先天性骨性外耳道发育畸形的CT表现及分类方法探讨

骨性外耳道发育不良是先天性外、中耳发育畸形的常见形式之一,CT表现较为复杂,目前认为骨性外耳道发育畸形分为以下3种类型:骨性外耳道闭锁、骨性外耳道狭窄和垂卣外耳道~([1-4]).     

皮质发育畸形的分类方法及影像学表现

随着影像学技术的不断发展，对皮质发育畸形(MCD)有了更深入的认识。常见MCD根据其病理类型大致分为4型：神经元和神经胶质增殖异常、神经元移行异常、皮质组织形成异常、不能分类的其他皮质发育异常。各型分类还包括相应的亚型。不同类型的MCD在MRI上有不同的表现。介绍了常见MCD的分类方法及相应的影像学表现以及影像学技术在MCD方面的研究进展。     

皮质发育畸形的分类方法及影像学表现

随着影像学技术的不断发展,对皮质发育畸形(MCD)有了更深入的认识.常见MCD根据其病理类型大致分为4型:神经元和神经胶质增殖异常、神经元移行异常、皮质组织形成异常、不能分类的其他皮质发育异常.各型分类还包括相应的亚型.不同类型的MCD在MRI上有不同的表现.介绍了常见MCD的分类方法及相应的影像学表现以及影像学技术在MCD方面的研究进展.     

先天性内耳发育畸形的多层螺旋CT表现

目的 探讨先天性内耳发育畸形的多层螺旋CT表现。资料与方法 回顾性分析17例（32耳）先天性内耳发育畸形患者的CT表现,所有患者均做多层螺旋CT横断面扫描及多平面重建,对患耳做单侧重叠放大重建,并利用容积再现技术（VRT）对骨迷路进行三维重建。结果 本组先天性内耳发育畸形有以下几种：（1）Michel型（1耳）：内耳结构完全缺如。（2）共同腔畸形（2耳）：耳蜗和前庭呈一囊状结构,二者不能相互区分。（3）不完全分隔Ⅰ型（3耳）：耳蜗缺乏完整的蜗轴,呈囊状改变,同时前庭扩大呈囊状。（4）不完全分隔Ⅱ型（Mondini型）（4耳）：耳蜗仅1．5圈,中圈和顶圈融合,前庭扩大。（5）前庭及半规管畸形（14耳）：耳蜗正常,前庭扩大,半规管短小、粗大或缺如。（6）前庭导水管扩大（14耳,其中6耳伴随其他畸形）：前庭导水管扩大呈喇叭口状或与总脚相通。（7）内耳道畸形（8耳均伴随其他畸形）：内耳道缺如、狭窄或扩大。结论 先天性内耳发育畸形有其特殊的形态学表现,多层螺旋CT扫描结合后处理成像可清晰显示各种畸形的二维和三维解剖特征,对诊断有重要价值。     

外耳道胆脂瘤的CT表现

外耳道胆脂瘤是原发于外耳道的含有胆固醇结晶脱落上皮团块所致的外耳道疾病。本文回顾性分析2001年1月至2008年4月本院收治的20例（24耳）经手术和术后病理证实外耳道胆脂瘤的CT表现。     

婴幼儿先天性气道发育畸形低剂量双源CT诊断价值

目的 探讨低剂量双源CT(DSCT)在婴幼儿先天性气道畸形中的临床应用价值。方法 选取并分析36例先天性气道畸形患者的低剂量DSCT检查资料,经支气管镜检查和手术证实诊断,对照支气管镜检查或手术结果作为金标准,计算DSCT诊断的准确性。成像质量应用五点量表进行评估。结果 DSCT诊断婴幼儿先天性气道发育异常的敏感性、特异性、阳性预测值、阴性预测值和准确率分别为90. 0%、99. 5%、97. 3%、98. 1%和98. 0%。主观图像质量平均得分为(4. 4±0. 8)分。平均DLP为(17. 50±9. 26) m Gy. cm。平均有效剂量为(0. 33±0. 16) m Sv。结论 低剂量DSCT应用较低的有效辐射剂量,可提供清晰的图像,能准确诊断婴幼儿先天性气道畸形。     

