| Abstract: | The magnetic resonance absorption spectrum, T1 and T2 relaxation time distributions, and magnetization transfer properties of ex vivo breast tissue have been characterized at 1.5 T and 37°C. The fraction of fibroglandular tissue within individual tissue samples (n = 31) was inferred from the tissue volumetric water content obtained by integration of resolvable broad-line fat and water resonances. The spectroscopically estimated water content was strongly correlated with that extracted enzymatically (Pearson correlation coefficient 0.98, P « 0.01), which enabled the assignment of principal relaxation components for fibroglandular tissue (T2 = 0.04 ± 0.01, T1 = 1.33 ± 0.24 s), and for adipose tissue (T2 = 0.13 ± 0.01, T1 = 0.23 ± 0.01 s, and T2 = 0.38 ± 0.03, T1 = 0.62 ± 0.16 s). The relaxation components for fibroglandular tissue exhibited strong magnetization transfer, whereas those for adipose tissue showed little magnetization transfer effect. These results ultimately have applicability to the optimization of clinical magnetic resonance imaging and research investigations of the breast. |
