颅脑血管外皮细胞瘤的CT、MRI与病理对照研究

目的：探讨颅脑血管外皮细胞瘤的临床、病理和ＣＴ、ＭＲＩ特征。材料与方法：收集经ＣＴ和ＭＲＩ诊断为脑膜瘤,经手术病理证实为血管外皮细胞瘤１２例,年龄３４￣５８岁。ＣＴ检查７例,均采用增强前、后常规扫描。ＭＲＩ检查１２例,采用ＳＥ序列增强前、后扫描。结果：１２例肿瘤全部发生在颅内脑外,７例ＣＴ平扫呈低等混合密度２例,呈等高混合密度５例;增强后扫描呈不均匀强化６例,均匀强化１例。骨窗显示病灶局部侵蚀性骨质破坏４例。ＭＲＩ平扫,Ｔ１ＷＩ呈等高不均匀信号１０例,呈等信号２例;Ｔ２ＷＩ呈不均匀等高信号１０例,呈等信号２例。１２例中７例显示脑膜尾征;增强后扫描１ 均呈不均匀强化。结论：血管外皮细胞瘤具有一定的ＣＴ、ＭＲＩ特征性表现：分叶状、丰富的血管流空、肿瘤内密度或信号不均匀、无肿瘤内钙化和骨质增生、局部颅骨呈溶骨性破坏。     

颅内血管外皮细胞瘤的磁共振影像研究

目的　分析颅内血管外皮细胞瘤的磁共振影像表现。方法　选取经手术病理证实的颅内血管外皮细胞瘤 2 7例 ,男 1 6例 ,女 1 1例 ,所有病例均进行了MR检查 ,回顾分析其MR影像表现。结果　颅内血管外皮细胞瘤在MR影像表现上有如下特点 :(1 )肿瘤主要表现为等长T1 、等长T2 混杂信号影 ,偶可见短T1 或短T2 信号影 ,注药后 ,肿瘤增强明显但不均匀 ;(2 )外形呈不规则分叶状 ;(3)半数以上的肿瘤与硬膜窄基底相连 ;(4)肿瘤内常可见血管流空影而见不到钙化影 ;(5)肿瘤附近骨质可见破坏而见不到增生硬化。结论　颅内血管外皮细胞瘤有比较典型的MR影像特点 ,结合临床表现有助于其术前正确诊断     

颅内血管外皮细胞瘤的MRI／CT影像学表现

目的：探讨颅内血管外皮细胞瘤（hemangiopericytoma,HPC）的影像特征。方法回顾性分析经病理及免疫组织化学证实的16例HPC患者的CT及MRI表现。所有患者均行MR扫描,6例行CT扫描。结果所有病变均为单发病灶,均位于颅内脑外,均为分叶状肿块,15例位于幕上,1例位于幕下。6例CT平扫均呈稍高密度、间杂低密度,均未见钙化,1例邻近颅底骨质呈侵蚀破坏,5例增强扫描均呈明显不均匀强化,并可见明显增粗的血管影,4例可见明显的瘤周水肿带。T1WI以等、低信号、T2WI以低、高混杂信号为主,2例信号均匀、14例信号不均,13例周围有水肿。增强扫描中15例病灶均明显不均匀强化,1例中度强化。2例病灶与硬膜呈宽基底相连,14例为窄基底相连。16例病灶均未出现“脑膜尾征”。DWI中,7例肿瘤呈等低混杂信号为主。MRS中,4例Cho峰明显升高;2例NAA峰及Cr峰降低。结论HPC影像表现具有一定特点,当脑外肿瘤呈分叶状,内部密度不均匀,有囊变坏死,周围骨质无增生硬化,甚至有破坏吸收改变,水肿较严重,肿瘤内未见钙化,侵犯周围脑组织或并发颅外转移时,提示HPC可能性大。     

Intracranial meningeal hemangiopericytomas in children and adolescents: CT and MR imaging findings

