神经纤维瘤病中枢神经系统的MRI表现

目的 探讨神经纤维瘤病(NF)的中枢神经系统(CNS)MR表现。方法 回顾性分析10例神经纤维瘤病患的临床资料并对其中枢神经系统MR表现进行分析，所有病例均行常规MR平扫及增强扫描。结果 10例病例中，NF—1型6例，表现为脑内胶质瘤、椎管内神经纤维瘤，4例合并皮肤损害，其中一例有家族史，NF—2型4例，表现为双侧听神经瘤、多发脑膜瘤或神经纤维瘤，皮肤损害少见。所有病例中增强扫描均发现平扫未发现之病灶。结论 MR能很好显示病变的大小、形态及信号特点，对检出神经纤维瘤病中枢神经系统的损害方面有优势，增强扫描可帮助发现平扫未见病灶。     

神经纤维瘤病多灶性分布的临床影像学表现分析

目的 回顾性分析神经纤维瘤病(NF)多灶性分布的影像学表现,以期提高对该病的诊断水平.方法 对11例经病理证实的NF患者的病变部位及分布的影像学资料进行回顾性分析.结果 本组11例中,NFⅠ型7例,其中发生于脊柱及脊柱旁病变4例,胸壁伴脊柱病变1例,单纯胸壁及腹部病变各1例.NFⅡ型4例,均为女性,单侧听神经瘤伴椎管内病变1例,双侧听神经瘤3例(其中1例伴有多发脑膜瘤,1例伴有椎管内病变).结论 NF病变呈多灶性分布,NFⅠ型病变以皮肤色斑、脊柱及脊柱旁病变为多见,胸壁及腹部也可发生.NFⅡ型病变以双侧听神经纤维瘤为特点,多伴有脑膜瘤及椎管内病变.     

神经纤维瘤病Ⅰ型的MRI影像学表现

目的分析神经纤维瘤病I型(NF1)的MRI影像学表现,提高对本病的认识。方法回顾性分析26例确诊神经纤维瘤病I型患者的临床及影像学资料,26例患者均接受MRI的检查,3例患者同时接受了CT的检查,1例患者同时接受了X线检查。结果 26例神经纤维瘤病I型(NF1)中有16例颅内中枢神经系统肿瘤,5例椎管内肿瘤,1例腹腔及腹膜后内肿瘤,1例臀部丛状神经纤维瘤,1例膝关节及2例小腿肿瘤,20例合并有皮肤的咖啡牛乳色斑,12例有家族史。结论神经纤维瘤病I型具有典型MRI表现,与临床表现结合可以确诊该病。     

神经纤维瘤病的影像诊断10例分析

病例资料　回顾性分析 10例神经纤维瘤病的影像学表现 ,其中男 4例 ,女 6例 ,年龄 13～ 5 3岁 ,5例有家族史。NF Ⅰ型 8例 ,同时具有Ⅰ型和Ⅱ型特点的 2例。临床上除 2例分别有听力和视力障碍 (听神经瘤、视神经肿瘤 )外 ,均无明显症状。全部病例符合神经纤维瘤病的临床诊断标准。影像学检查包括X线平片、CT平扫、MRI( 7例行增强扫描 )。10例中 ,6例均有皮肤或皮下的多发性神经纤维瘤 ,另外伴随的局部异常有 :右侧听神经瘤 ;蝶骨大翼缺损、局部蛛网膜囊肿及相邻脑叶的异常 ;T1 、T2 椎弓缺损并脊膜膨出 ;椎旁肿物并寰枢椎脱位和C2 4椎…     

神经纤维瘤病的CT和MRI表现

目的:探讨神经纤维瘤病的CT和MRI影像表现,并就二者的优劣进行比较.方法:分析17例神经纤维瘤病的临床特点和CT、MRI表现,并就NFⅠ型与其它神经皮肤综合症、NFⅡ型与常见发生于桥小脑角区的肿瘤进行了鉴别.结果:17例神经纤维瘤病中,NFⅠ型6例,NFⅡ型11例.CT显示NF不及MRI,后者能够全面准确地显示病灶分布,病变大小、形态和信号特征以及与相邻组织结构的关系,特别是MR增强扫描能够显现伴发的颅内小病灶.结论:MRI是目前诊断神经纤维瘤病的最佳影像学检查方法,优于CT.     

