抄録
Over the last decade in vivo imaging modalities and tools have become more sophisticated increasing in sensitivity, specificity and resolution. At the same time pharmaceutical companies have made translational imaging an integral part of the drug development process. Initially imaging was mainly used for CNS drug development due to the inaccessibility of the target. Applications were proof of concept (POC), target engagement (TE), time on target, efficacy and dose selection. Lately imaging applications are being added in the field of safety because in vivo imaging can often detect drug induced changes in tissue long before they can be detected in peripheral compartments like blood or urine. Amongst the different imaging modalities positron emission tomography (PET), magnet resonance (MR) and computer tomography (CT) are being utilized. PET imaging helps minimizing adverse events by prescreening drug candidates, aiding in dose selection and screening for off-target activity. MRI allows for the acquisition of high resolution anatomical images as well as measuring functional processes. We recently conducted MRI studies showing the sensitivity of MRI to depict early changes of brain vasculature (e.g. model of induced vasculitis) as well as its importance as prescreening tool prior to occlusion of the middle cerebral artery as a model of stroke. Quantitative CT has been applied to measure drug effects on bone mineral density while CT perfusion studies measure changes in functionality of selected organs. The important task is to apply the best imaging modality to a given problem.
