PET/MRI is a technique that combines the molecular imaging capabilities of PET with the imaging capabilities of MRI, also known as PET-MRI. PET is a new imaging technique that uses positron emission computed tomography to show biomolecular metabolism, receptor and neuromediator activity through radionuclide labeling. MRI is an examination modality that utilizes a strong magnetic field and the body’s hydrogen nuclei, which are re-imaged by the magnetic resonance phenomenon produced by the action of specific radiofrequency pulses. PET/MRI is a new technology that integrates the detection advantages of PET with the imaging advantages of MRI, and is used to diagnose early tumors, tumor metastasis, cardiovascular and cerebrovascular diseases, etc., with high sensitivity, precise anatomical positioning and good accuracy. However, PET/MRI examination is expensive and requires high level of operation, which is not popularized in grassroots hospitals, so if you consider doing PET/MRI for health checkup or diagnosis of diseases, you need to go to a slightly larger hospital.