Purpose: To determine whether the bony and soft-tissue obliterations of the intralabyrinthine fluid spaces reported in pathologic studies of patients with Cogan syndrome can be detected with MR or CT.
Methods: The inner ears of six patients with Cogan syndrome were studied. High-resolution CT was performed in five patients; all six patients were studied with MR, including T1-weighted spin-echo images with and without gadolinium administration, T2-weighted spin-echo images, and three-dimensional Fourier transform constructive interference in steady state images.
Results: In two patients, small calcified obliterations were detected on CT but the three-dimensional Fourier transform constructive interference in steady state images revealed more extensive soft-tissue obliteration in five of the six patients. High signal inside the membranous labyrinth on precontrast T1-weighted images and contrast enhancement inside the membranous labyrinth on the postcontrast T1-weighted images were seen in one patient.
Conclusions: The study showed that calcific obliteration and soft-tissue obliteration of the intralabyrinthine fluid spaces in patients with Cogan syndrome can be demonstrated radiologically and that soft-tissue obliteration is more frequent than calcified obliteration. MR detected the intralabyrinthine disease far more frequently than did CT. The three-dimensional Fourier transform constructive interference in steady state sequence proved to be the most sensitive MR sequence. Hyperintensity inside the membranous labyrinth on the precontrast T1-weighted images and enhancement on the contrast-enhanced T1 images were less frequent and probably represent leakage through the abnormal labyrinthine membrane from active disease.