MR imaging of intradural inflammatory diseases of the spine

Twenty-eight patients with intradural inflammatory disease of the spine were studied in order to characterize the MR imaging findings of infectious and inflammatory conditions. Patients were categorized according to the spinal compartment involved. Among the 12 patients in the intradural extramedullary group, unenhanced scans were either normal or nonspecific while contrast-enhanced scans were helpful in visualizing and localizing the lesion. Nevertheless, contrast-enhanced MR studies were unable to differentiate infection and inflammation from tumor in this compartment. Among 16 patients with intramedullary lesions, four had granulomatous disease and 12 had nongranulomatous disease. The granulomatous lesions resembled tumors and displayed MR characteristics of a focal lesion with large nodular enhancement. The patients with nongranulomatous intramedullary lesions exhibited two subsets of MR findings. In the first subset of nine patients, diffuse cord swelling and high signal were seen on long TR images, combined with either no enhancement or peripheral, diffuse, or speckled enhancement of the spinal cord on contrast-enhanced short TR images. In the second subset of three patients, minimal or no spinal cord swelling was displayed despite the visualization of high signal on long TR scans and nodular enhancement with contrast administration on short TR scans. Both subsets were sufficiently unique that nongranulomatous myelitis could usually be differentiated from spinal cord tumors.     

脊髓室管膜下瘤的MR影像诊断

目的 研究脊髓内室管膜下瘤的MRI特征。方法 4例脊髓室管膜下瘤均行MR检查并经手术病理证实，均为男性，年龄15—47岁，平均36．3岁。回顾性分析脊髓内室管膜下瘤的MRI表现，结合术中所见总结MRI诊断与鉴别诊断要点。结果 4例脊髓内室管膜下瘤分别位于C3～T3、C2～6、T6～12、C1—T2段脊髓，肿瘤均位于脊髓腹侧，呈偏中心性生长。1例有轻度脊髓空洞。MR T1WI为等或低信号，信号不均，内有更低信号；T2WI为高信号。2例伴有小出血灶。增强扫描，3例肿瘤无强化或强化轻微，1例强化明显。结论 MRI可以很好评价脊髓内室管膜下瘤，当患者具备上述特点时高度提示脊髓内室管膜下瘤的可能。     

结核性脊髓脊膜炎的MRI诊断价值

目的：探讨MRI对结核性脊髓脊膜炎的诊断价值。方法：对21例结核性脊髓脊膜炎增强前后的MRI进行回顾性分析。结果：所有21例MRI平扫均可见脊膜受累,主要表现为脊膜不规则增厚,蛛网膜下腔狭窄或闭塞、分隔样改变、囊肿形成,神经根增厚;增强扫描表现为增厚的脊膜呈线状、斑块状、结节状和环状强化。本组21例中脊髓肿胀17例,脊髓空洞6例,髓内结核瘤5例。结论：MRI平扫和增强扫描可清晰显示结核性脊髓脊膜炎的病变部位和累及范围,可为临床治疗及判断预后提供影像学参考。     

Intramedullary lesions of the pediatric spinal cord: correlation of findings from MR imaging, intraoperative sonography, surgery, and histologic study

Findings of preoperative magnetic resonance (MR) imaging and radiologist-directed intraoperative sonography (IOS) were correlated with surgical and pathologic findings in 11 pediatric patients with intramedullary spinal cord lesions. There were seven gliomas and one each of primitive neuroectodermal tumor, venous vascular malformation, neuroenteric cyst, and active schistosomiasis. MR imaging provided discrete preoperative anatomic localization and excluded multicentric lesions but did not reliably distinguish between solid and cystic lesions. IOS helped (a) define the limits of intramedullary mass before the dura mater was opened and (b) differentiate cystic from solid components. The internal architecture of intramedullary lesions, as shown with MR imaging and sonography, was strikingly similar, allowing discrete correlative localization for biopsy or tissue resection. Gadolinium-enhanced MR imaging and IOS are complementary imaging techniques that should be used in concert for the evaluation and management of intramedullary lesions of the pediatric spinal cord. Both techniques display regions of cord abnormality, but neither definitively characterizes underlying tissue histology.     

Subacute necrotizing myelopathy: MR imaging in four pathologically proved cases.

