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01 Nov 19. Featured Paper

Standardization of preclinical PET/CT imaging to improve quantitative accuracy, precision and reproducibility: a multi-center study

The Journal of Nuclear Medicine

 

Authors

Wendy McDougald, Christian Vanhove, Adrienne Lehnert, Barbara Lewellen, John Wright, Marco Mingarelli, Carlos Corral, Jurgen Schneider, Sven Plein, David Newby Andy Welch, Robert Miyaoka, Stefaan Vandenberghe and Adriana Tavares

 

Abstract

Preclinical Positron Emission Tomography/Computed Tomography (PET/CT) is a well-established non-invasive imaging tool for studying disease development/progression and the development of novel radiotracers and pharmaceuticals for clinical applications. Despite this pivotal role, standardization of preclinical PET/CT protocols, including CT absorbed dose guidelines, is essentially non-existent.

This study: (1) quantitatively assesses the variability of current preclinical PET/CT acquisition and reconstruction protocols routinely used across multiple centers and scanners; and (2) proposes acquisition and reconstruction PET/CT protocols for standardization of multi-center data, optimized for routine scanning in preclinical PET/CT laboratory.

Methods:

Five different commercial preclinical PET/CT scanners in Europe and USA were enrolled.

Seven different PET/CT phantoms were used for evaluating biases on default/general scanner protocols; followed by developing standardized protocols.

PET, CT and absorbed dose biases were assessed.

 

Results:

Site default CT protocols: Greatest extracted Hounsfield Units (HU) for water was 133HU and -967HU for air, significant differences in all tissue equivalent material (TEM) groups were measured.

Average CT absorbed dose for mouse and rat was 72mGy and 40mGy, respectively.

Standardized CT protocol: Greatest extracted HU for water was -77HU and -990HU for air, TEM precision improved with a reduction in variability for each tissue group.

Average CT absorbed dose for mouse and rat was reduced to 37mGy and 24mGy, respectively.

Site default PET protocols: Uniformity was substandard in one scanner, Recovery Coefficients (RCs) were either over or under estimated (maximum of 43%), standard uptake values (SUVs) were biased by a maximum of 44%.

Standardized PET protocol: Scanner with substandard uniformity improved by 36%, RC variability was reduced by 13% points and SUV accuracy improved to 10%.

 

Conclusion:

Data revealed important quantitative bias in preclinical PET/CT and absorbed doses with default protocols.

Standardized protocols showed improvements in measured PET/CT accuracy and precision with reduced CT absorbed dose across sites.

Adhering to standardized protocols generates reproducible and consistent preclinical imaging datasets, thus augmenting translation of research findings to the clinic.

 
Keywords
  • Animal Imaging
  • PET-CT
  • CT Absorbed dose
  • Preclinical PET-CT
  • Recovery coefficients
  • Standardisation