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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Morphometric analyses were performed using an objective semiautomated algorithm on 5 sequential three-dimensional T1-weighted magnetic resonance imaging scans of a metastatic choroid plexus carcinoma, concurrent with a course of chemotherapy. The 5 scans were positionally normalized in a three-dimensional coordinate system for uniform definition of the borders of the mass. Volumes were calculated for the gadolinium-DTPA enhancing and nonenhancing cystic-appearing regions. Volumetric changes of up to 145% were measured using this method which were associated with changes in the calculated (spherical) radii of only up to 2.7 mm. Volumetric changes of up to 59% were not appreciated by visual inspection, most probably due to irregular borders and positional variability across the scans. Volumetric analyses were also performed on the right cerebellar hemisphere, producing a 1.83% coefficient of variability across the 5 scans. The growth rates of this mass were estimated from the sequential computations, permitting in vivo observations on tumor behavior otherwise not obtainable. These analyses demonstrate the potential of this morphometric method to detect significant volumetric changes, and illustrate its use to define in vivo the growth properties of central nervous system tumors in response to therapeutic interventions.
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PMID:Volumetric analyses of central nervous system neoplasm based on MRI. 176 36

A 24-year-old female patient complained of headache and right abducens nerve paralysis. No abnormality was found in plain CT scan, but a ring-like enhanced mass was disclosed behind the right posterior clinoid process in enhanced CT scan. MRI revealed a low intensity mass in T1-weighted image and a ring-like enhanced mass in gadolinium-DTPA enhanced image. It was a circumferential high intensity mass in T2-weighted image and an isointensity mass in proton image. Cerebral angiography indicated that it was avascular. Preoperative diagnosis was trigeminal neurinoma or petroclival meningioma. The tumor was removed almost completely by orbitozygomatic infratemporal approach. Histologically, it was low grade chondrosarcoma. Postoperatively, neither radiation therapy nor chemotherapy was added. Differential diagnosis and treatment was discussed. It was suggested that MRI was the most useful diagnostic tool to distinguish chondrosarcoma from other skull base tumors.
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PMID:[A case of chondrosarcoma in the cavernous sinus]. 176 42

To assess the utility of gadolinium-DTPA (Gd) and of MR imaging in the evaluation of spinal cord tumors, ten consecutive patients were prospectively evaluated. T1-proton density-, and T2-weighted images were obtained in sagittal or axial planes. T1-weighted images were obtained before and after intravenous administration. Five tumors were within the cervical spinal cord; 3 neoplasms were within the thoracic cord; 1 neoplasm extended from the cervical to the thoracic cord and 1 neoplasm extended from the cervical cord to the conus medullaris. Four tumors were ependymomas; 3 were astrocytomas; 1 was an hemangioblastoma, and 1 was a metastatic malignant peripheral nerve sheath tumor. The remaining patient died prior to spinal surgery and no autopsy was obtained. Of the precontrast sequences, tumors were best evaluated using T1-weighted images. Abnormal findings included cord widening, presence of a tumor mass, intratumoral or other associated cyst(s), and hemorrhage. Nevertheless, T1-weighted images obtained following the administration of GD were superior relative to all other pre- and post-contrast sequences for defining tumor margins, characterizing cyst(s) and delineating tumor masses. Based primarily on their appearance on post-contrast T1-weighted images, tumor-associated cysts could be subcategorized into 3 types: intratumoral cysts (found within the contrast-enhancing soft tissue mass); nonenhancing extratumoral cysts (found eitherrostral or caudal to the enhancing tumor mass); and enhancing extratumoral cysts (having an enhancing wall or containing an enhancing nodule).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Spinal cord tumors: gadolinium-DTPA-enhanced MR imaging. 178 46

Investigations into the use of streptavidin-conjugated antibodies and labeled biotin to improve radioimmunotargeting have shown background levels drastically reduced over the conventional approach. Nevertheless, accumulation of 111In-biotin in normal tissue as well as streptavidin-independent accumulation in tumor, was observed. In this work, the effect of altering the biotin molecule to reduce this nonspecific uptake without decreasing specific localization has been investigated. Three EDTA and DTPA derivatives of biotin have been synthesized and investigated along with a commercial biotin derivative (DTPA-B2). The labeled biotin chelates were administered i.p. to normal mice implanted with avidin beads in one thigh. A wide variation in biodistribution was seen among the biotin derivatives. The most favorable results were obtained with biotinyl-hydrazino-EDTA (EDTA-B1), which showed the lowest accumulation in normal tissues but equivalent uptake in the target with respect to the other compounds. Averaged over 8 tissues sampled, the target-to-nontarget ratio was 140 vs 9 for EDTA-B1 vs DTPA-B2 (N = 6) at 24 h post administration. Similar observations have been made in culture with two tumor cell lines: positive accumulation of both DTPA-B2 and EDTA-B1 was measured in tumor cells independent of streptavidin-antibody conjugate, however in the case of the latter derivative, this accumulation was 3-5 fold lower. These studies show that modification of the biotin species can alter accumulation in normal tissues as well as the antibody-streptavidin independent accumulation in tumor tissue.
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PMID:New indium-111 labeled biotin derivatives for improved immunotargeting. 178 80

