Patlak plot based on the first 30 minutes post-injection dynamic ¹⁸F-florbetaben positron emission tomography scan...

This work aims to search for the shortest duration of an early ¹⁸F-florbetaben positron emission tomography (PET) dynamic acquisition to obtain reliable information on the brain amyloid-β (Aβ) deposition and perfusion.

25 patients that underwent an early ¹⁸F-florbetaben PET dynamic acquisition starting immediately post-injection (maximum of 60 min duration) were retrospectively included. Reference region-based Patlak plot [Formula: see text] (transference rate to the irreversible compartment) and [Formula: see text] (distribution volume) were computed. Shorter early dynamic acquisitions were simulated to a minimum of 15 min duration. Three nuclear medicine physicians evaluated qualitatively the [Formula: see text] parametric images obtained in comparison with those obtained from the standard clinical protocol defined by a late acquisition of 20 min duration starting 90 min post-injection.

All the [Formula: see text] parametric images obtained with at least an early 30-min dynamic acquisitions were suitable for visual classification. Shorter early acquisitions originated images with too much noise, making qualitative assessment difficult. Aβ deposition visual classification based on the [Formula: see text] images were highly concordant with the evaluation of standard late acquisitions (readers consensus agreement of 92%). [Formula: see text] images obtained from the different early dynamic acquisition's duration were visually indistinguishable from each other (voxelwise r ≥ 0.98).

Patlak plot method applied to early 30-min ¹⁸F-florbetaben PET dynamic acquisition may be an alternative to the dual acquisition protocol sometimes used in clinics. This improves patients' comfort, service logistics and reduces radiation exposure.

This work shows, for the first time, that early (0-30 min post-injection) ¹⁸F-florbetaben dynamic PET scans with reference region-based Patlak plot method could replace the dual acquisition protocol and the 90-110 min standard acquisition.