Coronary calcium score scan-based attenuation correction in cardiovascular PET imaging

Area of Science:

• Nuclear Medicine
• Radiology
• Cardiovascular Imaging

Background:

• Cardiac positron emission tomography (PET)/CT is vital for assessing coronary artery disease (CAD).
• Accurate quantitative analysis relies on CT-based attenuation correction (AC).
• Current protocols use a separate low-dose CT (ACCT) for AC, increasing patient radiation exposure.

Purpose of the Study:

• To evaluate the feasibility of using coronary artery calcium scoring CT (CaScCT) images for attenuation correction (AC) in cardiac PET/CT.
• To reduce patient radiation dose by eliminating the need for a separate ACCT scan.

Main Methods:

• Reconstructed CaScCT data with an extended field-of-view (ExCaScCT) for AC.
• Assessed 10 patients undergoing NH3 perfusion or ¹⁸F-FDG viability PET/CT.
• Evaluated PET images using qualitative assessment, regression analysis, Bland-Altman plots, and myocardial bull's eye analysis.

Main Results:

• Good agreement between ACCT and ExCaScCT for viability and stress perfusion PET images (correlation coefficients > 0.94).
• Weak correlation for rest perfusion PET images due to misalignment between CaScCT and rest ACCT scans.
• Increased differences in uptake values in the inferior wall observed due to diaphragm motion.

Conclusions:

• CaScCT shows potential for attenuating correction in cardiac PET, particularly for viability and stress perfusion studies.
• Eliminating ACCT in these protocols can significantly reduce patient radiation dose.
• Further research is needed to address discrepancies in rest perfusion imaging and diaphragm motion artifacts.