This report describes the MR and correlative imaging findings of four histologically proved cases of subacute necrotizing myelopathy in which there was no evidence of a spinal dural arteriovenous fistula. Subacute necrotizing myelopathy is characterized clinically by progressive motor and sensory deterioration, and pathologically by necrosis in the spinal cord. Initial MR imaging showed focal enlargement of the spinal cord and nonspecific T1 and T2 lengthening. Rimlike enhancement was demonstrated in one case. Clinically, steroid therapy failed in all four patients. Follow-up MR scans showed two slightly enlarged lesions, one stable thoracolumbar lesion, and atrophy of a cervical lesion. Open spinal cord biopsies revealed foci of necrosis and abnormal parenchymal vessels with thickened hyalinized walls. A prolonged course distinguishes subacute necrotizing myelopathy from acute transverse myelitis, but the clinical course and imaging appearance are similar to those of intramedullary tumor. Rimlike rather than solid contrast enhancement may be a distinguishing feature. In the absence of a demonstrable spinal dural arteriovenous fistula, the radiologic differentiation of subacute necrotizing myelopathy from tumor is probably impossible, and biopsy establishes the correct diagnosis.     

Unique linear and nodular MR enhancement pattern in schistosomiasis of the central nervous system: report of three patients.

OBJECTIVE: The purpose of this paper is to describe the unique MR imaging appearance of schistosomiasis of the central nervous system (CNS). CONCLUSION: Contrast-enhanced T1-weighted MR images in all three patients with CNS schistosomiasis revealed a central linear enhancement surrounded by multiple enhancing punctate nodules, forming an "arborized" appearance. Pathologically, this enhancement pattern correlated with a host granulomatous response to Schistosoma species ova. Although the pattern is not present in all cases of CNS schistosomiasis, when it is observed, a diagnosis of CNS schistosomiasis should be considered.     

椎管内硬膜外海绵状血管瘤的MRI诊断及鉴别诊断

目的探讨椎管内硬膜外海绵状血管瘤的MRI诊断及鉴别诊断价值。资料与方法回顾性分析5例经病理证实的椎管内硬膜外海绵状血管瘤的MRI表现,并与硬膜外其他病变进行鉴别。结果5例中,4例位于胸段,1例位于胸腰段,均沿脊椎纵轴生长,呈梭形或长椭圆形;病变平面脊髓明显受压,3例肿块呈"钳"状包绕脊髓;5例均表现为T2WI高信号,T1WI等或稍高信号,增强扫描均匀一致明显强化;2例肿瘤沿相邻的椎间孔呈"哑铃"状生长,并使椎间孔扩大。结论椎管内硬膜外海绵状血管瘤的MRI表现具有一定特征性,但需与硬膜外其他病变相鉴别。     

硬膜外麻醉神经并发症的MRI表现

目的探讨硬膜外麻醉神经并发症的MRI诊断价值. 资料与方法对12例硬膜外麻醉出现神经并发症的MRI资料进行回顾性分析,重点观察椎管内结构的形态、MRI信号特征. 结果脊髓损伤4例,1例合并硬膜外血肿,表现为髓内条状长T1、长T2信号;单纯硬膜外血肿5例,表现为梭形或半月形T1、T2不均匀高信号;硬膜外脓肿3例,表现为硬膜后外方梭形或长圆形稍长T1、长T2信号,增强扫描脓肿壁明显强化.诊断结果与临床和术后诊断结果符合. 结论 MRI对硬膜外麻醉神经并发症诊断具有很大价值,宜作为首选方法.     

Intramedullary Spinal Cord Metastases: Visibility on PET and Correlation with MRI Features

