Evaluation of attenuation correction in cardiac PET using PET/MR

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiology

Background:

• Simultaneous Positron Emission Tomography/Magnetic Resonance (PET/MR) imaging offers research and clinical potential.
• Cardiac PET acquisition requires validated MR imaging for attenuation correction (AC).

Purpose of the Study:

• To evaluate the feasibility of using a standard 2-point Dixon volume interpolated breathhold examination (VIBE) MR sequence for AC in simultaneous PET/MR cardiac imaging.

Main Methods:

• Phantom and patient studies were conducted using both PET/MR and PET/CT scanners.
• 30 patients underwent whole-body 18F-fluorodeoxyglucose PET/CT followed by simultaneous cardiac PET/MR.
• A chest phantom with heart, lungs, and lesion insert was utilized.

Main Results:

• Phantom study indicated a 3% reduction in myocardial activity values due to the exclusion of the phased array coil in AC.
• Patient scans (n=30) demonstrated no significant difference in average standardized uptake values (SUVs) between PET/CT and PET/MR (4.6 ± 3.5 vs 4.7 ± 2.8, P=0.47).
• An excellent per-patient correlation (R² = 0.97) was observed between PET/CT and PET/MR values.

Conclusions:

• Myocardial SUVs from PET imaging using MR for AC correlate excellently with those from standard PET/CT.
• The 2-point Dixon VIBE MR technique is feasible for AC in simultaneous PET/MR data acquisition.