Tail Sign Research Articles

Tentorial Schwannoma Mimicking Meningioma -Case Report-

A 58-year-old woman presented with a rare tentorial schwannoma manifesting as a chief complaint of headache. Magnetic resonance imaging showed an infratentorial extra-axial mass lesion with both cystic and solid components and dural tail sign. The tumor was easily separated from the surrounding structures, and the origin was apparently the tentorial branch of the trigeminal nerve. Tentorial schwannoma should be considered in the differential diagnosis of mixed cystic and solid mass lesions associated with the tentorium around the ambient cistern.

Significance of dural tail sign in cerebellar stroke

Significance of dural tail sign in cerebellar stroke

Metastatic Skull Base Tumor From Thymic Carcinoma Mimicking Tolosa-Hunt Syndrome -Case Report-

A 39-year-old male without contributory medical history had sustained progressive double vision, ptosis, and trigeminal pain for 2 weeks. Physical examination revealed total ophthalmoplegia and visual field defect with normal blood examination and chest radiography. Cranial computed tomography revealed a hyperdense mass in the left frontotemporal fossae with bony erosion. Magnetic resonance imaging confirmed a broad-based, intensely enhanced extraaxial tumor of 4x4x4 cm diameter with dural tail sign. Cerebral angiography demonstrated insignificant blood supply both from the internal carotid and middle meningeal arteries. Nearly total tumor resection was achieved via orbitofrontotemporal craniotomy. Intraoperative findings revealed the extraaxial tumor with broad attachment to the dura mater and invasion to the optic and oculomotor nerves. Histological examination revealed hypercellular tumor with significant cell atypism, mitotic activity, and focal necrosis. Immunohistochemical staining was positive for AE1/3 and c-kit, but negative for glial fibrillary acidic protein. Systemic examination performed postoperatively revealed a thymic tumor without additional remote lesions. The final diagnosis was metastatic brain tumor from thymic carcinoma. Rapid progression of neurological impairment inconsistent with a benign extraaxial tumor needs prompt surgical intervention.

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.

Pathologic significance of the “dural tail sign”

The exact nature of the “dural tail sign” (thickening of the dura adjacent to the tumour in contrast enhanced T1-MRI imaging) is still not clearly established. In this study we tried to verify the histological appearance of the “dural tail sign” and probable correlation between different MRI findings and dural tail histology.

Radiological findings of spinal schwannomas and meningiomas: focus on discrimination of two disease entities

This study evaluates the effectiveness of CT and MR imaging in differentiating intradural extramedullary spinal schwannomas and meningiomas in a large group of patients. In addition, the study correlates tumour location, morphologic characteristics and enhancement pattern. From January 2000 to June 2007, we retrospectively reviewed 128 consecutive patients (51 male, 77 female; mean age at admission 53.8 years; range 17-83 years) with spinal intradural extramedullary tumours (92 schwannomas, 36 meningiomas) at our institution. Fifty-one of ninety-two schwannomas (55.4%) showed fluid signal intensity on T2-weighted MR images. Twenty-two of thirty-six meningiomas (61.1%) showed hyperintense signal intensity and thirteen of thirty-six meningiomas (36.1%) showed isointense signal on T2-weighted MR images. Fifty-four schwannomas (58.7%) showed rim enhancement and thirty-three meningiomas (91.7%) showed diffuse enhancement on contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed dural tail sign in contrast-enhanced T1-weighted MR imaging. Twenty-one meningiomas (58.3%) showed calcification on CT images. MR and CT imaging results are therefore useful for the differentiation of schwannomas from meningiomas of the spine.

