Value of high resolution MRI in the evaluation of small intralabyrinthine lesions with the symptom of vertigo / 中华放射学杂志

ABSTRACT

Objective To discuss the value of high resolution MRI in the evaluation of small intralabyrinthine lesions with the symptom of vertigo. Methods We retrospectively analyzed the imaging examination techniques and imaging finding of 13 cases of labyrinthine hemorrhage or exudate and 6 cases of intralabyrinthine schwannoma (ILS) with the symptom of vertigo. Two cases of labyrinthine hemorrhage or exudate and 3 cases of ILS underwent temporal bone high resolution CT(HRCT) scan and all the 19 patients received highresolution MR examination. Patients of labyrinthine hemorrhage or exudate received fluid?attenuated inversion recovery (FLAIR)T2WI in addition to routine pre?contrast temporal bone MR. Pre?and post?contrast MR of the temporal bone were performed on the ILS patients. In particular, 3 ILS cases received three?dimensional sampling perfection with application?optimized contrasts by using different flip angle evolutions (3D?SPACE) sequence. Results There was no abnormal finding on HRCT of the inner ear of the 2 labyrinthine hemorrhage cases. On T1WI, regions of mild increased signal intensity of the labyrinth of affected side could be spotted in 7 patients whereas no abnormal signal intensity was found in the other 6 patients. On T2WI, all the 13 labyrinthine hemorrhage or exudate cases had no abnormal finding in the inner ear. On FLAIR T2WI sequence, regions of increased signal intensity of the labyrinth of affected side could be found in all the 13 cases. Thress ILS patients that received HRCT scan showed no valuable finding. On T1WI, no abnormal signal intensity was found in the labyrinth of the 6 patients. On T2WI, regions of decreased signal intensity of the labyrinth could be found in only 3 patients. All the 3 cases that received 3D?SPACE sequence appeared as a filling defect in the high?signal labyrinth clearly while 2 of the 3 lesions could not be found on T2WI. After Gadolinium administration, all the 6 ILSs were obviously enhancing. Conclusions High resolution MRI is valuable in the diagnosis of labyrinthine hemorrhage or exudate and ILS. The use of FLAIR T2WI sequence can help us to find labyrinthine hemorrhage or exudate more sensitively. The use of 3D?SPACE sequence can help us to detect and diagnose small intralabyrinthine lesions.