metrizamide and Astrocytoma

The sensitivity of magnetic resonance imaging (MRI) to tissue alterations is particularly useful in spinal cord imaging. In addition to excellent anatomic display of this compact and complex area, syrinx cavities, tumors, and degenerating disks can be identified before they cause the anatomic distortion often necessary for detection by conventional means.

Topics: Astrocytoma; Bone Marrow Diseases; Brain Diseases; Ependymoma; Humans; Intervertebral Disc Displacement; Lipoma; Magnetic Resonance Spectroscopy; Meningeal Neoplasms; Metrizamide; Myelography; Neurofibroma; Spinal Cord; Spinal Cord Diseases; Spinal Cord Neoplasms; Spinal Diseases; Spinal Injuries; Spine; Syringomyelia; Tomography, X-Ray Computed

CT follow-up studies of liposome-entrapped metrizamide after intraneoplastic injection into neurogenic s.c. rat tumors were performed. By closely resembling clinical examination conditions, the experimental design has proven suitable in determining the in vivo kinetics of these interstitial liposome deposits. When compared to free metrizamide which may be considered an analogue of water-soluble chemotherapeutics, the encapsulation of metrizamide in liposomes resulted in a retarded decline of the contrast enhancement. Diffusion of liposomes could not be detected and the X-ray attenuation values measured within the liposome deposits continuously decreased with time for both types of liposomes. In the case of multilamellar vesicles, this significantly corresponded to a zero order kinetics with a mean halflife of 300 h. An initial increment in the X-ray attenuation of the liposome deposits might be due to the interstitial absorption of the water component of the liposome-dispersion. Because of the pronounced retardation effect of multilamellar liposomes resulting in a 140-fold prolongation of the interstitial retention time of metrizamide and due to their release kinetics these vesicles may be an appropriate carrier system for a local interstitial chemotherapy modality. Small unilamellar vesicles having an interstitial half-life of 14 h may be used as a faster component of a composed therapy system.

Topics: Animals; Astrocytoma; Blood-Brain Barrier; Brain Neoplasms; Liposomes; Metrizamide; Neoplasm Transplantation; Rats; Rats, Inbred Strains; Tomography, X-Ray Computed

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.

Topics: Adolescent; Adult; Aged; Astrocytoma; Child; Child, Preschool; Ependymoma; Female; Humans; Infant; Iothalamate Meglumine; Male; Metrizamide; Middle Aged; Myelography; Neurilemmoma; Retrospective Studies; Spinal Cord Neoplasms; Tomography, X-Ray Computed

The authors discuss their original observations using computed tomography (CT) in the diagnosis of posterior fossa neoplasms in children. The subject of CT diagnosis of childhood supratentorial tumors is also reviewed. However, despite the documented value of CT, the authors believe that magnetic resonance imaging (MRI) will eventually offer certain advantages that will make MRI the primary imaging modality for intracranial neoplasms in children.

Topics: Astrocytoma; Brain Neoplasms; Brain Stem; Cerebellar Neoplasms; Cerebral Ventricle Neoplasms; Child; Cranial Fossa, Posterior; Ependymoma; Humans; Medulloblastoma; Metrizamide; Tomography, X-Ray Computed

Computed tomography (CT) is currently the primary and generally the definitive imaging modality for the diagnosis, evaluation, and management of intracranial neoplasms in children. The value of CT in the postoperative period is discussed. The role of CT and myelography is stressed in the evaluation of cerebrospinal fluid seeding. CT is also important in demonstrating the iatrogenic disturbances of the central nervous system as a result of radiation and chemotherapy. The authors recommend that CT scans with and without contrast be obtained 2 weeks after surgery and before starting any form of adjuvant treatment. CT slices should be contiguous and 5-mm thick. Subsequent scans should be obtained every 3 to 4 months for the first year and every 6 months thereafter. Where necessary, CT scans after the introduction of intrathecal metrizamide may be necessary to evaluate the lower portion of the posterior fossa and brain stem.

