Reducing bias in dynamic equilibrium PET studies
22nd January 2021
Cláudia Régio Brambilla, Jürgen Scheins, Ahlam Issa, Lutz Tellmann, Hans Herzog, Elena Rota Kops, N. Jon Shah, Irene Neuner, Christoph Lerche
Iterative reconstruction is a widely used image reconstruction algorithm in positron emission tomography (PET). The algorithm begins with an assumption of an image and compares it to real time measured values while making constant adjustments until the two are in agreement. Although the technique is superior to that of analytic image reconstruction methods, it is known to contribute to quantitation bias, particularly during commonly conducted dynamic studies using 11C-labeled radiotracers.
This study evaluated the impact of different framing schemes on quantitation bias and its propagation into binding potential using a phantom decay study with 11C and 3D OP-OSEM. Based on this, the authors have proposed a novel framing scheme that keeps the true counts per frame constant over the acquisition time.
The approach uses the fundamental principles of PET imaging and binding potential evaluation and is therefore generally applicable to all dynamic, quantitative PET acquisitions.
Although further studies are required to estimate the bias introduced by other sources, such as scatter correction, and to study the effect of image reconstruction regularisation methods and resolution modelling, the novel framing scheme represents an interesting development in the field of iterative reconstruction.
Original publication: