RT Journal Article SR Electronic T1 Characterization in Humans of 18F-MNI-444, a PET Radiotracer for Brain Adenosine 2A Receptors JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 586 OP 591 DO 10.2967/jnumed.114.152546 VO 56 IS 4 A1 Olivier Barret A1 Jonas Hannestad A1 Christine Vala A1 David Alagille A1 Adriana Tavares A1 Marc Laruelle A1 Danna Jennings A1 Ken Marek A1 David Russell A1 John Seibyl A1 Gilles Tamagnan YR 2015 UL http://jnm.snmjournals.org/content/56/4/586.abstract AB PET with selective adenosine 2A receptor (A2A) radiotracers can be used to study a variety of neurodegenerative and neuropsychiatric disorders in vivo and to support drug-discovery studies targeting A2A. The aim of this study was to describe the first in vivo evaluation of 18F-MNI-444, a novel PET radiotracer for imaging A2A, in healthy human subjects. Methods: Ten healthy human volunteers were enrolled in this study; 6 completed the brain PET studies and 4 participated in the whole-body PET studies. Arterial blood was collected for invasive kinetic modeling of the brain PET data. Noninvasive methods of data quantification were also explored. Test–retest reproducibility was evaluated in 5 subjects. Radiotracer distribution and dosimetry was determined using serial whole-body PET images acquired over 6 h post-radiotracer injection. Urine samples were collected to calculate urinary excretion. Results: After intravenous bolus injection, 18F-MNI-444 rapidly entered the brain and displayed a distribution consistent with known A2A densities in the brain. Binding potentials ranging from 2.6 to 4.9 were measured in A2A-rich regions, with an average test–retest variability of less than 10%. The estimated whole-body radiation effective dose was approximately 0.023 mSv/MBq. Conclusion: 18F-MNI-444 is a useful PET radiotracer for imaging A2A in the human brain. The superior in vivo brain kinetic properties of 18F-MNI-444, compared with previously developed A2A radiotracers, provide the opportunity to foster global use of in vivo A2A PET imaging in neuroscience research.