LAUSR

The current standard-of-care imaging technique for the diagnosis of osteomyelitis is gadolinium-contrasted MRI (Gd-MRI). However, Gd-MRI has imperfect specificity for osteomyelitis because signal enhancement also occurs in the presence of Charcot joints and other forms of sterile inflammation. The diagnosis of osteomyelitis has substantial clinical implications; there is a 15–25% lifetime risk of diabetic foot infections in diabetic patients. These infections are the basis for more than half of the nontraumatic lower extremity amputations performed. Furthermore, the intravenous infusion of gadolinium salts in the presence of chronic kidney disease (CKD) can lead to incurable nephrogenic systemic fibrosis. Recent research has suggested that superparamagnetic iron oxide nanoparticles (SPIONs) present an attractive alternative to gadolinium-based contrast agents for the MRI-aided diagnosis of inflammation and infection. SPIONs are taken up by macrophages and give rise to negative T2-weighted MRI contrast (darkening) in areas of inflammation. Preclinical and clinical studies suggest that iron oxide nanoparticle-contrasted MRI may be superior to gadolinium in distinguishing active osteomyelitis from other sterile forms of inflammation. Ferumoxytol is a SPION preparation that has been approved by the Food and Drug Administration in the United States for intravenous use as an iron replacement drug for patients with CKD. Unlike gadolinium-containing preparations, ferumoxytol may be safely used in patients who have kidney disease, a common comorbidity in diabetic patients with osteomyelitis. The purpose of this pilot study is to determine if ferumoxytol given to patients with clinically suspected osteomyelitis would cause negative T2weighted MRI contrast changes. Materials and Methods