QUANTITATIVE MAGNETIC-RESONANCE-IMAGING PARAMETERS AND THEIR RELATIONSHIP TO MAMMOGRAPHIC PATTERN

Background: Breast cancer exhibits wide international variation in incidence, which has led to the identification of several factors correlating with the risk of the disease. Magnetic resonance imaging (MRI) techniques can provide quantitative information about the biological and physical properties of tissue. Purpose: This work tested several magnetic resonance tissue parameters for their ability to distinguish quantitatively between breast tissues in subjects at substantially different risk for breast cancer as defined indirectly by their parenchymal pattern on mammograms. Methods: Quantitative MRI parameters (relative water content, longitudinal relaxation time [T1], and transverse relaxation time [T2]) were measured for breast tissue using newly developed techniques in two groups of women with mammographic parenchymal appearance associated with high (Dy pattern [i.e., extensive nodular or diffuse density]; n = 12) or low (N1 pattern [i.e., breast containing mainly fat]; n = 11) risk of breast cancer. Results: The two groups have significantly different average relative water content (P < .0001) and average T1 (P < .0001). Pixel histograms of T2 values show marked differences between the two groups which can be characterized with a fourth moment parameter. Conclusions: Quantitative MRI techniques exhibit good potential for assessing tissue characteristics in the breast that are associated with risk of breast cancer. Implications: Future work will address the direct correlation of MRI parameters with risk of breast cancer.