先天性二尖瓣及三尖瓣发育畸形1例

患者男性．20岁。因憋喘及心前区杂音来诊。听诊：心尖区可闻及舒张期滚筒样杂音．并伴有震颤．肺动脉瓣区第二心音亢进。超声心动图显示：双房、右室扩大．左室腔内径偏小．右室壁增厚（约11mm）．室间隔及左室游离壁厚度及动度正常。     

16排螺旋CT对先天性内耳发育畸形的诊断价值

目的 探讨16排螺旋CT对先天性内耳骨迷路发育畸形的诊断价值.方法 105例感音神经性耳聋患者接受16排螺旋扫描,取层厚0.625 mm,Bone Plus骨算法,单侧DFOV 9.6 cm或7.5 cm放大重建,行MPR和VR重建.结果 105例患者中有75例150耳CT显示正常,30例56耳为先天性内耳畸形,包括骨迷路未发育(Michel畸形)4例5耳,耳蜗未发育1例1耳,共腔畸形3例5耳,阶间隔Ⅰ型(囊状耳蜗-前庭畸形)1例1耳,耳蜗发育不全3例4耳,阶间隔Ⅱ型(Mondini畸形)12例21耳,前庭-半规管畸形5例9耳,前庭导水管扩大15例27耳,内耳道畸形12例19耳及内耳骨迷路畸形伴颈静脉球高位10例15耳.结论 多排螺旋CT检查对先天性内耳骨迷路发育畸形的诊断具有重要价值.     

先天性支气管闭锁的CT表现

目的 探讨分析先天性支气管闭锁的CT表现,以提高对该病的认识和诊断水平。方法 选取11例经病理及临床确诊的先天性支气管闭锁的CT资料进行回顾性分析。其中4例行CT平扫检查,7例同时行平扫及增强扫描。结果 11例先天性支气管闭锁中8例位于左侧,3例位于右侧;发生于段支气管5例,亚段6例。10例同时显示粘液栓和周围肺气肿改变,1例仅显示粘液栓。7例增强后在粘液栓周围均可见细小伴行动脉。结论 粘液栓、周围肺气肿及伴行细小动脉是先天性支气管闭锁的典型CT表现,CT平扫及增强扫描可有效显示其征象,并正确诊断该病。     

先天性肝母细胞瘤CT表现及误诊分析

目的 探讨先天性肝母细胞瘤(CHB)的CT特征,分析误诊原因,提高对CHB的认识和诊断能力.资料与方法 回顾性分析经手术病理证实的7例新生儿CHB的临床及CT表现,并与易误诊病变进行鉴别诊断.结果 7例新生儿CHB中,1例甲胎蛋白阳性.7例CHB均为肝内单发肿块;最大径2.9～10.2 cm(中位值4.7 cm);类球...     

High-resolution CT of mastoid sinus pneumocele with external auditory canal stenosis.

A 34-year-old man presented with tinnitus and conductive hearing loss. CT demonstrated an expansile, air-containing cavity contiguous with mastoid air cells, narrowing the external auditory canal. This is a case of symptomatic pneumocele resulting in an air collection beneath external canal lining, possibly related to an abnormality in mastoid fusion.     

Soft-tissue abnormalities of the external auditory canal: subject review of CT findings

We review the normal anatomy and discuss characteristic findings of soft-tissue abnormalities of the external auditory canal (EAC). The indications for computed tomography (CT) of the temporal bone have been significantly expanded with the inclusion of soft-tissue abnormalities of the external ear and the auditory canal. Soft-tissue abnormalities of the EAC that can be evaluated with CT include atresia, edema, hemorrhage, fracture, posttraumatic or infection-caused keloid, malignant external otitis, hemangioma, lymphangioma, papilloma, keratosis obturans, acquired cholesteatoma, adenoma, ceruminoma, fibroma, mixed tumor, sarcoma, and basal cell, squamous cell, or adenocystic carcinoma. CT scans of 25 patients who had soft-tissue abnormalities of the EAC were reviewed. The clinical data were correlated with the radiographic findings. We conclude that CT is the best overall radiographic modality for evaluating the extent and character of soft-tissue abnormalities of the EAC. Significant clinical information that is helpful in patient management decisions is added by this technique.     

