Quantifying Brain [¹⁸F]FDG Uptake Noninvasively by Combining Medical Health Records and Dynamic PET Imaging Data.

Abstract

Full quantification of regional cerebral metabolic rate of glucose (rCMRglu) with [¹⁸F]fluorodeoxy-glucose ([¹⁸F]FDG) positron emission tomography (PET) imaging requires measurement of an arterial input function (AIF) curve, which is obtained with an invasive arterial blood sampling procedure during the scan. We previously proposed a non-invasive simultaneous estimation (nSIME) method that quantifies binding of a PET radioligand by combining individual electronic health records information and a pharmacokinetic AIF (PK-AIF) model. Initially applied only to [¹¹C]DASB data, in this study we validate nSIME for a different radioligand, [¹⁸F]FDG, adapting the algorithm to the specific distribution and metabolism of this radioligand. We evaluate the impact of the PK-AIF model, the number of [¹⁸F]FDG-specific soft constraints, and the type of predictive strategy. The accuracy of nSIME is then compared to a population-based approach. All analyses are conducted on 67 [¹⁸F]FDG PET scans with arterial blood data available for comparison. nSIME performance is optimal for [¹⁸F]FDG when using the PK-AIF model, two soft constraints, and an aggregate model to predict the soft constraint values. Higher correlation and lower Bland-Altman spread against gold standard rCMRglu values based on arterial blood measurements are observed for nSIME (r = 0.83, spread = 1.55) compared to the population-based approach (r = 0.77, spread = 2.12). nSIME provides a data-driven estimation of both amplitude and shape of the AIF curve at the individual level and potentially enables non-invasive quantification of PET data across radioligands, avoiding the need for arterial blood sampling.