Congenital nasal masses: CT and MR imaging features in 16 cases

The imaging studies of 16 children with pathologically proved nasal encephaloceles (eight), nasal dermal sinuses/nasal dermoids (seven), and nasal cerebral heterotopias, more commonly known as nasal gliomas (one), were retrospectively reviewed and compared with normal control subjects to define the normal anatomy and analyze deformities caused by these lesions. Nasal encephaloceles were always identified as complex masses of mixed soft tissue and CSF intensity that were contiguous with intracranial structures. The nasal glioma appeared as a mixed-intensity mass that, on the basis of the CT scan, appeared to be continuous with intracranial structures. Nasal dermal sinuses could only be identified as they coursed through the skin and subcutaneous soft tissue. They could not be identified when intraosseous. Moreover, on CT and, particularly, on MR, a number of potential diagnostic pitfalls were encountered. The most important of these was the normal fat deposition that occurs within bone during normal maturation and during aeration of the frontal sinuses and nasal bones. These fatty changes can easily be mistaken for fatty tumors if they are not recognized as normal anatomic changes. Interestingly, the classic plain film findings for congenital nasal masses were present only in the encephaloceles and nasal glioma; dermoids and dermal sinuses showed none of the classic plain film findings. In the six patients who had both CT and MR, the masses were easily identified and characterized by each imaging method. Congenital nasal masses are well characterized by both CT and MR. It is important to understand the normal changes in the anatomy of the nasofrontal region in the pediatric age group to avoid false-positive diagnoses in this region.     

Hemangioma of the interatrial septum: CT and MRI features

Hemangioma of the heart is a rare primary benign tumor mainly appearing as enhancing, homogenous, well-circumscribed mass. We report a case of a 61-year-old asymptomatic woman, whose echocardiography showed a cardiac mass, which was described as the atypical myxoma of the right atrium. For further imaging, contrast-enhanced computed tomography and cardiac magnetic resonance imaging were undertaken, which showed a tumor located in the interatrial septum with imaging characteristics of hemangioma. In the literature, cardiac hemangioma is usually described as an intensely enhancing mass. In our opinion, early peripheral puddling of contrast material with filling in on delayed images is a typical pattern of its enhancement. This characteristic, in addition to high signal intensity on T2-weighted images, allows differentiation of a hemangioma from other benign and malignant tumors.     

Pleomorphic adenoma of the nasal septum: MR features

We report the MR imaging features of a pleomorphic adenoma of the nasal septum. To our knowledge, whereas the CT findings of pleomorphic adenomas of the nasal septum have been reported, the MR features of this rare entity have not been reported in the English-language literature.     

Multiple glioblastomas: CT and MR features

The aim of this study was to analyze the CT and MR features of multiple glioblastomas, and to determine the best imaging modality for the initial diagnosis. The CT (four exams) and MR imaging (eight exams) of eight patients with proven multiple glioblastomas were reviewed by two neuroradiologists. The lesions were always hypo- or isodense on CT and hyperintense on T2-weighted images (100 %). They were usually hypo- or isointense on T1-weighted images (90 %). Edema and mass effect were very variable. After contrast media administration, the enhancement was mostly strong (71 % on CT and 70 % on MR), often either heterogeneous or ring-like. The different lesions of a patient often had a different pattern on MR (75 % of cases). Meningeal or ventricular enhancement, suggestive of a possible way of dissemination, was rare. In case of multiple cerebral masses, multiple glioblastomas should be considered as a possible diagnosis in addition to the better known diagnosis of brain metastases, abscesses, or multifocal lymphomas. Moderate edema and mass effect on MR associated with strong and heterogeneous enhancement are suggestive of feature of multiple glioblastomas. Magnetic resonance allows rarely the visualization of a dissemination route. Received: 10 March 2000 Revised: 18 May 2000 Accepted: 22 May 2000     

Hemangiopericytoma of the parotid gland: CT and MR features

Hemangiopericytomas are uncommon vascular neoplasms with rare occurrence in the head and neck region. They originate from the pericytes, which are small, oval cells encircling capillaries. Hemangiopericytomas traditionally appear in the retroperitoneum and in the capillaries of the extremities. A case of hemangiopericytoma of the parotid gland is presented. The clinical, surgical, histologic, and radiologic features are described and discussed. Received: 7 February 2000 Revised: 3 March 2000 Accepted: 4 April 2000     

Neurinoma of the oculomotor nerve: CT and MR features

The authors present a case of neurinoma of the oculomotor nerve without evidence of von Recklinghausen disease. The literature is reviewed and CT and magnetic resonance findings are discussed.     

