Off-Target 18 F-AV-1451 binding in the basal ganglia correlates with age-related iron accumulation

Abstract

Off-target binding in the basal ganglia is commonly observed in the 18 F-AV-1451 PET studies of the elderly. We sought to investigate the relationship between this phenomenon in the basal ganglia and iron accumulation using iron-sensitive R 2 * MRI. Methods: Fifty-nine healthy controls and 61 patients with Alzheimer disease and mild cognitive impairment underwent 18 F-AV-1451 PET and R 2 * MRI studies. A correlation analysis was performed for age, 18 F-AV-1451 binding, and R 2 * values. Results: There was an age-related increase in both 18 F-AV-1451 binding in the basal ganglia and R 2 * values in the putamen in both the controls and the Alzheimer disease/mild cognitive impairment patients. 18 F-AV-1451 binding in the basal ganglia increased with R 2 * values. Conclusion: Off-target 18 F-AV-1451 binding in the basal ganglia is associated with the age-related increases in iron accumulation. Postmortem studies are required to further investigate the nature of this association.