Digital PET vs Analog PET: Clinical Implications?

Positron emission tomography (PET) is a functional imaging technique introduced in 1970s. Over the years, PET was used alone but is in 2000 when the first hybrid PET/CT device was clinically introduced. Since then, PET has continuously been marked by technological developments, being the most recent one the introduction of silicon photomultipliers (SiPMs) as an alternative to standard photomultiplier tubes used in analog PET/CT systems. SiPMs, the basis for the so called digital PET/CT systems, are smaller than standard photo-multiplier tubes (enabling higher spatial resolution) and provide up to 100% coverage of the crystal area, as well as high sensitivity, low noise, and fast timing resolution. SiPMs in com-bination with optimized acquisition and reconstruction parameters improve the localization of the annihilation events, provide high definition PET images, and offer higher sensitivity and higher diagnostic performance. This article summarizes the evidence about the supe-rior performance of the state of the art digital PET and highlights its potential clinical impli-cations. Digital PET opens new perspectives in the quantification and characterization of small lesions, which are mostly undetectable using analog PET systems, potentially chang-ing patient management and improving outcomes in oncological and non-oncological dis-eases. Moreover, digital PET offers the possibility to reduce radiation dose and scan times which may facilitate the implementation of PET to address unmet clinical needs.Semin Nucl Med 52:302-311 (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

This article summarizes the evidence and potential clinical implications of state-of-the-art digital PET, which offers superior performance compared to analog PET in terms of spatial resolution, sensitivity, and diagnostic capability. Digital PET is particularly important for quantification and characterization of small lesions, and it also has the potential to reduce radiation dose and scan times.