ABSTRACT

Biomedical imaging plays an increasingly important role in primary staging, biopsy guidance, prognostic assessment, selection of treatment protocol, monitoring of treatment response and assessment of recurrent disease in medical oncology. Positron emission tomography/magnetic resonance (PET/MR) imaging which is the third major hybrid imaging modality after combined PET/CT and single-photon emission computed tomography combines high resolution anatomical and functional data of MR imaging with the quantifiable functional and molecular information provided by PET with fluorodeoxyglucose (FDG) and other radiotracers. This imaging modality can provide potential clinical advantages and higher diagnostic accuracy in tumor staging, assessment of therapy response and detection of recurrent disease. Furthermore simultaneous PET/MR imaging has practical advantages including reduced scanning time, improved coregistration, MR imaging-based motion correction. PET/MR imaging also has an advantage over PET/CT in decreasing ionizing radiation exposure especially in patients who require multiple PET imagings. MR imaging has the advantage of high soft tissue contrast, so PET/MR imaging can be used instead of PET/CT in evaluation of primary and metastatic brain tumors, head and neck cancers, breast tumors, abdominopelvic tumors, assessment of intramedullary lesions in hematological malignencies or it can be used as regional imaging method which will be complementary to PET/CT. PET/CT is preferred especially in MR imaging-contraindicated situaitons and assessment of small pulmonary nodules. PET/CT is also more clinically available than PET/MR imaging. In the future, standardization of PET/MR imaging protocols, technical optimizations, technological advances, detection of optimal clinical indications of whole body and regional PET/MR imaging, usage of highly spesific non-FDG PET tracers and additional value of multiparametric MR imaging data will clarify clinical availability this new imaging method.