A method for co-registering attenuation data of MR coils in a MR/PET imaging system with PET emission data includes computing a likelihood of PET emission data on a grid in a parameter space based on an algorithm, wherein the algorithm defines L(λ, μbody, μcoils{p}) as a log-likelihood of measured PET data, where λ is an emitter distribution (image), μbody is a known linear attenuation coefficient (LAC) distribution of the body from MRI, μcoils is a linear attenuation coefficient map of MRI coils, and {p} is a set of parameters governing the position of each coil, wherein if μcoils is assumed, then λ can be reconstructed and forward projected and L can be computed. The method includes adjusting the estimated position of the MR coils to maximize the likelihood of emission data based on the computed L.
Co-registering attenuation data and emission data in combined magnetic resonance/positron emission tomography (MR/PET) imaging apparatus