眼内异物CT定位图的设计和应用

目的 评价眼内异物CT定位图在眼内异物定位中的有效性和准确性。方法 参阅CT水平或冠状扫描序列片将显影异物按照测量结果标画在相应的眼内异物CT定位图上，然后根据异物所在的经线和深度进行手术摘出异物。结果 47例(47眼)眼内异物中，有40例为眼内磁性金属异物，采用此法定位，全部迅速、准确地摘出异物。结论 眼内异物CT定位图应用在眼内异物的定位中，简便易行、迅速准确，特别适用眼内磁性金属异物定位。     

磁共振成像与CT在眼内非磁性异物诊断和定位中的比较

目的探讨磁共振成像（ｍａｇｎｅｔｉｃｒｅｓｏｎａｎｃｅｉｍａｇｉｎｇ，ＭＲＩ）和ＣＴ在眼内异物诊断和定位中的特点。方法以手术结果作为验证标准，比较２８例（４２枚）眼内非磁性异物在ＭＲＩ和ＣＴ图像上的显示及定位情况。结果４２枚眼内非磁性异物，ＭＲＩ和ＣＴ的检出率分别为９０．５％和９５．２％（ｘ２检验，Ｐ＞０．５）。ＭＲＩ与ＣＴ显示异物位置的准确率分别为８９．５％和６０．０％（ｘ２检验，Ｐ＜０．０５）。结论ＭＲＩ可用于眼内非磁性异物的诊断和定位，检出率高，在揭示异物与眼内组织的位置关系及显示眼内非磁性低密度异物方面优于ＣＴ，但对于眼球壁异物的显示则不如ＣＴ可靠。ＭＲＩ不宜用于眼内磁性异物的检查。     

Hyphema caused by a metallic intraocular foreign body during magnetic resonance imaging

PURPOSE: To report a 63-year-old man with a retained intraocular foreign body who developed a hyphema during magnetic resonance imaging (MRI) of the brain. METHODS: Case report and review of the current literature on ocular injury caused by intraocular foreign bodies when subjected to an electromagnetic field. RESULTS: Our patient underwent a brain MRI, and the intraocular foreign body caused a hyphema and increased intraocular pressure. The presence and location of the intraocular foreign body were determined by computed tomography (CT). CONCLUSION: Magnetic resonance imaging can cause serious ocular injury in patients with ferromagnetic intraocular foreign bodies. This case demonstrates the importance of obtaining an occupational history, and, when indicated, a skull x-ray or CT to rule out intraocular foreign body before an MRI study.     

眼内磁性异物摘出的临床观察

探讨64排螺旋CT定位下眼球内磁性异物摘出的临床效果。 方法：对48例48眼眼球内磁性异物患者进行回顾性分析。其中32例巩膜探查摘出异物后,24例再行白内障超声乳化并人工晶状体植入术,8例行玻璃体切割,摘出异物的同时清除玻璃体积血或积脓。 结果：一期异物全部摘出。术后视力全部不同程度地提高。 结论：64排螺旋CT定位下眼球内磁性异物摘出是眼球内异物摘出的一种有效方法     

Intraocular lens implants (pseudophakoi) and steelwire sutures: a contraindication for MRI?

The strong magnetic field of the super-conducting MRI (Magnetic Resonance Imaging) apparatus could cause problems in the presence of metallic foreign material, such as the metal clips and loops of intraocular lenses and steel as suturing material. If the magnetic field were to induce movement this could be dangerous for the eye. In this study these materials were tested with the 0.5 Tesla MRI and a 1.0 Tesla permanent magnet. Intraocular lenses with a platinum clip, or metallic or plastic loops, and 5 × 0/6 × 0 steelwire used as suturing material experienced no magnetic movement or change of position in the strong magnetic field. Neither did these foreign materials have any effect on the images obtained (spin-echo pulse sequence, 0.5 T Gyroscan). No artefacts were produced, the normal MRI picture of the T₁ -T₂ calculated images, made with a special deticated eye surface coil, were obtained.     

