Imaging of Osteonecrosis With Ferumoxytol-Enhanced MRI

The goal of the project is to evaluate osteonecrosis before and after decompression surgery with ferumoxytol-enhanced MRI. The investigators approach relies on the FDA-approved iron supplement ferumoxytol (Feraheme), which is used off label as a contrast agent for MRI. Ferumoxytol is composed of iron oxide nanoparticles, which provide a strong T1- and T2-signal on magnetic resonance (MR) images and are taken up by cells in bone marrow. 20 patients will undergo MRI before and after decompression surgery and transplantation of bone marrow derived cells. 10 patients will receive a single intravenous injection of ferumoxytol prior to their surgery. 10 additional patients will serve as untreated controls. The investigators hypothesize that MR images after intravenous injection of ferumoxytol will improve lesion detection and allow to track transplanted bone marrow cells. MR imaging findings will be correlated with clinical outcomes.