Gadolinium-based contrast agent attenuation does not impact PET quantification in simultaneous dynamic contrast...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiochemistry

Background:

• Simultaneous PET/MR imaging combines positron emission tomography (PET) and magnetic resonance (MR) imaging.
• Gadolinium-based contrast agents (GBCAs) are often administered during PET/MR scans.
• The potential impact of GBCAs on PET quantification requires investigation.

Purpose of the Study:

• To evaluate the attenuating effect of GBCAs on standardized uptake value (SUV) quantification of 18F-fluorodeoxyglucose (FDG) uptake in breast cancer patients using simultaneous PET/MR.
• To compare PET quantification metrics before and after GBCA administration in vivo.

Main Methods:

• 13 women with invasive breast cancer underwent simultaneous prone breast PET/MR with FDG.
• PET data acquisition and MR-based attenuation correction preceded GBCA administration.
• SUVmax and SUVmean were calculated for malignant tissue, normal breast tissue, aorta, and liver before and after GBCA injection.
• Statistical analysis using Wilcoxon signed-rank tests assessed changes in SUV metrics.

Main Results:

• No statistically significant changes in SUVmax or SUVmean were observed for breast malignancies or normal tissues.
• The administration of GBCAs did not measurably alter PET quantification in the evaluated regions.

Conclusions:

• GBCAs do not introduce significant additional attenuation affecting PET quantification in simultaneous PET/MR.
• Corrections for GBCA attenuation are unnecessary when MR-based attenuation correction precedes contrast administration.
• Further research may be needed to explore potential indirect effects of GBCAs on MR-based attenuation correction.