We are developing technology specifically designed for in vivo molecular imaging. The focus of our research is around non-invasive techniques, like positron emission tomography (PET), x-ray micro computed tomography (microCAT) and optical imaging systems. In this process, we design and simulate from detectors to complete imaging systems, construct detectors and complete prototype systems, develop and implement linear and iterative data correction and image reconstruction algorithms as well as data analysis and visualization tools. We are also developing hardware and software solutions to complex computationally intensive problems like iterative image reconstruction, deformable model image registration from data acquired by multiple imaging modalities as well as high throughput screening. These tools have been used by biologists to transform in vitro mammalian biology into the setting of living animals.