Validation of early‐frame 18F‐FDG PET for CBF quantification: Comparison to simultaneous eASL measurements in memory patients

Abstract

AbstractBackgroundThis study aimed to validate early [18F]‐FDG (eFDG) imaging for the quantification of cerebral blood flow (CBF), enabling dual‐marker imaging of perfusion and metabolism with a single tracer.Method19 participants with memory concerns underwent simultaneous [18F]‐FDG PET and multi delay pseudo‐continuous arterial spin labeling (eASL) MR imaging on a hybrid 3T PET/MRI scanner. eFDG‐CBF maps were generated from the first 30s, 60s, 120s and 300s after injection, and measurements were compared to ASL‐CBF using voxel‐wise cross correlation and concordance correlation for 7 regions derived from the MNI‐structural atlas.ResultHighest voxel‐wise cross‐correlation to ASL‐CBF maps were reported for 300s (5 min) eFDG (r = 0.77).Concordance correlation (CC) values were strong in all ROIs, ranging from (CC = 0.88) to (CC = 0.65) in temporal and occipital regions respectively. Mean of measurements in all ROIs were in good agreement between eFDG and ASL CBF maps, with a reported voxel‐wise mean absolute error of ±6.73 ml/100g/min between two maps.ConclusionBy simultaneous measurement of hemodynamics across modalities with a TOF‐enabled PET/MRI, we were able to demonstrate that eFDG PET is a reliable measure in mapping CBF based on strong inter‐modality correlation with ASL‐CBF, irrespective of pathophysiological variations in memory patients.