眼眶脑膜瘤的MRI诊断研究

目的：探讨眼眶脑膜瘤的发生部位、MRI的信号特征及鉴别诊断。方法：搜集经手术病理证实的眼眶脑膜瘤43例，行MRI扫描及增强脂肪抑制扫描，分析其发生部位与信号特征。结果：依据眼眶脑膜瘤的发生部位分为下列4种：①视神经鞘脑膜瘤，肿瘤呈不规则管状软组织增生，环绕视神经生长，等信号、T2WI及增强脂肪抑制成像显示肿瘤与视神经界限清楚。②眶壁(内)脑膜瘤，肿瘤呈宽基底等信号软组织块与眼眶壁紧贴，突向眶内，或位于肌锥内，边界清楚，增强明显。③蝶骨嵴脑膜瘤，肿瘤沿蝶骨嵴内外侧生长，向内侵犯眶内组织，向外累及翼腭窝。④眶颅沟脑膜瘤，肿瘤通过眶上裂、视神经管或骨质破坏缺损区呈哑铃形向眶内及颅内生长，等信号，增强显著。结论：应用合适的MRI扫描技术，可清晰准确地显示眼眶脑膜瘤的范围、部位、形态及信号特征，为临床手术治疗提供明确的定位、定性信息和诊断依据。     

眶内脑膜瘤的CT诊断

目的探讨眶内脑膜瘤的CT表现,提高其CT诊断水平。方法回顾性分析1997-10—2006-10在我院经手术及病理检查确诊的眶内脑膜瘤(原发或继发)17例CT表现和临床资料。结果视神经鞘脑膜瘤11例,眶骨膜脑膜瘤4例,蝶骨嵴脑膜瘤2例。增强扫描,病变大多数呈均匀性强化。"车轨征"、"套袖征"及眶骨增生性改变是眶内脑膜瘤较为特征性的征象。结论CT检查对眶内脑膜瘤的诊断具有重要价值。     

眶颅沟通性病变的CT和MRI研究

目的 研究、探讨眶颅沟通性病变的沟通路径、CT和MRI表现及其影像学特征。方法 51例患者,男28例,女23例,年龄2－68岁,平均41岁,为手术病理和随访结果证实。51例均行 CT扫描,45例行MR扫描,CT和MR增强扫描各44例。结果 通过眶上裂或视神经管沟通的颅眶沟通笥病变31例,占60.8％。其中9例通过视神经管沟通,包括4例视神经和视交叉胶质瘤、3例视神经鞘脑膜瘤,以及2例视网膜母细胞瘤侵犯视神经和视交叉;通过眶上裂沟通者,包括5例脑膜瘤、4例神经源性肿瘤、2例Tolosa-Hunt综合征、3例炎性假瘤、1例眼眶和海绵窦皮样囊肿,以及7例鼻咽癌同时侵犯海绵窦和眼眶,通过眶骨穿支血管间隙沟通的病变或骨质破坏缺损区沟通的眶颅沟通性病变20例,占39.2％,包括5例眶骨扁平性脑膜瘤、10例眶壁转移瘤、1例眶壁软骨肉瘤侵犯筛窦、额窦和额叶、3例泪腺囊腺癌侵犯颅内和1例额底脑膜瘤侵犯眼眶。结论 CT和MRI,尤其是使用脂肪抑制技术和增强扫描的T1WI能明确显示眶颅沟通性病变的沟通路径和病变特征,为制订治疗方案和手术入路提供重要和直接的依据。     

CT扫描对眼眶炎性假瘤的诊断价值

目的　探讨CT扫描对眼眶炎性假瘤的诊断价值。方法　对 2 1例经临床、病理及手术证实的眼眶炎性假瘤作回顾性分析。结果　CT征象包括眼球突出、眼外肌增粗、眼环增厚、视神经增粗、眶内脂肪密度增高、泪腺肿大、合并鼻副窦炎等。结论　CT扫描对眼眶炎性病变的诊断有重要价值。     

