Sturge-Weber syndrome. Diagnostic imaging relative to neuropathology

Clinical presentation of a child with port-wine stain and seizures leads to the suspicion of Sturge-Weber disease (SWD). This diagnosis can be confirmed by the detection of a meningeal angiomatosis. In rare cases, early detection of meningeal pathology by ultrasound has been reported. Key findings are brain atrophy, gyriform cortical calcifications demonstrated by skull radiographs after the first year of life or earlier by cranial CT, and dys- or aplasia of the deep cerebral veins on angiography. Radionuclide imaging shows focal or diffuse tracer accumulation over the affected brain regions. MR demonstrates an abnormal appearance of the affected meninges, especially thickening and pathologically increased signal intensity after Gd-DTPA application. This, in association with the demonstration of abnormal enhancement in deep medullary veins, is the most characteristic finding. Contrast-enhanced MR allows early and non-invasive diagnosis of SWD, mainly by revealing leptomeningeal angiomatosis and abnormal venous vessels.     

系统性恶性肿瘤所致脑膜癌病的磁共振成像表现

目的 探讨脑膜癌病的MRI表现特点,提高对脑膜癌病的影像学认识和诊断水平。方法 经确诊的脑膜癌病11例,MR常规扫描后均行钆喷替酸葡甲胺（Gd－DTPA）增强扫描,对其增强特点及病变类型进行回顾性分析。结果 MR平扫均未见脑膜异常信号。增强扫描后9例显示软脑膜异常增强,表现为脑表面连续的、可延伸至脑沟内的细线状高信号,累及范围包括小脑、脑干及大脑表面,但未见明确的蛛网膜下腔异常增强。3例显示硬脑膜－蛛网膜异常增强,表现为大脑凸面,其中1例同时累及小脑凸 面和小脑幕。9例累及软脑膜者脑脊液均为异常,2例仅累及硬脑膜－蛛网膜者脑脊液均为正常。结论 MR增强扫描能很好地显示脑膜癌病,根据增强特点可以区分脑膜癌 病的类型,结合临床对脑膜癌病能作出诊断并指导治疗。     

Metastatic disease of the brain: extra-axial metastases (skull, dura, leptomeningeal) and tumour spread

Extra-axial intracranial metastases may arise through several situations. Hematogenous spread to the meninges is the most frequent cause. Direct extension from contiguous extra-cranial neoplasms, secondary invasion of the meninges by calvarium and skull base metastases, and migration along perineural or perivascular structures are less common. Leptomeningeal invasion gives rise to tumour cell dissemination by the cerebrospinal fluid (CSF), eventually leading to neoplastic coating of brain surfaces. Contrast-enhanced magnetic resonance (MR) imaging is complementary to CSF examinations and can be invaluable, detecting up to 50% of false-negative lumbar punctures. MR findings range from diffuse linear leptomeningeal enhancement to multiple enhancing extra-axial nodules, obstructive communicating and non-communicating hydrocephalus. Both calvarial and epidural metastases infrequently transgress the dura, which acts as a barrier against tumour spread. Radionuclide bone studies are still a valuable screening test to detect bone metastases. With computed tomography (CT) and MR, bone metastases extending intracranially and primary dural metastases show the characteristic biconvex shape, usually associated with brain displacement away from the inner table. Although CT is better in detecting skull base erosion, MR is more sensitive and provides more detailed information about dural involvement. Perineural and perivascular spread from head and neck neoplasms require thin-section contrast-enhanced MR.     

Correlation of MRI and clinical features in meningeal carcinomatosis

Ten patients with meningeal carcinomatosis associated with nonhaemoatological neoplasms were examined: six with breast, two with gastrointestinal and one with lung cancer, plus one with a tumour of unknown origin. Cytology was positive in all but one. The patients were classified into four groups according to the gadolinium-enhanced MRI (Gd-MRI) appearances: group 1 had pure leptomeningeal carcinomatosis, group 2 dural carcinomatosis, group 3 spinal leptomeningeal carcinomatosis, and group 4 had normal Gd-MRI except for hydrocephalus. In group 1, Gd-MRI showed diffuse enhancement of the subarachnoid space, including the cisterns around the midbrain, the sylvian fissures, or cerebellaar and cerebral sulci. In group 2, Gd-MRI showed diffuse, thick, partially nodular enhancement of the duramater. No leptomeningeal or subependymal enhancement was evident. In group 3, nodular masses were seen only in the spinal canal. In group 4, no definite evidence of meningeal carcinomatosis was demonstrated on contrast-enhanced CT (CE-CT) or Gd-MRI. The median suvival time was 2.0 months in group 1, 1.0 month in group 3, and 4.5 months in group 4, but the two patients in group 2 were alive 10 and 15 months after a definite diagnosis of meningeal carcinomatosis was made. In all patients examined by both CE-CT and Gd-MRI, the latter was superior for identification of meningeal carcinomatosis. Hydrocephalus in an important indirect sign of leptomeningeal carcinomatosis, but was not seen in patients with dural carcinomatosis despite the presence of increased intracranial pressure.     