Intracranial meningeal hemangiopericytomas in children and adolescents are prone to bleeding during surgery. CT and MR imaging may serve a role in preoperative diagnosis. The purpose of this report was to describe the radiologic findings in 9 pathologically proved cases of intracranial meningeal hemangiopericytomas in children and adolescents. The average duration of symptoms was short (mean, 4.0 months; median, 1.5 months). The intraoperative blood loss was large (mean, 3561 mL; median, 1000 mL). Tumors were extra-axial, irregularly multilobular, and hypervascular. Radiologically, they showed mixed attenuation on precontrast CT images, heterogeneous signal intensity on precontrast MR imaging, and marked and heterogeneous enhancement on postcontrast MR imaging. Bone erosion was sometimes present, but hyperostosis was not present. On MR imaging, multiple signal intensity voids of vessels were observed in 100% (8/8) of tumors with AVM-like signal intensity flow voids in 25% (2/8) of tumors. These results suggest that CT and MR imaging findings may be helpful for preoperative diagnosis.     

鼻腔、鼻窦血管外皮瘤的CT和MRI表现

目的 探讨鼻腔、鼻窦血管外皮瘤的CT和MRI表现.方法 回顾性分析9例经组织学证实鼻腔、鼻窦血管外皮瘤的CT(9例)和MRI(7例)资料,并分析其中3例动态增强扫描的TIC.结果 血管外皮瘤位于鼻腔5例、上颌窦3例,蝶窦1例;病变呈梭形4例、类圆形3例,不规则形2例,病灶最大径18～52 mm,平均31 mm,边界清楚7例,模糊2例.CT表现:与脑灰质比较,平扫病变呈等密度6例,略高密度3例,2例增强后呈较均匀的显著强化;邻近骨质受压、吸收7例,骨质侵蚀破坏2例.MRI表现:与脑灰质比较,T1WI呈较均匀低信号、T2WI呈高信号3例,T1WI、T2WI均呈等信号4例,其中2例信号不均匀;增强后显著均匀强化4例,不均匀强化3例.3例TIC均为持续上升型.病变侵犯眼眶2例,侵犯海绵窦、前颅底脑膜及翼腭窝、颞下窝1例.5例随访3～8年,其中2例复发.结论 MRI增强后显著强化、持续上升型TIC是鼻腔、鼻窦血管外皮瘤较典型的影像表现;骨质表现有助于良、恶性判断;影像检查能够准确显示病变的范围.     

脑膜血管外皮细胞瘤的影像诊断与鉴别诊断

目的 提高对脑膜血管外皮瘤的认识。资料与方法 回顾性分析经手术病理证实的4例脑膜血管外皮瘤的CT和MRI表现，并结合文献进行复习。结果 脑膜血管外皮瘤的CT和MRI表现类似脑膜瘤，但具有恶性征，无颅骨增生和硬膜强化（硬膜尾征），与脑膜瘤不同。结论 CT和MRI表现类似脑膜瘤的颅内肿瘤，具有恶性征，没有颅骨增生和硬膜强化者要考虑脑膜血管外皮瘤的可能。     

Malignant lymphoma of the gingiva: MR evaluation.

PURPOSEOur purpose was to document the MR imaging findings of malignant lymphoma of the gingiva.METHODSFive patients with histologically proved malignant lymphoma of the gingiva were studied by MR imaging. The MR images were analyzed for tumor size, extent, and signal characteristics, bone involvement, and associated cervical lymph node enlargement.RESULTSClinical examination tended to underestimate the size of lymphomatous lesions. The signal intensity of the lesions was isointense to hyperintense relative to muscle on noncontrast T1-weighted images and showed variable contrast enhancement patterns. On T2-weighted images, signal intensity was isointense to hypointense relative to the oral mucosa. In one case, the mass extended to the submandibular space; in the remaining cases, the masses were limited to the gingiva and the adjacent bone. MR imaging revealed that gingival lymphomatous masses were broad-based along the mandible or maxilla and eroded through the cortex into the marrow space, but the cortex was still recognizable. No nodal involvement was noted in any of the patients with malignant lymphoma.CONCLUSIONThe signal characteristics of gingival lymphoma overlap those of other tumors. The cortex separating marrow involvement from the broad-based gingival mass generally appears to be permeated with small erosions but is still recognizable.     

MR of esthesioneuroblastoma (olfactory neuroblastoma) and appearance after craniofacial resection.

