1/314. meningioma in four patients with human immunodeficiency virus infection.We describe four patients infected with the human immunodeficiency virus (hiv) who had development of meningiomas. In contrast to those in the general population who have meningiomas, all our patients were young men; the mean age was 40 years (range, 32 to 50). Their risk behavior for hiv was homosexuality (three patients) and intravenous drug use (one patient). The CD4 cell count in each of the three homosexual men was less than 50/microL and was 280/microL in the drug user. Imaging studies showed enhancing lesions in three of the patients. Although each of these meningiomas could have occurred in otherwise normal young to middle-aged men, we speculate that the meningiomas may have grown in these hiv-infected hosts because of either loss of immune function or dysregulation of cytokines.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
2/314. Biomodel-guided stereotaxy.OBJECTIVES: To simplify the practice of stereotactic surgery by using an original method, apparatus, and solid anatomic replica for trajectory planning and to validate the method and apparatus in a laboratory and clinical trial. methods: The patient is marked with fiducials and scanned by using computed tomography or magnetic resonance imaging. The three-dimensional data are converted to a format acceptable to stereolithography. Stereolithography uses a laser to polymerize photosensitive resin into a solid plastic model (biomodel). Stereolithography can replicate blood vessels, soft tissue, tumor, and bone accurately (<0.8 mm). A stereotactic apparatus is referenced to fiducials replicated in the biomodel. The trajectory for the intervention is determined and saved. The apparatus is attached to the patient fiducials, and the intervention is replicated. RESULTS: Three types of apparatus (template, Brown-Roberts-Wells frame, and D'Urso frame) were tested on phantoms and patients requiring the excision/biopsy of tumors. The localization errors determined from the phantom studies were template, 0.82 mm; Brown-Roberts-Wells frame, 1.17 mm; and D'Urso frame, 0.89 mm. The surgeons reported that clinical use of the template and D'Urso frame was accurate and ergonomic. The Brown-Roberts-Wells frame was more difficult to use and somewhat inaccurate. CONCLUSION: Biomodel-guided stereotaxy has significant advantages. It is performed quickly; it is based on simple, intuitive methodology; it enhances visualization of anatomy and trajectory planning; it enhances patient understanding; it uses inexpensive equipment; it does not require rigid head fixation; and it has greater versatility than known techniques. Disadvantages are biomodel cost and a manufacturing time of 12 to 24 hours.- - - - - - - - - - ranking = 0.89932907078834keywords = visual (Clic here for more details about this article) |
3/314. Intraventricular meningiomas: MR imaging and MR spectroscopic findings in two cases.CT, MR imaging, MR spectroscopy, and angiography were performed in two men (ages 21 and 48, respectively) with intraventricular meningioma. In both cases, CT and MR imaging showed large tumors located in the trigone of the right lateral ventricle that enhanced intensely after contrast administration. MR spectroscopy was helpful in supporting a preoperative diagnosis of meningioma in both cases.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
4/314. Falx meningioma presenting as acute subdural hematoma: case report.BACKGROUND: Acute subdural hematomas caused by meningiomas have been rarely encountered. Pathophysiologic mechanisms and clinical considerations in these patients have not been sufficiently explored. We addressed the possible mechanism of spontaneous hemorrhage in our case and briefly discuss the optimal treatment. CASE DESCRIPTION: This case of falx meningioma presenting as an acute subdural hematoma in a 78-year-old woman is described. On initial computed tomography (CT), an enhancing tumor of the falx appeared to be the cause of hemorrhage. Only faint contrast staining in the periphery of the tumor was seen on right external carotid arteriograms, with no evidence of other vascular supply. Extravasation of contrast material during the procedure occurred suddenly and was successfully treated by endovascular embolization using a microcatheter. The hematoma was emergently evacuated with gross total removal of the tumor. Pathologic examination confirmed a transitional meningioma with abundant hyalinized structures. Disruption of a thin-walled vessel adjacent to the tumor capsule was assumed to be the site of hemorrhage. CONCLUSIONS: The longstanding ischemia of the tumor was considered to have produced the deposition of hyalin in the tissue, which changed the hemodynamics within the tumor, producing vascular stress leading to rupture. The prognosis of patients with meningiomas complicated by acute subdural hematoma is generally poor, with mortality reported in approximately one-half of such patients. Surgical exploration is the most effective treatment and should be conducted before irreversible brain damage has occurred.- - - - - - - - - - ranking = 2keywords = contrast (Clic here for more details about this article) |
