue changes including malignant transformations, and thus may serve as a biomarker for early diagnosis and therapeutic monitoring of breast disease.