Intracranial hemangiopericytomas: MR and CT features.

PURPOSETo describe the MR and CT imaging features of hemangiopericytoma and to identify the characteristics that might distinguish them from meningioma.METHODSWe retrospectively reviewed the CT and MR findings in 34 pathologically proved cases of hemangiopericytoma. We evaluated the size, shape, and location of the tumor; the presence of hydrocephalus, edema, and mass effect; the type of dural attachment (broad-based or narrow-based) and bone changes (erosion, hyperostosis); and the tumor''s density, signal, and contrast-enhancement characteristics.RESULTSThirty of 34 tumors were 4 cm or more in greatest dimension, 32 were lobular, and only seven were in the posterior fossa. Hydrocephalus was present in 18, edema in 30, and mass effect in 33. Twenty-three had broad-based dural attachment and 11 had narrow-based attachment. All 26 unenhanced CT scans showed hyperdense tumors; 19 were heterogeneous and seven homogeneous. All 27 contrast-enhanced CT scans showed enhancement; 17 were heterogeneous and 10 homogeneous. Bone erosion was present in 17 of 29 hemangiopericytomas imaged with CT. None had hyperostosis or tumor calcifications. On T1-weighted MR images, 13 of 17 tumors were isointense with cortical gray matter; on T2-weighted image, 10 of 17 were isointense. All 14 tumors imaged with contrast enhanced T1-weighted MR imaging showed enhancement, and 13 of these were heterogeneous; eight of the 14 had a "dural tail" sign.CONCLUSIONIntracranial hemangiopericytomas are multilobulated, extraaxial tumors, sometimes associated with narrow-based dural attachment and bone erosion. Unlike with meningiomas, hyperostosis and intratumoral calcification are not present.     

鼻息肉的CT表现与诊断价值

目的：总结分析鼻息肉的CT表现特点,评价CT扫描对鼻息肉的诊断价值。方法：97例均行轴位及冠状位扫描,其中轴位24例,冠状位73例,全部病例经鼻内窥镜手术及病理证实。结果：97例中双侧发病72例,单侧发病25例。鼻息肉主要发生在筛窦及中鼻道,部分累及上颌窦及下鼻道,在CT断面上表现为鼻腔内息肉样肿块,均合并不同程度的鼻窦炎,冠状位CT扫描比轴位显示清楚。结论：鼻息肉在CT断面上有比较特征性的表现,诊断明确,冠状位能提供与功能鼻内窥镜手术方位一致的解剖层面,能清楚显示鼻道解剖结构和病变特点,对指导纤维内窥镜手术进路及防止并发症有重要指导意义。     

节细胞神经瘤的影像学表现

目的 探讨节细胞神经瘤的CT和MR表现.方法 回顾性分析18例经手术病理证实的节细胞神经瘤的CT、MR影像学资料,所有患者均接受CT平扫及增强扫描,2例接受MR平扫.结果 节细胞神经瘤好发于中青年,位于后纵隔8例,肾上腺5例,腹膜后4例,颈部1例.均为单发病灶、边界清楚,嵌入式生长可呈多种形态.CT平扫:12例为均匀低密度,平均CT值22～37 HU;6例密度不均,平均CT值13～46 HU,其中2例伴有坏死、囊变.2例见斑点状钙化.增强扫描:肿瘤各期均无强化4例,仅动脉期轻度强化5例,仅静脉期轻度强化2例,静脉期及延迟期呈轻、中度渐进性强化1例,三期呈渐进性强化6例;坏死及囊变部分未见强化.2例肿瘤内见肋间后动脉穿行,1例见腰动脉穿行并见细小分支滋养肿瘤.2例下腔静脉推挤受压移位,1例见颈部大血管被包绕.MR平扫:1例信号均匀,1例信号不均;T1WI表现为低信号,T2 WI呈高信号为主,脂肪抑制(SPIR)及扩散加权成像(DWI)呈高信号.结论 节细胞神经瘤的CT及MR表现具有一定特征性,尤其是CT示肿瘤为均匀低密度、伴有斑点状钙化、肿瘤内血管穿行但未受侵,增强扫描动脉期无明显强化或轻度强化,呈渐进性强化方式,DWI示肿瘤呈高信号时,应考虑节细胞神经瘤的可能.     

