Enhanced attenuation correction in FDG-PET/CT with respiratory mismatch correction

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Computed tomography (CT) is crucial for attenuation correction in positron emission tomography/computed tomography (PET/CT).
• Respiratory motion can introduce artifacts (RMA) in up to 30% of PET/CT evaluations, often requiring rescans.
• Enhanced AC (EAC) is a novel reconstruction method designed to mitigate respiratory motion artifacts.

Purpose of the Study:

• To evaluate the effectiveness of the Enhanced AC (EAC) method in reducing respiratory misalignment artifacts (RMA) in PET/CT.
• To assess the utility of EAC through radiologist visual assessment and scoring.
• To determine if EAC is a practical solution for improving PET/CT image quality affected by respiratory motion.

Main Methods:

• Consecutive F-18 fluorodeoxyglucose (FDG) PET/CT cases with identified misalignment were included.
• Two radiologists independently assessed image deviation, designating cases for the misalignment group.
• Five radiologists scored PET images before and after EAC reconstruction using a 5-point misalignment scale.

Main Results:

• Fifty-four patients were identified with respiratory misalignment.
• Radiologists assigned significantly lower misalignment scores to EAC-reconstructed images compared to pre-EAC images (p < 0.01).
• Average misalignment scores decreased substantially with EAC, indicating improved image quality.

Conclusions:

• Enhanced AC (EAC) is an effective and practical method for reducing respiratory misalignment artifacts in PET/CT.
• EAC is easily adaptable for individual patients and suitable for routine diagnostic use.
• The method does not require extensive deep-learning datasets, facilitating its clinical implementation.