Dural tail sign in spinal meningiomas

ObjectiveTo study the association between the “dural tail sign” and spinal meningiomas on MR imaging.MethodsRetrospective review of MR examinations of all pathologically proven spinal meningiomas from 1998 to 2005 was performed. Lesions were evaluated for size, signal intensity, enhancement pattern, and presence or absence of dural tail. The dural tail length and direction in reference to the meningioma were also evaluated.ResultsSeven spinal meningiomas were identified in seven patients. One lesion was purely extradural, while the remaining were intradural extramedullary. Dural tail was present in four cases (57%) and its length ranged between 5 and 21 mm. The tail was seen cranial and caudal to the meningioma in three cases and only cranially in one. Coronal images were available in three cases and in two of these; the dural tail was clearly depicted.Conclusions“Dural tail sign” is as common in spinal meningiomas as in cranial meningiomas.     

Dural congestion accompanying meningioma invasion into vessels: the dural tail sign

Our purpose was to verify the histological appearance of the dural tail accompanying meningiomas on MRI. We studied seven patients such a dural tale. We examined the point of attachment of the tumour and the adjacent dura mater histologically. In all patients, rich vascularity and dilated vessels were observed in the dura mater at the point of attachment of the tumour; tumour cells invaded the dura mater and vessels, packing the latter. In the adjacent dura mater, showing as a dural tail on MRI, there was tumour-cell invasion in only one patient. Vascular congestion around the vessels compacted by the tumour cells in the dura mater and dilated vessels were seen in all patients. We therefore suggest that the mechanism of the dural tail sign is as follows. First, tumour cells invade vessels and pack them at the point of tumour attachment. Then, vessel congestion is induced in the adjacent dura mater, as a result of which it enhances markedly, giving rise to the dural tail sign. Received: 31 July 2000 Accepted: 29 September 2000     

A review on dural tail sign

"Dural tail sign" (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected.     

Dural invasion of meningiomas adjacent to the tumor margin on Gd-DTPA-enhanced MR images: histopathologic correlation

In intracranial meningiomas a flat, contrast-enhancing, dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA-enhanced MR images. We wished to evaluate whether there is a correlation between MR images and meningeal invasion of intracranial meningiomas. The study included 54 patients with intracranial meningioma and the meningeal sign. MR studies included T2-weighted and gadolinium-DTPA-enhanced T1-weighted images in axial, coronal, and sagittal planes. Histopathologic examinations were done on the meningiomas adjacent to the dura mater. The meningeal sign on MRI was observed from 2 up to 35 mm from the main tumor mass in 31 (57 %) of the 54 patients. In 20 of these 31 the histopathologic examination showed tumor invasion, while 11 patients had no tumor invasion but tissue proliferation, hypervascularity, and vascular dilatation. Seven of the 23 meningiomas without the meningeal sign had histologically proven infiltration of the adjacent dura. MR imaging is not able to determine definitive whether or not there is dural infiltration of the meningiomas. In conclusion, resection of the tumor with a wide margin is necessary to achieve complete excision of meningioma and to avoid recurrence. Received 23 July 1997; Revision received 10 October 1997; Accepted 17 October 1997     

The dural tail of intracranial meningiomas on fluid-attenuated inversion-recovery images

We evaluated the dural tail associated with 48 intracranial meningiomas on fluid-attenuated inversion-recovery (FLAIR) and contrast-enhanced T1-weighted images. In 30 (62.5%), a dural tail was observed on contrast-enhanced T1-weighted images, and thickening of the dura mater and abnormal signal were identified in the corresponding region on FLAIR images. Thus, FLAIR imaging was useful for showing dural abnormality associated with meningiomas without the needed for contrast medium.     

