Attenuation correction in cardiac PET/CT with three different CT protocols: a comparison with conventional PET

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• CT-based attenuation correction in cardiac PET may differ from conventional methods due to misalignment susceptibility.
• Evaluating CT-based attenuation correction's impact on cardiac PET tracer distribution is crucial.

Purpose of the Study:

• To assess changes in cardiac PET tracer distribution with CT attenuation correction compared to conventional (68)Ge scans.
• To determine an optimal CT protocol for cardiac PET/CT transmission imaging.

Main Methods:

• 27 patients underwent PET/CT with varying CT protocols: low-dose CT (LDCT), slow CT (SCT), and ultra-low-dose CT (ULDCT).
• Regression analysis and visual assessment compared CT-corrected PET with (68)Ge-corrected PET.
• Effective dose for each CT transmission protocol was calculated.

Main Results:

• Moderate correlations were found between CT-corrected and (68)Ge-corrected PET across all CT groups (r=0.78-0.82).
• No significant differences in visual misalignment scores or regression analysis outcomes were observed between groups.
• Ultra-low-dose CT resulted in the lowest effective radiation dose.

Conclusions:

• CT-based attenuation correction is a viable technique for cardiac PET imaging.
• Ultra-low-dose CT is recommended as the optimal transmission scan protocol for cardiac PET/CT.