A study of artefacts in simultaneous PET and MR imaging using a prototype MR compatible PET scanner

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) offers complementary molecular and anatomical information.
• Integrating PET and MRI presents technical challenges due to potential electromagnetic interference and magnetic field interactions.

Purpose of the Study:

• To evaluate potential artifacts and image quality degradation during simultaneous PET and MRI acquisition.
• To assess the performance of a prototype MR-compatible PET scanner (McPET) in a combined imaging setting.

Main Methods:

• MR images were analyzed for artifacts caused by PET system operation (magnetic field inhomogeneities, RF interference, susceptibility effects).
• PET images were assessed for artifacts induced by the MR system's static and time-varying magnetic fields and RF interference.
• Susceptibility artifacts from McPET components were examined using biological tissue and specific MRI sequences.
• Simultaneous PET-MRI scans of phantoms were performed across a range of magnetic field strengths (0.2-4.7 T).

Main Results:

• No significant artifacts or loss in image quality were observed in either PET or MR images during simultaneous acquisition.
• A minor reduction in signal-to-noise ratio was noted with gradient echo MRI sequences.
• The McPET scanner showed no detrimental interactions with the MR system across various field strengths.

Conclusions:

• Simultaneous PET and MRI acquisition is achievable without compromising image integrity.
• The prototype McPET scanner is suitable for high-quality, artifact-free simultaneous PET-MRI.