Intraorbital wood. Detection by magnetic resonance imaging

The authors present two cases in which intraorbital wooden foreign bodies remained undetected after initial ophthalmologic examination and radiologic investigation which included plain orbital x-rays, orbital computed tomography (CT) scans, and, in one case, orbital ultrasound. In each case, subsequent magnetic resonance imaging (MRI) showed a well-delineated low-intensity lesion suggestive of a retained foreign body. Investigation of a case of suspected wooden foreign body in the orbit should include an MRI scan if there is no contraindication, and no foreign body has been defined on CT scan, ultrasound, or plain orbital films.     

Orbitocranial injury caused by wood

A rare case of a patient with orbitocranial injury by a wooden foreign body is reported. Penetrating periorbital wound by a wooden stick with entry site at the right upper eyelid was related to the invasion into the temporal lobe. Fortunately, the anterior and posterior segments of eye were unharmed, but right ocular motility was markedly restricted mechanically in all directions. Forced duction test was strong positive, especially the dextroversion of the right eye. Computed tomography scan showed a well-delineated low density from the orbital wall into the temporal lobe. The wooden foreign body was subsequently removed from the orbit and the temporal lobe, through the neurosurgical frontotemporal approach. After the wooden foreign body was removed, the ocular movement of the right eye fully recovered without any intracranial or ocular complications.     

Intraorbital organic foreign body--a diagnostic challenge

Intraorbital organic foreign bodies pose a diagnostic and management challenge to ophthalmologists. A high degree of suspicion of an orbital foreign body is needed when patients present with injuries to the eyelids and orbit. We present a case of retained intraorbital wooden foreign body which was initially undetected. A 10-year-old boy presented to the eye casualty with signs and symptoms suggestive of orbital cellulitis. He was started on intravenous antibiotics and urgent CT of the orbits did not reveal any foreign bodies. There was spontaneous extrusion of a wooden foreign body through the upper lid two days later, followed by spontaneous resolution of symptoms. Wood has a density similar to air and fat and can be difficult to distinguish from soft tissue in both a plain X-ray film and a computed tomogram. Clinicians should be alerted to the possibility of retention of an intraorbital foreign body in all patients presenting with periorbital trauma. The clinician should also obtain a careful history of the type of injury and should examine the patient in detail. In cases where a wooden foreign body is suspected, investigation by magnetic resonance imaging is preferred.     

A case of retained wooden foreign body in orbit

A 41-year-old man visited our clinic complaining of esodeviation of the right eye. He had been operated on for corneal laceration 3 years before. One month later, exodeviation of the right eye had developed. The result of computed tomography (CT) was reported as orbital abscess and cellulitis. Although antibiotic treatment was administered for 2 weeks, the exodeviation didn't improve. On ocular examinations performed in our hospital in November-2001, his right eye was esotropic and had a relative afferent pupillary defect. Vision of the right eye was decreased to 0.02. Fundus examination showed optic atrophy. A new CT scan disclosed a foreign body introduced into the right medial orbital wall, nasal cavity and ethmoidal sinus. Although foreign body was surgically removed, vision and eye movement were not improved. In the case of a patient who has undergone orbital trauma, complete history taking and physical examinations must be performed. On suspicion of a foreign body, imaging study such as CT or MRI must be performed. However, because CT findings can be variable, careful follow-up is needed.     

Wooden spike orbital injury

A 71-year-old female patient fell in her garden, inducing a skin wound on the temporal left eyebrow. Skin disinfection and wound closure were performed elsewhere, an X-ray image did not reveal a foreign body. She was referred to our service three days later with a progressive left periorbital swelling. Clinical inspection demonstrated a painfully, fluctuant swelling around the wound with an inflammatory pseudoptosis of the left eye. Vision was reduced on the left eye; anterior and posterior segments of both eyes were unharmed. After opening the wound sutures a purulent liquid was drained and a wooden fragment was found, measuring 22 x 0.5 mm. Because of restriction of abduction of the left eye, magnetic resonance imaging (MRI) was performed, detecting another organic intraorbital foreign body and a fracture of the left medial orbital wall. Anterior orbitotomy was performed and a wooden fragment was removed, measuring 47 x 0.6 mm. Under administration of intravenous antibiotics vision and ocular motility recovered uneventfully. This case emphasizes the value of MRI in the diagnostics of retained wooden foreign bodies as well as the importance of a soigneuse inspection of skin wounds with a high risk for remaining foreign bodies.     