Clock face model applied to tibial intraneural ganglia in the popliteal fossa

Tibial intraneural ganglia occurring in the popliteal fossa are often misdiagnosed because of their relative rarity. Their joint connection is typically not recognized and therefore not treated, leading to recurrence. This is a retrospective clinical study. Magnetic resonance images (MRIs) of six patients with confirmed tibial intraneural ganglia arising from the superior tibiofibular joint were analyzed and were compared to ten individuals with normal tibial nerves who were imaged with MRI. All studies were interpreted as left-sided. A previously designed clock face model introduced for peroneal intraneural ganglia was used to describe the superior tibiofibular joint connection (tail sign). A single axial image was sought to determine the normal anatomic and pathologic relationships of the tibial nerve and tibial articular branch to the superior tibiofibular joint. In all patients with intraneural ganglia, a single conventional axial image at the mid-fibular head level could reliably demonstrate: (1) intraneural cyst within the articular branch at the superior tibiofibular joint connection (tail sign) between 8 and 9 o'clock and intraneural cyst within the tibial nerve, (2) the central location of the tibial nerve posterior to the tibia, and (3) popliteus muscle denervation changes and atrophy (popliteus sign). This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning of tibial intraneural ganglia. Similar to its use with the clock face model in peroneal intraneural ganglia, a standard axial image at the mid-fibular head level can be used to interpret key features of tibial intraneural ganglia and identify the joint connection. Improved identification of the presence of a joint connection will change the therapeutic approach of this pathology and reduce cyst recurrences.

Ultrasonographic diagnosis of urinary calculus caused by melamine in children

Background Intake of melamine can cause renal and ureteral lithiasis in infants and children. The present study aimed to understand the value of ultrasonography in the diagnosis of renal and ureteral lithiasis in infants and young children caused by melamine, and the characteristics of ultrasonograms of melamine-associated calculi. Methods Ultrasonographic examination on the urinary system was performed for 28 332 children who ingested milk powder that was possibly tainted with melamine; 395 of the children were diagnosed by ultrasonography as having urinary calculus, and 231 cases had lump-like calculi and 164 cases had sand gravel-like calculi. The features of the calculi, the sites of obstruction and the status of hydronephrosis and hydroureterosis were analyzed. Ultrasonographic reexamination was performed for 116 patients and the findings were compared with those of the first ultrasonography, and the short-term expulsion of the calculi was evaluated. Results Most of the 395 patients with urinary lithiasis, except for those who developed renal failure, had no symptoms. The whole profile of the calculi could be seen in most of the cases, because the echogenicity of the calculi with no sharp or absent acoustical shadowing, was weaker as compared with those from calcium-containing calculi. Comet tail sign could be seen behind the echogenicity of single gravel calculus. The rate of diagnostic consistency of ureteral lithiasis between the ultrasound and the results of clinical observation (including stones expelled spontaneously or after cystoscopic intervention) in 51 cases for 76 ureters was 100%. Percutaneous renal biopsy was performed for one case, and histopathological examination showed flocculent, fine strip-like, ellipse and circular deeply stained sand gravel-like material in the renal tubules, and the circular calculi were found to be attached to the walls of the tubules. Chemical analysis of the calculi expelled from 12 cases showed that the main contents of the calculi were uric acid and melamine. Short-term ultrasound reexamination in 116 patients showed that gravel-like calculi disappeared in 80.4% of the cases; in 26 non-hospitalized cases who had lump-like calculi without hydronephrosis or hydroureterosis, none of the lump-like calculi were expelled. Conclusions The ultrasonograpic findings of urinary calculi in children caused by ingestion of melamine-tainted milk powder have a certain features as compared to the calculi containing calcium. Careful ultrasound examination can avoid missed diagnoses of ureteral calculi. Most of the gravel-like calculi can be expelled within a short period of term, while lump-like calculi can hardly be expelled. Ultrasonography is an accurate and reliable method of diagnosis of urinary calculus caused by melamine intake in children and it can be used as diagnostic method of choice although abdominal X-ray plain film can also visualize some of larger calculi.

Signs in chest imaging: a pictorial review

A radiological sign can sometimes resemble a particular object or pattern and is often highly suggestive of a group of similar pathologies. Awareness of such similarities can shorten the differential diagnosis list. Many such signs have been described for X-ray and computed tomography (CT) images. In this article, we present the most frequently encountered plain film and CT signs in chest imaging. These signs include for plain films the air bronchogram sign, silhouette sign, deep sulcus sign, Continuous diaphragm sign, air crescent ("meniscus") sign, Golden S sign, cervicothoracic sign, Luftsichel sign, scimitar sign, doughnut sign, Hampton hump sign, Westermark sign, and juxtaphrenic peak sign, and for CT the gloved finger sign, CT halo sign, signet ring sign, comet tail sign, CT angiogram sign, crazy paving pattern, tree-in-bud sign, feeding vessel sign, split pleura sign, and reversed halo sign.