Ⅱ型神经纤维瘤病的头部MRI表现

目的：强调Ⅱ型神经纤维瘤病头部ＭＲＩ的诊断和增强扫描价值。材料与方法：搜集我院行ＭＲ检查并经手术证实符合神经纤维瘤病诊断标准者３例，分析其头部ＭＲＩ表现。结果：３例中２例为双侧听神经鞘瘤，其中１例伴有双侧三叉神经鞘瘤及脑膜瘤，另１例为单侧听神经鞘瘤伴有多发小的其他颅神经鞘瘤和脑膜瘤。结论：Ⅱ型神经纤维瘤病最常表现为三叉神经和听神经肿物，ＭＲ增强扫描对发现小的病变最为敏感。     

II型神经纤维瘤病的头部MRI表现

目的：强调Ⅱ型神经纤维瘤病头部ＭＲＩ的诊断和增强扫描价值。材料与方法：搜集我院行ＭＲ检查并经手术证实符合神经纤维瘤病诊断标准者３例，分析其头部ＭＲＩ表现。结果：３例中２例为双侧听神经鞘瘤，其中１例伴有双侧三叉神经鞘瘤及脑膜瘤，另１例为单侧听神经鞘瘤伴有多发小的其他颅神经鞘瘤和脑膜瘤。结论：Ⅱ型神经纤维瘤病最常表现为三叉神经和听神经肿瘤，ＭＲ增强扫描对发现小的病变最为敏感。     

神经纤维瘤病I型的颅脑CT及MRI评价

目的：认识神经纤维瘤病I型的颅脑影像学表现，评价MRI和CT在诊断方面的价值。材料和方法：回顾性分析11例经临床确诊神经纤维瘤病患者的CT和MRI图像，同时查阅近年国内外相关研究资料，提出神经纤维瘤病I型的主要颅脑影像学表现及有关病理解释。结果：CT、MRI显示眼眶周围丛状神经纤维瘤6例，其中5例伴蝶骨翼发育不良，1例伴视神经增粗。11例中MRI显示苍白球T2WI高信号8例，其中4例表现为TlWI等信号，2例T1WI高信号，2例T1WI低信号，所有病例增强扫描均无强化。而CT扫描仪2例显示低密度。此外，MRI显示丘脑、小脑半球、脑干T2WI高信号各2例，CT无异常。结论：神经纤维瘤病I型有明显特征性颅脑改变，在显示基底节及脑白质病变方面MRI比CT更具优越性。     

神经纤维瘤病的脑部CT评价

目的：探讨神经纤维瘤病的脑部CT表现及其相关问题。方法：对15例经临床手术病理证实的神经纤维瘤病患者的临床资料与脑部CT资料进行了回顾性分析。结果：15例CT检查诊断为颅内肿瘤,其中双侧听神经瘤13例,脑膜瘤6例,单侧听神经瘤、三叉神经瘤、双侧脑室内肿瘤、胶质瘤各1例,侧脑室内脉络丛广泛钙化斑块6例。结论：CT扫描能直接全面地显示神经纤维瘤病在脑部的表现,对本病的诊断具有很高的价值。     

神经纤维瘤病I型脑内影像学表现探讨

目的探讨神经纤维瘤病I型(NF1)患者脑内影像学表现。方法回顾性分析16例临床确诊NF1患者头颅影像学资料,患者均行常规MRI平扫(T_2 WI、T_1 WI、FLAIR),增强扫描。结果 11例病变表现为基底节受累的T_2/FLAIR高信号,其中1例单侧,10例双侧;累及丘脑5例,脑干受累4例;脑内病灶形态呈斑片状,T_2WI序列共检出27个,FLAIR序列共检出39个。仅1例患者病灶呈肿块样改变;5例增强未见强化;1例MRS显示Cho/Cr:1.93,Cho/NAA:2.52;DWI未见弥散受限。其中6例CT平扫显示阴性。结论 NF1患者在颅脑具有特征性MRI表现,基底节好发,FLAIR序列较T_2序列检出病灶更具有优势;磁共振在NF1患者基底节病变的检出及定性、随诊方面具有明显优势。     

