Molecular Imaging Assessment of ACL Viability

This Phase I feasibility trial will evaluate knee injuries utilizing a standard of care non-contrast 3 Tesla (T) MRI. In addition, knee injuries will be assessed with a low dose (1/5 of the dose given for standard of care PET scans) fluorodeoxyglucose (FDG) PET research scan with CEST sequences. Patients enrolled in this study will include both those with and without a history of ACL repair; however, patients receiving the standard of care MRI will not be currently suspected of having an ACL injury based on physical examination and history. Patients with and without a history of ACL reconstruction will undergo a low dose FDG PET scan in the same setting as their MRI. The PET examination will be performed such that the early phase of imaging is performed prior to the MRI and the delayed phase is completed immediately following the MRI. This dual-phase scanning will allow for both assessment of the vascularity of the graft as well as its metabolic activity. Patients will be asked to provide study personnel with authorization to their medical records regarding the outcome of the knee graft. This authorization will be provided for 10 years from date of signed consent. Comparisons of the finding in normal and reconstructed ligaments as well as between graft types based on time from reconstruction will demonstrate the feasibility of this imaging technique and allow for generation of an imaging based hypothesis that will provide metabolic activity of the graft in a post-operative knee.