Reimann Katrin, Klose Uwe, Ehrenpfordt Ulrike, Thangavelu Kruthika, Schulze Maximilian
Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany.
Department of Neuroradiology, University of Tübingen, Tübingen, Germany.
Otol Neurotol Open. 2024 Jan 25;4(1):e047. doi: 10.1097/ONO.0000000000000047. eCollection 2024 Mar.
High-resolution parallel transmit T2 sampling perfection with application optimized contrast using different flip angle evolution sequence with improved edge discrimination and semiautomatic determination of nerve cross-sectional area (CSA) can be used to evaluate nerve degeneration in the inner auditory canal (IAC) in long-term deaf patients.
In patients with hearing loss, temporal bone MRI is routinely acquired to evaluate the morphology of the nerves within the IAC. Earlier studies have shown that the diameter of the cochlear nerve can be used as prognostic marker for the auditory performance after cochlear implantation in postlingually deaf patients.
Eighty-two consecutive MRI scans were analyzed using a semiautomatic tool to measure CSA of cranial nerves in the IAC. Results were correlated with patient history and audiology testing as well as with age and gender.
There was a significant reduced CSA of the cochlear nerve in ears with moderate-to-profound hearing loss and deafness compared with ears with normal hearing, but no significant difference in ears with mild-to-moderate hearing loss compared with normal hearing. In detail, normal hearing ears had a CSA of 1.23 ± 0.11 mm, whereas ears with pantonal hearing loss of more than 40 dB had 1.02 ± 0.05 mm ( = 0.026). Maximal CSA of the facial nerve was not different among all groups (average, 1.04 mm ± 0.03; linear regression, = 0.001) and stable with age. However, vestibular nerve CSA decreased significantly with age (average, 1.78 ± 0.05 mm; linear regression, = 0.128).
In long-term deaf patients, smaller the diameter of cochlear nerve is the more severe the hearing loss is. The new semiautomatic tool can primarily be used to assess nerve diameter and possibly determine ears with nerve degeneration.
采用具有不同翻转角演进序列、优化对比度应用、改善边缘分辨能力以及半自动测定神经横截面积（CSA）的高分辨率并行发射T2采样完美序列，可用于评估长期耳聋患者内耳道（IAC）的神经退变情况。
在听力损失患者中，常规进行颞骨磁共振成像（MRI）以评估IAC内神经的形态。早期研究表明，在语后聋患者中，蜗神经直径可作为人工耳蜗植入后听觉表现的预后指标。
使用半自动工具分析82例连续的MRI扫描，以测量IAC内颅神经的CSA。结果与患者病史、听力学检查以及年龄和性别相关。
与听力正常的耳朵相比，中重度听力损失和耳聋耳朵的蜗神经CSA显著降低，但与听力正常的耳朵相比，轻度至中度听力损失的耳朵无显著差异。具体而言，听力正常的耳朵CSA为1.23±0.11mm，而听力损失超过40dB的耳朵为1.02±0.05mm（P=0.026）。所有组之间面神经的最大CSA无差异（平均为1.04mm±0.03；线性回归，P=0.001）且随年龄稳定。然而，前庭神经CSA随年龄显著降低（平均为1.78±0.05mm；线性回归，P=0.128）。
在长期耳聋患者中，蜗神经直径越小，听力损失越严重。这种新的半自动工具主要可用于评估神经直径，并可能确定存在神经退变的耳朵。
