Spinal tumours in neurofibromatosis type 1: an MRI study of frequency, multiplicity and variety

In neurofibromatosis type 1 (NF1) spinal tumours cause neurological symptoms in about 2 % of patients. Among over 1400 patients with NF1 we saw symptomatic spinal tumours in 23 (1.6 %). MRI of the entire spinal canal was obtained in 54 patients aged 5–56 years with NF1. The number, site, morphology and signal characteristics of the spinal tumours were recorded and analysed. There were 24 patients with symptoms such as sensory impairment or paralysis; 30 patients had no neurological deficits. Of the 24 symptomatic patients, 23 (96 %) had spinal tumours, while we saw spinal tumours in 12 (40 %) of the 30 patients without neurological deficits. No spinal segment was preferred in symptomatic or asymptomatic patients. Most intraspinal extramedullary tumours were primarily extradural and intraforaminal. MRI showed intramedullary tumours in 3 patients (6 %), intraspinal extramedullary tumours in 18 (33 %) and intraforaminal tumours in 31 (57 %). Only neurological deficits in patients with NF1 should prompt further diagnostic clarification. In patients with neurological symptoms there may be a multiplicity of masses in the spinal canal, which can lead to difficulties in attaching symptoms to a certain tumour. In patients who do not satisfy the NIH criteria, it can be a helpful observation that spinal tumours in NF1 are primarily intraforaminal, extending into the spinal canal, while in NF2 they are mostly intraspinal intradural tumours. Received: 7 April 1998 Accepted: 15 December 1998     

Spinal intradural tumors

Spinal intradural tumors are uncommon lesions but may cause significant morbidity. In establishing the differential diagnosis for a spinal lesion, location, age, and the patient's clinical presentation are important. Magnetic resonance imaging plays a central role in the visualization of spinal tumors, easily allowing tumors to be classified as extradural, intradural extramedullary, or intramedullary which is very useful in tumor characterization. We describe intradural tumors; the majority is extramedullary, with nerve sheath tumors being the most frequent. Intramedullary tumors are uncommon spinal tumors. Ependymomas and astrocytomas comprise the majority of this group. Typical imaging features of both intradural extramedullary and intramedullary tumors are described.     

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.     

Application of turbo fluid-attenuated inversion-recovery MRI in evaluation of intraspinal tumors

PURPOSE: Although fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) is widely applied to diagnose central nervous system diseases, its role in diagnosis of intraspinal tumors is unclear. In this study, we evaluated the potential clinical application of a turbo FLAIR sequence for imaging of intraspinal tumors. MATERIALS AND METHODS: Forty-eight consecutive patients with intraspinal tumors underwent MRI with turbo FLAIR and turbo spinal echo (TSE) sequences. Turbo FLAIR images were then qualitatively and quantitatively compared with T2-weighted TSE images. RESULTS: Turbo FLAIR images were evaluated as superior to T2-weighted TSE images for image artifact, extradural tumor conspicuity, and intradural extramedullary tumor conspicuity and detection. Intramedullary tumor conspicuity with turbo FLAIR was less than T2-weighted TSE. Similar capabilities in detection of extradural and intramedullary tumors were found between turbo FLAIR and T2-weighted TSE. Turbo FLAIR and T2-weighted TSE displayed similar normal spinal cord signal-noise ratio (SNR) and tumor-to-cerebrospinal fluid (CSF) contrast-to-noise ratio (CNR). In addition, turbo FLAIR yielded significantly higher tumor-to-CSF contrast than T2-weighted TSE. However, tumor SNR, tumor-to-normal spinal cord contrast and CNR with turbo FLAIR images were lower than those with T2-weighted TSE images. CONCLUSION: This study demonstrated (a) a superiority of turbo FLAIR to T2-weighted TSE in displaying and detecting intradural extramedullary tumors, (b) a superiority of turbo FLAIR to T2-weighted TSE in demonstrating extradural tumors, and (c) less usefulness in displaying intramedullary tumors with turbo FLAIR than with T2-weighted TSE.     

