Figure 4.

DCE-MRI imaging of vascular changes induced by gemcitabine in KCI-18 kidney tumors. In separate experiments, mice bearing established kidney tumors were treated with gemcitabine at 20 mg/kg (Gem20) or with vehicle (control). Mice were imaged by DCE-MRI at 24 hours after gemcitabine treatment after receiving one dose (day 14), three doses (day 18), or four doses (day 21), given 3 days apart. (A) T1 images: Baseline images before Gd contrast agent injection. The full kidney was selected as the ROI for the tumor-bearing kidney (blue contour on left of T1 image) and the contralateral normal kidney (red contour on right of T1 image). (B) C(t) kinetics of Gd contrast uptake and clearance: The first 10 time points represent baseline data. Gd was injected at time point 10, and images were collected for 20 more time points. (C) IAUC graphs: Data from the C(t) curves were compiled for 16 time points (112 seconds) after Gd injection to draw IAUC₁₁₂. The small black bar indicates the peak position of normal kidney in control mice and can be used as a reference for curve shifting in normal kidneys and kidney tumors treated with gemcitabine. (D) CIAUC graphs: CIAUC curves were derived from IAUC curves. In panels A, B, C, and D, blue lines are for kidney tumors and pink lines are for normal kidneys. (E) AUC parametric map: Parametric color maps were constructed based on uptake and concentration of Gd in the tissue, represented by the colors blue, green, yellow, and red with gradual increase of Gd from lowest values (blue) to highest values (red). The tumor-bearing kidney is on the left, and the normal contralateral kidney is on the right of the MR images. The color coding in the kidneys are shown for integrated AUC. Data from a representative mouse from each treatment group are presented.