AUTHOR=Mortazi Aliasghar , Udupa Jayaram K. , Odhner Dewey , Tong Yubing , Torigian Drew A. 

TITLE=Post-acquisition standardization of positron emission tomography images

JOURNAL=Frontiers in Nuclear Medicine

VOLUME=Volume 3 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/nuclear-medicine/articles/10.3389/fnume.2023.1210931

DOI=10.3389/fnume.2023.1210931

ISSN=2673-8880

ABSTRACT=Purpose: Tissue radiotracer activity measured from positron emission tomography (PET) images is an important biomarker that is clinically utilized for diagnosis, staging, prognostication, and treatment response assessment in patients with cancer and other clinical disorders. Using PET image values to define a normal range of metabolic activity for quantification purposes is challenging due to variations in patient-related factors and technical factors. Although the formulation of standardized uptake value (SUV) has compensated for some of these variabilities, significant non-standardness still persists. We propose an image processing method to substantially mitigate these variabilities.
Results: Our data set consisted of 84 FDG-PET/CT scans of the body torso including 38 normal subjects and two repeat-scans of 23 patients. We utilized one of two objects – liver and spleen – as a reference object and the other for testing. The proposed standardization method reduced CVO and MDO by a factor of 3-8 in comparison to other standardization methods and no standardization. Upon standardization by our method, the image intensities (both for AC and SUV) from two different brands of scanners become statistically indistinguishable, while without standardization, they differ significantly and by a factor of 3-9.  
Conclusions: The proposed method is automatic, outperforms current standardization methods, and effectively overcomes the residual variation left over in SUV and inter-scanner variations.