This is a Phase II (determine the safety and response of a drug) study that is looking at how long the contrast agent Gadopiclenol stays in the plasma (part of blood not including red cells) after a single injection during an MRI in children aged up to and including 23 months. Gadopiclenol is an investigational drug, which means that it is not approved by the FDA. This study will be assessing the safety of gadopiclenol for up to 3 months following the administration of gadopiclenol at the MRI, and will evaluate the quality of the images obtained from when gadopiclenol was used at the MRI. Blood samples will be collected three times within the 8 hours following the MRI for analysis of how much gadopiclenol is left in the blood.

Twelve patients with osteoarthritis of the knee will undergo Geniculate Artery Embolization for treatment of knee pain. Prior to the procedure, patients will undergo MRI imaging of the affected knee which will include contrast enhanced images and dynamic contrast enhanced images. The MRI will measure the degree of abnormal blood flow in the synovial lining of the knee joint as well as change in the knee joint structure found in osteoarthritis. Patients will be followed at 1, 6, and 12 months after the procedure, and knee pain as well as medication usage will be assessed at each interval. At the 6-month visit, patients will undergo a second MRI with contrast that will be used to compare the changes in blood flow and knee joint structure.