MR imaging of intraspinal tumors—Capability in histological differentiation and compartmentalization of extramedullary tumors

Summary Magnetic resonance (MR) images of 29 consecutive patients with intraspinal neoplasms (9 intramedullary tumors, 20 extramedullary tumors) were reviewed to evaluated the utility of MR imaging in distinguishing the intraspinal compartmental localisation and signal characteristics of each lesion. Compartment and histology of all neoplasms were surgically proven. MR correctly assigned one of three compartments to all lesions, 9 intramedullary, 14 intradural extramedullary (6 schwannomas, 3 neurofibromas, 5 meningiomas), and 6 extradural (3 schwannomas, 1 meningioma, 1 cavernous hemangioma, 1 metastatic renal cell carcinoma). All intramedullary tumors showed swelling of the spinal cord itself. In all five extradural tumors a low intensity band was visualized between the spinal cord and tumor. On the other hand, a low intensity band was demonstrated in no cases with intradural tumors. Visualization of this low intensity band is important in differentiating extradural from intradural-extramedullary lesions. We call this low intensity band, the extradural sign. Signal intensity of intradural tumors varied with histology. In extramedullary tumors, signal intensity of schwannomas was similar to that of the cerebrospinal fluid (CSF) both on T1 weighted (inversion recovery) and T2 weighted spin echo (SE) images. On the other hand, meningiomas tended to be isointense to the spinal cord on both T1 and T2 weighted SE images. We found relatively reliable signal characteristics to discriminate meningioma from schwannoma.     

Bildgebung intraduraler Raumforderungen

Spinal tumors are often categorized into extradural, intradural extramedullary, or intramedullary. Although this classification represents somewhat of an overgeneralization as a lesion may reside in two compartments, it still helps to characterize spinal tumors. In the intradural, extramedullary space, primary tumors, such as neurofibroma and meningioma, are relatively common. Secondary tumors or leptomeningeal enhancement also occur.In the intramedullary space, primary tumors are far more common than secondary tumors or metastases.     

Advantages of supplementary CT in myelography of intraspinal masses

Computed tomographic (CT) myelography subsequent to nonionic water-soluble contrast medium myelography has provided additional diagnostic information for evaluating intraspinal mass lesions. In 20 patients thus studied, there were eight intramedullary tumors, eight intradural extramedullary masses, and four extradural neoplasms. In intramedullary tumors CT enabled more precise delineation of the extent and location of expansion of the spinal cord. In intradural and extradural tumors, rotation and compression of the spinal cord as well as bony and paraspinal soft-tissue changes were more accurately demonstrated in the axial plane. When a complete block was present, the greater contrast sensitivity of CT permitted visualization beyond the level of the block. Histologic prediction is not feasible by CT myelography except for hyperlucent lipoma. CT can provide useful supplemental information to conventional metrizamide myelography.     

MR imaging of intradural extramedullary tumors.

Thirty-one consecutive intradural extramedullary spinal tumors examined with MR at 0.3 T were reviewed. In 13 of the patients myelography had been performed. There were 11 patients with meningeoma, 14 with neuroma, one ependymoma, 3 metastases, and 2 lipomas. All tumors were surgically removed and verified by histology. The intradural extramedullary location of the tumors was accurately assessed by MR imaging in all patients and by myelography in 10 of 13. The MR diagnoses were in accordance with the histologic findings in 74% of cases. Compression of the spinal cord or cauda equina with widening of the subarachnoid space above and below the mass or outward displacement of epidural fat was characteristic of the intradural extramedullary tumors. The signal intensity of meningeoma as well as of neuroma was slightly lower or equal to that of the cord on T1-weighted images, and equal to or higher than cord signal on T2-weighted images. Neuroma had a lower signal intensity on T1-weighted images and a higher signal intensity on T2-weighted images than meningeoma. Meningeoma appeared more homogeneous than neuroma and had a broad base towards the dura.     

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.     

Value of intravenous contrast enhancement in the CT evaluation of intraspinal tumors

The usefulness of intravenous contrast-enhanced CT in delineating intraspinal cord tumors has not been well documented. To determine if intradural spinal tumors enhance, if the location and type of tumor can be determined, and if a double dose of contrast material provides more information than a single dose, a retrospective study of 23 patients with proven intradural extramedullary or intramedullary tumors was performed. All the tumors studied with CT after intravenous contrast enhancement showed that most lesions (18/23) enhanced, contrary to published reports. Contrast-enhanced studies delineated the extent of the tumor, helping to separate solid and cystic components. The enhancement pattern of ependymomas and astrocytomas was similar, while schwannomas had a characteristic appearance. A double dose of intravenous contrast material had no apparent advantage over a single dose.     

