According to Gd-MRI evaluation, a total of 92 ears from 78 patients were diagnosed with endolymphatic hydrops, there were 8 definite bilateral MD (hydropic ears,
n = 16), 6 definite unilateral MD (hydropic ears both in affected sides and contralateral asymptomatic sides,
n = 12), 62 definite and 2 probable unilateral MD (hydropic ears in affected sides,
n = 64). A total of 90 ears from 77 patients were diagnosed with no endolymphatic hydrops, there were 62 definite and 2 probable unilateral MD (non-hydropic ears in contralateral unaffected sides,
n = 64), 1 patient with definite MD and 12 patients with probable MD (non-hydropic ears in bilateral sides,
n = 26). High jugular bulb (HJB) was evaluated in the following 2 groups: i) Hydropic ears, including 92 ears from 78 patients (43 females and 35 males; aged 18–78 years; mean age, 48.5 years); ii) non-hydropic ears, including 90 ears from 77 patients (41 females and 36 males; aged 26–78 years; mean age 49.6 years). No statistical difference in age or sex was identified between the hydropic and non-hydropic ears (
P > 0.05). Table
1 shows the presence of different types of HB based on the Manjila and Semaan classification system for JB [
17]. The overall incidence of HJB, including types 2, 3 and 4 was 36 (39.1%) in hydropic and 31 (34.4%) in non-hydropic ears, which was not statistically significant (
P = 0.512). In addition, no statistically significant differences in the frequency of types 1, 2 and 3 JB were observed between the hydropic and non-hydropic ears (P = 0.512,
P = 0.556 and
P = 0.805, respectively). However, a significant difference in the presence of type 4 JB was observed between hydropic and non-hydropic ears (
P = 0.018). Table
2 shows the anatomical variables investigated in 36 hydropic and 31 non-hydropic ears with HJB, including types 2, 3 and 4. The mean ± standard deviation of the JB height was 9.2 ± 3.4 mm in hydropic and 6.6 ± 2.1 mm in non-hydropic ears. There was a significant difference in the average height of the JB between the values in two groups (
P = 0.000). The mean ± standard deviation values of the anteroposterior and mediolateral diameters of the JB were 8.2 ± 2.2 mm and 9.2 ± 2.4 mm in hydropic ears, and 8.5 ± 1.9 mm and 8.8 ± 2.2 mm in non-hydropic ears, respectively. There were no differences in the mean anteroposterior (
P = 0.556) or mediolateral diameters of the JB (
P = 0.482) between two groups. The non-visualization of the external aperture of the VA in the Pöschl plane was found in 9 hydropic and 2 non-hydropic ears, which was statistically significant (
P = 0.041). The presence of JB diverticulum or dehiscence with a VA was detected in 11 hydropic and 8 non-hydropic ears. There was no difference in the frequency of JB diverticulum or dehiscence between the two groups (
P = 0.666). The anatomical relationship between VA and HJB, as determined by 3DRC, was classified into types I, II and III. Type I was identified in 25 hydropic ears and 27 non-hydropic ears, and type II was identified in 6 hydropic ears and 4 non-hydropic ears. There was no statistically significant difference in the presence of types I (
P = 0,084) and II (
P = 0.666) between the two groups. Type III was identified in 5 hydropic and no non-hydropic ears. A statistically significant difference was observed in the presence of type III between the two groups (
P = 0.031). Moreover, all type IIIs were found in hydropic ears with type 4 JB.
Table 1
The presence of different types of JB classified by Manjila and Semaan [
13] in 92 hydropic ears and 90 non-hydropic ears
Type 1 | 56 (60.9%) | 59 (65.6%) | P = 0.512 |
Type 2 | 21 (22.8%) | 24 (26.7%) | P = 0.556 |
Type 3 | 7 (7.6%) | 6 (6.7%) | P = 0.805 |
Type 4 | 8 (8.7%) | 1 (1.1%) | P = 0.018 |
Table 2
Comparison of variables investigated in 36 hydropic ears and 31 non-hydropic ears showing HJB including type 2, type 3 and type 4
Height of the JB (mm), Mean ± SD | 9.2 ± 3.4 | 6.6 ± 2.1 | P = 0.000 |
Anteroposterior diameter of the JB (mm), Mean ± SD | 8.2 ± 2.2 | 8.5 ± 1.9 | P = 0.556 |
Mediolateral diameter of the JB (mm), Mean ± SD | 9.2 ± 2.4 | 8.8 ± 2.2 | P = 0.482 |
Nonvisualization of the Pöschl plane external aperture of VA (n, %) | 9 (25%) | 2 (6.5%) | P = 0.041 |
Presence of diverticulum or dehiscence with vestibular aqueduct (n, %) | 11 (30.6%) | 8(25.8%%) | P = 0.667 |
Anatomic relationship between VA and HJB on 3DCT (n,%) |
Type I | 25 (69.4%) | 27 (87.1%) | P = 0.084 |
Type II | 6 (16.7%) | 4 (12.9%) | P = 0.666 |
Type III | 5(13.9%) | 0 (0%) | P = 0.031 |