Radiological investigation of neurofibromatosis type 2

The radiological findings in six patients fulfilling the criteria of neurofibromatosis type 2 (NF2) were reviewed. Subtle cutaneous lesions were found in three. All patients had bilateral acoustic schwannomas; two had small acoustic tumours and normal hearing. In these patients the presenting symptoms were caused by multiple intracranial meningiomas and spinal neurofibromas, respectively, whereas the remaining four patients presented with hearing loss. Two patients had other cranial nerve tumours. Three patients had rapidly growing multiple intracranial meningiomas; two had multiple spinal neurofibromas and one a spinal meningioma. NF2 is a rare disease with few cutaneous but frequent, typical radiological findings in the central nervous system. The presenting symptom is most commonly hearing loss due to acoustic schwannomas, although symptoms emanating from other intracranial or tumours are not uncommon. The discovery of multiple meningiomas or multiple spinal neurofibromas without cutaneous lesions should initiate a search for acoustic schwannomas even when the patient has normal hearing.     

Encephalic lesions in neurofibromatosis: clinical manifestations and typical magnetic resonance findings

Neurofibromatosis is the commonest neuroectodermal disease. It is characterized by dysplasias and/or tumors of organs and tissues derived from the embryonic ectoderm, mesoderm and endoderm, and most frequently presents with nervous system and cutaneous lesions. It can be classified as neurofibromatosis type 1 (NF-1 or von Recklinghausen disease) and neurofibromatosis type 2 (NF-2 or bilateral acoustic neurofibromatosis). In order to assess clinical presentation of the disease and diagnostic value of Magnetic Resonance Imaging (MRI), the authors retrospectively evaluated the clinical records and the cranial MR studies of 21 patients with neurofibromatosis (18 with NF-1 and 3 with NF-2). Distinctive abnormalities between the two types were found in both clinical presentation and MR studies. Clinically, NF-1 patients presented most often with blindness, while NF-2 patients were deaf and had fewer cutaneous lesions. The evaluation of MR studies showed that NF-1 patients were more likely to be affected with intracranial gliomas, predominantly of the optic pathways. Moreover, foci of prolonged T2 relaxation were frequently observed, primarily in the globus pallidus of the basal ganglia and in the dentate nucleus of the cerebellum. Some of the foci in the globi pallidi exhibited increased signal intensity on T1-weighted images as well. NF-2 patients more frequently presented with bilateral acoustic schwannomas, meningiomas and cerebral white matter foci of prolonged T2 relaxation, but they did not have dentate and basal ganglia lesions. The authors conclude that as a rule the manifestations of NF-1 and NF-2 on cranial MRI are separate and distinct; they do not overlap. MRI is an useful clinical tool for the diagnosis and the follow-up of patients with neurofibromatosis.     

Spinal MR findings in neurofibromatosis types 1 and 2.

PURPOSE: To evaluate the frequency and nature of spinal pathology, the frequency of clinically silent lesions, and the potential benefit of screening spinal MR in neurofibromatosis patients. PATIENTS AND METHODS: 28 neurofibromatosis type-1 (NF-1) patients and nine neurofibromatosis type-2 (NF-2) patients were studied with postcontrast spinal MR imaging. RESULTS: NF-1: One patient had a biopsy-proven low-grade glioma; five patients, intradural, extramedullary masses (N = 23); one patient, extradural masses (N = 2) (neurofibromas); 16 patients had bony abnormalities; and three patients thecal sac abnormalities. NF-2: Five patients demonstrated intramedullary masses (five/eight ependymomas); nine patients, intradural, extramedullary masses (meningiomas, schwannomas); and four patients, bony abnormalities. Eight/10 NF-1 and four/nine NF-2 patients had asymptomatic masses. CONCLUSION: Intradural disease is common, often asymptomatic, and often presents at a young age in NF-1 and NF-2 patients. Because of the propensity to develop significant asymptomatic as well as symptomatic intradural disease, screening of the entire spine with MR is recommended in both NF-1 and NF-2 patients.     

