STUDY OF RELAPSING-REMITTING EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS SJL MOUSE MODEL USING MION-46L ENHANCED IN-VIVO MRI - EARLY HISTOPATHOLOGICAL CORRELATION

MION-46L, a superparamagnetic iron oxide contrast agent, was investiga ted for its ability to increase the sensitivity of in vivo 3D MRI in t he detection of brain lesions in a chronic experimental allergic encep halomyelitis (crEAE) mouse model. Lesion conspicuity on postcontrast 3 D MRI was dramatically enhanced as compared to precontrast images corr esponding to areas of inflammatory and demyelinating lesions. MION-46L could be detected on Prussian blue iron stain in the vascular endothe lium, the perivascular space, and in macrophages within perivascular c uffs and areas of inflammation and demyelination, By taking advantage of the MION-46L induced macroscopic susceptibility effect, acute early lesions measuring only 100 mu m in diameter could be detected. MION-4 6L enhanced MRI may be used to 1) provide a unique sensitivity in EAE lesion detection and correlate imaging to histopathology; 2) help to u nderstand EAE lesion development and its underlying pathophysiology; a nd 3) eventually assist in preclinical screening of new experimental t herapies directed at patients with multiple sclerosis (MS). (C) 1998 W iley-Liss, Inc. dagger.