BACKGROUND AND PURPOSE:Studies systematically evaluating the detection of intramedullary spinal cord metastasis with PET are lacking. Our purpose was to evaluate the visibility of intramedullary spinal cord metastasis on PET in a single institutional series and to correlate PET and MR imaging features.MATERIALS AND METHODS:Patients were included if pretreatment MR imaging identifying an intramedullary spinal cord metastasis and an [¹⁸F] FDG-PET examination near the time of MR imaging were available. PET examinations were retrospectively reviewed, with reviewers blinded and then unblinded to the PET report and MR imaging findings. PET intramedullary spinal cord metastasis features were compared with and correlated with previously analyzed MR imaging lesion characteristics. Original clinical PET reports were reviewed.RESULTS:The final study sample was 10 PET examinations in 10 patients with 13 intramedullary spinal cord metastases. In 7 (70%) patients, retrospective blinded review demonstrated convincing evidence of 10 (77%) intramedullary spinal cord metastases. Three MR imaging features correlated with intramedullary spinal cord metastases being visible on PET compared with those nonvisible, respectively: larger lesion enhancement size: mean size: 32.1 mm versus 6.0 mm (P = .038); larger longitudinal extent of T2 signal abnormality: mean 5.6 versus 1.0 segments (P = .0081); and larger ratio of extent of T2 signal abnormality to contrast enhancement: 3.8 versus 1.0 (P = .0069). Intramedullary spinal cord metastasis was confidently reported clinically in 2 (20%) patients, accounting for 5 (38%) intramedullary spinal cord metastases.CONCLUSIONS:Most intramedullary spinal cord metastases can be detected on PET when performed near the time of pretreatment MR imaging. However, intramedullary spinal cord metastases may not be clinically reported on PET. Larger lesions with more edema are more likely to be visible. The spinal cord should be specifically and carefully assessed on PET for evidence of intramedullary spinal cord metastases to provide timely diagnosis.

Intramedullary spinal cord metastases (ISCMs) are rare and devastating manifestations of metastatic neoplasm. They are present at autopsy in 0.9–2.1% of patients with cancer^1,2 and comprise 1–4% of spinal metastases.^1–3 Early detection is important because ISCMs indicate a poor prognosis, and treatment may slow neurologic deterioration.⁴ However, ISCMs can be asymptomatic, especially at early stages, and are historically difficult to detect with imaging.^3,5 MR imaging is the cornerstone of spinal cord imaging,⁶ but this technique is generally not indicated for screening of asymptomatic patients.[¹⁸F] FDG-PET is the primary imaging technique used for whole-body screening for metastases and therefore is a technique that ideally locates most sites of metastases, including intraspinal. However, there are only scattered case reports of visualization of ISCMs on PET.^7–12 No large series systematically evaluating the detection of ISCMs with PET have been reported. The purpose of the current study was to retrospectively evaluate the visibility of ISCMs on PET in a single institutional series of patients with ISCMs, and to correlate PET and MR imaging features.     

Acute spontaneous spinal epidural hematomas.

BACKGROUND AND PURPOSE: Although previous reports have characterized MR imaging features of spinal epidural hematomas (EDH), few cases have been reported during the acute or hyperacute phase within the first 48 hours. Our goal in this investigation was to correlate the MR imaging features of acute (< or =48 hours) spontaneous EDH with clinical management and outcome. METHODS: Eight patients with acute spontaneous EDH (five men and three women; age range, 31-81 years) underwent MR imaging at 1.5 T (T1-weighted, n = 8; T1-weighted after the administration of 0.1 mmol/kg contrast material, n = 6; T2-weighted, n = 8; and T2-weighted, n = 4). The interval from symptom onset to hospital admission ranged from immediate to 5 days. Two neuroradiologists reviewed the MR images for signal characteristics, contrast enhancement, and cord compression. Treatment and clinical outcome were correlated with the imaging findings. RESULTS: The EDH were located in the cervical (n = 3), cervicothoracic (n = 2), thoracolumbar (n = 2), and lumbar (n = 1) regions. On T1-weighted images, the signal intensity of the EDH was isointense to spinal cord in five cases, hyperintense in two cases, and hypointense in one case and did not correlate with time to imaging. Isointensity on T1-weighted images persisted for 5 days in one case. On T2-weighted images, all EDHs were hyperintense with focal, heterogeneous hypointensity. Cord compression was severe in six patients, moderate in one patient, and minimal in one patient. Four cases were treated conservatively with complete resolution or improvement of symptoms within 1 to 3 weeks. CONCLUSION: MR imaging findings were useful in establishing the diagnosis of EDH but did not influence management or predict outcome in this series. Heterogeneous hyperintensity to cord with focal hypointensity on T2-weighted images should suggest the diagnosis of acute spinal EDH. Severity of neurologic impairment had the greatest impact on management and outcome. Nonoperative treatment may be successful in cases with minimal neurologic deficits, despite cord compression revealed by MR imaging.     

