Saeed S R, Woolford T J, Ramsden R T, Lye R H
University Departments of Otolaryngology, Manchester, UK.
Br J Neurosurg. 1995;9(4):497-503. doi: 10.1080/02688699550041133.
Magnetic resonance imaging (MRI) is currently the 'gold-standard' investigation in patients with a unilateral sensorineural hearing loss. The procedure, however, is expensive and of limited availability. Instead, such patients often undergo a series of audiovestibular tests and computed tomography in an attempt to exclude or diagnose a vestibular schwannoma. We describe seven cases of unilateral vestibular schwannoma in which conventional assessment was either equivocal or failed to demonstrate a tumour subsequently diagnosed by magnetic resonance imaging. Two patients with neurofibromatosis type 2 are also reported to show how magnetic resonance imaging confirmed the presence of a second vestibular schwannoma despite CT that showed only a unilateral lesion. We also illustrate how limited protocol MRI of patients is slightly more expensive yet much more cost effective than the usual battery of tests and propose that it should be the first line investigation for patients in whom the clinical picture requires exclusion of a retrocochlear lesion. Not all of these early diagnosed tumours have been immediately removed. In some of the more elderly or infirm patients a 'wait and rescan' policy has been adopted. Nevertheless, the early establishment of the correct diagnosis facilitates the subsequent management of these patients.
磁共振成像（MRI）目前是单侧感音神经性听力损失患者的“金标准”检查方法。然而，该检查费用高昂且可用性有限。相反，此类患者常接受一系列听前庭测试和计算机断层扫描，以试图排除或诊断前庭神经鞘瘤。我们描述了7例单侧前庭神经鞘瘤病例，其中常规评估结果不明确或未能显示出随后经磁共振成像诊断出的肿瘤。还报告了2例2型神经纤维瘤病患者，以展示磁共振成像如何证实存在第二个前庭神经鞘瘤，尽管CT仅显示单侧病变。我们还举例说明，患者的有限方案MRI虽略贵，但比通常的一系列检查更具成本效益，并建议对于临床表现需要排除蜗后病变的患者，它应作为一线检查方法。并非所有这些早期诊断出的肿瘤都立即被切除。在一些年龄较大或身体虚弱的患者中，已采用“等待并重新扫描”的策略。尽管如此，正确诊断的早期确立有助于这些患者的后续管理。
