Effect of Attenuation Correction on Regional Quantification Between PET/MR and PET/CT: A Multicenter Study Using a...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Positron Emission Tomography/Magnetic Resonance (PET/MR) imaging may exhibit spatial bias compared to PET/Computed Tomography (PET/CT) due to MR-based attenuation correction.
• This study investigated methods to mitigate this bias.

Purpose of the Study:

• To evaluate if CT-based attenuation correction (CTAC) minimizes spatial bias in brain PET/MR imaging.
• To compare the performance of PET/MR and PET/CT systems using a standardized protocol.

Main Methods:

• An anthropomorphic brain phantom was used across 4 institutions with 3 PET/MR and 4 PET/CT systems.
• Regional analysis was performed on 8 gray matter volumes of interest (VOIs).
• CTAC was applied as the reference method for attenuation correction on PET/MR systems.

Main Results:

• CTAC minimized visual and quantitative differences between PET/MR and PET/CT systems.
• Intersystem variation was within acceptable ranges for both PET/CT and PET/MR.
• Differences between PET/MR and PET/CT systems were not statistically significant (P ≥ 0.05).

Conclusions:

• Accurate and standardized attenuation correction, such as CTAC, can minimize differences between PET/MR and PET/CT.
• PET/MR systems can achieve performance comparable to PET/CT with appropriate attenuation correction methods.