High-resolution axial screening MR images (a–f) and corresponding histologic sections (g–h) of right (white arrows) and left (red arrows) lower mammary glands from one C3(1) SV40 Tag mouse. Each axial MR image represents only one cross sectional slice through the right and left lower glands, as indicated in (a) by the dashed outlines. Conversely, histologic sections represent the entire glands, as indicated in (g–h) by the dashed outlines. The agar grid, which can be visualized wrapped around the mouse, helps to facilitate correlation of MR images with histology. MR images demonstrate lymph nodes (arrowheads), invasive tumors (thick arrows) and MIN (thin arrows). FOV for MR images is ~ 2.25×2.25 cm.