Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This work describes the application of an object definition algorithm to the medical imaging environment for the task of automated detection of anatomical boundaries in three dimensions in the presence of low spatial frequency nonstationarities. We have chosen the Liou-Jain algorithm and have modified it for use with 3D medical image datasets and extended it by including a recruitment operator that corrects for the algorithm's inherent volume underestimation. The algorithm avoids problems in both traditional statistical segmentation and 2D techniques and elegantly bridges the gap between traditional gradient-based edge finding and regression-based segmentation techniques. Results are shown for MRI datasets from the human abdomen and brain and for a CT dataset of a liver tumor, as well as an MRI scan of a glioma in a rat brain. For comparison, the human abdomen dataset was processed by a multivariate, statistical classifier. The results demonstrate the statistical technique's susceptibility to low spatial frequency nonstationarities due to rf field inhomogeneity; the Liou-Jain algorithm is shown to be immune to this effect. Further, the results show spatial consistency as a result of inherent characteristics of the algorithm. Volumes identified by the algorithm are visualized and assessed qualitatively in three dimensions. Quantitative accuracy of the algorithm's volume estimates is assessed by the use of a phantom. This work demonstrates that this technique is effective in automatically detecting anatomical organ and lesion surfaces in 3D medical datasets that are corrupted by low spatial frequency nonstationarity and in obtaining volume estimates.
 ...
PMID:Robust three-dimensional object definition in CT and MRI. 870 38

We report a cohort of 34 cases, collected between 1978 and 1992, presenting with symptomatic intracranial tumours with a first negative CT scan. Subsequently, the tumours was revealed with a second CT scan or with an another neuroradiological technique (MRI or angiography). These "false negatives" represented 5% of all intracranial tumours seen during the same period of time in the same institution. Gliomas were observed in 67.7% of cases (a majority of them with a high grade). Initially, seizure was the most common clinical presentation (61.8%). Mean delay between the first scan and the definitive diagnosis was 13.4 months. The localization was supra-tentorial in 79.4% and infra-tentorial in 20.6%. This study leads us to discuss the attitude when a first CT scan is normal, more particularly in cases presenting with seizures, and the different factors that can explain the normality of this first CT scan.
 ...
PMID:[False negative results by X scanners in intracranial tumors in adults]. 878 5

In analogy with high-dose contrast-enhanced CT, there have been a few studies during recent years that have dealt with high-dose paramagnetic contrast dyes in MRI. One reason for these studies was the development of new and low-osmolar contrast agents in the MR field. Depending on the clinical problem, a high-dose contrast study in MRI is rarely indicated: (1) in metastatic disease, MR imaging with high-dose contrast material is indicated when the standard dose study is negative or only shows a solitary cerebral lesion or a number of lesions just suitable for radiosurgery; (2) in patients with malignant glioma the high-dose study allows better definition of the tumor margins. If a radical surgical approach is planned, the diagnostic potential should be fully used; if only a biopsy or subtotal debulking is planned, a standard dose study is enough. (3) in patients with MS, a high-dose study is only recommended within therapeutic trials in which the number of active plaques is a primary variable.
 ...
PMID:[High dosage administration of paramagnetic contrast media in diagnosis of focal brain lesions]. 886 26

This study represents our experience with eight cases (males: 4; females: 4; 13-47 years old, average age 28.5 years) of a "glial tumourette" (minute glioma), which measured less than 15 mm in diameter on an MRI. Four tumours were located in the frontal lobe, one in the rostrum of the corpus callosum, two in the midbrain, and one in the thalamus. The symptoms and signs lasted from two days to 15 months prior to diagnosis, and they consisted of epileptic seizures in five patients and increased intracranial pressure due to hydrocephalus resulting from aqueductal stenosis in three. All patients had a CT scan and an MRI as a part of their initial neuroimaging evaluations. While the CT findings failed to show the lesion in four patients, MRI demonstrated it in all cases. Five tumours were either totally or subtotally removed while the remaining three were biopsied. Histological examinations revealed six tumours to be low-grade gliomas (fibrillary astrocytoma: 4; oligoastrocytoma: 2) and two to be high-grade gliomas (anaplastic astrocytoma: 1; anaplastic oligodendroglioma: 1). Regarding adjuvant therapy, three patients received radiation and/or chemotherapy. One of the patients with midbrain fibrillary astrocytoma died of the disease 38 months after the operation, however, no evidence of progression in the remaining seven has been observed in the follow-up period ranging from five to 65 months after the operation (average: 25.4 months). The histogenesis of benign and malignant gliomas and the importance of surgical exploration in the management of such patients with minute intracerebral tumours are also discussed.
 ...
PMID:Glial tumourettes (glial microtumours): their clinical and histopathological manifestations. 886 9