酷似海绵状血管瘤的眼眶海绵状淋巴管瘤的影像学表现

目的 探讨酷似海绵状血管瘤的眼眶海绵状淋巴管瘤的影像学表现.资料与方法 回顾性分析7例经手术病理证实的眼眶海绵状淋巴管瘤的CT和MRI表现以及MR动态增强扫描的特点.结果 7例均表现为眼眶椭圆形肿块,其中4例累及眼眶后部和眶尖,视神经明显受压移位.7例CT表现均呈等密度,密度均匀.MRI显示7例均呈略长T1长T2信号,信号不均匀,T2WI显示肿块内有散在的条状和小片状低信号.7例MR动态增强扫描都表现为"渐进性强化"征象,其中5例肿块强化范围扩大较快.结论 表现为眼眶内椭圆形肿块的海绵状淋巴管瘤与海绵状血管瘤非常相似,但肿块累及眼眶后部和眶尖及动态增强扫描显示肿瘤强化范围扩大较快高度提示肿瘤为海绵状淋巴管瘤.     

CT、MRI在眼眶炎性假瘤的诊断价值

目的:探讨CT和MRI对眼眶炎性假瘤的诊断和鉴别诊断价值。方法:回顾性分析经临床、病理证实的63例眼眶炎性假瘤的影像学表现。结果:根据病变累及部位及形态学表现分为:①隔前型2例,表现为眼睑肿胀;②巩膜周围炎型1例,表现为眼球壁增厚;③视神经束膜炎型3例,表现为视神经增粗;④弥漫型10例,病变可同时累及眶隔前组织、眼肌、视神经、眼环、泪腺、眶内脂肪或眶周组织;⑤肿块型12例,表现为边界清楚的肿块;⑥泪腺炎型9例,表现为泪腺肿大;⑦肌炎型26例,表现为1条或数条眼外肌增粗、肥大。结论:CT和MRI能对眼眶炎性假瘤确切定位及分型,为临床治疗方案提供重要依据,二者的结合极大地提高了眼眶炎性假瘤的正确诊断率。     

MRI平扫及增强三维重建技术在视神经损伤中的诊断

目的 探讨MRI三维重建技术在视神经损伤中的诊断价值.方法 13例视神经损伤病例分别行CT、磁共振平扫及增强扫描,并行脂肪抑制T2WI、 T1WI下三维重建.结果 13例视神经管内段和/或眶内段损伤中,CT仅显示视神经管骨折和/或眼眶骨折,视神经均未见异常表现.8例T1WI及T2WI表现为视神经管内段增粗、迂曲,视神经未见异常信号,5例脂肪抑制T2WI表现为视神经异常信号;13例病人经过脂肪抑制T2WI、T1WI平扫及增强扫描下三维重建,均有阳性表现.结论 MRI平扫及增强下三维重建技术在视神经损伤中具有重要的诊断价值.     

头颈部CT、MR扫描规范指南(修改稿)

CT扫描规范指南 一、眼眶 适用于眼部各类病变。 1．基本要求：扫描或重组体位及基线。横断面：扫描基线为听眶下线；冠状面：扫描基线为听眶下线的垂线；斜矢状面：重组基线平行于视神经。     

狭颅症的影像学诊断

目的:探讨狭颅症的X线、CT和MRI表现以及不同影像学检查方法对本病的诊断价值。方法:回顾性分析5例狭颅症患者的临床及影像学资料,包括X线、CT和MRI。结果:5例狭颅症,1例表现为舟状头畸形,2例表现为尖头畸形,2例表现为短头畸形,5例均可见脑回压迹加深,4例可见蝶骨体前移及眼眶变浅,1例尖头畸形CT扫描可见幕上脑室扩大,1例短头畸形CT扫描示颅骨内板呈波浪状凹陷,视神经孔变窄,双侧眼球明显突出,MRI扫描示双侧脑室轻度扩大,后颅窝显示狭窄,中脑导水管及四脑室轻度受压,后移。垂体变薄。结论:狭颅症影像学表现极具特征性,X线片具有较高诊断价值,CT和MRI对判断颅内继发改变和鉴别诊断具有一定价值。     

