Peter Herrick1, Richard Ansorge1,
Rob Hawkes2, Steve Sawiak2, Joe Stevick1,
1Cavendish Laboratory, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Wolfson Brain Imaging Centre, Addenbrooke's Hospital, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom
An engineering challenge of simultaneous PET/MR is to minimize and quantify the effect of RF coil hardware on PET signal intensity. This RF hardware is usually invisible in MRI, thus proposed segmentation methods for MR-based attenuation correction are not suitable. We have used Monte Carlo simulations of gamma-ray interactions to demonstrate the impact of structural components and coil positions on PET images. This shows that the adverse effects of using conventional RF coils can be dramatic, resulting in 25% loss of PET signal intensity and 0.5mm loss in spatial resolution. Quantitative measurements of uptake values are crucial for PET diagnosis.