Figure 4.

Assessment of tumor growth and regression by MRI. Images were acquired on a 7T Bruker MRI using T1-weighted multi-spin-multi-echo (MSME) or axial T2-weighted TurboRARE sequences in the presence of gadolinium-based contrast agent pre-treatment (21 days of age) and at the indicated ages during or after doxycycline treatment. A. MRI data from a representative mouse demonstrating the presence of a tumor pre-treatment, absence of a tumor following 90 days of doxycycline treatment, and continued remission at 238 days of age (127 days after doxycycline withdrawal). B. Representative MRI data of a resistant tumor before and after 16 and 36 days of doxycycline treatment. The numbers in the lower left corner of each image indicate the age of the mouse at the time of the scan. Arrows are pointing to the tumor in each T1 image. C. MRI data from a representative tumor-bearing mouse demonstrating absence of a tumor after 90 days of doxycycline treatment followed by recurrence 107 days later.