Dose and scanning delay using USPIO for central nervous system macrophage imaging
- 100 Downloads
Rationale and objectives: In experimental allergic encephalomyelitis (EAE), central nervous system (CNS) macrophage imaging is achievable by MRI using AMI-227 an ultra-small particle iron oxide contrast agent at a dose of 300 μmol/kg Fe. The objective was to test the feasibility at the human recommended dose of 45 μmol/kg Fe.Methods: Two groups of EAE rats were tested with AMI-227 using 45 and 300 μmol/kg Fe respectively. Following i.v. injection of AMI-227, they were scanned after a delay of 4–6 and 20–24 h.Results: With a high dose of AMI-227, all animals showed low signal intensity related to iron-loaded macrophages in the CNS. At low dose no abnormalities were found in the CNS. Furthermore, a delay of 4–6 h failed to demonstrate abnormalities even at high dose.Conclusions: Dose, scanning delay after administration and blood half-life are major parameters for T2* CNS macrophage imaging.
KeywordsMRI Allergic encephalomyelitis Macrophages Contrast agents
Unable to display preview. Download preview PDF.
- Anzai Y, Blackwell KE, Hirschowitz SL, Rogers JW, Sato Y, Yuh WTC, Runge VM, Morris MR, McLachan SJ, Lufkin RB. Initial clinical experience with dextran-coated superparamagnetic iron oxide for detection of lymph node metastases in patients with head and neck cancer. Radiology 1994;192:709–15.PubMedGoogle Scholar
- Guimareas R, Clément O, Bittoun J, Carnot F, Frija G. MR lymphography with superparamagnetic iron nanoparticles in rats: pathologic basis for contrast enhancement. AJR 1994;162:201–7.Google Scholar