Gadofluorine M-enhanced magnetic resonance nerve imaging: Comparison between acu

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Exp Neurol. 2007 Nov 4

Gadofluorine M-enhanced magnetic resonance nerve imaging: Comparison

between acute inflammatory and chronic degenerative demyelination in

rats.

Wessig C, Jestaedt L, Sereda MW, Bendszus M, Stoll G.

Department of Neurology, University of Würzburg, f-Schneider-

Strasse 11, D-97080 Würzburg, Germany.

Nerve imaging by magnetic resonance imaging (MRI) is an emerging

tool for the diagnostic work-up of patients with PNS disorders. We

have recently shown that the experimental MR contrast agent

gadofluorine M (Gf, Bayer Schering Pharma AG, Berlin) accumulates in

nerves undergoing Wallerian degeneration and in areas of acute focal

demyelination allowing in-vivo assessment of nerve pathology. The

exact pathomechanism underlying Gf accumulation in peripheral nerve

disorders is unknown so far. In the present study we compared nerve

signal alterations on T2-w and Gf-enhanced T1-w MRI in two different

models of acute inflammatory and chronic degenerative demyelination:

experimental autoimmune neuritis (EAN) induced by immunization with

PNS myelin and experimental Charcot-Marie-Tooth (CMT) disease in

rats overexpressing the myelin protein PMP22. During the acute stage

of inflammation and demyelination, strong Gf enhancement on T1-w MRI

was seen in nerve roots and peripheral nerves in EAN, which resolved

with completed remyelination. Similarly, Gf accumulation was seen in

CMT rats during early stages with active demyelination at 6 weeks

while at chronic stages (9 months) Gf enhancement decreased despite

numerous demyelinated axons and onion bulb formation. At all disease

stages no signal alterations were seen on T2-w MRI. In conclusion,

our data show that the novel MR contrast agent Gf, but not

Gadolinium (Gd)-DTPA, facilitates detection of ongoing demyelination

by MR neurography independent from the underlying pathology. It

appears that the extent of Gf enhancement depends on the acuity of

demyelination and is probably related to a transient disturbance of

the blood-nerve barrier. Clinical development of Gf may help to

further improve the sensitivity of nerve lesion assessment by MRI in

patients with peripheral neuropathies.