ABSTRACT

The integration of PET and MRI imaging, to make these devices simultaneously work in a single system has been an ongoing research project for at least 20 years. The incompatibility of MRI and PET was mainly due to the high magnetic field of the MRI device which interfered with the photomultiplier tubes of the PET systems and rendered it inoperable. Therefore, integrated PET/MRI systems developed much later than the integrated PET/CT systems. Over the years the PET/CT imaging modality gained popularity worldwide because of its high clinical availability and usability and of the valuable information it provided. After the development of avalanche photodiodes which are photodetectors that are insensitive to large magnetic fields this problem of interference was circumvented and simultaneous PET/MRI imaging was made possible. PET/MRI imaging is a very innovative method of imaging that has various advantages. PET/MRI integrated systems gives the opportunity to utilize the information from MRI which has high soft tissue contrast and spatial resolution and multi-parametric imaging properties and the valuable molecular information from PET simultaneously. Also, it decreases the dose of radiation that the patient is subjected to approximately 70-80 percent compared to PET/CT imaging which is beneficial especially in the pediatric age group and in circumstances where multiple imaging is required. The usage of FDG and especially other radiopharmaceutical agents (Ga-68-PSMA, Ga-68-DOTATATE, F-18-FDOPA, F-18-FLT, F-18-FET, F-18-FMISO ect) and the simultaneous evaluation of the information gathered about different biological processes using PET with the information from multiparemetric MRI images will pave the way for PET/MRI to be used as a primary diagnostic tool. We are happy to lead this process in our country as the first center to implement PET/MRI imaging in Turkey and amongst the 80 countries in our region and to share our experiences with the readers at this issue.