MAGNETIC-RESONANCE-IMAGING OF PERILYMPHATIC FISTULA

Perilymphatic fistula (PLF) is considered to be a most challenging oto logic issue. There are no currently agreed upon objective tests for th e diagnosis of PLF. In an effort to improve diagnostic accuracy in pat ients with suspected PLF, a novel diagnostic test involving magnetic r esonance (MR) contrast imaging was designed. An experimental PLF was c reated in the cochlear round window membrane of healthy adult cats. Si nce cochlear perilymph is thought to be an ultrafiltrate of cerebral s pinal fluid, gadodiamide (gadolinium-diethylenetriamine penta-acetic a cid [DTPA] bismethylamide), a nonionic paramagnetic contrast agent, wa s injected intrathecally in an attempt to enhance imaging of the creat ed fistula. Post-contrast images of the fistualized cochlea demonstrat e a significant increase in the signal intensity of the cochlear peril ymph with pooling of enhanced perilymph observed in the ipsilateral ma stoid bulla. Magnetic resonance contrast imaging may prove to be a val uable technique in human studies involving perilymphatic fistula.