腮腺腺淋巴瘤的CT和MRI表现

目的探讨腮腺腺淋巴瘤(Warthin瘤)的CT及MRI表现,旨在提高对本病的认识。资料与方法回顾性分析经手术病理证实的14例腮腺淋巴瘤的CT和MRI表现。12例行CT平扫,其中10例行增强扫描;2例行MRI平扫,其中1例行增强扫描。结果 14例共22个病灶,单侧多发3例,单侧单发9例,双侧单发2例且其中1例为术后14年对侧再发。16个(72.7%)病灶或病灶主体位于腮腺浅叶后下极,长径0.8～5.0cm,平均长径(2.3±1.3)cm,病灶呈圆形或卵圆形;19个(86.4%)病灶边缘光整,3例单发病灶边缘模糊,手术证实合并感染。12例(共18个病灶)CT平扫14个(77.8%)病灶密度均匀,4个(22.2%)病灶密度不均匀;10例(共15个病灶)增强扫描7个(46.7%)病灶呈明显强化,5个(33.3%)病灶呈中度强化,3个(20%)病灶呈轻度强化。3个病灶可见边缘线样强化。MRI上肿瘤呈均匀或不均匀信号,T1WI呈低信号,T2WI呈中等或高信号;平扫包膜呈环状低信号,增强扫描呈轻度强化。结论中老年男性,病灶位于腮腺后下极,边缘清晰,明显强化,特别是双侧或多发病灶,并有吸烟史者,应首先考虑腮腺腺淋巴瘤的诊断。     

Sensitivity of Gd-DTPA-enhanced MR imaging of benign extraaxial tumors

The effect of gadolinium diethylenetriaminepentaacetic acid (DTPA) on the sensitivity of cranial magnetic resonance (MR) imaging was measured in a prospective blinded study. Twenty-two consecutive patients with benign extraaxial tumors underwent MR imaging on a 1.5-T system without and with intravenous administration of Gd-DTPA. Readers independently interpreted the unenhanced and enhanced images without clinical information. The interpretations were compared with the anatomically verified diagnoses. Gd-DTPA improved the sensitivity of MR imaging for benign extraaxial tumors, especially in cases of residual or recurrent acoustic neuromas, multiple tumors (e.g., neurofibromatosis), or inconclusive unenhanced MR images. Enhancement with Gd-DTPA impaired the identification of a skull base tumor.     

Extracerebral neoplastic manifestations in neurofibromatosis 1: integrated diagnostic imaging

PURPOSE: To analyze the extracerebral manifestations of type 1 neurofibromatosis (NF-1), with special reference to peripheral nerve tumors. MATERIAL AND METHODS: The findings of 376 NF-1 patients (194 men and 182 women; age range: 0.1-48 years, mean: 8.1) were retrospectively reviewed. The patients had been submitted to abdominopelvic and superficial US and, in case of abnormal US findings or in the presence of symptoms, to CT and/or MRI. In addition, we considered 5 more patients (2 men and 3 women; age range: 50-72 years, mean: 64.4) with incomplete forms of NF-1 diagnosed after the finding of nerve sheath tumors. Biopsy (12 cases), surgery (10 cases), or clinical-instrumental follow-up were the study criteria. RESULTS: In the first group of patients we identified 91 cutaneous, 222 subcutaneous, 11 pendulous and 25 internal neurofibromas. Plexiform neurofibromas were found in the neck (1 case), chest (6 cases), abdomen (16), pelvis (8). We also found 1 benign and 1 malignant Schwannomas, 2 nerve sheath fibrosarcomas, 1 dopamine-producing sympatoma and 1 spermacytoma. As for the second group of patients, we had 2 Schwannomas, 1 pulmonary neurofibroma, and 2 multiple plexiform neurofibromas. The neurofibromas exhibited homogeneous US hypoechogenicity or slight echogenicity, with little contrast enhancement at CT. MR showed peripheral hyperintensity and central hypointensity on T2-weighted sequences and marked contrast enhancement after gadolinium, sometimes with mostly central uptake. The plexiform neurofibromas, which are typical of NF-1, had poorly-defined or infiltrating margins, with similar findings to the previous ones but sometimes with less homogeneous patterns at both US and CT. The Schwannomas, which are a less common finding in NF-1, exhibited different features at MRI and CT, namely pseudo-liquid or solid-inhomogeneous patterns with irregular and inhomogeneous contrast enhancement relative to the Antoni A/B tumor component. In the malignant lesions we observed infiltrating patterns, with irregular and inhomogeneous contrast enhancement, arranged asymmetrically relative to the contralateral lesion. CONCLUSIONS: Extra-axial neoplasms are a frequent finding in NF-1. Despite the extremely variable appearances of some lesions (particularly Schwannomas), the typical plexiform neurofibroma exhibits characteristic patterns. The diagnosis of malignancy often requires bioptic confirmation.     

