Effective methods to correct contrast agent-induced errors in PET quantification in cardiac PET/CT.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Combined positron emission tomography/computed tomography (PET/CT) utilizes CT for X-ray attenuation correction.
• Iodine-containing contrast agents in CT scans can introduce artifacts into attenuation maps.
• These artifacts lead to inaccurate radioactivity distribution in corrected PET images.

Purpose of the Study:

• To evaluate two CT data thresholding methods for correcting contrast agent-induced artifacts in PET/CT.
• To assess the impact of these methods on PET quantification accuracy.

Main Methods:

• Simulated cardiac torso phantom data and patient data were used.
• Two electrocardiography-gated CT scans (with and without contrast agent) were acquired from patients with coronary artery disease.
• Positron emission tomography (PET) scans using (18)F-FDG were performed.
• Contrast-enhanced CT data were processed using two thresholding methods before PET attenuation correction.

Main Results:

• Using contrast-enhanced CT data for attenuation correction overestimated regional radioactivity in the heart.
• Patient data showed a mean decrease of 23% in the left ventricular wall after correction.
• The proposed compensation methods reduced quantification errors to below 5%.

Conclusions:

• Contrast-enhanced CT significantly impairs PET quantification in cardiac PET/CT.
• The developed CT correction methods effectively reduce contrast agent-related artifacts.
• The user-independent method is time-efficient and accurate for artifact correction.