The clock face guide to peroneal intraneural ganglia: critical “times” and sites for accurate diagnosis

The aim of this study is to exploit the normal nature of peroneal nerve anatomy to identify constant magnetic resonance imaging (MRI) patterns in peroneal intraneural ganglia. This study is designed as a retrospective clinical study. MR images of 25 patients with peroneal intraneural ganglia were analyzed and were compared to those of 25 patients with extraneural ganglia and 25 individuals with normal knees. All specimens were interpreted as left-sided. Using conventional axial images, the position of the common peroneal nerve and either intraneural or extraneural cyst was determined relative to the proximal fibula and the superior tibiofibular joint using a symbolic clock face. In all patients, the common peroneal nerve could be seen between the 4 and 5 o'clock position at the mid-portion of the fibular head. In patients with intraneural ganglia, a single axial image could reproducibly and reliably demonstrate both cyst within the common peroneal nerve at the mid-portion of the fibular head (signet ring sign) between 4 and 5 o'clock and within the articular branch at the superior tibiofibular joint connection (tail sign) between 11 and 12 o'clock; in addition, cyst within the transverse limb of the articular branch (transverse limb sign) was seen at the mid-portion of the fibular neck between the 12 and 2 o'clock positions on serial images. Extraneural ganglia typically arose from more superior joint connections with the epicenter of the cyst varying around the entire clock face without a consistent pattern. There was no significant difference between the visual and template assessment of clock face position for all three groups (intraneural, extraneural, and controls). We believe that the normal anatomic and pathologic relationships of the common peroneal nerve in the vicinity of the fibular neck/head region can be established readily and reliably on single axial images. This technique can provide radiologists and surgeons with rapid and reproducible information for diagnosis and treatment planning. By using conventional bony anatomy as reference points (namely fibular neck and mid-portion of fibular head), standard axial images can be used to interpret key features of peroneal intraneural ganglia and to establish their accurate diagnosis (rather than extraneural ganglia) and pathogenesis from an articular origin (rather than from de novo formation), a fact that has important therapeutic implications. Because of the relative rarity of peroneal intraneural cysts and physicians' (radiologists and surgeons) inexperience with them and the complexity of their findings, they are frequently misdiagnosed and joint communications are not appreciated preoperatively or intraoperatively. As a result, outcomes are suboptimal and recurrences are common.

Extraordinary effects of liquid capsule application after resection of a giant meningioma

Extraordinary effects of liquid capsule application after resection of a giant meningioma

Pathologic significance of the “dural tail sign”

Objective The exact nature of the “dural tail sign” (thickening of the dura adjacent to the tumour in contrast enhanced T1-MRI imaging) is still not clearly established. In this study we tried to verify the histological appearance of the “dural tail sign” and probable correlation between different MRI findings and dural tail histology. Material and methods In this study, 129 patients with intracranial lesions underwent MRI imaging with 1.5 T scanner. The “dural tail sign” was defined using Goldsher et al. criteria. Size and pattern of enhancement of the tumour and adjacent dura was noted in MRI and in the pathologic samples, dural tail and the dura beneath the tumour was assessed. Results In 30 cases, “dural tail sign” was evident on MRI, dural tail noted in 17 of these cases in histological samples (12 meningiomas, 3 pituitary adenomas and 2 schwannomas). All of them had vessel dilatation, 6 showed tumoural invasion, 4 demonstrated intravascular growth of the lesion and 1 showed inflammation of the dura. Conclusion In our study MRI findings failed to predict tumoural invasion of the dural tail in histologic samples and because of frequent presence of tumour nests in it, the dura matter should be resected as widely as possible.

A Meningioma with Hyperintensity on T1-Weighted Images in a Dog

A male six-year-old Pomeranian showed recurrent seizures and progressive left hemiparesis. MRI revealed a mass in the right paramedian frontal-temporal region with hyperintensity on T1-weighted (T1W) and mixed-intensity on T2-weighted (T2W) images. After gadolinium enhancement, the mass was enhanced homogenously and demonstrated the dural tail sign. Surgical resection of mass was performed and its histological diagnosis was meningioma. The meningioma of this case had a high cellular density with some lipid contents and intra- and extra-tumor hemorrhage, however, calcification was not found. These cellular characteristics may contribute to a higher signal intensity on T1W imaging.

