以眼部症状首诊的良性颅内压增高的MRI影像学特征

目的 探讨以眼部症状首诊的良性颅内压增高（BIH）患者的眼部MRI影像特点。设计 回顾性病例系列。研究对象 65例经临床确诊的良性颅内压增高病例。方法 回顾性分析患者临床资料及颅脑、眼眶MRI数据，统计各主要影像征象在本组患者中出现的比例，比较各影像征象在特发性颅内压增高（IIH）、颅内静脉窦血栓形成（CVST）及细胞数增多的BIH之间的差异及MRI诊断与眼底镜检查结果的差异。主要指标 颅脑、眼眶MRI影像表现。结果 65例良性颅内压增高患者中，多数存在空蝶鞍（78.5%）、视神经周围蛛网膜下腔增宽（74.1%），其次是视乳头隆起（55.9%），视神经走行迂曲（37.3%）、眼球后壁后巩膜变扁平（34.0%）和视神经本身（粗细、信号、强化程度）异常（33.9%），小脑扁桃体下疝（7.7%）。视神经周围蛛网膜下腔增宽在IIH组发生率与CVST和细胞数增多的BIH均存在差别（χ2=10.161，P=0.001； χ2=6.065，P=0.014）。与眼底镜结果比较MRI检测视乳头水肿的敏感度52.8%，特异度58.3%。结论 除空蝶鞍外，视神经周围蛛网膜下腔增宽是以眼部症状首诊的BIH患者常见MRI表现，可单独或合并多种MRI征象出现。（眼科，2015, 24： 296-300）

MRI features of benign intracranial hypertension presenting with primary ocular symptoms

Objective To study MRI features of patients with benign intracranial hypertension(BIH) presenting with ocular symptoms as a chief complaint. Design Retrospective case series. Participants Sixty-five patients with clinical definite benign intracranial hypertension. Methods The orbit or craniocerebral MRI and clinical data of 65 patients were analyzed retrospecticvely. The incidence of each possible MR imaging sign in this group of BIH with ocular symptoms were recorded and the differences among idiopathic intracranial hypertension (IIH), cerebral venous sinus thrombosis (CVST) and pleocytosis caused intracranial hypertension (ICH) were compared. MR imaging sign and fundus examination findings were also compared. Main Outcome Measures Presence or absence of special abnormal MR findings in the orbit or craniocerebral MRI. Results The MR imaging disclosed empty sella in 78.4% of patients with BIH, distension of the perioptic subarachnoid space in 74.1%, intraocular protrusion of the prelaminar optic nerve in 55.9%,vertical tortuosity of the orbital optic nerve in 37.3%, flattening of the posterior sclera in 34%, abnormality of thickness and signal intensity and enhancement of the optic nerve in 33.9%, and cerebellar tonsillar hernia in 7.7%. The incidence of distension of the perioptic subarachnoid space in IIH was significantly different from that of CVST and pleocytosis（χ2=10.161，P=0.001； χ2=6.065，P=0.014）. Sensitivity and specificity of MRI examination for papilledema was 52.8% and 58.3% respectively. Conclusions  Elevated intracranial pressure produced a constellation of MR imaging signs in orbit. Besides empty sella, distension of the perioptic subarachnoid space is the most common promising MRI finding that may suggest BIH. This sign may provide valuable clues for further etiological diagnosis. (Ophthalmol CHN, 2015, 24: 296-300)