Imaging of tumors of the spine and spinal cord

Imaging of the spine and spinal cord has traditionally been accomplished with plain radiography, myelography, and CT. Recently, MR imaging has become the technique of choice in the assessment of lesions of the spine and spinal cord. MR imaging provides accurate localization of intramedullary, intradural extramedullary, and extradural tumors. Ependymomas and low-grade astrocytomas are the most common intramedullary tumors. MR imaging findings are distinguishable by the delineation and size of the lesion, and the signal intensity on T2-weighted images. Other less common tumors include malignant astrocytomas, hemangioblastomas, and intramedullary metastasis. Numerous foci of high-velocity signal loss are seen in the hemangioblastomas. Metastasis, meningiomas, and schwannomas are the most common intradural extramedullary tumors. Meningiomas are characterized by dural enhancement on postcontrast T1-weighted images. Schwannomas and neurofibromas often erode bony structures and appear to be dumbbell-shaped. Epidural metastasis accounts for the majority of extradural tumors. Primary malignant extradural tumors include lymphomas, chordomas, and so on. The most common primary benign extradural tumor is hemangioma, which often appears to be hyperintense on both T1-weighted and T2-weighted images. Intramedullary non-neoplastic lesions include demyelinating, vascular, and infectious diseases. Diffuse, peripheral, or speckled contrast enhancement, and lack of contrast enhancement may suggest non-neoplastic lesions.     

Magnetic resonance imaging in the management of suspected spinal canal disease in patients with known malignancy

AIM: The aim of this study was to examine the spectrum of spinal canal disease in patients with known malignancy using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred and fifty-five patients underwent a total of 159 spinal MRI examinations over a three-year period. Patients were examined using a 1.0T magnet and a phased array surface spine coil. Sagittal T1 weighted spin echo and STIR sequences were routinely employed. Axial T1 and T2 weighted spin echo images were obtained at sites of identified pathology. Contrast enhanced sagittal and axial T1 weighted spin echo images were acquired when the unenhanced appearances did not correlate with the clinical findings or when the images suggested intradural or intramedullary disease. RESULTS: Malignant disease affecting the spinal cord or cauda equina was noted in 104/159 (65%) patients (extradural n= 78, intradural n= 20, intramedullary n= 7); one patient had evidence of both intradural and intramedullary deposits. Multiple levels of extradural cord/cauda equina compression were present in 18/78 patients (23%). The thoracic spine was the most frequently affected (74%). Bone elements were the major component of extradural compression in 11/78 patients (14%). Intradural metastases were multiple in 15/20 patients (75%). Four of the six solitary intramedullary metastases were situated in the conus medullaris. CONCLUSION: Magnetic resonance imaging of the entire spine is the investigation of choice in patients with known malignancy and suspected spinal canal disease. Contrast-enhanced images should be acquired when the unenhanced appearances do not correlate with the clinical findings or when they suggest intradural or intramedullary disease.Loughrey, G. J. (2000). Clinical Radiology55, 849-855.     

Spinal intradural extramedullary capillary hemangioma: MR imaging findings

SUMMARY: Spinal intradural extramedullary capillary hemangiomas are extremely rare. We present the MR imaging and histologic findings in three patients with this abnormality. The three patients were men who had symptoms of either myelopathy (n = 2) or radiculopathy (n = 1). The tumors were well demarcated, 1.5-2.0 cm in diameter, and were located at the posterior or posterolateral portion of the thecal sac (one at the L1 level and the other two at the midthoracic level). On MR images, the tumor showed isointensity relative to the spinal cord on T1-weighted images, hyperintensity on T2-weighted images, and strong homogeneous enhancement on contrast-enhanced T1-weighted images in all three patients. In two patients, the dural tail sign was observed. Capillary hemangioma should be included in the differential diagnosis of a spinal intradural extramedullary tumor.     

Intradural spinal tumors: current classification and MRI features

The differential diagnosis of intradural spinal tumors is primarily based on location, but the clinical presentation, age, and gender of the patient are also important factors in determining the diagnosis. This comprehensive review focuses on the current classification, clinical symptoms, and MRI features of the more common intradural extramedullary and intramedullary neoplastic lesions. This review does not include extradural lesions.     

Magnetic Resonance Imaging Characteristics of Primary Intraspinal Peripheral Primitive Neuroectodermal Tumour

Purpose

The purpose of our study was to describe the salient magnetic resonance imaging (MRI) findings in primary intraspinal peripheral primitive neuroectodermal tumour (PNET).

Methods

A retrospective review of the clinical and MRI images of 7 pathologically proven cases of intraspinal peripheral PNETs was performed. The various parameters, such as vertebral level of involvement; tumour location, size, focality, and margin; signal intensity of the lesion; the presence of hemorrhage or calcification; any signal voids; assessment of the adjacent cord for cord compression; cord dilatation; the presence of paraspinal tissue mass; or vertebral or other bony changes, were analysed.