Microcystic Meningioma

To investigate the sensitivity and specificity of various magnetic resonance imaging findings for microcystic meningioma. Magnetic resonance images of 26 patients with microcystic meningioma (8 from our series and 18 from the literature) and 32 control subjects with other types of meningiomas were evaluated for obvious hypointensity relative to the cerebral cortex on T1-weighted images (T1WIs), obvious hyperintensity relative to the cerebral cortex on T2-weighted images (T2WIs), a radial or sunburst vascular pattern, marginal and reticular enhancement, severe peritumoral brain edema, and the dural tail sign. Differences in the frequencies of these findings between the microcystic and control groups were examined by means of the chi2 test. The sensitivity, specificity, positive predictive value, and negative predictive value of these findings in the diagnosis of microcystic meningioma were calculated. Multivariate analysis of the findings was also performed. The frequencies of obvious hypointensity on T1WI, obvious hyperintensity on T2WI, marginal and reticular enhancement, and severe peritumoral brain edema significantly differed between the microcystic and control groups (all P < 0.005). Sensitivities and specificities of hypointensity on T1WI and hyperintensity on T2WI in the diagnosis of microcystic meningioma were greater than 87%. After multivariate analysis, obvious hypointensity on T1WI was the only significant predictor of microcystic meningioma, with an odds ratio of 75.0 (95% confidence interval, 3.7-1536.0). Obvious hypointensity relative to the cerebral cortex on T1WI was the most valuable magnetic resonance finding in the diagnosis of microcystic meningioma.

A Dural Tale

A 44-yr-old cushingoid-appearing male was referred to the Massachusetts General Hospital for evaluation of a new sellar mass. He presented with rapid onset of symptoms over 6 months, including weight loss and hypokalemia. The 3-cm T1-enhancing sellar mass tapered posteriorly along the left tentorium, forming a “dural tail” (Fig. 1), suggesting a meningioma. Endocrine evaluation revealed ACTH-dependent Cushing’s syndrome, with a urine-free cortisol of 303 g/24 h (normal 20–70 g/24 h) and an ACTH level of 83 pg/ml (normal 6–76 pg/ml). An inferior sinus petrosal catheterization, performed due to the unusual radiological characteristics of the sellar mass and symptoms of weight loss and hypokalemia, confirmed a central source of excess ACTH secretion. Tissue obtained during transsphenoidal debulking revealed a corticotroph macroadenoma without evidence of meningioma. The dural tail sign is usually associated with meningiomas (1–3). The sign was thought initially to be specific for meningioma but has been described in association with other pituitary and intracranial processes. The sensitivity and specificity of the dural tail sign are approximately 60 and 95%, respectively (4). The tail results from a reactive inflammatory process in the dura mater adjacent to the point of tumor attachment rather than direct tumor infiltration. This case demonstrates that the dural tail sign may be seen with pituitary macroadenomas, and such tumors should be included in the differential diagnosis associated with this sign. The tumor in this case is unusual for Cushing’s disease in its size and radiological presentation (5). This case also demonstrates that ACTH-secreting macroadenomas can be associated with severe symptoms of cortisol excess and mimic ectopic ACTH-secreting tumors.

Intracranial meningiomas: magnetic resonance imaging findings in 78 cases

To present the magnetic resonance (MR) imaging findings of 78 patients with meningiomas diagnosed in a single institution. 78 patients with histological proven intracranial meningioma were studied. There were 52 female and 26 male patients (median=56 years). All MR imaging examinations were performed with 1.5-T MR imaging unit with standard protocol. The images were studied by two neuroradiologists, who reached the decisions regarding the findings by consensus. Most of the tumors showed low signal on T1- (60%) and high signal on T2- (68%) and FLAIR (69%) weighted images. Also, the lesions showed heterogeneous signal on T1 (60%), T2 (68%) and FLAIR (64%) sequences. After contrast administration, 83% (n=65) of the tumors presented accentuated and 17% (n=13) showed moderate enhancement. The tumors were located in the frontal lobe in 44% of the cases, in the parietal lobe in 35%, the occipital lobe in 19% and the temporal lobe in 12% of the patients. Areas of vasogenic edema around the tumors were seen in 90% of the cases. Twenty six per cent of the cases showed bone infiltration, and the dural tail sign was seen in 59% of the tumors. Intracranial meningiomas usually show heterogeneous low signal on T1- and high signal on T2-weighted and FLAIR images, with intense enhancement after contrast administration. The frontal and parietal lobes are commonly affected. In addition, brain edema, dural tail sign and bone infiltration are the most frequent associated findings.

