Preclinical Applications of Multi-Platform Imaging in Animal Models of Cancer

Abstract

In animal models of cancer, oncologic imaging has evolved from a simple assessment of tumor location and size to sophisticated multi-modality exploration of molecular, physiological, genetic, immunological and biochemical events at microscopic to macroscopic levels, performed non-invasively and sometimes in real time. We briefly review animal imaging technology and molecular imaging probes together with selected applications from recent literature. Fast and sensitive optical imaging is primarily used to track luciferase-expressing tumor cells, image molecular targets with fluorescent probes, and report on metabolic and physiological phenotypes using smart switchable luminescent probes. MicroPET/ SPECT have proven to be two of the most translational modalities for molecular and metabolic imaging of cancers: Immuno-PET is a promising and rapidly evolving area of imaging research. Sophisticated MRI techniques provide high-resolution images of small metastases, tumor inflammation, perfusion, oxygenation and acidity. Disseminated tumors to the bone and lung are easily detected by microCT, while ultrasound provides real-time visualization of tumor vasculature and perfusion. Recently available photoacoustic imaging provides real time evaluation of vascular patency, oxygenation, and nanoparticle distributions. New hybrid instruments such as PET-MRI promise more convenient combination of the capabilities of each modality, enabling enhanced research efficacy and throughput.