PET-MRI has the potential to find and diagnose certain complex malignancies, including cancers of the neck, pelvis, and neck, with a high level of accuracy and certainty. This technique allows doctors to provide better disease diagnosis and treatment planning, thereby improving patient care. It also allows doctors to monitor how certain drugs travel through the patient's body to determine proper bodily functions. Additionally, PET-MRI allows researchers to monitor stem cells (undifferentiated, biological cells) as they are maturing and differentiate (develop) into different body tissues.