Purpose: To develop novel magnetic resonance (MR) imaging methods to monitor accumulation of macrophages in inflammation and infection. Positive-contrast MR imaging provides an alternative to negative-contrast MRI, exploiting the chemical shift induced by ultra-small superparamagnetic iron-oxide (USPIO) nanoparticles to nearby water molecules. We introduce a novel combination of off-resonance (ORI) positive-contrast MRI and T2r relaxation in the rotating frame (ORI-T2r) for positive-contrast MR imaging of USPIO. Materials and Methods: We tested ORI-T2r in phantoms and imaged in vivo the accumulation of USPIO-labeled macrophages at the infection site in a mouse model of burn trauma and infection with Pseudomonas aeruginosa (PA). PA infection is clinically important. The USPIO nanoparticles were injected directly in the animals in solution, and macrophage labeling occurred in vivo in the animal model. Results: We observed a significant difference between ORI-T2r and ORI, which leads us to suggest that ORI-T2r
OC. Andronesi, D. Mintzopoulos, V. Righi, N. Psychogios, M. Kesarwani, J. He, et al. (2010). Combined Off-Resonance Imaging and T2 Relaxation in the Rotating Frame for Positive Contrast MR Imaging of Infection in a Murine Burn Model. JOURNAL OF MAGNETIC RESONANCE IMAGING, 32(5), 1172-1183 [10.1002/jmri.22349].
Combined Off-Resonance Imaging and T2 Relaxation in the Rotating Frame for Positive Contrast MR Imaging of Infection in a Murine Burn Model
RIGHI, VALERIA;
2010
Abstract
Purpose: To develop novel magnetic resonance (MR) imaging methods to monitor accumulation of macrophages in inflammation and infection. Positive-contrast MR imaging provides an alternative to negative-contrast MRI, exploiting the chemical shift induced by ultra-small superparamagnetic iron-oxide (USPIO) nanoparticles to nearby water molecules. We introduce a novel combination of off-resonance (ORI) positive-contrast MRI and T2r relaxation in the rotating frame (ORI-T2r) for positive-contrast MR imaging of USPIO. Materials and Methods: We tested ORI-T2r in phantoms and imaged in vivo the accumulation of USPIO-labeled macrophages at the infection site in a mouse model of burn trauma and infection with Pseudomonas aeruginosa (PA). PA infection is clinically important. The USPIO nanoparticles were injected directly in the animals in solution, and macrophage labeling occurred in vivo in the animal model. Results: We observed a significant difference between ORI-T2r and ORI, which leads us to suggest that ORI-T2rI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
