Mechanisms of Accumulation of Small Particles of Iron Oxide in Experimentally Induced Osteosarcomas of Rats: A Correlation of Magnetic Resonance Imaging and Histology

Abstract

The findings help to advance the understanding of the distribution and kinetics of intravenous-injected small particles of iron oxide in osteosarcoma-like tumors. A first-pass accumulation of iron oxide could be documented by MR imaging in the periphery of osteosarcomas. Due to sieving of iron oxide particles by liver, spleen, and bone marrow, the signal intensity at 45 minutes after the injection of iron oxide returned to 89% (150 mumol iron oxide/kg) and 95% (50 mumol iron oxide/kg) of the preinjection intensity.

Superparamagnetic iron oxide contrast agents: physicochemical characteristics and applications in MR imaging

“…USPIO may accumulate in a zone of inflammation outside the tumor margin. A hypointense zone outlined the tumor margins on post-contrast T2W imaging improved visualization of the soft tissue component of the larger lesions [52,53].…”

Detection of Synovial Macrophages in an Experimental Rabbit Model of Antigen-induced Arthritis: Ultrasmall Superparamagnetic Iron Oxide–enhanced MR Imaging

“…Most authorities agree that the iron particles permeate through capillary walls into the interstitial spaces at sites of inflammation, where the particles are phagocytosed by phagocytic-active macrophages of the inflamed tissues (absorbtive endocytosis) (8,41,42). In addition, the duration of USPIO intravascular residency is long enough to allow phagocytosis of the particles already within the vascular space by macrophages, which are attracted by the inflammatory process (43).…”