Graves病患者眼眶CT定量

Graves眼病的典型CT征有:眼外肌肥大、突眼、眶内脂肪体积增加、视神经拉长、眶内脂肪脱出。眼外肌作为该病眶内主要受累组织,它的体积和形状可用CT定量和客观的测量。为了确定正常眼外肌密度的CT值和定量估计Graves病患者眼外肌的密度、体积及眼球的位置,作者临床检查了100例无眼眶和甲状腺疾患的副鼻窦疾病病人的200个正常眼眶和87例经临床和实验室检查诊断为Graves病患者的174个眼眶(均未经眶内手术和放疗),用CT评估了眼外肌的密度、体积,眼球位置和视神经复合     

神经纤维瘤病眼眶受累影像学诊断(附12例分析)

目的：探讨神经纤维瘤病眼眶受累的影像学表现。方法：回顾性分析12例经病理或临床表现和影像学证实的神经纤维瘤病眼眶受累患者的影像学资料,12例均行眼眶CT检查,其中5例行CT增强,6例行MRI或增强检查。结果：12例神经纤维瘤病病例中,Ⅰ型8例,Ⅱ型4例。眼眶内受累10例,视神经受累2例,眼球内受累3例,眼环增厚伴点状钙化1例,泪腺2例,视神经孔2例,海绵窦2例,眼睑部6例。CT表现为眶内不规则形等密度影,眼球内半月形等密度影,视神经孔开大,邻近骨质缺损或增生硬化。T1WI上病灶呈等信号,T2WI上呈高信号,增强后中度增强。MRI增强后脂肪抑制序列更能清晰显示病变。结论：神经纤维瘤病眼眶受累的CT和MRI表现多种多样,结合临床和其他部位影像学资料,可提高其诊断符合率。     

CT在机械性眼外伤中的应用价值

目的：探讨CT在机械性眼外伤中的应用价值。方法：使用Somatom CR型CT机对75例机械性眼外伤患者进行横断位、冠状位扫描,采用骨窗和软组织窗对CT图像进行分析。结果：75例中框壁骨折64例,眼球缩小或变形3例,眼环不连续3例,玻璃体积血4例,晶状体脱出2例,球后血肿7例,外伤性白内障2例,视神经增粗7例,眼外肌增粗、移位17例,球内异物2例,眶内积气28例。结论：CT检查可较全面地观察机械性眼外伤后眼眶及内容物的损伤情况,为临床处理提供重要依据。     

Orbit deformities in craniofacial neurofibromatosis type 1

BACKGROUND AND PURPOSE: The possible relationship of orbit deformities in neurofibromatosis type 1 (NF1) to plexiform neurofibromas (PNFs) have not been fully elucidated. Our purpose was to review orbital changes in patients with craniofacial NF1. METHODS: We retrospectively reviewed CT and MR imaging abnormalities of the orbit in 31 patients (18 male, 13 female; mean age, 14 years; age range 1-40 years) with craniofacial NF1. RESULTS: Orbital abnormalities were documented in 24 patients. Six had optic nerve gliomas with enlarged optic canals. Twenty had PNFs in the orbit or contiguous to the anterior skull. The posterior orbit was distorted by encroachment from an expanded middle cranial fossa in 13 patients, and 18 had enlargement of the orbital rim. Other changes included focal decalcification or remodeling of orbital walls adjacent to PNFs in 18 patients and enlargement of cranial foramina resulting from tumor infiltration of sensory nerves in 16. These orbital deformities were sometimes progressive and always associated with orbital infiltration by PNFs. CONCLUSION: In our patients with craniofacial neurofibromatosis, bony orbital deformity occurred frequently and always with an optic nerve glioma or orbital PNF. PNFs were associated with orbital-bone changes in four patterns: expansion of the middle cranial fossa into the posterior orbit, enlargement of the orbital rim, bone erosion and decalcification by contiguous tumor, and enlargement of the cranial foramina. Orbital changes support the concept of secondary dysplasia, in which interaction of PNFs with the developing skull is a major component of the multifaceted craniofacial changes possible with NF1.     