MRI appearances mimicking the dural tail sign: a report of two cases

We report two cases in which the MRI appearances mimicked the dural tail sign; a glioma extending into the subarachnoid space, and a meningioma extending to the subdural space. They indicate that tumour invasion into the subarachnoid or subdural space, should be considered when prominent linear enhancement is observed along the dura mater adjacent to tumours. Received: 31 March 1999/Accepted: 21 July 1999     

“Dural tail” adjacent to a giant posterior cerebral artery aneurysm: case report and review of the literature

The “dural tail” sign on gadolinium (Gd-DTPA)-enhanced MRI has been described in association with meningiomas. Various series with histopathological correlation have shown that in some cases there is tumour invasion into the dura mater, but in the majority of cases it represents a hypervascular, non-neoplastic reaction. While this sign was originally thought to be specific for meningioma, subsequent case reports have described the presence of a dural tail in other intra- and extra-axial lesions. We present a patient with a giant aneurysm arising from the P2 segment of the right posterior cerebral artery, adjacent to the tentorium, with a prominent dural tail on Gd-DTPA-enhanced MRI. In this location, differentiation of an aneurysm from a meningioma was critical. Received: 24 September 1996 Accepted: 7 October 1996     

脑膜瘤瘤周水肿的MRI表现与手术病理对照研究

目的：分析脑膜瘤瘤周水肿的MRI表现与手术、病理的关系。材料和方法：对51例磁共振图像中脑膜瘤的瘤周水肿特点进行分析，并与手术、病理对照。结果：51％脑膜瘤伴瘤周水肿，磁共振T2WI瘤周水肿有月晕型（50％）和指样型（50％）两种，该分型与显微外科手术界面相对应。结论：MRI有助于脑内、外肿瘤的鉴别诊断。     

脑膜血管外皮细胞瘤的影像诊断与鉴别诊断

目的 提高对脑膜血管外皮瘤的认识。资料与方法 回顾性分析经手术病理证实的4例脑膜血管外皮瘤的CT和MRI表现，并结合文献进行复习。结果 脑膜血管外皮瘤的CT和MRI表现类似脑膜瘤，但具有恶性征，无颅骨增生和硬膜强化（硬膜尾征），与脑膜瘤不同。结论 CT和MRI表现类似脑膜瘤的颅内肿瘤，具有恶性征，没有颅骨增生和硬膜强化者要考虑脑膜血管外皮瘤的可能。     

Correlating apparent diffusion coefficients with histopathologic findings on meningiomas

Purpose

To determine whether the apparent diffusion coefficient (ADC) correlates with histopathologic findings and whether ADC values can be used to differentiate benign from atypical/malignant meningiomas.

Materials and methods

MR images were reviewed retrospectively in 138 patients with meningiomas treated between September 1997 and July 2003. The ADC values were measured in the lesions and peritumoral edema, and the normalized ADC (NADC) ratios were calculated using the formula NADC = ADC of the tumor/ADC of the normal white matter. The ADC findings were compared with the histopathologic findings after resection using the World Health Organization criteria (2007).

Results

Meningiomas were histologically graded as malignant (9%), atypical (14%) and benign (77%). Of the 138 meningiomas, 32 (23%) were atypical (n = 19) or malignant (n = 13), whereas 106 (77%) were typical. The mean ADC values were statistically different between typical and atypical/malignant meningiomas (0.97 ± 0.21 × 10⁻³ mm²/s vs 0.85 ± 0.17 × 10⁻³ mm²/s). The mean NADC ratios were also significantly lower in the atypical/malignant group (1.09 ± 0.23) than in the benign group (1.24 ± 0.25; P = 0.002 < 0.05). The mean ADC values and NADC ratios did not differ significantly among fibrous, meningothelial, transitional and atypical tumors (P > 0.05). The mean ADC values and NADC ratios were higher in the angiomatous and secretory subgroups than in the fibrous, meningothelial, transitional, atypical and malignant subgroups (P < 0.05). The ADC values and NADC ratios were the lowest in the malignant subgroup, and the difference between atypical and malignant meningiomas was statistically significant (P < 0.05).

