颅内胶质瘤柔脑膜扩散的MR影像学研究

目的 探讨颅内胶质瘤柔脑膜扩散的ＭＲ影像学特征。为临床治疗及估计预后提供参考。方法 共集颅人胶质瘤９４５例,其中星形细胞瘤６２０例,多形成胶质细胞溜３２５例,对其中具有柔脑扩散的７２例胶质瘤的临床及ＭＲＩ资料进行回顾性分析。结果 ７２例具有柔脑膜扩散的胶质瘤中,星形细胞瘤２９例,多形成胶质细胞瘤４３例,柔脑膜发生率分别为４．７％和１３．２％。颅内胶瘤中,星形细胞瘤２９例,多形成胶质细胞瘤４３例,柔     

颅内多发原发性肿瘤的CT与MRI诊断

目的：报道１５例颅内多发原发性肿瘤的ＣＴ和ＭＲＩ表现，并评价ＣＴ与ＭＲＩ的诊断价值。方法：１５例颅内多发原发性肿瘤均行ＣＴ检查，其中４例行ＭＲＩ检查，均经手术病理证实。结果：多发胶质瘤４例，其中恶性室宫膜瘤３例，表现为脑室内及额顶叶脑实质内实质性肿块或囊性病变，多发星形细胞瘤１例，病变分别位于额叶及小脑蚓部；双侧听神经瘤及多发脑膜瘤各３例、ＣＴ和ＭＲＩ表现均较典型；脑膜瘤合并胶质瘤３例、脑膜瘤合并听神经瘤１例和垂体瘤合并胶质瘤１例。结论：结合肿瘤的ＣＴ和ＭＲＩ表现特点，可对大多数颅内多发原发性肿瘤作出正确诊断，ＭＲＩ对脑膜瘤的诊断优于ＣＴ。     

脑内神经节胶质瘤一例报告及文献复习

报告１例颅内神经节胶质瘤，并通过复习文献，着重分析和讨论了中枢神经系统神经胶质瘤的临床和ＣＴ及ＭＲＩ表现。     

颅内淋巴瘤的MRI诊断

目的 探讨颅内淋巴瘤的ＭＲＩ影像学特征。材料与方法 对１１例经手术及立体定向活检病理证实的颅内淋巴瘤的ＭＲＩ影像学表现进行回顾性分析。结果 病灶单发或多发,以幕上分布为主;圆形或不规则形,Ｔ１ＷＩ呈低信号,Ｔ２ＷＩ呈等或高信号,信号多均匀;瘤周水肿及占位效应多较轻;增强扫描病灶均明显强化;可侵及软脑膜和／或室管膜并沿之播散;对放、化疗敏感;形态、大小可变化。结论 颅内淋巴瘤ＭＲＩ表现缺乏特征性,活     

侧脑室肿瘤的CT和MRI诊断

目的：评价ＣＴ和ＭＲＩ对侧脑室肿瘤的诊断价值。材料和方法：经手术病理证实的侧脑室肿瘤共５６例，回顾性分析其ＣＴ和ＭＲＩ表现，病变按部位分为侧脑室三角区、侧脑室体部、室间孔区３个部分，按年龄分为＜１０岁、１０～３９岁、＞４０岁３个年龄组。结果：（１）大多数侧脑室肿瘤如脑膜瘤、星形胶质细胞瘤、少枝胶质瘤、脉络丛乳头状瘤等具有特征性的ＣＴ和ＭＲＩ表现；（２）部分肿瘤具有其好发部位，如脑膜瘤、脉络丛乳头状瘤、海绵状血管瘤好发于三角区，少枝胶质瘤好发于体部，室管膜下巨细胞型星形胶质瘤、室管膜下瘤好发于室间孔区；（３）某些肿瘤具有年龄学特征，如脉络丛乳头状瘤均＜１０岁，脑膜瘤３０岁以上者占８２．３５％，室管膜下瘤均超过４０岁。结论：侧脑室肿瘤的诊断主要依据其ＣＴ和ＭＲＩ表现，结合发生部位和年龄特征，可进一步提高诊断正确率。     

颅内混合瘤的CT、MRI诊断(附七例报告)

目的提高对颅内混合瘤影像学表现的认识，丰富诊断学知识。材料与方法７例颅内混合瘤均经手术病理证实，其中脑膜瘤和胶质母细胞瘤的混合瘤２例，脑膜瘤和垂体瘤的混合瘤２例，多形性胶质母细胞瘤和血管母细胞瘤的混合瘤１例，胆脂瘤和黑色素瘤的混合瘤１例，垂体瘤和脑膜瘤的混合瘤１例。回顾性分析此７例混合瘤的ＣＴ、ＭＲＩ表现。结果颅内混合瘤的ＣＴ、ＭＲＩ表现酷似脑膜瘤、胶质瘤和垂体瘤等，不熟悉此类肿瘤的临床和病理知识，可错诊为常见肿瘤。对照临床和手术病理改变，可发现有４例混合瘤的ＣＴ、ＭＲＩ显示在同一部位的同一肿瘤有两种肿瘤表现特点。结论颅内混合瘤无特征性ＣＴ、ＭＲＩ表现，对于酷似脑膜瘤、胶质瘤和垂体瘤等，高度可疑混合瘤者，应结合临床考虑诊断。     