Intracranial meningeal disease: comparison of contrast-enhanced MR imaging with fluid-attenuated inversion recovery and fat-suppressed T1-weighted sequences

BACKGROUND AND PURPOSE: Contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging has been reported to have higher sensitivity for detecting leptomeningeal disease compared with contrast-enhanced T1-weighted MR imaging. The purpose of this study was to compare contrast-enhanced T1-weighted MR images with fat suppression to contrast-enhanced FLAIR images to determine which sequence was superior for depicting meningeal disease. METHODS: We reviewed MR images of 24 patients (35 studies) with a variety of meningeal diseases. The MR imaging protocol included contrast-enhanced T1-weighted MR images with fat suppression (FS) and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images that were reviewed by three neuroradiologists and were assigned a rating of positive, equivocal, or negative for abnormal meningeal enhancement. The two sequences were compared side by side to determine which better depicted meningeal disease. RESULTS: Abnormal meningeal enhancement was positive in 35 contrast-enhanced T1-weighted MR images with FS and in 33 contrast-enhanced FLAIR studies. In the first group, which had the T1-weighted sequence acquired first (21 of 33 studies), contrast-enhanced T1-weighted images with FS showed superior contrast enhancement in 11 studies (52%), inferior contrast enhancement in six studies (29%), and equal contrast enhancement in four studies (19%) compared with the contrast-enhanced FLAIR images. In the second group, which had the FLAIR sequence acquired first (12 of 33), contrast-enhanced T1-weighted images with FS showed superior contrast enhancement in seven studies (58%), inferior contrast enhancement in two studies (17%), and equal contrast enhancement in three studies (25%). CONCLUSION: Contrast-enhanced T1-weighted MR imaging with FS is superior to contrast-enhanced FLAIR imaging in most cases for depicting intracranial meningeal diseases.     

脑膜癌病的MRI表现

目的探讨脑膜癌病的MRI表现特点. 资料与方法对13例确诊为脑膜癌病的患者,行头颅MRI常规扫描和Gd-DTPA增强扫描,分析脑膜癌病患者的MRI表现. 结果 MRI常规扫描脑膜均未见异常.增强后,按脑膜强化的部位分:硬脑膜-蛛网膜强化1例,软脑膜-蛛网膜下腔强化2例,混合型强化8例;按脑膜强化的形式分:线型强化7例,混合型强化4例,无单纯结节型强化.2例脑膜无任何形式强化的患者,其中1例腰髓增强MRI检查见硬脊膜线型强化.其他影像学表现为脑沟回消失、侧脑室增大、交通性脑积水等. 结论国内脑膜癌病患者的MRI表现与国外不一致,国内患者更适合采用脑膜强化的形式分类方法,增强MRI检查在显示脑膜异常方面极为敏感,对诊断脑膜癌病有重要作用.     