PURPOSETo analyze the MR characteristics of a series of patients with esthesioneuroblastoma and discuss the typical surgery and its postoperative MR appearance.METHODSThe MR studies of 15 patients with the pathologic diagnosis of esthesioneuroblastoma (also known as olfactory neuroblastoma) were retrospectively reviewed and correlated with CT and surgical findings. The postoperative MR studies of 10 patients who underwent craniofacial resection were also reviewed.RESULTSIn all cases the tumors arose in the superior nasal cavity and extended into the ethmoid cells. In some instances the tumors extended into the other paranasal sinuses, orbits, anterior cranial fossa, and cavernous sinus. The tumors were typically expansile and destructive in their growth patterns. Compared with brain gray matter, the tumors were hypointense on T1-weighted images and isointense to hyperintense on T2-weighted images. Nine tumors were heterogeneous and 6 were homogeneous. Contrast enhancement ranged from mild to marked. MR was useful for characterizing the various tissues and distinguishing fluid in the postoperative nasal cavity.CONCLUSIONSEsthesioneuroblastoma, although an uncommon tumor, may be suspected in lesions of the superior nasal cavity demonstrating both expansile and destructive growth properties. The MR findings are otherwise nonspecific. MR is the imaging modality of choice for depicting local tumor extension and evaluating for recurrence after craniofacial resection.     

肺血管外皮瘤的影像学诊断

目的　探讨肺血管外皮瘤的影像学表现。方法　分析 3例经病理证实的肺血管外皮瘤的CT、MRI表现。结果　 3例患者均表现为肺内单发的巨大肿块 ,CT平扫示密度不均匀 ,强化扫描示肿块实质明显强化 ,并可以见到其中异常强化的血管影。MRI平扫示肿块信号不均匀 ,并可以见到血管流空征象。结论　肺内单发的巨大肿块 ,CT强化扫描见到异常强化的血管 ,MRI扫描见到血管流空征象 ,可以高度提示肺血管外皮瘤的诊断     

In vivo and in vitro MR imaging of renal tumors: histopathologic correlation and pulse sequence optimization

Magnetic resonance (MR) imaging has given mixed results in the detection of renal masses. To identify the reasons for this and to determine the optimal pulse sequences for evaluating renal tumors, the authors imaged 12 primary renal tumors in vivo and 17 in vitro at 0.35 T. Histopathologic findings for each specimen were closely correlated with the MR images. Four of seven solid tumors imaged in vivo were isointense with surrounding normal renal parenchyma at all pulse sequences. The other three tumors were hyperintense in vivo at T2-weighted sequences. At heavily T2-weighted sequences eight solid tumors were hyperintense in vitro and four were hypointense. There was no correlation between signal intensity and specific tissue type or histologic pattern for solid tumors. The five cystic tumors were well seen both in vivo and in vitro on T2-weighted images. However, the signal intensity of the cyst fluid was an unreliable indicator of benignancy. SE MR imaging at 0.35 T has significant limitations in the detection of solid renal masses.     

Melanotic neuroectodermal tumor of infancy: clinical, radiologic, and pathologic findings in five cases.

Five pathologically proved melanotic neuroectodermal tumors of infancy are reported. These rare neoplasms of infancy exhibit a distinct predilection for the maxillary bone. Three tumors originated in the maxilla, one in the calvaria, and one in the cerebellar vermis. Those occurring in bone did not metastasize but were locally invasive, as reflected in their radiologic appearance. Bone erosion, expansion, hyperostosis, and osteogenesis can occur in the same neoplasm and were appreciated best on CT. MR imaging showed the soft-tissue component and extent of the neoplasm better than CT did. The pathologic findings from all five cases (and one possibly related melanotic tumor of the face) revealed abundant melanin. MR imaging of two melanotic tumors showed isointense T1-weighted and slightly hyperintense T2-weighted signals. This appearance is contrary to that of most melanin-containing tumors, which exhibit enhanced T1 and T2 relaxation, and indicates that variables other than the absolute amount of melanin may determine the MR signal. Clinically, rapid neoplastic growth and excessive melanin production by the tumor cells caused facial disfigurement and visible blue black discoloration. All five melanotic neuroectodermal tumors were resected and the vermian tumor was also irradiated. Four of five children were well and free from disease 1 month to 7 years after resection. The calvarial tumor was incompletely resected and involved the underlying brain, eventually causing death. The clinical, radiologic, and pathologic features of melanotic neuroectodermal tumors of infancy are reviewed. Melanotic neuroectodermal tumors of infancy that involve bone can be diagnosed from the clinical and radiologic findings. Prompt diagnosis and surgical resection are essential for cure.     

