Multianimal Magnetic Resonance Imaging for Tumor Measurements in Pancreatic Cancer Mouse Models.

Advanced in vivo imaging modalities, such as magnetic resonance imaging (MRI), are essential research tools to effectively detect tumors in preclinical mouse models. MRI provides detailed anatomical information on tumor location and size. However, this imaging modality is expensive and time-consuming. To overcome this access barrier without compromising imaging quality, a multianimal MRI protocol was implemented. This protocol uses a four-chamber bed insert to obtain high-resolution multianimal anatomical MRI scans within a single acquisition session. Simultaneously imagining multiple mice reduces the time and cost of this procedure. This protocol describes a multianimal MRI workflow designed to increase the efficiency of tumor detection and longitudinal tumor monitoring in a genetically engineered Kras-driven, p53-deleted (KPC) mouse model of pancreatic ductal adenocarcinoma. This well-established clinically relevant KPC model has provided invaluable insight into the molecular mechanisms underlying pancreatic carcinogenesis, tumor progression, and treatment resistance. As proof-of-concept, this protocol is applied to validate the therapeutic benefit of the standard-of-care chemotherapeutic agent gemcitabine in the KPC model. Future applications of this MRI-guided preclinical study design are briefly discussed to evaluate the therapeutic efficacy of combination therapies.