Magnetic resonance imaging and computed tomography in a model of wooden foreign bodies in the orbit

Wooden foreign bodies in the orbit are not detectable by standard roentgenography. Reports in the literature on the ability of computed tomography (CT) to detect orbital wooden foreign bodies have varied. To evaluate whether magnetic resonance imaging (MRI) would offer any advantage over CT in detecting wood in the orbit. MRI and CT were performed on an in vitro model of wooden foreign bodies in the orbit. Woods of different types and sizes were studied in vegetable fat backgrounds chosen to simulate orbital fat. On CT, most types of wood were hypodense to fat. Appropriate window settings were critical in the detection of wood by CT: in this model, a window width of 1000 Hounsfield units was optimal. On MRI, all types of wood were hypointense to fat. Small pieces of wood were surrounded by an MRI truncation artifact consisting of hyperintense spots. T1-weighted images demonstrated wood better than T2-weighted images and required less scanning time than either proton density or T2-weighted images, MRI was superior to CT in detecting the smallest pieces of wood. The role of MRI in the detection of orbital wooden foreign bodies in clinical practice remains to be determined.     

眼眶植物性异物的诊断和治疗

目的：通过对眼眶植物性异物的临床分析，该病最好的诊断和治疗方法。方法：复习我院收治的眼眶植物性异物21例,分析其各项检查及治疗方法。结果：眼眶瘘管形成占眼眶植物性异物的57．14％；B型超声检查异常者占64．70％，可提示异物存在者占41．18％；CT扫描异常者94．12％，可提示异物存在者占41．18％；2例行MRI检查均清晰地显示出异物影像，21例患者均手术取出异物，证实术前诊断。结论：眼眶植物性异物影像学检查显示率较低，对于显示异物，MRI优于超声和CT。正确诊断必须结合病史和眼部体征，尤其是眼眶瘘管的存在，手术摘出异物的同时需将瘘管一同切除，以求彻底治愈。     

眶内非金属异物25例临床分析

目的 总结眶内非金属异物的临床特征及诊治方法.方法 回顾性系列病例研究.收集2002至2009年经手术证实的眶内非金属异物患者资料25例,总结临床表现、影像学征象、治疗与随访结果.结果 外伤性异物23例,包括:植物性异物11例,玻璃、油脂和石块各3例,塑料笔头2例,爆竹残渣1例.另2例为医源性异物.特征性临床表现为眶周皮肤或结膜瘘道,共11例,发生率为44%,以植物性异物最为多见.CT征象因异物性质不同而各异.植物性异物在外伤早期呈低密度,随时间延长密度逐渐增高,压缩窗宽,异物显示更加清晰.油脂异物表现为与脂肪相近的低密度,石块和玻璃表现为高密度块影.植物性异物在MRI的T1和T2加权像均呈低信号,周围的脓液在T2加权像呈环形高信号影,异物周围的炎性组织强化明显.油脂异物在T1和T2加权像均呈高信号,脂肪抑制显像呈低信号.所有患者均在全身麻醉下接受眶内异物清除术,均经一次手术清除全部异物及周围腐烂组织,感染伤口一期不予缝合.术后半年随访,伤口愈合良好,症状改善,未见与手术相关并发症.结论 眶内非金属异物种类较多,病情复杂各异,处置不当易眶内残留.CT为首选检查方法.正确认识病史及临床表现,运用恰当的手术技巧,彻底清除异物,预后良好.

