Figure 1

Non-invasive imaging techniques (MRI) for small rodents. A: T²weighted images of the lungs from 10, 20 and 30 weeks old K-ras^LA1/p53^R172HΔ males (left panels) and females (right panels) mice. Tumors appear as white opaque hyper-intense regions (white arrows). B and C: Quantification of the tumor burden of both males (black bars) and females (white bars) mice at 10, 20 and 30 weeks of age. B: Tumor volume per animal was quantified by calculating the area of visible lung opacities present in each axial image sequence (usually 18-20 per mouse) and then multiplying the total sum of the areas by the distance between each MRI sequence. Data are shown as mean ± SEM of the areas occupied by the tumors in the lung of each mouse (** p = 0.005, *** p = 0.0001, Student' t test). C: Percentage of lung volume occupied by tumors; data are shown as mean ± SEM of each mouse (** p = 0.005, Student' t test).