Chordoid meningioma: a report of two cases

Objective: To explore the clinical, imaging and pathological features of chordoid meningioma (CM). Methods: Retrospectively analysis the clinicopathologic features of 15 CM and review related literatures. Results: There was obvious female preponderance with male to female ratio of 4:11, the average age is 47.4 (15-71) years old. Mostly happens in the convex of frontal and parietal lobe, sphenoid ridge. Clinical symptoms including headache, blurred vision, weakness of limbs, facial paresthesia and slurred speech, and so on. Imaging mainly manifests the typical features of meningiomas, such as clear boundaries, dural tail sign and high-low mixed signs caused by mucus. Microscopically, in addition to the typical meningioma, there were different proportion of chordoid components (20%~100%), that was, tumor cells arrange to cords, mesh-like, false daisy-type groups or nest pattern in the

Meningioma in the Posterior Fossa Without Dural Attachment -Case Report-

A 14-year-old boy presented with a very rare meningioma in the posterior cranial fossa without dural attachment. Magnetic resonance imaging revealed a 3-cm, well-circumscribed, heterogeneously enhanced, round mass without dural tail sign in the right side of the posterior fossa. Right vertebral angiography revealed very faint tumor staining supplied by the right posterior inferior cerebellar artery. Total removal of the tumor was performed. Intraoperatively, the mass exhibited no attachment to the dura mater, cerebellar parenchyma, or choroid plexus, but was firmly attached to the arachnoid tissue near the foramen of Luschka. Histological and immunohistochemical studies established the diagnosis of meningothelial meningioma (World Health Organization grade I).

Dural tail sign in spinal meningiomas

Objective To study the association between the “dural tail sign” and spinal meningiomas on MR imaging. Methods Retrospective 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. Results Seven 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.

The Cystic Transverse Limb of the Articular Branch: a Pathognomonic Sign Forperoneal Intraneural Ganglia Atthe Superior Tibiofibular Joint

The preoperative diagnosis of peroneal intraneural ganglia has been difficult to establish, and superior tibiofibular joint connections may not be identified. Misdiagnosis leads to incomplete treatment in that the articular branch connection may not be addressed, which can result in cyst recurrences. We analyzed 20 surgically confirmed cases of paraarticular cysts arising from the superior tibiofibular joint to assess for joint connections and to determine common magnetic resonance imaging characteristics in intraneural ganglia that would allow distinction from extraneural ganglia. We identified and tested three radiographic signs describing the cysts and analyzed cyst morphology (i.e., size, shape, pattern), muscle compartments affected (i.e., for denervation), and neighboring joints (for associated pathology). Twelve cases of peroneal intraneural ganglia and eight cases of extraneural ganglia were connected to the superior tibiofibular joint. Retrospective review confirmed that these cysts were frequently misdiagnosed, and joint connections often were not recognized. The magnetic resonance imaging appearance of peroneal intraneural ganglia was stereotypical. These intraneural ganglia were tubular, whereas the extraneural were more mass-like. The tail sign was 100% sensitive for identifying joint connections but could not distinguish between intra- and extraneural cysts. The "transverse limb" sign (cystic material within the portion of the articular branch traversing the anterior surface of the fibula) was present in all cases of peroneal intraneural ganglia and none of the extraneural ganglia. The signet ring sign (the eccentric displacement of fascicles by cyst within the epineurium) was 100% sensitive for peroneal intraneural ganglia and 86% specific (it did not identify two cysts that did not extend more proximally into the common peroneal nerve). There was 100% interobserver concordance between the prospective interpretations by a single, blinded, radiologist and a trained first-year medical student with intraoperative findings. In this series, muscle denervation was more common and more pronounced in the intraneural than extraneural ganglia. Abnormalities in neighboring joints were noted nearly universally. This article demonstrates reproducible magnetic resonance imaging features that will easily allow one to identify the joint connection (the tail sign) in paraarticular cysts and also to distinguish between peroneal intraneural and extraneural ganglia (the transverse limb sign and the signet ring sign) at the superior tibiofibular joint with accuracy and confidence and with subsequent improvement in treatment and patient outcomes.