Abstract：

Objective To evaluate the clinical features,diagnostic methods and treatment of intraorbital nonmetallic foreign body injuries. Methods In a retrospective study,the records of 25 consecutive cases with nonmetallic foreign bodies in the orbit confirmed by surgery were analyzed with special attention to the types of injury,history,clinical manifestations,imaging findings,treatment and follow-up results. Results Among 25 cases with nonmetallic foreign bodies,23 cases were caused by trauma,including 11 cases with wooden bodies,3 cases with glass,grease,or stone,2 cases with plastic pen point,and one case with firecrackers. The remaining two cases had iatrogenic foreign bodies. The distinctive clinical manifestation was the periorbital fistula recorded in 11 (44%) cases,mostly in patients with wooden foreign bodies. The CT findings were different in various foreign bodies. The wooden foreign bodies showed low density in the acute stage and the density increased gradually from the acute to the chronic stage. CT images with lower windows could distinguish a wooden foreign body better. The grease was seen as low density mimicking orbital fat on CT. The stone or glass showed as masses with high density. Wooden foreign bodies displayed low signals on both MRI T1- and T2-weighted images. The surrounding pus was seen as a ring with high signal on T2-weighted images. The inflammatory infiltration showed marked enhancement. The grease displayed high signal on both T1- and T2-weighted images and showed lower signal than that of the fat. All patients underwent surgical removal of retained foreign bodies and the surrounding decomposed tissues. The infected wounds were not sutured at one stage operation. After follow-up for 6 months,all wounds healed normally and all patients recovered well No complications were encountered.Conclusions There are various types of intraorbital nonmetallic foreign bodies. The clinical manifestations of these different foreign bodies are complex. CT is the preferred examination for this condition. With the combination of correct diagnosis,proper surgical skills,and complete removal of foreign bodies and surrounding decomposed tissues,nonmetallic foreign bodies can be treated efficiently.     

An extraordinary orbital foreign body

The authors report a unique case of a broken motorbike handle that presented as a bilateral orbital foreign body. A 30-year-old male sustained an injury to the right side of his face when he skidded from his motorbike while riding. He had bilateral sudden loss of vision and presented to emergency services with bilateral proptosis, motility restriction, and a right lower eyelid laceration. CT scan revealed a 7-cm-long motorbike handle lodged in the retrobulbar space of both orbits, close to the cribriform plate. Left lateral orbitotomy was performed to remove the foreign body; the right eye regained normal vision and function. The unique features of this case include the nature of the foreign body, its bilateral location, its proximity to the optic nerve and cribriform plate, and the challenges in its removal. The clinical presentation and management is presented, along with the surgical video.     

Magnetic resonance imaging and computed tomographic scanning of fresh (green) wood foreign bodies in dog orbits

Wooden foreign bodies in the orbit can extend into the intracranial cavity without diagnostic clues from the small eyelid entrance wound, from neurologic examination, and from imaging studies such as ultrasound, plain x-rays, or computed tomography (CT) scans. In cadaver magnetic resonance imaging (MRI) studies, dry wood in the orbit can be seen as a negative or hypointense image in contrast to orbital fat. We studied fresh, green wood in dogs to determine the reliability of CT and MRI scans to image hydrated wood. Wood was placed into each orbit of two dogs. After 24 h the wood was removed from one orbit, but not the other. The dogs were then scanned with CT and MRI. Radiologists were asked to determine if any wood had been left in either or both orbits. The fresh wooden foreign bodies could not be detected despite an intensive effort. MRI does not appear to reliably demonstrate fresh wood in the orbit. MRI can show dry wooden foreign bodies that have not become hydrated, but has not yet been reliable in the clinical situation to rule out the presence of wood in the orbit.     