5/314. Leptomeningeal carcinomatosis and cranial nerve palsy as presenting symptoms of a clinically inapparent gallbladder carcinoma.We present an occult metastatic signet-ring cell gallbladder carcinoma in a 78-year-old woman, who complained of recurrent headaches, dysarthria, and paresis of the tongue. Cranial imaging showed contrast enhancement of the basal leptomeninges, and the cerebrospinal fluid displayed clusters of adenocarcinoma cells proposed as leptomeningeal carcinomatosis of the breast, lung or gut. However, postmortem examination revealed the gallbladder as the site of the primary carcinoma with focal signet-ring cell differentiation. In patients with progressive neurologic deterioration due to leptomeningeal carcinomatosis, adenocarcinomas from the gastrointestinal and hepatic systems should be considered. It is likely that signet-ring cell carcinomas display an increased affinity to leptomeningeal spread.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
6/314. Long-term magnetic resonance imaging follow-up of asymptomatic sellar tumors. -- their natural history and surgical indications.Serial magnetic resonance (MR) images and clinical symptoms were analyzed in 23 patients with sellar lesions, who were followed up without initial therapy for mass reduction to evaluate their natural history and surgical indication for these lesions. The patients were aged 17 to 78 years (mean 47.3 years) and the follow-up period was 1.5 to 11.6 years (mean 5.1 years). Lesions were divided into two types based on the MR imaging findings, regardless of their histological types. Type C was cystic with or without enhancement of the smooth and thin wall. Type S had enhanced solid components. Ten patients had Type C tumors. Three patients presented with sudden onset of headache. The tumor size spontaneously decreased with intensity change, indicating pituitary apoplexy as the trigger of the onset and intensity change. Four patients presented with the visual disturbance which improved with the reduction of tumor size, but three patients deteriorated and required surgery. The operation revealed Rathke's cleft cyst. The remaining three patients were found incidentally and have been asymptomatic without MR imaging changes. Thirteen patients had Type S tumors. Six patients of nine with 14 mm or larger tumors developed symptomatic tumor enlargement over the follow-up period of 1.2 to 8.6 years (mean 4.9 years) and required treatment. The remainder showed no change. Type C tumors frequently shrink or even disappear spontaneously. We can justify conservative follow-up of Type C tumors in patients with no or only transient symptoms. Type S tumors, larger than 14 mm in size, need closer observation or treatment because they often enlarge and become symptomatic.- - - - - - - - - - ranking = 0.89932907078834keywords = visual (Clic here for more details about this article) |
7/314. thallium-201 SPECT of adjacent intracranial tumours: a contrast in thallium kinetics.We report a case of adjacent intracranial tumours: malignant fibrous histiocytoma (MFH) and meningioma. thallium-201 single-photon emission computed tomography demonstrated different thallium kinetics between the tumours (slow washout from the MFH and rapid clearance in the meningioma) and could be said to have been useful for preoperative histological estimation.- - - - - - - - - - ranking = 4keywords = contrast (Clic here for more details about this article) |
8/314. Meningeal leiomyoma in an adult with AIDS: CT and MRI with pathological correlation.We describe the imaging features of a meningeal leiomyoma with pathological correlation in an adult with AIDS. On CT the tumour showed a central low-attenuation area and an enhancing peripheral ring. It gave low signal on T1 weighting and on T2-weighted images a central high-signal area was surrounded by a markedly low-signal band, which showed contrast enhancement. As far as we know, this is the first report of this condition in the radiological literature.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
9/314. Unique radiological appearance of a microcystic meningioma.A 35-year-old female presented with partial complex seizures. Computed tomography (CT) showed a slightly high density mass over the right frontal convexity, with heterogeneous contrast enhancement. T1-weighted magnetic resonance (MR) imaging showed the tumour as a hypo-intense lesion, with faint reticular enhancement after intravenous injection of gadolinium-diethylenetriaminepenta-acetic acid. The tumour was totally removed. The specimen was extremely soft and moist. The histological diagnosis was microcystic meningioma. The tumour cells were composed of typical meningothelial cells and stellate cells. The degenerative character of the tumour may be reflected in the poor enhancement on CT and MR imaging. This faint enhancement effect may be a neuro-imaging characteristic indication of this rare microcystic variant of meningioma.- - - - - - - - - - ranking = 1keywords = contrast (Clic here for more details about this article) |
10/314. Melanocytoma of the left optic nerve head and right retrobulbar optic neuropathy compressed by a tuberculum sellae meningioma.A 40-year-old woman had a highly pigmented, slightly elevated tumor on the left optic disc. She had no visual disturbance in the left eye. The tumor was stationary for 5 years. At age 45 years, she complained of decreased visual acuity in the right eye. magnetic resonance imaging showed a right-shifted homogeneous lesion at the tuberculum sellae. Histopathologic study of the excised lesion revealed interlacing bundles of spindle-shaped fibroblast-like cells with whorl formation. We believe that a relationship between melanocytoma of the optic nerve head and a tuberculum sellae meningioma may exist rather than a chance occurrence, as previously suggested by others.- - - - - - - - - - ranking = 1.7986581415767keywords = visual (Clic here for more details about this article) |
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