Elsevier

JACC: Cardiovascular Imaging

Volume 15, Issue 12, December 2022, Pages 2098-2108
JACC: Cardiovascular Imaging

Original Research
Parametric Imaging of Biologic Activity of Atherosclerosis Using Dynamic Whole-Body Positron Emission Tomography

https://doi.org/10.1016/j.jcmg.2022.05.008Get rights and content
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Abstract

Background

For molecular imaging of atherosclerotic vessel wall activity, tracer kinetic analysis may yield improved contrast versus blood, more robust quantitative parameters, and more reliable characterization of systems biology.

Objectives

The authors introduce a novel dynamic whole-body positron emission tomography (PET) protocol that is enabled by rapid continuous camera table motion, followed by reconstruction of parametric data sets using voxel-based Patlak graphical analysis.

Methods

Twenty-five subjects were prospectively enrolled and underwent dynamic PET up to 90 minutes after injection of 2-[18F]fluoro-2-deoxy-D-glucose (FDG). Two sets of images were generated: 1) the established standard of static standardized uptake value (SUV) images; and 2) parametric images of the metabolic rate of FDG (MRFDG) using the Patlak plot–derived influx rate. Arterial wall signal was measured and compared using the volume-of-interest technique, and its association with hematopoietic and lymphoid organ signal and atherosclerotic risk factors was explored.

Results

Parametric MRFDG images provided excellent arterial wall visualization, with elimination of blood-pool activity, and enhanced focus detectability and reader confidence. Target-to-background ratio (TBR) from MRFDG images was significantly higher compared with SUV images (2.6 ± 0.8 vs 1.4 ± 0.2; P < 0.0001), confirming improved arterial wall contrast. On MRFDG images, arterial wall signal showed improved correlation with hematopoietic and lymphoid organ activity (spleen P = 0.0009; lymph nodes P = 0.0055; and bone marrow P = 0.0202) and increased with the number of atherosclerotic risk factors (r = 0.49; P = 0.0138), where signal from SUV images (SUVmax P = 0.9754; TBRmax P = 0.8760) did not.

Conclusions

Absolute quantification of MRFDG is feasible for arterial wall using dynamic whole-body PET imaging. Parametric images provide superior arterial wall contrast, and they might be better suited to explore the relationship between arterial wall activity, systemic organ networks, and cardiovascular risk. This novel methodology may serve as a platform for future diagnostic and therapeutic clinical studies targeting the biology of arterial wall disease.

Key Words

atherosclerosis
parametric imaging
Patlak graphical analysis
positron emission tomography
whole-body imaging

Abbreviations and Acronyms

CT
computed tomography
CVD
cardiovascular disease
DV
distribution volume
ER
experienced reader
FDG
2-[18F]fluoro-2-deoxy-D-glucose
IR
inexperienced reader
MR
metabolic rate
PET
positron emission tomography
ROI
region of interest
SUV
standardized uptake value
TBR
target-to-background ratio

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