1. Cardiovascular Imaging & Contrast Media Research, Therapeutic Research Group Diagnostic Imaging, Bayer Schering Pharma AG, 13353 Berlin, Germany, nanoPET Pharma GmbH, 10115 Berlin, Germany, and Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmacy, Martin Luther University, Halle-Wittenberg, 06120 Halle/Saale, Germany