Topics: Adolescent; Astrocytoma; Brain Neoplasms; Cerebral Ventricle Neoplasms; Child; Female; Glioma; Humans; Infant; Male; Meningeal Neoplasms; Meningioma; Metrizamide; Myelography; Neoplasm Seeding; Spinal Cord Neoplasms; Tomography, X-Ray Computed

The normal CT configuration and dimension of the conus medullaris and adjacent spinal cord were determined in 30 patients who had no clinical evidence of conus compression. CT studies were also correlated with anatomic sections in cadavers. The normal conus on CT has a distinctive oval configuration, an anterior sulcus, and a posterior promontory. The anteroposterior diameter ranged from 5 to 8 mm; the transverse diameter from 8 to 11 mm. Intramedullary processes altered both the dimensions and configuration of the conus.

Topics: Astrocytoma; Humans; Metrizamide; Myelography; Radiographic Image Enhancement; Spinal Cord; Spinal Cord Diseases; Spinal Cord Neoplasms; Tomography, X-Ray Computed

Intramedullary spinal cord tumours may present as scoliosis without neurological signs. Those treating spinal deformities should be alert to this possible aetiology. The clinical features of 12 such cases are discussed with reference to early diagnosis and treatment. Patients with a painful scoliosis should be investigated with myelography as well as bone scintigraphy. Many intrinsic spinal cord tumours are now amenable to surgical removal. The prognosis for neurological recovery is poor once a severe deficit becomes established. The importance of early diagnosis and joint orthopaedic and neurosurgical management is emphasised.

Topics: Adolescent; Adult; Astrocytoma; Child; Child, Preschool; Female; Humans; Laminectomy; Male; Metrizamide; Myelography; Retrospective Studies; Scoliosis; Spinal Canal; Spinal Cord Neoplasms; Spinal Fusion; Time Factors; Tomography, X-Ray Computed

Either EMT Head Scanner, CT 1010 (slice thickness 10mm) or EMI Body Scanner, CT 5005 (slice thickness 13mm) was used. The concentration of metrizamide was 170-250 mgI/microliter and the amount was 7-10 microliters. Either lumbar puncture or lateral C puncture was made.. 26 cases were included in this study. 1) disc disease: 11 cases, 2) spinal cord tumor: 6 cases, 3) Arnold-Chiari malformation: 3 cases, 4) atlantoaxial dislocation: 3 cases, 5) ossification of the posterior longitudinal ligament (associated with ossification of the ligamentum flavum): 2 cases (1 case), 6) spinal foreign body (acupuncture needle): 1 case.. 1) CT metrizamide myelography visualizes the subarachnoid space and makes it possible to know the lesion in the spinal canal in relation to the spinal cord in transverse plane. 2) It is difficult to determine the exact level of the lesion in axial plane. 3) The present technique does not allow to visualize the root sleeves. 4) It is difficult to delineate a compression of the subarachnoid space by small localized lesions (esp., disc diseases) due to overlapping the patent adjacent subarachnoid space within a slice 10 mm to 13 mm thick.

Topics: Astrocytoma; Humans; Meningeal Neoplasms; Meningioma; Metrizamide; Myelography; Neurilemmoma; Spinal Cord Neoplasms; Spinal Diseases; Tomography, X-Ray Computed

In children, hypothalamic-hypophyseal syndromes such as diabetes insipidus, precocious puberty, growth retardation, and panhypopituitarism can be due either to structural lesions or to functional disorders of the cerebral endocrine complex. When clinical and endocrinological parameters fail to distinguish between these etiologies, neuroradiographical diagnosis becomes extremely important. Although conventional intravenously enhanced computed tomography (IVCT) is satisfactory for the diagnosis of lesions larger than 1 cm, metrizamide CT cisternography (MCTC) greatly improves the diagnostic yield for smaller juxtapituitary masses in the suprasellar cistern, clearly defines their sizes and relationships with contiguous structures, and definitively confirms the diagnosis of empty sella syndrome. Six patients with endocrinopathies and normal or ambiguous IVCT findings are presented to illustrate how MCTC can influence their management and outcome without the patient discomfort and technical complexity associated with pneumoencephalography.

