Combined Positron Emission Tomography and Magnetic Resonance Imaging: A Technical Challenge

A clinical prototype of combined Combined Positron Emission Tomography (PET) / Computed Tomography (CT) system went under the clinical evaluation in 1998. After three years of research and clinical evaluation first clinical combined PET/CT system was installed in a clinic in 2001 [1-3]. Gradually clinical utilization of combined PET/CT increased tremendously particularly in oncological imaging [3-6]. The success of PET/CT as a medical diagnostic device led to the development of other combined modality like SPECT/CT. the superiority of Magnetic Resonance Imaging (MRI) over CT as anatomical imaging device in providing unmatched soft tissue details along with a reasonable array of functional information through techniques such as MRI spectroscopy and functional MRI imaging has led to development of combined PET/MRI system. The first PET/MRI combined modality introduced in nuclear medicine practice for brain imaging to diagnose the complex disease processes based on improved and reliable anatomical and functional information provided by this combined system and gradually whole body PET/MRI is developed for clinical use [7]. Combining Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) in a single device was a challenging task as both the imaging device faced lots of interference from each other resulting in many new developments and changes in both the system [7-14]. Hence it is very important to understand the real technical problem faced by two systems in the process of combining with each other. Ways in Which PET Can Affect MRI