PT  - JOURNAL ARTICLE
AU  - Okamoto, K.
AU  - Furusawa, T.
AU  - Ishikawa, K.
AU  - Sasai, K.
AU  - Tokiguchi, S.
TI  - Focal T2 Hyperintensity in the Dorsal Brain Stem in Patients with Vestibular Schwannoma
DP  - 2006 Jun 01
TA  - American Journal of Neuroradiology
PG  - 1307--1311
VI  - 27
IP  - 6
4099  - http://www.ajnr.org/content/27/6/1307.short
4100  - http://www.ajnr.org/content/27/6/1307.full
SO  - Am. J. Neuroradiol.2006 Jun 01; 27
AB  - BACKGROUND AND PURPOSE: The vestibular nucleus cannot be visualized on MR imaging, but some patients with vestibular schwannoma show a tiny area of hyperintensity in the dorsal brain stem on T2-weighted images. The aim of this study was to determine whether this tiny area is characteristic of vestibular schwannoma.METHODS: We retrospectively reviewed the postoperative MR images of 53 patients with cerebellopontine angle tumor. MR images were obtained with a 1.5T scanner. Spin-echo pre- and postcontrast 3-mm-thick T1-weighted axial images, 3-mm-thick fast spin-echo (FSE) T2-weighted axial images, and 0.8-mm-thick constructive interference in steady state (CISS) axial images were acquired. Surgical and histopathologic diagnosis was vestibular schwannoma (41/53 = 77%), meningioma (7/53 = 13%), epidermoid cyst (3/53 = 6%), glioma with exophytic growth (1/53 = 2%), and chordoma (1/53 = 2%).RESULTS: A tiny area of hyperintensity was observed at the lateral angle of the fourth ventricle floor in 6 patients (3 men, 3 women; age range, 24–54 years; mean age, 43 years) with vestibular schwannoma larger than 2 cm in maximal diameter on both FSE T2-weighted and CISS images. Preoperative MR images with the same pulse sequences showed the same area of hyperintensity in all these patients.CONCLUSION: Because the location of the area of hyperintensity is coincident with the vestibular nucleus, the hyperintensity may represent degeneration of the nucleus. This hyperintensity should not be confused with a postoperative lesion or a small infarction. If such hyperintensity is seen in a patient with a large cerebellopontine angle tumor, a diagnosis of vestibular schwannoma is suggested.