Radiographic manifestations of congenital anomalies of the skull

Congenital anomalies of the pediatric skull are caused by a diverse group of disorders. For the purposes of this discussion, these entities can be classified according to the radiographic appearance of the skull, which may be similar in a variety of different diseases. Enlarged parietal foramina, sinus pericranii, aplasia cutis congenita, anterior fontanelle dermoid, cephaloceles, and craniolacunia are all examples of loceles, and craniolacunia are all examples of calvarial defects. Although there are numerous causes for wormian bones (Table 1), OI, cleidocranial dysplasia, congenital hypothyroidism, and hypophosphatasia are disorders that are commonly associated with defective ossification and the appearance of wormian bones. Osteopetrosis is an important example of rare bony dysplasias that cause sclerosis and hyperostosis of the skull. A partial list of other disorders causing similar radiographic findings is found in Table 2. Craniosynostosis results in an abnormality of skull shape. The suture(s) involved may be predicted by the deformed calvarial configuration. Knowledge of the growth and development of the skull and an understanding of the varied causes of congenital skull anomalies can enable the radiologist to provide the diagnosis or an informed differential diagnosis when confronted with a specific radiographic finding.     

High-resolution CT of the temporal bone in dysplasia of the auricle and external auditory canal.

PURPOSETo determine CT findings in the external, middle, and inner ear of patients with microtia and external auditory canal dysplasia.METHODSWe used high-resolution CT, with multiplanar or axial 1-mm continuous sections, coronal or sagittal reformations, or low-dose spiral acquisitions, to examine 184 temporal bones of children with microtia.RESULTSIn cases of minor microtia, auditory canal stenosis was the most common associated abnormality; in those with major microtia, atresia was predominant. Middle ear malformations depended on the severity of the auricular anomalies. Inner ear changes could also be noted. Ossicle dysplasias occurred in 98% of patients (stapes, 72%), absence of the oval window in 36%, labyrinthine malformations in 13%, closed round window in 6%, facial canal displacement in up to 75%, and aberrations of the vascular canal in 38% of patients with third-grade auricular deformity.CONCLUSIONA variety of external, middle, and, less frequently, inner ear changes were detected in connection with microtia.     

Radiographic manifestations of congenital anomalies of the spine

Although the foregoing review of embryologic development and congenital anomalies of the spine in infants and children is necessarily brief, the most commonly encountered abnormalities have been reviewed, and when possible, an attempt has been made to cite the stage of embryologic development at which the various abnormalities originate. As noted, congenital abnormalities of the spine are relatively uncommon but may be of profound clinical significance. During the past decade, the most significant developments in the diagnosis and treatment of these abnormalities have been ultrasonography, CT scanning, and MR imaging. In the neonate, the spinal cord and neural outflow can be evaluated by ultrasonography until the osseous elements begin to fuse. Thereafter, MR imaging is the procedure of choice because it permits evaluation of the spine and spinal cord in all planes of imaging and provides detailed evaluation of the effect of osseous abnormalities on neural structures. Finally, plain radiographs of the spine for evaluation of neonates who have any of a spectrum of sacral dimples are rarely helpful, and in the presence of significant cutaneous or subcutaneous abnormalities, ultrasonography is the preferred modality for evaluation.     

Radiographic manifestations of congenital anomalies affecting the airway

Congenital anomalies of the airway are generally uncommon, but a vast array of possibilities exists. Some present life-threatening emergencies at birth, and others go undiagnosed for years. Clinical symptoms are often nonspecific, and radiographic evaluation is frequently requested to localize and characterize the lesion before endoscopy, surgery, or medical management. The most common intrinsic congenital anomalies causing airway compromise in infants include choanal atresia, mandibular hypoplasia, laryngomalacia, vocal cord paralysis, and congenital subglottic stenosis. The radiologist must be on the alert for unsuspected additional anomalies involving the airway, lungs, and esophagus, which occur with relative frequency. Numerous extrinsic congenital masses of the head, neck, and mediastinum may compromise the airway. Hemangiomas, lymphangiomas, and teratomas are more likely to be noted at birth, whereas branchial cleft cysts, thyroglossal duct anomalies, and dermoid cysts frequently present later. Mass location and radiographic characteristics usually allow accurate preoperative diagnosis. Intracranial involvement by nasal or nasopharyngeal masses, intrathoracic involvement by lower neck mass, and intraspinal involvement by posterior neck mass must always be sought for radiographically. Persistence of respiratory symptoms after removal of such masses is not uncommon because tracheal deformity and laxity may take months or years to resolve. Recent advances in cine CT and MR imaging promise to improve imaging of the airway in general and in the pediatric population in particular. Significant limitations in imaging of the pediatric larynx remain. As a result, endoscopy continues to be the primary diagnostic tool for airway anomalies of this region.     