Gd-DTPA enhanced MR imaging in intracranial tuberculosis

Summary Twenty-six patients with intracranial tuberculosis (Tb) (10 with acute meningitis, 5 with chronic meningitis, 5 with meningitic sequelae and 6 with localized tuberculoma(s) were examined with MR before and after Gd-DTPA enhancement (0.1 mmol/kg), using 2.0T superconducting unit, and the images were retrospectively analyzed and compared with CT scans. Without Gd-DTPA enhancement, the MR images were generally insensitive to detection of active meningeal inflammation and granulomas. The signal intensity of granulomas was usually isointense to gray matter on both T1- and T2-weighted images, whether they were associated with diffuse meningitis or presented as localized tuberculoma(s). A few granulomas showed focal hypointensity on T2-weighted images. Calcifications seen on CT of the meningitic sequelae group usually appeared markedly hypointense on all spin-echo sequences. On Gd-DTPA enhanced T1-weighted images, abnormal meningeal enhancement indicating active inflammation was conspicuous, and the granulomas often appeared as conglomerated ring-enhancing nodules, which seems to be characteristic of granulomas. Thin rim enhancement around the suprasellar calcifications were observed in two out of 5 patients with meningitic sequelae. Compared with CT, MR detected a few more ischemic infarcts, hemorrhagic infarcts, meningeal enhancement and granulomas in the acute meningitis group, but missed small calcifications in the basal cisterns well shown on CT in the sequelae group. Otherwise, MR generally matched CT scans. MR imaging appears to be superior to CT in evaluation of active intracranial Tb only if Gd-DTPA is used, while CT is better than MR in evaluating meningitic sequelae with calcification.     

FLAIR MR imaging for diagnosing intracranial meningeal carcinomatosis

OBJECTIVE: The purpose of this study was to compare unenhanced and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging with other sequences to visualize meningeal carcinomatosis. MATERIALS AND METHODS: Unenhanced FLAIR images were compared with spin echo T2-weighted and contrast-enhanced FLAIR images in five patients with documented meningeal carcinomatosis and four patients with suspected meningeal carcinomatosis. Comparisons were also made between contrast-enhanced T1-weighted and FLAIR images. RESULTS: In six patients, the unenhanced FLAIR images showed areas of abnormal hyperintensity within the sulci that were not noted on the spin-echo T2-weighted images. In all patients, the contrast-enhanced FLAIR images also showed meningeal enhancement, periventricular enhancement, or both. The contrast-enhanced T1-weighted and FLAIR images were equivalent in their depiction of abnormal enhancement in five of the nine patients; contrast-enhanced FLAIR images were superior in three patients. CONCLUSION: Unenhanced FLAIR images are of more value than spin-echo T2-weighted images for the diagnosis of intracranial meningeal carcinomatosis. Contrast-enhanced FLAIR images can sometimes surpass contrast-enhanced T1-weighted images in their quality.     

High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. Received: 5 June 1997 Accepted: 12 June 1997     

Neoplastic vs inflammatory meningeal enhancement with Gd-DTPA

We studied 40 consecutive patients clinically suspected of having meningeal disease, in whom both Gd-diethylenetriamine pentaacetic acid (DTPA)-enhanced magnetic resonance (MR) examinations and CSF or surgical pathologic samples were obtained. The MR examinations were retrospectively reviewed for the presence of abnormal meningeal enhancement, as well as pattern and site of enhancement. The MR findings correctly correlated with pathology results in 15 of 19 patients with suspected tumor involvement (including one true negative) and in 18 of 21 patients with suspected inflammatory meningeal conditions (including 2 true negatives). Pial enhancement was demonstrated in 62% (10 of 16) of patients with meningitis and in 29% (4 of 14) of patients with meningeal neoplastic involvement. A diffuse meningeal distribution was commonly present with inflammatory conditions (69%, 11 of 16). A nodular appearance was seen in two patients with tumor involvement of the meninges as well as in a single case of sarcoidosis but was not seen with infectious meningitis. Our data suggest that Gd-DTPA-enhanced MR imaging is sensitive to the presence of meningeal pathology but is nonspecific as to disease entity. Recognition of certain MR patterns in conjunction with clinical presentation may improve diagnosis and management of patients with suspected meningeal disease.     

Meningeal carcinomatosis in the VX2 rabbit tumor model: detection with Gd-DTPA-enhanced MR imaging

Meningeal carcinomatosis developed in 14 of 14 New Zealand White rabbits after infusion of a VX2 tumor cell suspension into the cisterna magna. All died or were killed 7-15 days after inoculation. Within days of the tumor infusion, magnetic resonance (MR) imaging with gadolinium-diethylenetriaminepentaacetic acid (DTPA) at 0.5 or 1.5 T demonstrated enhancement of the cerebrospinal fluid (CSF) secondary to disruption of the blood-CSF barrier by plaquelike lesions along the meninges. Eventually, meningeal enhancement was observed along the base of the brain and cervical spine. Quantitative assessment of the contrast enhancement on T1-weighted images revealed an increase in mean signal intensity of 213% +/- 130%. Contrast enhancement was not observed in four control animals who received an infusion of cell culture medium. These results demonstrate in an animal model that contrast material-enhanced MR imaging can be used to detect meningeal carcinomatosis by revealing breakdown of the blood-CSF barrier.     

Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

AIM: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. MATERIALS AND METHODS: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. RESULTS: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. CONCLUSION: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas.     

非脑膜瘤所致脑膜异常强化的MRI研究

目的分析不同脑膜病变(不包括脑膜瘤导致的脑膜改变)MRI表现,探讨MRI对不同病因所致脑膜异常强化的诊断及鉴别诊断。方法资料完整的脑膜病变28例,MRI常规扫描后均加增强扫描(Gd-DTPA0.1mmol/kg)。对显示脑膜异常强化的病例进行回顾性分析。结果有7例MRI平扫显示脑膜有异常表现,增强扫描28例均有异常表现。按脑膜主要异常强化方式可以分为:硬脑膜-蛛网膜强化10例,软脑膜-蛛网膜强化15例,全脑膜强化3例。按病因不同分为:感染性脑膜炎8例,脑膜转移瘤12例,脑梗死2例,开颅术6例。结论不同脑膜病变MRI上表现形式不同,特别是MRI增强扫描。MRI检查有助于明确脑膜病变。全面分析MRI表现并结合临床对鉴别不同病因的脑膜病变具有重要作用。     

The contribution of MRI to the diagnosis of diffuse meningeal lesions

We analysed MRI findings in patients in whom a diffuse abnormality of the meninges was revealed by MRI. We looked at T1 and T2-weighted spin-echo or fast spin-echo images and contrast-enhanced T1-weighted images. There were 15 patients with abnormalities on MRI, clinically suspected in ten. Four had meningoencephalitis, one meningeal and subcortical sarcoidosis nodules, four meningeal malignancies - one disseminated oligodendroglioma, one with meningeal infiltration around an adenocarcinoma, three meningeal infiltration by a haematological malignancy, and one a chronic subdural haematoma without a history of injury. We excluded patients with primary meningeal tumours and typical injury-related meningeal bleeding. The relatively small number of patients is due to both the infrequency of diffuse meningeal disease and to the low frequency of suspected meningeal pathology as an indication for MRI. The latters diagnostic contribution is greatest in infectious disease and neoplastic infiltration, and less obvious in haematological malignancies. Contrast-enhanced T1-weighted images are most useful.     

Primary diffuse meningeal melanomatosis: radiologic-pathologic correlation

We report a case of primary diffuse meningeal melanomatosis, a rare variant of primary malignant melanoma of the CNS, in a 68-year-old woman. The disease mimicked intracranial hypotension syndrome and was diagnosed only at autopsy (CSF cytologic results were negative). CT revealed hydrocephalus with effacement of the cerebral convexity sulci and abnormal contrast enhancement in the right sylvian and frontoparietal fissures, whereas MR imaging showed diffuse marked dural and leptomeningeal contrast enhancement. In retrospect, these nonspecific findings correlated with the extensive leptomeningeal invasion in the cerebral hemispheres, brain stem and spinal cord. The clinical, radiologic, and pathologic features of diffuse meningeal melanomatosis are reviewed.     

肝脏原发性神经内分泌肿瘤影像学表现及病理对照

目的 探讨肝脏原发性神经内分泌肿瘤(PHNET)的CT、MRI表现及其病理基础.方法 收集经手术病理证实的PHNET 14例(14例均行CT检查,其中9例行MR检查),分析病灶的CT、MRI表现,探讨形成影像表现的病例基础.结果 PHNET呈单发(8例)或多发结节(5例),弥漫性全肝分布1例.CT平扫呈低密度,1例可见液-液平面病理为内部出血;动脉期呈结节状或环形强化,1例呈弥漫性强化,门静脉期或延迟期强化减低.MRI呈长T1长T2信号,出血呈短T1短T2信号,强化形式与CT相同.随病理分级的提高,病灶由G1单发实性-G2实性或囊实性-G3弥漫性分布或出现肝内转移.扩散加权成像(DWI)呈扩散受限改变.结论 CT、MRI能够显示出PHNET的影像学特殊表现和组织学特征.     

