Voxelwise Quantification of [¹¹C](R)-Rolipram PET Data: A Comparison Between Model-Based and Data-Driven Methods

Abstract

This study compared model-based and data-driven methods to assess the best methodology for generating precise and accurate parametric maps of the parameters of interest in [11 C](R)-rolipram brain positron-emission tomography studies. Parametric images were generated using (1) a two-tissue compartmental model (2TCM) solved with the hierarchical basis function method (H-BFM) linear estimator; (2) data-driven spectral-based methods: standard spectral analysis (std SA) and rank-shaping SA (RS); and (3) the Logan graphical plot. Nonphysiologic V T estimates were eliminated and the remaining ones were compared with the reference values, i.e., those obtained with a voxelwise 2TCM solved with a nonlinear estimator. With regard to voxelwise V T estimates, H-BFM showed the best agreement with weighted nonlinear least square (WNLLS) values and the lowest percentage of mean relative difference (1 ± 1%). All methods showed comparable variability in the relative differences. H-BFM provided the best correlation with WNLLS (y ¼ 1.034x À 0.013; R 2 ¼ 0.973). Despite a slight bias, the other three methods also showed good agreement and high correlation (R 2 40.96). H-BFM yielded the most reliable voxelwise quantification of [ 11 C](R)-rolipram as well as the complete description of the tracer kinetic. The Logan plot represents a valid alternative if only V T estimation is required. Its marginally higher bias was outweighed by a low computational time, ease of implementation, and robustness.

Identification andin vivoevaluation of a fluorine-18 rolipram analogue, [18F]MNI-617, as a radioligand for PDE4 imaging in mammalian brain

“…Binding potentials (BP ND ) calculated using non‐invasive Logan graphical analysis with cerebellar vermis as reference region (low PDE4) ranged between 0.3 (frontal cortex, anterior cingulate) and 0.7 (thalamus). Although these BP ND values are low, they are comparable with similar values measured for R ‐(−)‐[ 11 C]rolipram . The radiotracer was rapidly metabolized in vivo , with less than 5% of the parent d 2 ‐[ 18 F]11f remaining in the plasma after 15 min.…”

Measuring specific receptor binding of a PET radioligand in human brain without pharmacological blockade: The genomic plot

“…All PET images were acquired using an Advance tomograph (GE Medical Systems, Waukesha, WI, USA) after a bolus injection of 695 ± 152 MBq of [ 11 C ]( R )-rolipram The data were analysed as previously reported in (Rizzo et al, 2013). PET data were acquired at the NIH PET centre, Bethesda, Maryland (USA).…”

Kinetic Modeling without Accounting for the Vascular Component Impairs the Quantification of [11C]PBR28 Brain PET Data

“…K 1 , k 2 , k 3 and k 4 values were derived from a 2TCM applied to the reversible tracer [ 11 C](R)-rolipram. 32,33 This has been done in order to avoid using data from a ligand (i.e. [ 11 C]PBR28) that may include a trapping component.…”