ABSTRACT
This chapter discusses some of those efforts that lead to the development of integrated positron emission tomography (PET) - magnetic resonance imaging (MRI) systems capable of simultaneous acquisition. PET and MRI are widely used in cardiovascular imaging and have very complementary attributes. MRI offers excellent anatomical and functional information, while PET provides highly sensitive readouts of molecular and metabolic processes. In the recent years, integrated scanners capable of simultaneously acquiring MRI and PET data have been developed, first for small-animal imaging and, more recently, for whole-body studies in humans. Organ deformations related to the physiologic cardiac and respiratory motion affect PET data quality and quantification in cardiac studies. MRI can provide high spatial resolution anatomic images with exquisite soft tissue contrast by exploiting the differences in relaxation times of protons in different biochemical environments. Preliminary testing demonstrated interference-free operation both on the magnetic resonance (MR) and PET side and very high PET sensitivity.
