Comparison of 18F FDG PET/CT TO PET MRI

Inclusion criteria 1. Subject must have a clinical indication for a PET/CT exam 2. Subject must be at least eighteen (18) years of age 3. Female subjects that are determined to be non-pregnant by a physician investigator or are demonstrated non-pregnant by negative urine pregnancy test administered within the 24 hour period before PET/CT imaging 4. Subject must be able to hear and understand instructions without assistive devices 5. Subject must provide written informed consent 6. Subject has the necessary mental capacity to understand instructions, and is able to comply with protocol requirements 7. Subject is able to remain still for duration of imaging procedure (approximately 60 minutes total for PET/MRI); and 8. Subject must be able to participate in a PET/MR imaging session within 1 hour of concluding their PET/CT exam. Exclusion criteria 1. Subjects who have any axial diameter larger than 55 cm 2. Subjects with a weight greater than 499 lbs 3. Subjects that have metallic/conductive or electrically/magnetically active implants without MR Safe or MR Conditional labeling, with the exception of dental devices/fillings, surgical clips, and surgical staples determined to be safe for MRI scanning by a physician investigator 4. Subjects that have implants with MR Unsafe labeling; 5. Subjects that have implants labeled as MR Conditional by the manufacturer for which the allowable conditions are not expected to be achieved by the MR/PET environment or scan protocol; 6. Subjects who have a contraindication to MRI per the screening policy of the participating site.