Topics: Adenoma; Adolescent; Astrocytoma; Brain Diseases; Brain Neoplasms; Child; Dysgerminoma; Empty Sella Syndrome; Female; Hamartoma; Humans; Hypothalamo-Hypophyseal System; Infant; Male; Metrizamide; Pituitary Neoplasms; Tomography, X-Ray Computed; Tuber Cinereum

Topics: Astrocytoma; Humans; Lipoma; Meningeal Neoplasms; Meningioma; Metrizamide; Myelography; Neurilemmoma; Radiographic Image Enhancement; Spinal Cord Neoplasms; Tomography, X-Ray Computed

The diagnosis of intracranial cystic lesions is greatly facilitated by cranial computerized tomography (CT) which eliminates the need for further invasive neuroradiological studies. However, cystic lesions with thin walls that do not enhance following intravenous contrast infusion, especially when they are located in the midline and at the base of the skull, may become a diagnostic problem preventing proper management and therapy. We discuss 12 midline intracranial lesions, including one that is noncystic, to emphasize the limitations of CT in showing these lesions and the need for further diagnostic studies such as pneumoencephalography and metrizamide CT. The limitations of CT in diagnosing these lesions are related to the variations in the anatomy at the base of the skull (supra-sellar region); the varying pathological nature and behavior of certain cystic lesions such as epidermoid tumors and craniopharyngiomas; and the compromising of the spatial and density resolutions due to the partial volume effect. The complementary role of studies such as pneumoencephalography and CT metrizamide cisternography for the evaluation of the dynamics of the cerebrospinal fluid that are necessary for the proper management and therapy of patients is discussed.

Topics: Adult; Astrocytoma; Brain Diseases; Brain Neoplasms; Child, Preschool; Craniopharyngioma; Cysts; Diatrizoate Meglumine; Epidermal Cyst; Female; Humans; Male; Metrizamide; Pneumoencephalography; Radiographic Image Enhancement; Subarachnoid Space; Tomography, X-Ray Computed

Topics: Astrocytoma; Chondroma; Hemangioma; Humans; Medulloblastoma; Meningioma; Metrizamide; Neurofibromatosis 1; Spinal Cord Neoplasms; Tomography, X-Ray Computed

The communication between the subarachnoid space and the surgically created tumor cavity in glioma patients was evaluated by metrizamide cisternography. It was necessary to know the presence or absence of such a communication to determine the route of administration of autologous lymphocytes as a form of immunotherapy. The contrast injections were made either into the spinal subarachnoid space or directly into the tumor cavity. The presence of communication was demonstrated and followed by computerized tomographic (CT) scanning. The results were also corroborated by comparing the white cell counts in the fluid from the tumor cavity and the spinal subarachnoid space 24 hours after autologous lymphoid cell infusion. In only two of seven patients was a communication present. In the five patients without a communication, the blocks were at the tentorial hiatus (one patient), due to a nonpatent subarachnoid space over the cerebral convexity (two patients), and the result of adhesions at the pial margin of the tumor cavity (three patients). In addition, certain limitations in the use of computerized tomography in the evaluation of glioma patients are demonstrated. These problems include the effects of steroids on tumor size, the poor correlation between "enhancement" on CT scan and tumor recurrence, and the difficulty of differentiating metrizamide and hemorrhage by CT scan in the immediate postoperative period. (Neurosurgery, 5: 576--582, 1979).

Topics: Adult; Astrocytoma; Blood Transfusion; Brain Neoplasms; Female; Glioblastoma; Glioma; Humans; Injections, Spinal; Lymphocyte Transfusion; Male; Metrizamide; Pneumoencephalography; Tomography, X-Ray Computed; Transplantation, Autologous