Juvenile Huntington disease: CT and MR features.

PURPOSETo describe the clinical and radiologic manifestations of juvenile Huntington disease and to determine whether adult imaging criteria for Huntington disease are helpful for pediatric patients.METHODSSix patients (3 to 18 years of age; mean age, 9.8 +/- 5.6 years; 3 female, 3 male) with juvenile Huntington disease were studied with CT (n = 6) and/or MR (n = 3). CT and MR studies were evaluated for frontal horn distance/intercaudate distance and bicaudate ratios, which were compared with those of 24 age-matched healthy children and 12 age-matched patients with Leigh (n = 9) or Wilson (n = 3) disease.RESULTSAtrophy of the caudate nuclei was identified in all Huntington patients. The frontal horn distance/intercaudate distance (1.64 +/- 0.39) and bicaudate (0.205 +/- 0.060) ratios of the patients with juvenile Huntington disease were found to be significantly different from those of healthy children and that of those patients with Leigh/Wilson disease. The 3 patients with Huntington disease who underwent MR evaluation were noted to have increased proton density- and T2-weighted signal in the caudate nuclei and putamina.CONCLUSIONAs in adult patients, the use of frontal horn distance/intercaudate distance and bicaudate ratios are helpful for the diagnosis of Huntington disease in pediatric patients. On MR, increased proton density- and T2-weighted signal in the atrophic caudate nuclei and putamina are additional features of juvenile Huntington disease.     

Eccentric cystic facial schwannoma: CT and MR features

Facial schwannomas are uncommon lesions with a fairly characteristic range of clinical and radiographic presentations. This report describes an unusual case of facial schwannoma that clinically and radiographically mimicked a cystic skull base lesion extrinsically compressing the facial nerve. The MR findings are presented.     

Acute disseminated encephalomyelitis: MR and CT features.

We describe three cases of acute disseminated encephalomyelitis (an immune-mediated inflammatory demyelinating disease of the central nervous system) and their histology, showing different radiological features. One appearance is a few ring-shaped enhancing lesions, which are found predominantly in the supratentorial white matter, the other is solid disseminated lesions.     

Degenerative thalamic hamartoma: CT and MR imaging features

We describe hamartomas of possible thalamic origin. CT revealed marked calcification in the mass lesion, and MR imaging revealed contrast enhancement. Histologically, outgrowth of the glia was observed, but no neoplastic component was confirmed. Immunohistochemical staining was positive for the cell-adhesion factor N-CAM and negative for polysialic acid.     

Cellular leiomyoma of the nasal cavity: findings of CT and MR imaging

Nasal leiomyoma, a benign tumor composed of smooth muscle cells, is rare in the head and neck region. Cellular leiomyomas of the uterus exhibit high intensity on T2-weighted images. Here we present a case of nasal leiomyoma in which the pathologic findings are similar to those of cellular leiomyoma. The present case exhibited slightly elevated intensity on T2-weighted images and marked enhancement on postcontrast images. CT findings showed a soft tissue lesion without bone erosion. These findings appear to be characteristic of intranasal leiomyoma.     

Pyogenic granuloma gravidarum of the nasal fossa: CT features.

We present a case of a pregnant patient with a rapidly growing mass within the nasal fossa that was imaged by CT 2 weeks postpartum. Concern for malignancy existed and biopsy was performed, revealing pyogenic granuloma gravidarum. This uncommon lesion should be considered in any gravid patient when a mass occurs within the mouth or nasal fossa.