Results

All 7 patients had lesions in the thoracolumbar region. Three patients had extradural lesions, 4 had intradural extramedullary lesions, and none had intramedullary lesions. Six lesions were well circumscribed. Only 1 patient had multifocal involvement. All lesions were of hypointense or isointense signal on T1-weighted imaging, whereas all but one were hyperintense on T2-weighted imaging. Lesions enhanced heterogeneously except 1 intradural extramedullary lesion, which enhanced homogeneously. A paraspinal mass was noticed in 2 patients. Vertebral collapse was present in 1 patients.

Conclusion

Intraspinal peripheral PNETs are rare spinal tumours. Although imaging characteristics are not specific, a focal circumscribed lesion in a young individual at the intramedullary, extramedullary intradural, or extradural spinal location that shows hypointense and hyperintense signal on T1- and T2-weighted images, respectively, requires PNET to be considered in the differentials.     

Importance of absence of CSF pulsation artifacts in the MR detection of significant myelographic block at 1.5 T

MR imaging was performed on 21 patients who had high-grade myelographic block due to various diseases in all spinal compartments (extradural, intradural/extramedullary, and intramedullary) and in all portions of the spinal canal (cervical, thoracic, and lumbosacral). Loss of CSF pulsation artifacts due to significant compression of the spinal cord was demonstrated on non-motion-compensated T2-weighted examinations in each case. We believe that the absence of such artifacts on these sequences indicates significant spinal cord compression in patients without classic signs and symptoms of cord compression but with intraspinal disease identified on T1-weighted studies.     

Pädiatrische intraspinale Neoplasien

With an overall incidence of 10?% of all central nervous system tumors, spinal tumors are relatively rare in children. The majority of these tumors are astrocytomas and ependymomas (70?%) followed by rare non-glial tumor entities, such as gangliogliomas. They can be differentiated into intramedullary, extramedullary intradural and extramedullary extradural tumors according to their occurrence within the anatomical intraspinal compartments. The clinical presentation is generally unspecific. Longer lasting back pain or a gradually worsening scoliosis are often the first signs of the disease. Neurological deficits, such as gait disturbances and paresis often occur after a time delay. In rare cases increased intracranial pressure has been reported. Knowledge concerning potential organ manifestations, resulting complications and typical radiological presentation, especially in magnetic resonance imaging are mandatory for adequate diagnosis and treatment of affected patients.     

Spinal intradural capillary hemangioma: MR findings

We report a case of a spinal intradural capillary hemangioma. On MR images, a well-circumscribed intradural mass was detected at the T8-T9 level. The signal intensity of the mass relative to the spinal cord was isointense on T1-weighted images, hyperintense on T2-weighted images, and showed homogeneous, strong enhancement on contrast-enhanced T1-weighted images. The mass had both extramedullary and intramedullary components.     

Intradural schwannomas of the spine: MR findings with emphasis on contrast-enhancement characteristics.

Intradural extramedullary schwannomas are nerve sheath neoplasms that consist of focal proliferations of Schwann cells involving a spinal nerve. We reviewed the MR findings in seven patients with pathologically proved intradural schwannomas. The contrast-enhancement characteristics on MR images were determined and compared with the histologic features of the tumor. Six lesions were variably hyperintense on T2-weighted images and one was uniformly hypointense compared with the signal intensity of the spinal cord. Signal on T1-weighted images ranged from hypointense to isointense. All seven tumors showed heterogeneous enhancement; in five, the enhancement involved only the periphery of the lesion. The pattern of enhancement did not correlate with the signal characteristics noted on unenhanced T1- and T2-weighted images. Pathologically, hyaline thickening of vessel walls and cyst formation were prevalent in the peripherally enhancing lesions. However, enhancement did not correlate with the relative proportion of Antoni type A and type B tissue. Recognition of the MR characteristics of intradural extramedullary schwannomas may be helpful in the differential diagnosis of spinal tumors. In particular, peripheral contrast enhancement of an intradural extramedullary tumor on MR images should suggest the diagnosis of schwannoma.     

磁共振脊髓成像诊断椎管病变的价值

探讨ＭＲＭ诊断椎管病变的价值及ＭＲＭ技术方法。材料与方法：对７１例椎管病变的常规ＭＲＩ检查及ＭＲＭ表现进行了分析,其中髓内肿瘤８例,髓外硬膜内肿瘤１４例,硬膜外肿瘤９例,结核３例,脊椎外伤７例,脊柱闭合不全６例,椎间盘突出及骨性椎管狭窄２４例。