眼眶植物性异物的影像学表现

目的分析眼眶植物性异物的影像学表现,为临床治疗提供帮助。设计回顾性病例系列。研究对象手术证实眼眶内植物性异物患者10例。方法对10例眼眶植物性异物患者行CT检查,轴位CT扫描5例、冠位CT扫描1例,轴位 冠位CT扫描4例。2例行MRI。对上述病例的影像学表现进行回顾性分析。主要指标眼眶植物性异物的急性期、亚急性期和慢性期的CT和MRI表现。结果急性期2例CT显示植物性异物为低密度,周围无软组织增生;亚急性期4例(包括1例上述急性期病例转为亚急性期者)CT显示植物性异物为低密度伴周围炎性软组织增生;慢性期6例(包括1例上述急性期病例转为慢性期者)CT显示植物性异物为高密度机化影,周围有炎性肉芽肿包裹。1例亚急性期异物MRI在T_1WI、T_2WI显示偏低信号,1例慢性期肉芽肿在T_1WI、T_2WI显示为中等信号。结论CT扫描对于急性期、亚急性和慢性期植物性异物均能明确诊断,MRI没有明显优势。(眼科,2007,16:323-325)     

Penetrating transorbital foreign body with ocular preservation.

Large penetrating transorbital foreign bodies may initially appear to be of a devastating character to the ocular tissues. However, several reports of such large foreign bodies have proved to spare the eye. A case report of a large wooden foreign body with transorbital penetration into the right frontal lobe is reported. The globe remained intact and was only displaced, with a final visual acuity of 20/40. However, complete ophthalmoplegia and ptosis persisted. A low pressure hydrocephalus ensued following intracranial debridement.     

Corneal ulcer caused by a wooden foreign body in the upper eyelid 6 months after minor injury

PURPOSE: To describe a case of a wooden foreign body in the upper eyelid that remained asymptomatic for 6 months. CASE REPORT: A 9-year-old boy was presented with moderate upper lid swelling. Medical history was positive for trauma with a wooden stick 6 months ago. At first, the condition resolved under local antibiotic treatment. Three weeks later, the inflammation recurred and a corneal ulcer developed. Examination under general anesthesia revealed a wooden foreign body which had remained in the upper eyelid since the first injury. CONCLUSION: Organic foreign bodies in the eyelid can remain asymptomatic for a long period of time and can play a role in periocular inflammation. In case of doubt, children and other less cooperative patients should be examined under general anesthesia.     

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。     

精神病患者巨大眶内异物1例

患者,男,39岁,以右眼红、痛入院。他受到一个老者暗示将自己的右眼用木棒击伤。临床表现为右眼中度突出,完全性眼肌麻痹和严重眶周皮肤肿胀。眼科影像学表现为右眼眼窝蜂窝组织炎及眼下静脉血栓形成,两侧海绵窦综合征和海绵窦血栓。报告中无眼内及眶内异物。积极使用静脉抗生素,患者的病情并没有得到改善。在麻醉下检查发现在穹窿下有一个巨大的木质异物。异物去除及强力抗生素治疗下患者病情明显恢复。诊断中发现受伤原因可能是由这个精神病患者自我伤害引起。详细的病史、检查及合理的调查揭示其潜在的病因。敏锐的察觉及相关的临床发现与影像学研究在眶内异物及眶蜂窝组织炎处理中显得尤为有效的。及时诊断和治疗可能进一步减少患者的发病率或死亡率。     

An unusual case of intraorbital foreign body and its management

A 36-year-old aboriginal female presented following an assault with a wooden fence paling. Examination revealed a wooden object protruding lateral to the left eyebrow. CT scan showed a blow-in fracture of lateral orbital wall and a hypodense foreign body causing indentation of the globe and stretching of the optic nerve. The case was managed successfully with complete recovery of the visual acuity on day 1 post-surgery. This case highlights the importance of prompt removal of large lateral wooden intraorbital foreign body to achieve an excellent visual outcome.     

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.     

内镜在眼眶深部植物性异物摘出中的应用

目的探讨内镜在眼眶深部植物性异物摘出术中的临床应用价值。方法术前行眼眶CT或MRI冠状和水平扫描准确定位，应用硬性内窥镜沿异物窦道或皮肤切口进入眶内，沿异物长轴方向夹取异物。结果5例眼眶异物均成功摘出，同时在内窥镜下清除窦道内肉芽及坏死组织，手术后伤口均一期愈合，无手术并发症。结论应用内镜取眼眶深部异物损伤小，恢复快，异物容易取尽无残留：     

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.