Abstract #2893

Li K, Zaharchuk G, Wilmes L, Gibbs J, Joe B, Hess C, Hylton N, Han E

Tissue contrast from magnetization transfer (MT) and blood flow in arterial spin tagging (AST) experiments was investigated in volunteers. Fifteen breast cancer patients undergoing neoadjuvant chemotherapy were imaged using the gradient-echo arterial spin tagging (GREAST) sequence to assess the impact of preserved MT on detection and differentiation of breast lesions. Texture analysis was performed on the GREAST difference (∆M) image for each tumor to assess response to therapy. Mean and median signal intensity, and the inverse difference moment (IDM)--a texture measure, showed significant (P=0.03, 0.02, and 0.005) changes following chemotherapy. Assuming that MT-induced signal is not significantly changed after treatment, GREAST ∆M images provided useful information in depicting changes in local blood flow in breast tumors.