Neoplasms of the spinal cord and filum terminale: radiologic-pathologic correlation.

Intramedullary spinal cord neoplasms are rare, accounting for about 4%10% of all central nervous system tumors. Despite their rarity, these lesions are important to the radiologist because magnetic resonance (MR) imaging is the preoperative study of choice to narrow the differential diagnosis and guide surgical resection. On contrast materialenhanced MR images, intramedullary spinal tumors almost always manifest as expansion of the spinal cord and show enhancement. Syringohydromyelia and cystic lesions are frequently associated with intramedullary tumors. Nontumoral cysts tend to be located at the poles of the tumors and do not enhance on contrast-enhanced MR images, whereas cysts within the substance of the tumor are considered tumoral cysts and typically demonstrate peripheral enhancement. Spinal cord ependymomas are the most common type in adults, and cord astrocytomas are most common in children. Both entities constitute up to 70% of all intramedullary neoplasms. A central location within the spinal cord, presence of a cleavage plane, and intense homogeneous enhancement are imaging features that favor an ependymoma. Intramedullary astrocytomas are usually eccentrically located within the cord, are ill defined, and have patchy enhancement after intravenous contrast material administration. Even with these characteristics, it may not be possible to differentiate these two entities on the basis of imaging features alone. Cord hemangioblastomas are the third most common type of intramedullary spinal tumor. Gangliogliomas commonly extend over more than eight vertebral segments. Paragangliomas and primitive neuroectodermal tumors have an affinity for the filum terminale and cauda equina. Other spinal cord tumors include metastatic disease, which is characterized by prominent cord edema for the size of the enhancing portion, and primary lymphoma.     

Spinal vascular malformations: MR angiography after treatment

PURPOSE: To evaluate the role of magnetic resonance (MR) angiography in the assessment of spinal vascular malformation therapy. MATERIALS AND METHODS: Thirty-four patients with spinal vascular malformations (30 dural arteriovenous fistulas, two perimedullary arteriovenous fistulas, and two intramedullary arteriovenous malformations) underwent MR angiography and MR imaging before and after endovascular or surgical treatment. RESULTS: MR angiography showed residual flow in perimedullary vessels in seven patients with dural fistula after embolization with liquid adhesive. In all seven, treatment failure was confirmed with arteriography. Long-lasting disappearance of flow in perimedullary vessels was demonstrated at MR angiography in 22 patients with dural fistula. MR imaging demonstrated normalization of spinal cord volume in 16 of 22 patients and signal intensity on T2-weighted images in three patients. Disappearance of cord enhancement was observed in five of 21 patients and of perimedullary enhanced vessels in six of 13 patients. In one additional patient with dural fistula treated with embolization, early posttreatment MR angiography showed disappearance of flow in perimedullary vessels, which reappeared at follow-up and was consistent with reopening of a small residual fistula. Posttreatment MR angiography demonstrated transient reduction of flow in the nidus in two patients with intramedullary malformations treated with embolization. Permanent disappearance of flow in the perimedullary vessel was seen after endovascular treatment in two patients with perimedullary fistula. CONCLUSION: MR angiography is more sensitive than MR imaging in depicting residual or recurrent flow in peri- or intramedullary vessels, which indicates patency of the vascular malformation.     

髓内肿瘤的磁共振诊断与鉴别诊断

本文通过对30例髓内肿瘤和20例非肿瘤病变MR表现的回顾性对比分析,总结了髓内肿瘤MR诊断和鉴别诊断经验。指出髓内肿瘤的MR主要征象为脊髓局部增宽、膨大,病灶Gd-DTPA明显强化,以及伴有囊变。而非肿瘤病变脊髓轮廓改变较轻,Gd-DTPA为轻至中度强化。增强特点为偏心性、点片状或环状,较具特异性。     

