The Stanford Quantitative Imaging Laboratory (QIL) conducts research to extract and use objective information in images (quantitative measurements and qualitative ("semantic") observations described using controlled terminologies) in machine-processible form for biomedical discovery and clinical applications. For discovery, we aim to identify novel imaging biomarkers of disease for diagnosis, prediction, and assessment of treatment response. For clinical applications. we are developing decision support applications that leverage quantitative information in images to reduce variation in practice and to improve the accuracy of physicians in diagnosing disease and in determining the best treatment in individual patients. We are also building computerized models that characterize the imaging phenotype of disease to enable precision medicine. Work in QIL thus spans a spectrum of activities ranging from basic imaging and informatics science to translational research and clinical service in which quantitative iamging-based discoveries are operationalized and evaluated in clinical practice to transform the practice of medicine. Our work includes applications in Radiology, Pathology, and Ophthalmology.