The multi modality molecular imaging has brought a new perspective into diagnostic imaging and advanced medical diagnosis considerably. Positron emission tomography (PET) is a powerful molecular imaging technique but, its inability in providing anatomical details is a major limitation for PET only systems. Combining functional imaging with anatomical imaging like computed tomography (CT) and magnetic resonance imaging (MRI) has tremendously helped in disease detection at the cellular and subcellular levels. The wide clinical adaptation of PET-CT techno logy shows the positive influence of multimodality imaging in clinical practice by providing complementary information in function and morphology. The PET technology has advanced significantly over the years alongside multidetector CT technology and now supports whole-body PET-CT imaging in less than 10 min. concurrently, the MRI modality has evolved in providing soft-tissue contrast, tumor detection, tissue characterization and some functional imaging capabilities.