Feasibility of three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging as a prognostic factor in patients with sudden hearing loss

Abstract

The aim of this study was to confirm the feasibility of high signal on three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D FLAIR MRI) as one of the prognostic factors in recovery of sudden idiopathic hearing loss. A retrospective study was conducted using patients who were diagnosed with unilateral sudden idiopathic hearing loss from January 2008 to December 2010. A total of 120 patients were enrolled in for this study. High-intensity signal in the inner ear on precontrast 3D FLAIR MRI was observed in 31 patients (25.8%; FHS) and labyrinthine enhancement was not observed in another 89 patients (FNS; 74.2%). There was no significant difference in patients' characteristics between two groups except final hearing. Final puretone average of the FHS group was 49.4 dB, significantly worse than FNS group's 36.7 dB (p = 0.037 < 0.05). Final hearing was related to initial hearing, accompanying dizziness, and abnormal auditory brainstem response result by multiple regression analysis. However, presence of high-intensity signal on precontrast 3D FLAIR MRI did not affect final hearing significantly. Significant difference due to the presence of dizziness in final hearing was observed in whole patients and in the FHS group, whereas no significant difference in final hearing was observed in FNS group. (p = 0.063 > 0.05). From these findings, the presence of high-intensity signal on 3D FLAIR MRI is a subfactor related to dizziness rather than a single poor prognostic factor and the absence of high-intensity signal on 3D FLAIR MRI can possibly imply relative good prognosis.

Analysis of the 3-Dimensional Fluid-Attenuated Inversion-Recovery (3D-FLAIR) Sequence in Idiopathic Sudden Sensorineural Hearing Loss

“…Of the 13 3D-FLAIR-positive patients, 7 (54%) showed multiple subsites of high-intensity signal, while 6 patients (46%) had only 1 subsite of hypersignal (5 cases in the cochlea only, and 1 case in the cochlear nerve) (Figure 1). In 3 patients (23%), there was high-intensity signal in T1-weighted MRI images; in 3 patients (23%), a highintensity signal only in the 3D-FLAIR sequence; and in 7 From the combined analyses of T1 and FLAIR sequences, and from the findings of other researchers, 7,9,12 we identified 3 possible radiologic patterns:…”

“…However, this time interval was not consistently reported by all authors, and in particular, data are not available in the studies by Sone et al 15 and Lee et al 7 The time factor may be an element that significantly affects 3D-FLAIR MRI findings, which may be negative within 90-150 days after the onset of ISSNHL.…”

“…9 Also, 3D-FLAIR imaging can detect the BLB breakdown as the enhancement of the endolabyrinthic fluid signal and/or nerve signal after gadolinium injection owing to its high sensitivity to magnetic susceptibility. 7 In our experience 3D-FLAIR imaging is more sensitive to hematolabyrinthic and hematonervous barrier breakdown than T1 imaging, with fat suppression increasing the diagnosis accuracy.…”

“…Furthermore, our 3D-FLAIR MRI protocol had no significant technical differences from those used in the studies of Cadoni et al, 9 Yoshida et al, 14 Sone et al, 15 Ishida et al, 16 Tanigawa et al, 17 and Lee et al 7 Our mean (SD) delay between ISSNHL onset and 3D-FLAIR MRI (17 days [12]; range, 1-60 days) was similar to that already reported in literature, and in particular similar to the findings of Sugiura et al 4,12 (3-20 days). However, this time interval was not consistently reported by all authors, and in particular, data are not available in the studies by Sone et al 15 and Lee et al 7 The time factor may be an element that significantly affects 3D-FLAIR MRI findings, which may be negative within 90-150 days after the onset of ISSNHL.…”

The Technical and Clinical Features of 3D-FLAIR in Neuroimaging

“…63 Prognosis for hearing was not good in ears with a high signal on precontrast 3D-FLAIR. 65,66 Inflammation A signal increase in the labyrinthine fluid on 3D-FLAIR in various inflammatory diseases such as acute meningitis, acute otitis media, Wegener's granulomatosis, 27 mumps deafness, 26 RamsayHunt syndrome, [67][68][69] and labyrinthine fistula by a cholesteatoma 70 has been reported. Signal increase in the labyrinthine fluid on precontrast 3D-FLAIR suggests the presence of a small degree of hemorrhage or protein, and on post-contrast 3D-FLAIR, enhancement of the labyrinthine fluid suggests the active breakdown of the blood-labyrinthine barrier.…”