Normal appearance of arachnoid granulations on contrast-enhanced CT and MR of the brain: differentiation from dural sinus disease.

PURPOSETo determine the imaging appearance and frequency with which arachnoid granulations are seen on contrast-enhanced CT and MR studies of the brain.METHODSWe retrospectively reviewed 573 contrast-enhanced CT scans and 100 contrast-enhanced MR studies of the brain for the presence of discrete filling defects within the venous sinuses. An anatomic study of the dural sinuses of 29 cadavers was performed, and the location, appearance, and histologic findings of focal protrusions into the dural sinus lumen (arachnoid granulations) were assessed and compared with the imaging findings.RESULTSDiscrete filling defects within the dural sinuses were found on 138 (24%) of the contrast-enhanced CT examinations. A total of 168 defects were found, the majority (92%) within the transverse sinuses. One third were isodense and two thirds were hypodense relative to brain parenchyma. Patients with filling defects were older than patients without filling defects (mean age, 46 years versus 40 years). Discrete intrasinus signal foci were noted on 13 (13%) of the contrast-enhanced MR studies. The foci followed the same distribution as the filling defects seen on CT scans and were isointense to hypointense on T1-weighted images, variable in signal on balanced images, and hyperintense on T2-weighted images. Transverse sinus arachnoid granulations were noted adjacent to venous entrance sites in 62% and 85% of the CT and MR examinations, respectively. Arachnoid granulations were found in 19 (66%) of the cadaveric specimens, in a similar distribution as that seen on the imaging studies.CONCLUSIONDiscrete filling defects, consistent with arachnoid granulations, may be seen in the dural sinuses on 24% of contrast-enhanced CT scans and on 13% of MR studies. They are focal, well-defined, and typically located within the lateral transverse sinuses adjacent to venous entrance sites. They should not be mistaken for sinus thrombosis or intrasinus tumor, but recognized as normal structures.     

Tectal tumors of childhood: clinical and imaging follow-up.

PURPOSEThis study was done to determine which clinical and imaging findings best correlate with outcome in children with tectal tumors.METHODSA retrospective review was done of the medical records and imaging studies of 32 children (16 boys and 16 girls; mean age, 8 years) with tectal tumors. Eight children had CT, 11 had MR imaging, and 13 had both CT and MR studies. Findings from surgical and pathologic reports as well as from follow-up examinations (mean follow-up period, 5 years; range, 3.6 months to 17 years) were included in the review.RESULTSAll patients had hydrocephalus and all but one required CSF diversion. The tectum was the center of the tumor in all cases and the majority of the tumors appeared isodense on CT scans, isointense on T1-weighted MR images, and hyperintense on T2-weighted images. Twenty patients required no further treatment. In this group, the mean maximum tumor diameter was 1.8 cm and enhancement occurred in two cases. At follow-up, 18 patients had stable tumor size, one had an increase in tumor size with cyst formation but no worsening of symptoms, and one had a decrease in tumor size. Twelve patients required further treatment (excision and/or radiotherapy) because of progression as indicated by either increased tumor size or worsening of symptoms. In this group, the mean maximum tumor diameter was 2.5 cm and contrast enhancement occurred in nine cases. Further follow-up in this group showed decreased tumor size in eight and stable residual tumor in three.CONCLUSIONTectal tumors in childhood have variable behavior. MR imaging assists in the clinical determination of which children need treatment beyond CSF diversion. Larger tumor size and enhancement are radiologic predictors of the need for further treatment.     

