Population-based input function and image-derived input function for [11C](R)-rolipram PET imaging: Methodology, validation and application to the study of major depressive disorder

► PBIF and IDIF are equivalent to arterial sampling for [11C](R)-rolipram studies. ► PBIF obtained from healthy subjects can be used for depressed patients. ► PBIF can successfully be applied to a test-retest study. ► IDIF and PBIF showed a decrease in [11C](R)-rolipram binding in depressed subjects.