In vivo MR Diffusion Investigation of Murine Tumors with Bacteria Infiltration
Yung K, He Q, Song X, Chibisov V, Ramus G
University of Pittsburgh Medical Center
Bacterial-based cancer treatment has shown great potential in attacking poorly vascularized tumor regions, especially when combined with conventional chemotherapeutic drugs. We report an in vivo MRI diffusion study of Murine LL/2 tumors injected with genetically altered E. Coli DH5 (Met) or JM109 (Hb) strains. The calculated diffusion maps show distinctive features not apparent in their MRI images with a mean ADC ~ 0.56 x 10-3 mm2/s. In correlation with histochemical staining results, the T2-weighted image of the E. Coli DH5-carrying tumor showed homogeneous yet fragmental tissue, but the tumor that eradicated the injected E. Coli JM109 strain presented more structural heterogeneity. These results demonstrate that MRI may be an important tool to detect tumor tissue remodeling by different types of bacterial interactions.