颅内恶性胶质瘤术后早期MR影像学表现－

目的 探讨颅内恶性胶质瘤术后的ＭＲＩ表现。方法 选取５５９例恶性胶质瘤作为试验组,１２６例良性星形细胞瘤作为对照组,回顾性分析其ＭＲ清现,所有病例均经手术与病理证实,并在术后２个月内至少行１次ＭＲ平扫及增强扫描,全部病例均追踪至软化灶形成或肿瘤复发。结果 颅内恶性胶质瘤术后ＭＲＩ表现主要有以下特点：⑴术后反应性增强的发生率为７６．４％（４１７/５５９）,在术后８～２５d时强化明显,其环形增强的厚度一     

颅内胶质瘤术后脑组织正常反应与肿瘤残存的MR影像学分析

目的 分析颅内胶质瘤术后脑组织反应性增强与肿瘤残存增强的影像学特点。方法回顾性分析２０４例胶质瘤术后的ＭＲＩ表现,其中男１４１例,女６３例,年龄１２－６８岁,平均３９．１岁。所有病例均在术前进行ＭＲＩ检查,并在术后１个月内至少行１次ＭＲＩ平扫及增强扫描,且均追踪至办化灶形成或肿瘤复发。使用Ｗｉｎｄｏｗｓ７．５版社会科学统计软件包（ｓｔａｔｉｓｔｉｃｓ ｐａｃｋａｇｅ ｆｏｒ ｓｏｃｉａｌ ｓｃｉｅ     

鼻咽癌颅内侵犯的MRI诊断

目的：评价Ｇｄ－ＤＴＰＡ增强后ＭＲＩ对鼻咽癌放疗后复发及颅内侵犯的诊断价值。材料和方法：对颅内侵犯的２０例放疗后复发和７例初发鼻咽癌患者比较ＣＴ及ＭＲＩ增强前后检查结果。结果：２７例鼻咽癌侵犯颅内者几乎均有颅底骨质破坏,比较ＣＴ和ＭＲＩ检查,增强ＣＴ显示颅内侵犯确定、可疑和不明确者各占１／３,增强ＭＲＩ都可显示清楚,且较好确定肿瘤的复发。结论：增强ＭＲＩ可作为鼻咽癌复发和颅内侵犯的主要诊断方法。     

颅内结核性脑膜炎的MRI诊断

目的 评估ＭＲＩ对颅内结核性脑膜炎的诊断价值。材料与方法 对１８例颅内结核怀脑膜炎的ＭＲＩ表现、Ｇｄ－ＤＴＰＡ增强的作用和追踪ＭＲＩ的变化进行分析。结果 ＭＲＩ显示脑膜炎１３例,表现为蛛网膜腔狭窄和消失,脑脊液分房。在增强ＭＲＩ上,受累的脑膜呈线形、弥漫性斑块和结节状或环状显著性强化。结核性脑膜炎合并结核瘤２例,结核性脑脓肿２例,脑梗塞１例。结论 结核性脑膜炎的ＭＲＩ表现有一定的特点,增强ＭＲＩ可     

Gd-DTPA-enhanced MR imaging of leptomeningeal spread of primary intracranial CNS tumor in children

Three children with known primary brain neoplasms and leptomeningeal disease were evaluated with MR imaging. Two of the patients had medulloblastoma and one had pineoblastoma. The presence of leptomeningeal tumor spread was established by positive CSF cytopathology in conjunction with compatible contrast-enhanced CT findings. Contrast-enhanced CT, nonenhanced MR, and Gd-DTPA-enhanced MR studies were then compared. In two cases, leptomeningeal lesions were seen better with Gd-DTPA-enhanced MR than with contrast-enhanced CT. In all three cases, Gd-DTPA MR imaging revealed lesions that were not identified on noncontrast MR. Gd-DTPA-enhanced MR imaging is useful when searching for intracranial leptomeningeal tumor deposits in pediatric patients at risk for this condition.     

Intraoperative MR imaging increases the extent of tumor resection in patients with high-grade gliomas.

