Gd-enhanced MR imaging of acute and chronic experimental demyelinating lesions.
Experimental allergic encephalomyelitis, a demyelinating disease with marked similarity to multiple sclerosis, was produced in two of 12 dogs. All dogs were studied with serial MR imaging. T1- and T2-weighted MR images were obtained both before and after IV Gd-DTPA. Multiple, new periventricular white matter demyelinating lesions were observed after each clinical episode of the disease. Like multiple sclerosis, the acute lesions of experimental allergic encephalomyelitis on T2-weighted MR images were indistinguishable from the older, more chronic lesions. However, after Gd-DTPA, there was bright paramagnetic enhancement of the acute lesions and, in one animal, no enhancement of the chronic lesions on T1-weighted MR images. At necropsy, the differences in the MR paramagnetic enhancement correlated well with the relative histologic age of the demyelinating lesions. Our results suggest that MR with Gd-DTPA may be used to differentiate acute, active demyelinating lesions from the more chronic, inactive lesions in this animal model.
D000208:Acute Disease; D000818:Animals; D002908:Chronic Disease; D003287:Contrast Media; D004285:Dogs; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000175:diagnosis*; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds; D004369:Pentetic Acid
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D019786:Gadolinium DTPA