Synovial sarcomas of the head and neck: CT and MR imaging findings of eight patients

BACKGROUND AND PURPOSE: Synovial sarcomas are soft-tissue tumors that rarely occur in the head and neck. The purpose of this study was to evaluate their CT and MR imaging appearance and to show that they may have a surprisingly benign imaging appearance. METHODS: Eight patients with histologically proved synovial sarcoma underwent CT; additionally, MR imaging examinations were performed in five of the eight cases. Attenuation and signal intensity on CT scans and MR images, respectively, were studied by two radiologists. They analyzed the location, size, margins, homogeneity, presence of adenopathies and infiltrative signs, and enhancement after injection of contrast medium. RESULTS: Four tumors were located in the hypopharynx, two arose from the infratemporal fossa, one arose from the maxillary sinus, and one arose from the faucial tonsil. Tumor sizes ranged from 27 to 70 mm. On CT scans and MR images, six lesions were homogeneous and well defined, with smooth margins. The remaining tumors were heterogeneous. In two cases, adjacent tissues were invaded. Calcifications were observed in one case and adenopathy in two cases. In three cases, the lesions were isointense on T1-weighted MR images and hypointense on T2-weighted MR images, and in the other two cases in which MR imaging was performed, the lesions were both isointense and hypointense on both T1- and T2-weighted images. Only the two local recurrent lesions were multilocular. CONCLUSION: Synovial sarcomas are aggressive sarcomas that may appear "benign" in some cases. In a young man, a synovial sarcoma may be suspected when a well-demarcated, homogeneous lesion is found in the head and neck.     

CT and MR imaging of benign primary cardiac neoplasms with echocardiographic correlation.

Benign primary cardiac neoplasms are rare but may cause significant morbidity and mortality. However, they are usually treatable and can often be diagnosed with echocardiography, computed tomography (CT), or magnetic resonance (MR) imaging. Myxomas typically arise from the interatrial septum from a narrow base of attachment. Fibroelastomas are easily detected at echocardiography as small, mobile masses attached to valves by a short pedicle. Cardiac fibromas manifest as a large, noncontractile, solid mass in a ventricular wall at echocardiography and as a homogeneous mass with soft-tissue attenuation at CT. They are usually homogeneous and hypointense on T2-weighted MR images and isointense relative to muscle on T1-weighted images. Paragangliomas usually appear as large, echogenic left atrial masses at echocardiography and as circumscribed, heterogeneous masses with low attenuation at CT. These tumors are usually markedly hyperintense on T2-weighted MR images and iso- or hypointense relative to myocardium on T1-weighted images. Cardiac lipomas manifest at CT as homogeneous, low-attenuation masses in a cardiac chamber or in the pericardial space and demonstrate homogeneous increased signal intensity that decreases with fat-saturated sequences at T1-weighted MR imaging. Cardiac lymphangiomas manifest as cystic masses at echocardiography and typically demonstrate increased signal intensity at T1- and T2-weighted MR imaging. Familiarity with these imaging features and with the relative effectiveness of these modalities is essential for prompt diagnosis and effective treatment.     

颅内血管外皮细胞瘤的CT和MRI诊断

目的：探讨颅内血管外皮细胞瘤（HPC）的CT及MRI特征。方法：回顾性分析经手术病理证实的16例颅内血管外皮细胞瘤患者的病例资料。所有患者均行CT平扫、MRI平扫、增强扫描及DWI检查,3例行MRA、MRV检查。结果：16例肿瘤均明显强化;15例有不同程度占位效应;14例外形波浪状分叶,2例呈类圆形;13例瘤内有囊变、坏死;10例可见瘤内血管流空信号。12例肿瘤T1WI上呈等低信号,4例呈高或略高信号;13例T2WI上呈混杂高信号,3例为等低信号;11例DWI上呈等低信号,5例为高信号。7例与脑膜以窄基底相连,9例与脑膜宽基底相连;4例邻近颅骨有破坏,4例可见脑膜尾征。结论：HPC的CT、MRI表现具有一定特征性,两种检查方法相结合有助于HPC的术前诊断。     