BACKGROUND AND PURPOSE: MR is being used increasingly as an intraoperative imaging technique. The purpose of this study was to test the hypothesis that intraoperative MR imaging increases the extent of tumor resection, thus improving surgical results in patients with high-grade gliomas. METHODS: Thirty-eight patients with intracranial high-grade gliomas underwent 41 operations. Using a neuronavigation system, tumors were resected in all patients to the point at which the neurosurgeon would have terminated the operation because he thought that all enhancing tumor had been removed. Intraoperative MR imaging (0.2 T) was performed, and surgery, if necessary and feasible, was continued. All patients underwent early postoperative MR imaging (1.5 T). By comparing the proportions of patients in whom complete resection of all enhancing tumor was shown by intraoperative and early postoperative MR imaging, respectively, the impact of intraoperative MR imaging on surgery was determined. RESULTS: Intraoperative MR imaging showed residual enhancing tumor in 22 cases (53.7%). In 15 patients (36.6%), no residual tumor was seen, whereas the results of the remaining four intraoperative MR examinations (9.7%) were inconclusive. In 17 of the 22 cases in which residual tumor was seen, surgery was continued. Early postoperative MR imaging showed residual tumor in eight patients (19.5%) and no residual tumor in 31 cases (75.6%); findings were uncertain in two patients (4.9%). The difference in the proportion of "complete removals" was statistically highly significant (P = .0004). CONCLUSION: Intraoperative MR imaging significantly increases the rate of complete tumor removal. The rate of complete removal of all enhancing tumor parts was only 36.6% when neuronavigation alone was used, which suggests the benefits of intraoperative imaging.     

颅内生殖细胞瘤转移的MRI表现

目的　探讨颅内生殖细胞瘤转移的MR影像学表现 ,为临床治疗方案的选择提供影像学依据。方法　结合文献资料 ,对10例具有转移灶的颅内生殖细胞瘤患者的临床与MRI资料进行分析。结果　 2 5例颅内生殖细胞瘤中的 10例发生转移 ,转移发生率 40 %,其增强MRI可表现为 :①软脑膜条索状增粗 ;②脑或脊髓表面的结节状信号 ,病变累及部位弥漫性肿胀 ,信号不均 ,脑沟消失 ;③肿瘤前部楔形缺损或三脑室后部“笔尖样”扩大 ;④室管膜下层片状或弥漫性高信号 ;⑤颅外转移征象等。结论　增强MRI能准确检测颅内生殖细胞瘤转移 ,为临床确立合理治疗方案提供有价值信息。     

Expanding experience with spontaneous dermoid rupture in the MRI era: diagnosis and follow-up

With widespread use of CT and MR imaging, experience with spontaneous dermoid rupture has significantly increased. What was previously believed to be a generally severe or even fatal accident, being the diagnosis made either at surgery or autopsy, or in patients with such consequent conditions as chemical meningitis or obstructive hydrocephalus, now appears to be more frequent than previously thought, and there is some evidence that it may also cause only a slight symptomatology or even be quite asymptomatic. We reviewed the clinical and imaging data of our series of five patients with spontaneously ruptured dermoids, spinal in one case, and intracranial supratentorial in four. These had their diagnosis following mild symptoms (number two cases) or incidentally (number two cases); the spinal tumor caused acute bladder dysfunction, possibly while undergoing rupture, and was associated with indolent intracranial fat spread. Three of the patients also had MR demonstration of asymptomatic persistence of fat spread in the subarachnoid spaces, respectively, 3, 4, and 5 years after rupture. One of the five cases, concerning a parasellar dermoid followed up over 6 years, provides the first demonstration of MR signal intensity change of the tumor prior to rupture.     

Radiation necrosis versus glioma recurrence: conventional MR imaging clues to diagnosis

BACKGROUND AND PURPOSE: Conventional MR imaging findings are considered to be inadequate for reliably distinguishing radiation necrosis from tumor recurrence in patients with glioma. Despite this belief, we hypothesized that certain conventional MR imaging findings, alone or in combination, though not definitive, may favor one or another of these diagnoses in proton beam-treated patients with new enhancing lesions on serial scanning. METHODS: MR imaging findings (axial T1-, T2-, and post-gadolinium T1-weighted) of 27 proton beam radiation therapy patients with high-grade gliomas were retrospectively reviewed. Entry criteria included new MR imaging enhancing lesions after treatment and histologically unequivocal biopsy proof of diagnosis. Readers rated corpus callosum involvement, midline spread, subependymal spread, new discrete multiple enhancing foci, a "spreading wavefront" appearance, and septum pellucidum involvement. Statistical analysis was by the Fisher exact test. RESULTS: Corpus callosum involvement in combination with multiple other findings was highly associated with progressive glioma. These combinations included involvement of the corpus callosum with multiple enhancing foci (P = .02), involvement of the corpus callosum with crossing the midline and multiple enhancing lesions (P = .04), and involvement of the corpus callosum with subependymal spread and multiple enhancing lesions (P = .01). CONCLUSIONS: In proton beam-treated patients with glioma, corpus callosum involvement, in conjunction with multiple enhancing lesions with or without crossing of the midline and subependymal spread, favors predominant glioma progression. Overall, combinations of enhancement patterns were more likely than individual patterns to distinguish necrosis from predominant tumor progression. Together with clinical and functional imaging findings, these results may assist in determining the need for biopsy.     