内镜在眼内异物诊断及摘出中应用的实验研究

目的：探讨纤维内镜应用于眼内异物诊断及摘出手术的可行性。方法：家兔实验，纤维内镜自角膜缘外4mm巩膜切口插入玻璃体，对眼内异物，特别是定位困难、不易摘出的异物及非磁性异物进行直视下确诊并摘出。结果：60只实验兔眼球内的磁性与非磁性异物均成功摘出，经术后1月观察，其中7眼发生眼球萎缩，其余53眼基本正常。结论：内镜直视下诊断并摘出眼内异物是可行的，而且有迅速和准确的优点。     

眼前段微小异物UBM定位及异物摘出联合手术

目的：探讨眼前段微小异物的超声生物显微镜（UBM）定位的意义及异物摘出联合白内障摘出等手术的效果，方法：应用其他检查方法未能确定的12例眼前段微小异物，同时合并铁质沉着症，通过UBM检查，明确异物位置并采取异物摘出联合白内障囊外摘出，玻璃体切除，晶状体切除和／或人工晶状体植入手术。结果：12眼均顺利摘出异物，同期植入人工晶状体9眼中的8眼获得0．5以上良好视力，结论：高度怀疑眼前段微小异物，UBM检查是一种极好的定位方法：联合手术可使视力迅速恢复。     

边界位眼内异物4种影像学检查方法诊断价值比较

目的:评估眼部X线、B超、CT及MRI对边界位眼内异物的诊断价值。方法:回顾性分析51例边界位眼内异物患者的X线、B超、CT和MRI影像学检查资料,并与手术结果进行比较。结果:边界位眼内异物患者51例行X线平片检查35例,检出率74%,定位准确率69%;行B超检查40例,检出率92%,定位准确率89%;行CT检查31例,检出率100%,定位准确率100%;行MRI检查4例,检出率100%,定位准确率100%。结论:在边界位眼内异物的诊断和定位中,X线、B超、CT与MRI四种检查方法各有优势。联合应用多种影像学检查方法可为手术提供较为全面的信息。     

Orbital helical computed tomography in the diagnosis and management of eye trauma

OBJECTIVE: To prospectively determine the accuracy of helical computed tomography (CT) and multiplanar reconstruction and its value in surgical planning for the management of ocular trauma with suspected intraocular and orbital foreign bodies using surgical and clinical follow-up findings as the gold standard. DESIGN: Prospective, observational case series. PARTICIPANTS: Thirty-six patients with ocular trauma and suspected foreign bodies were studied. INTERVENTION: All patients were examined using a standardized scanning protocol with helical CT direct scanning in the axial plane and multiplanar reconstruction of coronal and sagittal planes. MAIN OUTCOME MEASURES: The images were analyzed for the presence and number of intraocular and orbital foreign bodies, anatomic location, and foreign body size. The surgical and clinical follow-up findings (contact lens examination, gonioscopy, indirect ophthalmoscopy and scleral depression, perimetry, color testing, measurement of size) were used as the gold standard to which the image results were compared. RESULTS: Helical CT showed a single intraocular foreign body in 14 patients, a single orbital foreign body in 9 patients, and multiple orbital foreign bodies in 2 patients. Intraocular or orbital foreign bodies were excluded in 11 patients. Twenty foreign bodies were correlated with surgical results. Surgical and clinical follow-up findings were in agreement with helical CT results regarding the detection and determination of the number of presumed foreign bodies. Localization to intraocular versus orbital compartment and proximity to the optic nerve was accurate in all patients. Determination of size of the foreign bodies on the helical CT images was reliable and repeatable. CONCLUSIONS: Helical CT axial scanning with multiplanar reconstruction is accurate at detecting and localizing intraocular and orbital metallic, glass, and stone foreign bodies. This imaging method aids the surgeon in choosing the surgical approach to retained intraocular and orbital foreign bodies.     

Management of magnetic intravitreal foreign bodies in 71 eyes.

BACKGROUND AND OBJECTIVE: To evaluate the management of a series of eyes with magnetic intravitreal foreign bodies. PATIENTS AND METHODS: This retrospective review examined consecutive cases of ocular injury associated with intraocular foreign bodies; 71 eyes included had a single metallic intraocular foreign body (< 5 mm) located in the vitreous cavity removed by external magnet or intraocular forceps. Variables included preoperative and postoperative visual acuity, retinal break formation, retinal detachment, presence of an afferent pupillary defect, intraocular pressure, entrance site, foreign body size, method of extraction, and time between occurrence and surgical extraction. RESULTS: Factors predictive of good visual outcome (visual acuity > 20/200) were: shortest interval between trauma and foreign body extraction, preoperative visual acuity of 20/200 or better, and absence of afferent pupillary defect. CONCLUSIONS: In this nonrandomized study, good visual results could be obtained in eyes undergoing prompt foreign body removal, especially those with good preoperative visual acuity and no afferent pupillary defect.