MRI对脊髓型多发性硬化临床分期的价值

目的:探讨脊髓型多发性硬化(MS)的MRI表现及其病理基础,评价MRI对MS临床分期价值。方法:脊髓型MS患者43例,按临床特点分为急性期、静止期和缓解复发期。对所有患者行头部和脊柱磁共振检查,分析各期的MRI表现。结果:脊髓型MS的主要MRI表现为髓内长或等T1、长T2信号改变。脊髓型MS各期的MRI特点:①急性期11例,均表现为脊髓轻度~中度肿胀,增强扫描时10例(90.9%)髓内病灶有明显强化,其中9例呈斑片状或边缘环状强化,1例呈结节状强化,范围明显小于T2WI上所见;1例无强化。4例伴脊髓中央管扩张。有8例经治疗后病灶缩小,脊髓肿胀消失。②静止期17例,14例(82.4%)脊髓形态、大小未见异常,髓内病灶均无强化。③缓解复发期15例中,11例(73.3%)伴有脊髓萎缩,增强扫描时5例出现轻度点状或条状强化,病变范围与T2WI所见相似。各期脊髓型MS的病变范围及分布差异无显著性意义(P>0.05)。结论:MRI能反映脊髓型MS各期的病理变化,对脊髓型MS的分期具有重要价值。     

MRI diagnosis of intramedullary metastases from extra-CNS tumors

The purpose of this study was to evaluate the topography, morphology and contrast enhancement of the intramedullary metastases (IM) from extra-CNS neoplasms. We report the results of a multicenter retrospective study on 18 patients with 26 IM examined with a 0.5T MR imaging system; intravenous injection of Gd-DTPA was performed in all cases. We found that the lesions are most frequently single, oval shaped, and small, with little or no deformation of the spinal cord (14 of 26 IM). They appear isointense on spin-echo T1-weighted images (24 of 26 IM), with a homogeneous and generally nodular high contrast enhancement after Gd-DTPA injection (21 of 26 IM), and present on T2- and proton-density-weighted sequences with a pronounced perilesional, pencil-shaped hyperintensity of the surrounding cord which is more evident in the cranial part of the cord referring to the IM.     

Central nervous system tuberculosis: MRI

The MRI findings of 18 proven cases of central nervous system (CNS) tuberculosis were reviewed; 10 patients were seropositive for HIV. All had medical, laboratory, or surgical proof of CNS tuberculosis. Eleven patients had meningitis, of whom two also had arachnoiditis. Five patients had focal intra-axial tuberculomas: four brain masses and one an intramedullary spinal lesion. Two patients had focal extra-axial tuberculomas: one in the pontine cistern, and one in the spine. In all 11 patients with meningitis MRI showed diffuse, thick, meningeal enhancement. All intraparenchymal tuberculomas showed low signal intensity on T2-weighted images and ring or nodular enhancement. The extra-axial tuberculomas had areas isointense or hypoitense relative to normal brain and spinal cord on T2-weighted images. Although tuberculous meningitis cannot be differentiated from other meningitides on the basis of MR findings, intraparenchymal tuberculomas show characteristic T2 shortening, not found in most other space-occupying lesions. In the appropriate clinical setting, tuberculoma should be considered.     

Intramedullary Spinal Cord Metastases: Prognostic Value of MRI and Clinical Features from a 13-Year Institutional Case Series

BACKGROUND AND PURPOSE:In patients with intramedullary spinal cord metastases, the impact of MR imaging and clinical characteristics on survival has not been elucidated. Our aim was to identify MR imaging and clinical features with prognostic value among patients with intramedullary spinal cord metastases from a large retrospective series.MATERIALS AND METHODS:The relevant MR imaging examination and baseline clinical data for each patient from a consecutive group of patients with intramedullary spinal cord metastases had previously been reviewed by 2 neuroradiologists. Additional relevant clinical data were extracted. The influence of clinical and imaging characteristics on survival was assessed by Kaplan-Meier survival curves and log-rank tests for categoric characteristics.RESULTS:Forty-nine patients had 70 intramedullary spinal cord metastases; 10 (20%) of these patients had multiple metastases. From the date of diagnosis, median survival for all patients was 104 days (95% CI, 48–156 days). One clinical feature was associated with decreased median survival: lung or breast primary malignancy (57 days) compared with all other malignancy types (308 days; P < .001). Three MR imaging features were associated with decreased median survival: multiple intramedullary spinal cord metastases (53 versus 121 days, P = .022), greater longitudinal extent of cord T2 hyperintensity (if ≥3 segments, 111 days; if ≤2, 184 days; P = .018), and ancillary visualization of the primary tumor and/or non-CNS metastases (96 versus 316 days, P = .012).CONCLUSIONS:Spinal cord edema spanning multiple segments, the presence of multifocal intramedullary spinal cord metastases, and ancillary evidence for non-CNS metastases and/or the primary tumor are MR imaging features associated with decreased survival and should be specifically sought. Patients with either a lung or breast primary malignancy are expected to have decreased survival compared with other primary tumor types.

