Author contributions
All authors critically reviewed each draft of the manuscript for
important intellectual content, approved the final submitted version,
and agree to be accountable for all aspects of the work. In addition,
ER contributed to study design and data interpretation
AO contributed to study design and data interpretation
CB contributed to study design and data interpretation
GR analysed the PET data and contributed to data interpretation
YL managed the study and contributed to data interpretation
HD contributed to study design and data interpretation
GM contributed to study design and data interpretation
KS contributed to study design and data interpretation