Radiographic manifestations of congenital anomalies of the aortic arch

This article discusses congenital anomalies of the aortic arch. Many malformations of a left, right, or double aortic arch produce tracheal, bronchial, and esophageal compression and can be recognized on chest radiographs or esophagrams and confirmed by angiography, computed tomography, or magnetic resonance imaging. Other congenital lesions of the aortic arch are characterized by aortic obstruction and include supravalvular aortic stenosis, aortic arch interruption or atresia, and coarctation.     

CT and MRI findings of radiation-induced external auditory canal carcinoma in patients with nasopharyngeal carcinoma after radiotherapy

Objective:

To summarize the radiological and clinical features of radiation-induced external auditory canal carcinomas (RIEACCs) in patients with nasopharyngeal carcinomas (NPCs) after radiation therapy.

Methods:

CT, MRI and clinical features in 16 patients with histologically proven RIEACCs were retrospectively reviewed. There were 2 females and 14 males, with a median age of 52.5 years at the time of diagnosis of RIEACC. Imaging parameters including lesion extent, size, margin, shape, bone destruction, adjacent structure invasion, density/signal intensity, and pattern and degree of enhancement were assessed. Clinical features including clinical staging, histological type, treatment and radiation dose (RD) of primary NPC as well as the histological type, staging of radiation-induced tumour and the latent period between NPC and RIT were recorded.

Results:

All patients had a single RIEACC. The lesions had a size of 3.5 ± 1.4 cm and were localized (n = 7) or extensive (n = 9). Most of the lesions were partially or ill defined with an irregular shape and had an intermediate density/signal pattern and moderate homogeneous enhancement. The latent period of RIEACCs ranged from 10 to 20 years in nine patients with a RD of 68–70 Gy; from 2 to 10 years in five patients with a RD of 68–74 Gy; and more than 20 years in two patients with a RD of 70 or 72 Gy.

Conclusion:

An external auditory canal (EAC) mass with homogeneous, intermediate CT density or signal intensity in patients with NPC after radiotherapy is highly suggestive of RIEACC, which should be included in the routine surveillance for patients with NPC after radiotherapy.

Advances in knowledge:

RIEACCs could occur as short as 2 years after radiotherapy in patients with NPC and have distinct features from otitis media and sarcomas. This EAC malignancy should be included in routine surveillance for patients with NPC after radiotherapy.Radiotherapy is the conventional and main treatment method in patients with nasopharyngeal carcinoma (NPC). As one of the most common carcinogenic agents, ionization radiation can induce many complications such as radiation encephalopathy and radiation-induced tumours (RITs) in the irradiation field. The reported incidence of RITs ranges from 0.04% to 7% in post-radiation NPC.¹ Among them, radiation-induced sarcomas (RISs) such as fibrosarcoma and osteosarcoma arising in the paranasal sinuses and the nasal cavity are the most common tumours.^1–3 Their imaging features have been well documented previously.^1–3Radiation-induced external auditory canal carcinomas (RIEACCs) are rare, but are another clinically challenging problem of RITs in patients previously irradiated for nasopharyngeal neoplasm.⁴ Previously, MRI findings of only four cases of radiation-inducted squamous-cell carcinomas (SCCs) in the external auditory canal (EAC) had been described.¹ To date, there are few reports describing radiological features of RIEACCs. The CT and MRI features of RIEACC are far from well described. In this study, CT, MRI and clinical data in 16 cases of pathologically proven RIEACCs in patients with irradiated NPCs were retrospectively reviewed, and their main CT and MRI findings and clinical features were summarized.