Recent studies have elucidated the imaging features of intramedullary spinal cord metastases (ISCMs). MR imaging findings specific to these secondary compared with primary tumors of the spinal cord have been described.¹ Moreover, multiple MR imaging characteristics have been characterized in detail² and correlated with findings on physiologic imaging with PET.³ However, the prognostic value of MR imaging and clinical findings has not been assessed, to our knowledge. A recent literature review of 301 patients noted that there are no evidence-based treatment guidelines for ISCMs and that the various therapeutic options do not generally considerably affect survival.⁴ Thus, identification of pretreatment factors that may affect outcomes is relevant. The purpose of this retrospective study was to identify MR imaging and clinical features with prognostic value among patients with ISCMs from a large retrospective series.     

脊髓亚急性联合变性的MRI诊断要点分析

目的分析脊髓亚急性联合变性(SCD)的MRI诊断要点。资料与方法回顾性分析15例临床确诊SCD的病人临床及MRI资料,分析其脊髓MRI表现特点,统计分析SCD病人受累脊髓节段数与血清VB12水平、发病时间的相关性。结果 15例SCD病人均于横断面影像上显示颈胸段脊髓对称性等或长T1、长T2信号,13例病变主要位于颈胸段水平脊髓后索,2例同时累及后索、侧索及前索。但于横断面T2WI上颈段与胸段脊髓异常信号形态各具特点。颈段脊髓受累时于横断面T2WI上呈脊髓内"倒V"形或"反兔耳"形的对称性高信号。胸段脊髓受累时于横断面T2WI上呈脊髓内"哑铃"形的对称性高信号。统计学分析显示15例SCD病人脊髓受累节段数与血清VB12水平呈负相关,而与病程长短无相关性。结论脊髓MR成像对于SCD脊髓疾病的诊断有重要价值。     

椎管内结核性蛛网膜炎的MR成像

目的评估ＭＲＩ对椎管内结核性蛛网膜炎的诊断价值。材料与方法对１６例椎管内结核性蛛网膜炎的ＭＲＩ表现、Ｇｄ－ＤＴＰＡ增强ＭＲＩ的作用和追踪ＭＲＩ的变化进行分析。结果ＭＲＩ显示脊膜炎１２例，表现为蛛网膜下腔狭窄和消失、脑脊液分房和神经根增厚。在增强ＭＲＩ上，受累的软脊膜和硬膜呈线形、弥漫性斑块状和结节状或环形显著增强。脊髓受累见于全部１６例，包括脊髓水肿９例；脊髓空洞７例。在全部１６例中，髓内结核瘤２例。结论ＭＲＩ可以直接显示脊膜、脊髓和神经根受累后的形态学和病理学改变，增强ＭＲＩ可以更清楚地显示出髓内和髓外病变的程度。因此，ＭＲＩ对椎管内结核性蛛网膜炎的诊断价值，无论是在急性期或慢性粘连期，均优于脊髓造影和ＣＴ脊髓造影     

脊髓室管膜瘤的MRI表现

目的探讨脊髓内室管膜瘤的MRI表现,提高对本病的认识。方法收集我院经病理证实的脊髓室管膜瘤13例,分析肿瘤部位、信号特点、有无囊变、出血及帽征、椎间孔扩大及肿瘤强化方式。结果肿瘤位于颈髓6例,胸髓3例,终丝及马尾4例.在T1WI上呈等、低信号,在T2WI上呈高信号、混杂信号.9例见囊变,3例可见肿瘤内出血,2例椎间孔扩大.13例均出现不同程度强化,1例呈轻度强化,3例中度强化,9例重度强化,11例肿瘤与正常脊髓分界清楚。结论髓内室管膜瘤MRI表现具有一定特点,结合其发病部位、边界、囊变、出血、强化特征及临床资料常可作出正确诊断。