Figure 5.

Transverse T₁ maps of drug-treated and untreated EL-4 tumors in animals injected with PS-active (GST-C2A-Gd) and PS-inactive (GST-C2A-Gd) contrast agents. Color scale indicates T₁ values for image voxels. In this example, contrast agents were matched for relaxation rate. Images were acquired immediately before injection of contrast agent (a T₁ map acquired from a tumor before injection is shown on the left-hand side) and at 24 h after injection. Reference capillary was placed adjacent to the tumors, which were implanted on lower areas of backs of animals. Position of the tumor is indicated on the gray-scale image. (A) Etoposide+cyclophoshamide-treated tumor in animal injected with PS-active GST-C2A-Gd (TA). (B) Drug combination-treated tumor in animal injected with PS-inactive GST-C2A-Gd (TI). (C) Untreated tumor in animal injected with PS-active GSTC2A-Gd (UA). (D) Untreated tumor in animal injected with PS-inactive GST-C2A-Gd (UI). Drug combination-treated tumor in an animal injected with PS-active contrast agent shows greater accumulation at 24 h after injection (A). Courtesy of Dr. Kevin Brindle, University of Cambridge, UK.