Intraocular tumors: evaluation with MR imaging

Sixty-seven ocular tumors were studied with magnetic resonance (MR) imaging and computed tomography (CT). These tumors included primary uveal melanoma (n = 55), circumscribed choroidal hemangioma (n = 3), diffuse choroidal hemangioma (n = 1), retinal capillary hemangioma (n = 1), medulloepithelioma (n = 1), choroidal nevus (n = 1), retinoblastoma (n = 1), and choroidal metastases (n = 4). MR imaging demonstrated all these lesions, while CT demonstrated 88%. Associated retinal detachment was more easily distinguished from the neoplasms with MR imaging. Extrascleral extension of melanoma and hemorrhagic cystic necrosis within the melanoma were clearly demonstrated with MR imaging, but not with CT. Ninety-three percent of melanomas were markedly hyperintense, compared with the intensity of the vitreous body, on T1-weighted images and hypointense on T2-weighted images. All metastatic lesions were isointense on T1-weighted images and hypointense on T2-weighted images. The circumscribed choroidal hemangiomas were hyperintense on T1-weighted images and isointense on T2-weighted images. MR imaging is superior to CT in detection of intraocular tumors and may be more specific in diagnosis.     

颅内血管外皮细胞瘤的MRI及MRS诊断

目的:探讨颅内血管外皮细胞瘤的MRI及MRS表现特征. 材料和方法:回顾性分析7例颅内血管外皮细胞瘤的MRI、MRS表现,其中MRI检查7例,MRS检查4例. 结果:7例中,肿块呈多分叶状6例,MRI平扫中3例T1WI呈等信号,3例呈等、低信号,1例合并出血肿块内夹杂高信号灶,T2WI上2例呈等信号,4例呈等高混杂信号,1例呈混杂高信号,5个肿块内及周边均可见多发迂曲扩张的血管流空影,增强扫描肿块明显均匀(3例)或不均匀(4例)增强.4例MRS均表现为Cho明显升高及明显高耸Lip峰,NAA明显降低或消失,2例MI峰明显增高,未见Ala峰和Glx峰.结论:颅内血管外皮细胞瘤MRI表现具有一定特征性,结合MRS表现有助于与脑膜瘤的鉴别.     

Radiological findings of spinal schwannomas and meningiomas: focus on discrimination of two disease entities

This study evaluates the effectiveness of CT and MR imaging in differentiating intradural extramedullary spinal schwannomas and meningiomas in a large group of patients. In addition, the study correlates tumour location, morphologic characteristics and enhancement pattern. From January 2000 to June 2007, we retrospectively reviewed 128 consecutive patients (51 male, 77 female; mean age at admission 53.8 years; range 17–83 years) with spinal intradural extramedullary tumours (92 schwannomas, 36 meningiomas) at our institution. Fifty-one of ninety-two schwannomas (55.4%) showed fluid signal intensity on T2-weighted MR images. Twenty-two of thirty-six meningiomas (61.1%) showed hyperintense signal intensity and thirteen of thirty-six meningiomas (36.1%) showed isointense signal on T2-weighted MR images. Fifty-four schwannomas (58.7%) showed rim enhancement and thirty-three meningiomas (91.7%) showed diffuse enhancement on contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed dural tail sign in contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed calcification on CT images. MR and CT imaging results are therefore useful for the differentiation of schwannomas from meningiomas of the spine.     

Hyperostosis in meningiomas: MR findings in patients with recurrent meningioma of the sphenoid wings.

PURPOSEWe used MR imaging to analyze retrospectively the pattern of hyperostosis occurring concomitantly with recurrent sphenoid wing meningiomas.METHODSBone involvement was compared in 12 corresponding CT and MR studies of 10 female patients with sphenoid wing meningiomas recurrence after earlier surgical treatment. Four of these had histologically confirmed meningiomatous infiltration of the bone.RESULTSAll patients had CT findings of localized hyperostosis of parts of the sphenoid wings. MR revealed inhomogeneous areas of slightly increased signal intensity in hyperostotic bone on T2-, proton density- and T1-weighted sequences. In nine of 10 patients, segments of the hyperostotic bone showed different degrees of gadolinium enhancement.CONCLUSIONSBecause earlier studies have revealed high incidences of meningiomatous bone infiltration in sphenoid wing meningiomas, and because infiltration was confirmed in four of our patients, we postulate that the gadolinium enhancement in the area of hyperostosis may be related to meningiomatous bone infiltration.