MR tomographic characterization of suspicious breast lesions with dynamic susceptibility-weighted T2* sequences

Abstract

To increase specificity of MR-mammography by using dynamic T2* sequences. 23 patients with suspicious lesions of the breast underwent conventional dynamic T1-weighted (T1-dynamic) breast MRI and, subsequently, dynamic T2*-weighted (T2*-dynamic) perfusion studies. To assess the T1-dynamic, signal enhancement during the first minute (E1) was calculated. To evaluate the T2*-dynamic, relative signal intensity loss after administration of contrast medium was determined. After administration of contrast medium, 6 of 13 malignant lesions did not show a signal decrease during the T2*-dynamic. Two of them exhibited an atypical signal enhancement in the T1-dynamic, with E1 < 100%. On the other hand, in 5 of 10 benign tumors a relative signal decrease of between 5-17% occurred during the T2*-dynamic. Four benign lesions showed a strong early signal enhancement during the T1-dynamic (E1 > 100%), which is more typical for malignant lesions. The use of dynamic T2* sequences, following dynamic T1-weighted breast MRI and administration of contrast medium, does not sufficiently increase diagnostic sensitivity. Thus, this study does not support the potential advantage of susceptibility MR imaging for a further characterization of breast lesions.