ML-reconstruction for TOF-PET with simultaneous estimation of the attenuation factors

In positron emission tomography (PET), attenuation correction is typically done based on information obtained from transmission tomography. Recently, it has been shown that stable maximum-likelihood reconstruction of both the attenuation and the activity from time-of-flight (TOF) PET emission data is possible [1], [2]. Mathematical analysis revealed that the TOF-PET data determine the attenuation correction factors uniquely except for a scale factor [3].