Conclusions

Meningioma subgroups displayed different ADC values from each other. Thus, ADC values may provide a useful supplement to the information obtained from conventional contrast-enhanced MR imaging, enhancing the ability of medical professionals to differentiate among the subgroups of meningiomas.     

Multiple meningiomas. Clinical and computed tomographic observations

Summary The same histological types of tumor are found in multiple as in solitary meningiomas. Multiple meningiomas cannot be considered in every case to be a forme fruste of von Recklinghausen's disease. The incidence of multiple meningiomas in this paper is higher than had been reported before the introduction of computed tomography (CT) into clinical practice. The number of tumor nodes is determined more accurately by CT than by angiography because tumors are detected in patients without neurological deficit. CT has limitations in the verification of small meningioma nodules near the base of the skull and in the differentiation of multiple meningiomas from meningeal meningiomatosis or primary meningeal sarcomatosis.Presented in part at the 16. Jahrestagung der Deutschen Gesellschaft für Neuroradiology Munich, 9–11 October 1980     

Cavernous sinus meningiomas: An MRI study

Summary The authors report their experience in examining cavernous sinus meningiomas with MRI. The advantages of this diagnostic method particularly in comparison with conventional neuroradiological techniques are described.     

脑膜尾征”：与脑膜瘤相关的MR强化表现

目的分析脑膜瘤脑膜尾征的MR表现及组织学特点。方法对32例脑膜瘤患者均行MR平扫及增强扫描。结果32例34个脑膜瘤病灶中有23个病灶（67.6%）显示脑膜尾征,且与肿瘤的大小与位置无关。结论脑膜尾征是脑膜瘤在MR增强扫描时较常见和特有的表现,而且脑膜尾征与肿瘤侵犯脑膜部分相关。     

Intracranial adenoid cystic carcinoma mimicking meningioma: report of two cases

Two cases of intracranial adenoid cystic carcinoma mimicking meningioma are reported. In one, MRI showed not only a homogeneously enhancing extra-axial tumour attached to the dura mater of the posterior cranial fossa, but also surrounding dural enhancement, the dural tail sign. In the second, CT demonstrated a well-demarcated enhancing extra-axial tumour, indistinguishable from a sphenoid ridge meningioma extending into the orbit. The neuroradiological features of intracranial adenoid cystic carcinoma may thus closely resemble those of meningioma.     

脊膜瘤MRI表现及其病理基础相关性研究

探讨脊膜瘤ＭＲＩ表现特征与病理关系。材料与方法，搜集行ＭＲＩ扫描且有手术病理结果的脊膜瘤１９例，观察肿瘤部位，数目，瘤体信号，肿瘤与脊髓交界带信号及硬脊膜改变，与手术病理结果对照并统计学处理。结果：肿瘤单发１８例，多发１例。     

MR spectrum in spinal dysraphism

Spinal dysraphism is a general term which encompasses a wide variety of anomalies of the spine, all of which result from imperfect midline fusion of the embryonic neural tube. This term refers to large defects that involve the spine and not to small vertical clefts commonly seen within the spinal process of L5 or S1. We present a spectrum of MR imaging findings selected from a retrospective review of 100 patients of spinal dysraphism evaluated at our institution. Received: 18 May 2000 Revised: 13 July 2000 Accepted: 13 July 2000     

The MRI finding of the nerve root sedimentation sign: Its clinical validity and operative relativity for patients with lumbar spinal stenosis

Background

Lumbar spinal stenosis (LSS) is increasingly being recognised as a cause of disabling low back and lower extremities pain in adult population. Advanced spinal imaging thought as confirmation tool for the diagnosis and as preoperative tool to delineate the extent and precise location of the pathology. Nerve roots normally sediment, due to gravity, to the dorsal part of the dural sac, which was known as negative sedimentation sign. If there is MRI finding of nerve roots in the ventral part of the dural sac the sedimentation sign is positive.

