Multimodal correlation of dynamic [ 18 F]-AV-1451 perfusion PET and neuronal hypometabolism in [ 18 F]-FDG PET

Eur J Nucl Med Mol Imaging. 2017 Dec;44(13):2249-2256. doi: 10.1007/s00259-017-3840-z. Epub 2017 Oct 12.

Abstract

Purpose: Cerebral glucose metabolism measured with [18F]-FDG PET is a well established marker of neuronal dysfunction in neurodegeneration. The tau-protein tracer [18F]-AV-1451 PET is currently under evaluation and shows promising results. Here, we assess the feasibility of early perfusion imaging with AV-1451 as a substite for FDG PET in assessing neuronal injury.

Methods: Twenty patients with suspected neurodegeneration underwent FDG and early phase AV-1451 PET imaging. Ten one-minute timeframes were acquired after application of 200 MBq AV-1451. FDG images were acquired on a different date according to clinical protocol. Early AV-1451 timeframes were coregistered to individual FDG-scans and spatially normalized. Voxel-wise intermodal correlations were calculated on within-subject level for every possible time window. The window with highest pooled correlation was considered optimal. Z-transformed deviation maps (ZMs) were created from both FDG and early AV-1451 images, comparing against FDG images of healthy controls.

Results: Regional patterns and extent of perfusion deficits were highly comparable to metabolic deficits. Best results were observed in a time window from 60 to 360 s (r = 0.86). Correlation strength ranged from r = 0.96 (subcortical gray matter) to 0.83 (frontal lobe) in regional analysis. ZMs of early AV-1451 and FDG images were highly similar.

Conclusion: Perfusion imaging with AV-1451 is a valid biomarker for assessment of neuronal dysfunction in neurodegenerative diseases. Radiation exposure and complexity of the diagnostic workup could be reduced significantly by routine acquisition of early AV-1451 images, sparing additional FDG PET.

Keywords: Av-1451; Cerebral FDG metabolism; Cerebral perfusion; Neurodegeneration; Tau-imaging.

MeSH terms

  • Carbolines*
  • Fluorodeoxyglucose F18*
  • Humans
  • Neurodegenerative Diseases / diagnostic imaging
  • Neurodegenerative Diseases / metabolism
  • Neurodegenerative Diseases / pathology
  • Neurons / metabolism*
  • Perfusion Imaging*
  • Positron-Emission Tomography*

Substances

  • Carbolines
  • Fluorodeoxyglucose F18
  • 7-(6-fluoropyridin-3-yl)-5H-pyrido(4,3-b)indole