扩散张量成像在颅内肿瘤周围白质区的应用

目的：评价MR扩散张量成像技术在不同级别胶质瘤、脑膜瘤及转移瘤周围正常脑白质区的应用价值。方法：对43例颅内肿瘤患者行常规MRI及扩散张量成像检查,其中高级别胶质瘤12例,低级别胶质瘤10例,脑膜瘤12例、转移瘤9例。测量瘤周正常脑白质的FA值及对侧相应解剖部位正常脑白质的FA值,行组间统计学分析。结果：高级别胶质瘤瘤周正常脑白质FA值低于对侧正常脑白质FA值,差异有统计学意义（P〈0.05）;低级别胶质瘤、脑膜瘤及转移瘤FA值的差异无统计学意义。高级别胶质瘤瘤周正常脑白质FA值与低级别胶质瘤、脑膜瘤、转移瘤瘤周正常脑白质之间差异有统计学意义,后三者之间的差异比较无统计学意义。结论：MR扩散张量成像技术有助于颅内肿瘤的定性诊断及推测肿瘤细胞的浸润范围。     

MR recognition of supratentorial tumors

Eighty patients with intrinsic tumors of the cerebral hemispheres and thalami were studied with a 0.5 T superconducting system and third- or fourth-generation computed tomographic (CT) scanners. Twenty-eight patients had histologically verified gliomas, 34 were presumed to have primary brain tumors on clinical grounds, 13 had metastases, and five were postoperative. Lesions shown on CT were equally well demonstrated on magnetic resonance (MR) imaging; more metastases were seen on MR than on CT images. MR revealed abnormal signals in 10 cases in which CT findings were equivocal. It was not possible to differentiate edema from tumor in many cases using the MR imaging sequences currently available. The histologic types of the tumors could not be determined from the MR appearances.     

Invasive cervical carcinoma: MR imaging after preoperative chemotherapy

To evaluate assessment of tumor regression with magnetic resonance (MR) imaging, the authors studied 21 consecutive patients with cervical carcinoma tumors that were more than 3 cm in diameter. Thirteen of the 21 also demonstrated parametrial invasion. In all cases, MR imaging was performed both before and after chemotherapy. Pathologic specimens were obtained at hysterectomy in all patients. Comparison of pathologic and MR imaging findings after chemotherapy showed that all tumors decreased in size. Size of tumor was correctly determined at MR in 17 cases and was slightly overestimated in four cases. Five patients had residual parametrial invasion that was histologically confirmed. In detecting parametrial spread after treatment, MR imaging had an accuracy of 90.4%. Tumors had high signal intensity on T2-weighted images, whereas intratumoral necrosis was characterized by low signal intensity on the same images. Peritumoral inflammatory tissue found at pathologic examination in four of 21 cases was not specifically identified on MR images. In patients with invasive cervical carcinoma, MR imaging may be useful in evaluating tumor response to preoperative chemotherapy.     

Imaging and clinical characteristics of temporal bone meningioma

BACKGROUND AND PURPOSE: Imaging characteristics of temporal bone meningioma have not been previously reported in the literature. CT and MR imaging findings in 13 cases of temporal bone meningioma are reviewed to define specific imaging features. METHODS: A retrospective review of our institutional case archive revealed 13 cases of histologically confirmed temporal bone meningioma. CT and MR imaging studies were reviewed to characterize mass location, vector of spread, bone changes, enhancement characteristics, and intracranial patterns of involvement. Clinical presenting signs and symptoms were correlated with imaging findings. RESULTS: Thirteen temporal bone meningiomas were reviewed in 8 women and 5 men, aged 18-65 years. Meningiomas were stratified into 3 groups on the basis of location and tumor vector of spread. There were 6 tegmen tympani, 5 jugular foramen (JF), and 2 internal auditory canal (IAC) meningiomas. Tegmen tympani and JF meningiomas were characterized by spread to the middle ear cavity. IAC meningiomas, by contrast, spread to the cochlea and vestibule. Hearing loss was the most common clinical presenting feature in all cases of temporal bone meningioma (10/13). The presence of tumor adjacent to the ossicles strongly correlated with conductive hearing loss (7/9). CONCLUSION: Meningioma involving the temporal bone is rare. Three subgroups of meningioma exist in this location: tegmen tympani, JF, and IAC meningioma. Tegmen tympani and JF meningiomas spread to the middle ear cavity. IAC meningiomas spread to intralabyrinthine structures. Conductive hearing loss is commonly seen in these patients and can be surgically correctable.