Neurobrucellosis: clinical and neuroimaging correlation

BACKGROUND AND PURPOSE: Manifestation of nervous system involvement by neurobrucellosis, a treatable infection, is not well documented. We investigated patterns of nervous system involvement and determined if neuroimaging abnormalities correlated with clinical manifestations of neurobrucellosis. METHODS: We reviewed 23 MR imaging studies (17 of brain, six of spine) and seven CT scans of brain in 23 patients (14 male and nine female patients; age range 17-71 years) with positive Brucella titers in their serum and CSF. RESULTS: Twelve patients had central nervous system (CNS) involvement, four had peripheral nervous system (PNS) involvement, two had combined PNS and CNS involvement, and five had isolated hearing loss. Imaging findings were variable: five of seven brain CT studies were normal, and 10 of 23 MR studies were normal (eight brain, one thoracic, one lumbar). One brain CT study showed subthalamic hemorrhage, mild perivascular enhancement, left caudate lacunae, and diffuse white matter changes. One other brain CT study showed enhancement of the tentorium in addition to white matter changes. Abnormal MR findings were basal meningeal enhancement (n = 3), lumbar nerve root enhancement (n = 3), granuloma of the suprasellar region (n = 1), diffuse white matter changes (n = 7), and spinal cord atrophy (n = 1). All patients improved after treatment with three antimicrobial drugs for 3-12 months. Seven patients had follow-up imaging; the enhancement disappeared but the white matter and ischemic changes persisted despite almost complete clinical recovery. CONCLUSION: Clinical-radiologic correlation in neurobrucellosis varies from a normal imaging study despite positive clinical findings, to a variety of imaging abnormalities that reflect either an inflammatory process, an immune-mediated process, or a vascular insult.     

暂时性骨质疏松症的MRI表现

目的:探讨暂时性骨质疏松症的MRI表现。方法:对经临床证实的10例暂时性骨质疏松症(TOH)患者的临床及影像学资料进行回顾性分析。10例患者均行MRI平扫,其中5例行MRI增强扫描,4例行CT扫描。10例中男7例,女3例,年龄为25～40岁。结果:10例TOH中,双侧髋关节同时受累2例,单侧受累8例,主要MRI表现为弥漫性骨髓水肿,累及股骨头、颈及转子间,股骨头形态完整,1例可见软骨下应力性骨折,所有病例均无股骨头软骨下骨质缺损;关节囊肿胀和关节积液8髋;MRI增强扫描示病变区呈明显均匀强化。主要CT表现为股骨头骨密度弥漫性减低,骨皮质变薄。治疗5～11个月后患者疼痛症状消失,股骨内MRI信号恢复正常。结论:CT上表现为弥漫性骨质疏松、MRI表现为弥漫性骨髓水肿、缺乏软骨下骨质病变以及均匀一致强化是TOH性特征的影像学表现。     

Intracranial meningeal involvement in Churg-Strauss syndrome

We describe the case of a 54-year-old woman with a clinical diagnosis of Churg-Strauss syndrome (CSS). The patient had a fever of unknown origin, severe headache, progressing left ophthalmoplegia, and visual acuity disturbance. MR imaging revealed diffuse and thick hypointense lesions on T2-weighted images in the frontal meninges and anterior falx cerebri with diffuse enhancement. Similar lesions were also detected in the left superior ophthalmic fissure to the cavernous sinus. Nodular lesions in the fourth ventricle, which might have been the cause of hydrocephalus, were hypointense on T2-weighted images. These MR imaging findings suggested remote granulomatous involvement in the meninges and choroid plexus associated with CSS. To our knowledge, remote meningeal involvement in association with CSS has not been previously reported.     

非脑膜瘤脑膜异常强化的MRI与病因对比研究

目的：分析不同脑膜病变的强化特征，探讨脑膜强化形式与病因诊断的关系。材料与方法：回顾性分析资料完整的异常脑膜强化２６例，根据脑膜受累层次、范围将强化形式分为四种：（１）弥漫性脑膜强化；（２）弥漫性硬膜强化；（３）弥漫性软膜强化；（４）局限性硬膜强化。依病因不同将脑膜病变分为三组：（１）肿瘤组；（２）炎症组；（３）反应组。结果：２６例中，肿瘤组８例，其中弥漫性硬膜、软膜强化各３例，弥漫性脑膜强化、局限性硬膜强化各１例。炎症组８例，弥漫性软膜强化７例，局限性硬膜强化１例。反应组１０例，８例呈局限性硬膜强化，２例呈弥漫性硬膜强化。结论：不同的脑膜病变可表现不同的强化特征，但离开临床，仅根据强化特征尚难做出定性诊断。