肝再生性结节的MRI诊断

目的:总结肝再生性结节(RN)的MRI平扫及动态增强的表现,以与其它结节进行鉴别.方法:搜集行Gd-DTPA动态增强磁共振检查的RN病例共30例,全部病例均经手术切除病理或穿刺活检证实.MRI均行平扫、动态增强及延迟增强扫描,分析结节的信号特征及动态增强曲线.结果:肝再生性结节包括弥漫分布的小结节18例(铁质沉着性结节6例和非铁质沉着性结节12例)和大结节12例17个病灶.铁质沉着性结节在增强各期均无强化,时间-信号强度曲线较平直;大部分非铁质沉着性结节在T1WI上和T2WI上均为中等信号,周围纤维间隔为偏低信号,动态及延迟增强扫描结节轻度强化,时间-信号强度曲线与正常肝组织类似.本组所选大结节为直径大于0.5 cm、T1WI高信号、T2WI低信号的病灶,其中10个病灶(占58.8%)在T1W/WATS上信号高于T1W/IP.动态增强各期病灶无明显强化,时间-信号强度曲线显示病灶的曲线为缓慢上升型.结论:肝再生性结节有不同类型及表现形式,其中孤立的大结节型RN需与肝内其它结节鉴别.     

MR imaging of spinal neurofibromatosis

The MR findings in 7 patients with neurofibromatosis involving the spine were evaluated. Six patients had paraspinal tumors at multiple levels. In 4 they were bilateral. Five patients had multiple intraspinal lesions, frequently with growth through the neural foramen. In one patient paraspinal tumors were found in the lumbar sacral plexus and in another bony dysplasia and meningoceles but no tumors were disclosed. In 2 patients the lesions were associated with bilateral acoustic neuromas and multiple intracranial meningeomas. In one of these a spinal meningeoma with signal characteristics close to spinal cord was found. The other tumors had a signal that was equal to or slightly lower than the spinal cord and slightly higher than muscle on T1-weighted images. On T2-weighted images the tumors had a markedly increased signal compared to surrounding tissue. In 3 patients with tumors larger than 4 cm the signal intensity was inhomogeneous with decreased signal in the center on T2-weighted images, indicating the presence of increased fibrous tissue. Gadolinium-DTPA was given to one patient with marked increase in intensity of small tumors on T1-weighted images. The study shows that MR imaging is the modality of choice for evaluating most aspects of spinal and paraspinal neurofibromatosis.     

Whole body MR imaging in neurofibromatosis type 1

Objective

To assess the value of whole body MR imaging in patients with neurofibromatosis type 1 (NF1).

Materials and methods

24 patients (15–59 years; mean and median 36 years; 7 males; 17 females) with genetically proven neurofibromatosis type 1 were examined with whole body MR imaging. Axial and coronal T1- and fat-suppressed T2-weighted images (slice thickness 6–12 mm) were acquired on a 1.5 T MR unit (Symphony; Siemens, Erlangen, Germany). The images were reviewed by 2 radiologists: 1 senior, 1 junior. The criterion for a neurofibroma was a mass lesion with low signal intensity on T1 and high signal intensity on T2, along the course of a nerve. The location, size, general morphology and course along plexuses and nerves were evaluated. Cutaneous and subcutaneous neurofibromas were defined as “superficial” neurofibromas. The other neurofibromas were regarded as “deep” neurofibromas.

Results

There were no major problems to differentiate neurofibromas from lymph nodes, vessels or cysts. The latter three were easily recognised by their typical shape and location, whereas neurofibromas occurred in regions where no mass lesion was anatomically expected. There was no relation between age and total number of neurofibromas throughout the body. Classification according to location and number of neurofibromas: 8 patients had only superficial neurofibromas, 1 only deep and 15 both superficial and deep lesions. Twelve patients had less than 15 neurofibromas and 12 had more. Classification according to course: in 8 patients the neurofibromas occurred along plexuses or proximal part of the intercostal nerves; in 16 patients the lesions were more peripheral. Classification according to morphology: 4 patients had plexiform neurofibromas and 20 patients had multiple solitary lesions. Twelve of these 20 patients had less than 15 lesions, and 8 had more. In 2 patients multiple solitary neurofibromas occurred along the nerve in a chain configuration. In one patient a clinically unsuspected brain tumour was found.

Conclusion

Whole body MR imaging is a reliable method to evaluate the distribution, size and morphology of neurofibromas in patients with NF1.