Objectives

To evaluate the presence of the MRI finding of positive sedimentation sign in patients clinically suspected to have lumbar spinal stenosis and to follow up operated cases to identify the absence of the radiological signs in the operated cases.

Material and methods

70 patients clinically suspected to have lumbar spinal stenosis evaluated by MRI lumbosacral spine in supine position. A panel of two radiologists reviewed radiological data. MRI features were agreed by both radiologists in 48 patients. Out of these 48 patients; 25 were operated upon for central decompressive laminectomy, partial medial facetectomy and foraminotomy with instrumented fusion and fixation if indicated. Visual analogue score (VAS) collectively preoperative and postoperative was compared and the walking distance postoperative was reported and follow up MRI studies were done one year after the operation.

Results

Operated patients’ mean age was 58.2 years; nineteen patients were operated upon for simple decompressive laminectomy for the affected levels. Walking distance preoperative range 100–700 metres, improved postoperative to be 1474.0 ± 601.1. VAS for pain preoperative was 9.28 ± 0.84, improved at 12 month follow up to be 0.84 ± 0.62. Postoperative MRI done to evaluate the cross sectional area (CSA) became more than 80 mm² in the absence of the sedimentation sign and was negative in 22 cases.

Conclusion

The MRI finding of positive sedimentation sign is a good positive sign to rule in lumbar spinal stenosis with high specificity and sensitivity; negative sedimentation sign can be used in postoperative follow up of decompression patients.     

低场强MRI对脊椎转移瘤的诊断及鉴别诊断

目的:为了提高脊椎转移瘤诊断及其与其他椎体病变的鉴别诊断水平。方法:回顾性分析经病理证实的转移瘤79例和误诊病例15例的MRI特点,归纳其影像表现的差异。结果:79例转移瘤中,累及椎体125个,多为跳跃式分布;累及附件骨92个,占73.6%;椎体破坏变形81个,占64.8%;椎间盘均无变化;有软组织肿块22例(17.6%),软组织肿块常以破坏区为中心生长。T1WI均呈低信号,T2WI信号改变可以多种多样。结论:MRI检查在诊断脊椎转移瘤及与其他脊椎病变的鉴别诊断中更敏感、更具特异性。     

Preoperative subtyping of meningiomas by perfusion MR imaging

Introduction  This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Materials and methods  Thirty-seven meningiomas with peritumoral edema (15 meningothelial, ten fibrous, four angiomatous, and eight anaplastic) underwent perfusion MR imaging by using a gradient echo echo-planar sequence. The maximal rCBV (compared with contralateral normal white matter) in both tumoral parenchyma and peritumoral edema of each tumor was measured. The mean rCBVs of each two histological subtypes were compared using one-way analysis of variance and least significant difference tests. A p value less than 0.05 indicated a statistically significant difference. Results  The mean rCBV of meningothelial, fibrous, angiomatous, and anaplastic meningiomas in tumoral parenchyma were 6.93 ± 3.75, 5.61 ± 4.03, 11.86 ± 1.93, and 5.89 ± 3.85, respectively, and in the peritumoral edema 0.87 ± 0.62, 1.38 ± 1.44, 0.87 ± 0.30, and 3.28 ± 1.39, respectively. The mean rCBV in tumoral parenchyma of angiomatous meningiomas and in the peritumoral edema of anaplastic meningiomas were statistically different (p < 0.05) from the other types of meningiomas. Conclusion  Perfusion MR imaging can provide useful functional information on meningiomas and help in the preoperative diagnosis of some subtypes of meningiomas.     

Granulocytic sarcoma (chloroma) causing spinal cord compression

Granulocytic sarcoma (chloroma) is a rare solid tumor of myelogenous stem cells, usually appearing in patients with acute myelogenous leukemia and less commonly in patients with chronic myelogenous leukemia or myeloproliferative disorders. We present a spinal epidural granulocytic sarcoma causing thoracic spinal cord compression in a patient with chronic anemia secondary to myelofibrosis.