Whole animal imaging (e.g., Positron Emission Tomography, Magnetic Resonance Imaging, Computer Aided Tomography, Fluorescence or Luminesence Imaging, Intravital Microscopy) is widely available in San Diego. Dual IACUC approvals are obtained from LJIDI and the host institute. The rodent PET imager is GE eXplore Vista DR (UCSD In Vivo Imaging; Dr. David Vera, Director). The strength of PET imaging is in the relatively preserved biochemical behavior of positron emitting radiotracers. In live and sedated animals, dynamic PET imaging can measure the time-dependent cross-sectional tissue concentrations of a radiotracer that can then be used for kinetic modeling. Static PET images can provide tissue and whole body biodistribution of radiotracers similar to that of autoradiography. PET provides an alternative to MR imaging of receptor-based agents where the high dose required for adequate MR signal saturates the target. A 7.0T MRI Scanner – Bruker - Avance II Console (Center for Functional MRI) supports high resolution anatomical imaging, diffusion imaging, functional MRI, proton and phosphorous spectroscopy, cardiac imaging and cell tracking. It is designed to accurately quantify and visualize regional, time-varying distributions of positron-labeled radiopharmaceuticals. The GE eXplore RS rodent CT scanner (UCSD In Vivo Imaging) images small animals at resolutions of 45µm and in vitro specimens at 27 µm. A GE eXplore Optix (UCSD In Vivo Imaging) provides high sensitivity and temporal resolution than PET but is limited to a few centimeters of tissue depth. Intravital microscopy uses an Olympus Fluoview 1000 laser scanning confocal system mounted a BX61WI fluorescent microscope modified to accommodate intravital chambers, anesthesia apparatus, and high numerical aperture water immersion lenses (UCSD Intravital Imaging Core, Dr. Brian Elicieri, Director).