Test of Reproducibility of [15O]H20-PET Assessment of Brain Perfusion

The researchers wish to test how large the variance of their measurements of blood perfusion to the brain is in healthy participants when performing 2 identical examinations within 7 days of each other. To adress this aim the researchers have defined the following assumption that they will refute or confirm through their study: \- PET-perfusion measurements at their department have a high reproducibility. 8 healthy participants over 60 years will undergo a \[15O\]H2O-PET scan in order to assess the blood perfusion capacity of the brain. Within 7 days, the 8 healthy participants will undergo an additional \[15O\]H2O-PET scan assessing the blood perfusion capacity of the brain. Afterwards the researchers will quantify the variance in their \[15O\]H2O-PET scan in the same individuals within a 7-day time window.