Abnormal development of the lesser wing of the sphenoid with microphthalmos and microcephaly

We report two patients with abnormal development of the lesser wing of the sphenoid bone, globe, optic nerve and cerebral hemisphere without stigmata of neurofibromatosis type 1. The lesser wing of the sphenoid bone was abnormally formed and was not ossified ipsilateral to the dysmorphic eye and underdeveloped cerebral hemisphere. Maldevelopment of the sphenoid wing may interfere with the normal closure of the optic vesicle and normal growth of encephalic structures, possibly by disturbing developmental tissue interactions. These patients may exhibit a type of restricted primary sphenoid dysplasia, while the sphenoid dysplasia of neurofibromatosis type 1 may be secondary to orbital or ocular neurofibromas and other factors associated with that disease.     

神经纤维瘤病Ⅰ型的头颈部CT和MRI表现

目的 探讨神经纤维瘤病Ⅰ型(NF-1)的CT和MRI表现.资料与方法 回顾性分析33例经病理证实的NF-1患者的临床资料及头颈部CT、MRI特征.结果 单侧听神经瘤2例;单侧视神经瘤1例及单发凸面脑膜瘤1例;视神经增粗4例;眼球体积增大伴外凸(青光眼)6例;脉络丛粗大钙化3例;面颊部肿块2例;颌面骨及周围改变6例;蝶翼缺损及颞叶疝21例,其他部位颅骨缺损8例;颈深部肿块2例.结论 CT与MRI相结合能全面显示NF-1的头颈部病变,对NF-1具有重要诊断价值.     

Orbit: initial experience with surface coil spin-echo MR imaging at 1.5 T

Fifty-nine cases in which surface coil MR imaging of the orbit was performed were reviewed. MR imaging was performed with spin-echo techniques at 1.5 T with both short repetition time/echo time (TR/TE) and long TR/TE sequences in all cases. In all patients short TR/TE images were obtained with small-diameter surface coils; long TR/TE images were usually obtained with a standard head coil. Surface coil MR appears to be an important adjunct in state-of-the-art orbital imaging. Orbital MR imaging may be most useful, providing information not available on computed tomography (CT), in identifying lesions in the orbital apex, superior orbital fissure, and optic canal; differentiating inflammatory pseudotumor from malignancy in clinically similar patients; characterizing lesions containing hemorrhage or other paramagnetic material; defining the posterior extent of optic pathway gliomas; and detecting abnormal flow in intraorbital vascular structures. CT seems to be superior to MR imaging in the evaluation of small perioptic meningiomas, especially those that are calcified.     

Orbital "blow-in" fractures: clinical and CT features

During a 16 month period, seven patients were admitted to our trauma center with "blow-in" fractures of the orbital roof. This injury results from a significant direct blunt force applied to the supraorbital region of the frontal bone with transmission of energy to the thin orbital plate of this bone and displacement of bone fragments downward into the superior orbit. High resolution CT with multiplanar reformation and three-dimensional display proved very useful in identifying and characterizing the bone and soft tissue abnormalities found in our patients. Our experience suggests that CT demonstration of supraorbital frontal bone fractures and/or frontal lobe cerebral contusions is an indication for thin section CT of the entire orbit, even when there is no evidence of a superior orbital rim fracture. Demonstration of an orbital blow-in fracture should prompt careful clinical assessment of the globe, optic nerve, and extraocular muscles to identify and appropriately manage underlying injuries to these structures.