A case of cauda equina neurinoma associated with intracranial hypertension is reported. A 59-year-old female with a history of disturbed orientation was admitted. A neurological examination upon admission revealed the disorientation and gait disturbance. Superficial sensation under L3 was impaired. A computed tomographic(CT) scan presented the enlargement of ventricles and the slightly poor description of cerebral sulci. Since the patient had a high fever up to 40.1 C, meningitis was suspected. Cerebrospinal fluid revealed that cell count was only 2/3, while the protein concentration was markedly elevated (389mg/dl). Froin reaction was extremely positive and fibrin was observed. Based upon these findings, the spinal tumor was considered. Plain lumber film showed the posterior scalloping of the L5 and S1 vertebral bodies. Gd-DTPA enhanced MRI showed a high signal intensity area at the cauda equina. Diagnosed as a cauda equina tumor, the total resection of the tumor was performed via laminectomy of L3-S1. The tumor was involved with nerve filaments at the cauda equina. The pathological diagnosis was neurinoma. After the operation, her symptoms improved and a CT scan revealed the reduction of the ventricular size. However, the protein concentration of cerebrospinal fluid did not normalized.
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PMID:[Cauda equina neurinoma associated with intracranial hypertension--case report]. 179 22

The overall effects of intravenous Gd-DTPA on tissue signal in intracranial tumors are complex depending on dose, time of administration, pulse sequence, and tissue structure. Ultrahigh speed EPI permits the kinetics of tissue enhancement in intracranial tumors to be studied during the "wash-in" equilibrium and "wash-out" phases. Ongoing studies employing dynamic scanning have shown it to be a valuable adjunct to a morphological study of tumors, providing an assessment of vascularity which is important in planning resection; and demonstrating areas with maximal breakdown of the blood-brain barrier which are most suitable for stereotactic biopsy. There are grounds for anticipating that the analysis of the temporal profile of enhancement may allow discrimination between different tumor types and provide information on factors which relate to the malignant potential of a single type.
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PMID:Clinical experience with contrast enhanced echo-planar imaging of the brain. 181 55

The novel tissue-specific contrast agent, Gd-BOPTA/Dimeg, was tested in MR imaging of experimental focal liver disease and of acute myocardial ischemia in rats. Directly implanted liver tumors and blood-borne metastases were used as models for focal liver disease and occlusion of the lower anterior descending coronary artery as model for acute ischemia. The studies with implanted tumors, at a dose level of 250 mumol/kg, showed a very high (370%) and persistent (greater than 2 h) increase in the tumor-liver contrast-to-noise ratio (CNR), owing to selective enhancement of normal liver parenchyma signal intensity. While all blood-borne metastases showed a similar late CNR enhancement, some of them experienced early contrast loss due to transient signal intensity enhancement. In myocardial imaging, Gd-BOPTA/Dimeg produced a signal intensity enhancement in normal myocardium and an injured area-normal area CNR enhancement which were both much stronger and more persistent than those produced by Gd-DTPA/Dimeg.
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PMID:Gd-BOPTA/Dimeg: experimental disease imaging. 181 66

The use of GD-DTPA was introduced recently for MR imaging of the body. This paper presents our experience with GD-DTPA enhanced MRI in the evaluation of neuroblastoma in children. The characteristics of the tumor-enhancement are described, its contribution to the diagnosis and the follow-up of this disease are discussed.
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PMID:Neuroblastoma: evaluation with contrast enhanced MR imaging. 181 77

A patient with a diploic meningioma is presented. Computed tomography (CT) scan revealed an intradiploic tumor which seemed contiguous at a point to a contralateral, recurrent parasagittal meningioma. On CT, density of the diploic meningioma was similar to that of the parasagittal meningioma, but the contrast study showed that the former enhanced much less than the latter. Magnetic resonance (MR) imaging demonstrated that the diploic tumor was heterogeneous and much less enhanced with Gadolinium-DTPA (Gd-DTPA) than the parasagittal meningioma on T1-weighted image, although they were very similar in signal intensities on T2-weighted and proton density-weighted MR images without Gd-DTPA. Reasons for such marked differences in enhancement patterns are discussed.
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PMID:Diploic meningioma contiguous to a contralateral parasagittal meningioma: CT and MR features. 182 8

Dynamic MRI with injection of Gd-DTPA was performed in 7 patients with hepatocellular carcinoma associated with portal vein tumor thrombus. A portal vein tumor thrombus was clearly visualized as a low intense structure. The segment supplied with this portal vein shows high intensity, probably due to the decrease in portal blood flow and compensated arterial blood flow. A tumor itself, located in this segment, was shown as a low intense area. Thus dynamic MRI is a useful method for differentiating the tumor from the surrounding nontumorous tissue with decrease in portal flow.
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PMID:[Dynamic MRI of hepatocellular carcinoma with portal vein tumor thrombus]. 185 85


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