TY - JOUR T1 - Characterization in Humans of <sup>18</sup>F-MNI-444, a PET Radiotracer for Brain Adenosine 2A Receptors JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 586 LP - 591 DO - 10.2967/jnumed.114.152546 VL - 56 IS - 4 AU - Olivier Barret AU - Jonas Hannestad AU - Christine Vala AU - David Alagille AU - Adriana Tavares AU - Marc Laruelle AU - Danna Jennings AU - Ken Marek AU - David Russell AU - John Seibyl AU - Gilles Tamagnan Y1 - 2015/04/01 UR - http://jnm.snmjournals.org/content/56/4/586.abstract N2 - 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. ER -