The past decade has seen the identification of many clinical settings in the treatment of primary brain tumors in which information from fluorodeoxyglucose positron emission tomography (FDG-PET) might be useful, if not essential, to therapeutic formulation. FDG-PET is currently used at referral centers in the management of primary brain tumors. The clinical pattern of FDG-PET use was assessed and its value compared to other information sources in clinical decision making. The clinical records of 75 glioma patients who were evaluated by FDG-PET were reviewed. The range of circumstances in which FDG-PET was employed included: pretherapeutic baseline studies for monitoring the effect of a therapy (1% of all cases), mapping of hypermetabolic regions before surgery or biopsy (2%), mapping of hypermetabolic regions before radiotherapy (2%), postsurgical evaluation for residual tumor (2%), assessment of the malignancy of a mass as a substitute for biopsy (11%), and distinguishing between radiation necrosis and recurrent tumor (87%). Other sources of information that contributed to the therapeutic management of patients included: gadolinium-enhanced MRI, contrast-CT, and clinical findings.
 ...
PMID:Impact of fluorodeoxyglucose positron emission tomography on the clinical management of patients with glioma. 887 74

The case is described of an optic nerve glioma, mimicking an optic nerve meningioma in a man aged 41 years. CT, MRI and DSA revealed an enhancing tumor surrounding the optic nerve. Histopathologic examination of the removed optic nerve revealed a centrally located glioma surrounded by normal optic nerve fibres.
 ...
PMID:Optic nerve glioma mimicking an optic nerve meningioma. 888 1

Only a few cases reported in the literature fulfil the currently established criteria for accepting the traumatic origin of some intracranial tumors. A case of post-traumatic glioma is presented. Several years after sustaining a commotive left parietal trauma, our patient developed symptoms of intracranial tumor. Neuroimaging (CT and MRI) showed a large neoplasia in the left temporo-parietal-occipital region, and stereotactic biopsy revealed a mixed glioma in continuity with the scar resulting from the trauma.
 ...
PMID:Post-traumatic malignant glioma. Report of a case. 891 59

A 15-year-old boy had onset of unilateral facial weakness. A few days later, he experienced mild vertigo, double vision, and headache. Examination confirmed a peripheral right seventh nerve weakness in addition to an internuclear ophthalmoplegia. The neurologic features suggested a pontine glioma. A T2-weighted MRI scan revealed demyelinating lesions in the pons and in several areas of the cerebrum, including the periventricular region. Subsequent history revealed that he had been diagnosed with Lyme arthritis 7 years earlier while living in Connecticut. The radiographic studies favored a diagnosis of multiple sclerosis. However, studies of blood and cerebrospinal fluid established a diagnosis of Lyme neuroborreliosis.
 ...
PMID:Lyme neuroborreliosis masquerading as a brainstem tumor in a 15-year-old. 891 68

An analysis of 386 cases of Intracranial Space Occupying Lesions (SOL) including neoplastic and inflammatory masses diagnosed and treated at Jinnah Postgraduate Medical Centre, Karachi over a period of 2 years is presented. C.T. Scan and MRI were used for the diagnosis of midline, multiple and very small lesions. S.O.L. were more common in males in the age group 11-20 years. Gliomas comprised 32.1% of the total cases followed by meningiomas 13.7%, abscesses 13.2% and pituitary tumours 13.2%. Tuberculomas constituted 5.5% and therefore, should always be considered in the differential diagnosis.
 ...
PMID:Intracranial space occupying lesions--review of 386 cases. 892 Jun

Light and electron microscopic studies on tumor tissue from 5 autopsied and 7 rebiopsied patients with malignant glioma after receiving intratumor administration of anti-neoplastic agents were made. Four patients were correlated with their serial MRI. After craniotomy 0.5 mg of adriamycin was administered using an Ommaya reservoir into the tumor bed. Light microscopy of the recurrent tumor and adjacent necrotic tissue revealed massive coagulation necrosis which was aspirated into the tip of the Ommaya tube. Around the massive coagulation necrosis and cystic cavity, abundant reactive collagenous tissues, gliomesenchymal tissue, infiltrating lymphocytes, and a small amount of foreign body giant cells were found concomitantly with organized necrotic tissue. The electron microscopic study of the above mentioned tissue showed deposits of lipofuscin, lipid droplets, lysosomes in the tissue as well as abundant disintegrated myelin figures and fibrous strands. Furthermore, marked histological necrosis was found mainly at the tip of the Ommaya tube. These morphological findings corresponded to the high signal intensity areas on the gadolinium-enhanced T1-weighted MRI. These facts may indicate that the antineoplastic agents administered directly to a tumor per se cause morphological alternations. Moreover, these facts may suggest a therapeutic effect in the residual tumor cells which would be facilitated by formation of coagulation necrosis and collagenous tissue.
 ...
PMID:A clinicopathological study of malignant glioma done after local administration of chemotherapeutic agents. 892 97


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>