Differentiation of Bone Sarcomas and Osteomyelitis With Ferumoxytol-Enhanced MRI

BACKGROUND; In this study, T1, T2, and T2* represent parameters of magnetic resonance imaging (MRI).

The T1 relaxation time, also known as the spin-lattice relaxation time, is a measure of how quickly the net magnetization vector (NMV) recovers to its ground state in the direction of B0. T1 is assessed immediately post-contrast. A T1-weighted image (T1WI ) is one of the basic pulse sequences in MRI and demonstrates differences in the T1 relaxation times of tissues. A T1WI relies upon the longitudinal relaxation of a tissue's net magnetization vector (NMV).

T2 is a time constant for the decay of transverse magnetization arising from natural interactions at the atomic or molecular levels, and be considered the "natural" or "true" T2 of the tissue. However, in any nuclear magnetic resonance (NMR) experiment, transverse magnetization decays much faster than would be predicted by natural atomic and molecular mechanisms. Accordingly, T2 * is the time constant for the decay of transverse magnetization as observed in a tissue during a MRI scan, and be considered the"effective T2" (represented as T2*). T2* is always ≤ T2. In this study, T2 * is assessed after 24 hours.

OUTLINE:

Patients receive ferumoxytol intravenously (IV) and then undergo ferumoxytol-enhanced MRI up to 1 hour after infusion and up to 24 hours post-infusion.

PRIMARY OBJECTIVES:

• Establish magnetic resonance (MR) imaging characteristics of bone sarcomas and osteomyelitis based on their ferumoxytol-enhancement on relatively early post-contrast T1-weighted images.
• Establish MR imaging characteristics of bone sarcomas and osteomyelitis based on their ferumoxytol-enhancement on delayed postcontrast T2-weighted images.
• Establish T2-weighted MR imaging characteristics of iron-labeled mesenchymal stem cell (MSC) in osteonecrotic bone over time, before and after surgical core decompression and bone marrow implantation.
• Adding a second branch for patients who can not receive ferumoxytol but still getting the MRI exam. These patients will server as controls.

Inclusion criteria

• Age 10 to 21 years
• Suspected or confirmed diagnosis of a bone sarcoma or osteomyelitis
• Informed consent with assent as appropriate.

Exclusion criteria

• Contraindication to MRI
• Presence of metal implants
• Need for sedation or anesthesia
• Claustrophobia
• Hemosiderosis or hemochromatosis
• History of allergic reactions to similar compounds will be obtained and patients with positive history of allergic reactions will be excluded from the study
• Females who are pregnancy or nursing