Assessment of simplified ratio-based approaches for quantification of PET [11C]PBR28 data.

The reliability was good for SUVR, but poor for DVR. Both outcomes showed little to no association with VT, questioning their validity. The high interregional correlations for VT and SUV suggest that after dividing by a denominator region, most of the biologically relevant signal is lost. These observations imply that results from TSPO PET studies using SUVR or DVR estimates should be interpreted with caution.