Pilot 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.