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

At dynamic CT, Gd-DTPA-enhanced MRI, and digital subtraction angiography, a large adrenal adenoma verified by resection histology presented as a hypervascular tumor. In all imaging modalities, it showed a strong patchy enhancement during the early phases of the passage of contrast media and subsequent intralesional contrast equilibration. This case demonstrates that even high enhancement does not rule out an adrenal adenoma with certainty. In the oncologic patient, therapeutic decisions should not be made on the basis of the contrast behavior of an adrenal lesion alone.
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PMID:[A hypervascular adrenal adenoma. A differential diagnostic problem in dynamic CT and MRT]. 154 59

Using a 0.2 T permanent MR imaging system, the gradual changes of signal intensity after intravenous injection of Ferrite suspension were studied in liver of normal rabbits and those with intrahepatic VX2 tumor. After injection of Ferrite suspension, decreased signal intensities of liver were observed on both T1 and T2 weighted images. The decrease on T2 weighted images was more remarkable than that on the T1 weighted image. The image with 8 mg/kg (50 mumol/kg) dose of Ferrite suspension showed significant changes of signal intensity, while, the image with 24 mg/kg (150 mumol/kg) dose was hardly evaluated because of inducing intense artifacts. The decrease of signal intensity in liver was observed immediately after the injection and was lowest after 1 hour. After 48 hours, the signal intensity began to increase. However, a slight loss of signal intensity was visualized even after 4 weeks. A clear MRI of the intrahepatic tumor following injection of Ferrite suspension was acquired especially on T2 weighted image in comparison with MRI after Gd-DTPA administration. In addition, MRI using Ferrite suspension could detect the small intrahepatic tumors which had been unable to be visualized by plain CT or enhanced CT. It is of benefit, furthermore, that Ferrite suspension could be an useful tracer for observing the intrahepatic tumor growth by a first single injection. Histologically, Ferrite particles were accumulated in reticuloendothelial system of liver whereas no accumulated in intrahepatic tumor was verified. The particles produced changes in local magnetic field resulting that signal intensity of liver showed decrease on the image. Subsequently, relatively negative contrast enhancement of liver was displayed. As a result of the present investigation, the MR imaging following injection of Ferrite suspension was found to be useful for detection of intrahepatic tumors, particularly of metastatic tumors which were isointense or hypovascular to the surrounding tissue of liver. No evidence of acute toxicity by Ferrite administration has been noticed.
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PMID:[Experimental studies of ferrite as a MRI contrast agent]. 154 66

In an attempt to improve bifunctional chelate labelling of Mab, we investigated the use of a polyamino acid backbone for multiple DTPA substitutions. Poly-L-lysine (PL) (3.8 Kd, n = 25) was partially acetylated with MADTPA to yield 11 moles of DPTA per mole of PL. The average numbers of DTPA on PL were directly quantified with MADTPA-C-14. The remaining epsilon amino groups on PL-DTPA (I) were measured with TNBS reagent. A selective maleimide derivatization of (I) with S-SMPB yielded (II), which contains 2.3 moles of maleimide groups per mole of (I). The sulfhydryl activation of Mab-TP41.2F(ab')2 with 2-Iminothiolane hydrochloride produced (III), containing 1.3 moles of sulfhydryl groups per mole of Mab. Compounds (II) and (III) were combined to form a single thioether-spaced chain linkage of Mab-PL-DTPA (IV), which was subsequently chelated with 111In to yield (V), which was the compound of interest. Indium-111-PL-DTPA (VI) and 111In-DTPA-MabTP41.2F(ab')2 (VII) also were prepared for control studies. Direct cell binding assay revealed the mean immunoreactivity of (V) to be 79.4% and that of (VII) to be 39.5%. In a biodistribution study on melanoma tumor-bearing athymic mice at 4, 24, and 48 hr postinjection, the tumor/blood and tumor/liver ratios at 48 hr were 11.6 and 1.2 for (V), compared to 3.7 and 0.13, respectively, with (VII). Thus, the PL configuration for radiolabeled antibodies seems to result in decreased hepatic accumulation and retained tumor activity. The findings suggest that further studies of this new compound are warranted.
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PMID:Reduced hepatic accumulation of radiolabeled monoclonal antibodies with indium-111-thioether-poly-L-lysine-DTPA-monoclonal antibody-TP41.2F(ab')2. 155 42

MR study of 6 patients with concurrent venous angioma and brain tumor revealed that in 2 of the 6 cases, the draining vein of the venous angioma was located near to the tumor and was displaced by the tumor. Two of the 6 venous angiomas were too small to visualize prior to contrast enhancement, but could be detected following administration of Gd-DTPA. Angiography was required for definitive diagnosis of the venous angiomas. When a venous angioma is suspected or is detected incidentally, especially when very near a brain tumor, angiography should be considered before performing surgery to avoid surgical complications. Otherwise, ligation of the vein draining the venous angioma may lead to venous infarction.
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PMID:MR imaging and angiography of cerebral venous angiomas associated with brain tumors. 155 34

The use of magnetic resonance imaging (MRI) for diagnosis and preoperative staging of renal cell carcinoma was evaluated in 79 patients with 88 tumors. Gradient-echo and spin-echo images before and after intravenous administration of Gadolinium-DTPA were compared with the results of computed tomography (CT) and histologic staging. The two imaging techniques had comparable results: T-stage was predicted correctly with CT in 78.4% and with MRI in 84.0% of the cases, while the N-stage was accurately assessed in 81.8% and 79.5%, respectively. MRI had some advantages in diagnosing perirenal tumor spread and in excluding an infiltration beyond Gerota's fascia. Therefore, MRI is a true alternative to CT for staging large renal cell carcinomas and especially for patients with contraindications for iodinated contrast agents.
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PMID:[The importance of magnetic resonance tomography in the diagnosis and staging of renal cell carcinoma]. 156 92

MR findings of five posterior fossa hemangioblastomas were reported. In the cystic type, a cyst was low intensity on T1WI and high intensity on T2WI. Mural nodule was clearly enhanced by Gd-DTPA. In the solid type, the tumor was shown as an isointense lesion on T1WI and as high intensity on T2WI, but it was markedly and homogeneously enhanced by Gd-DTPA. Multiple extremely low-intensity serpentine "flow void" signs, indicating afferent and efferent vessels, were observed within or around the tumor. These were characteristic pictures in this tumor.
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PMID:MR findings of posterior fossa hemangioblastomas. 156

Radioimmunoscintigraphy (RIS) using 99mTc-labeled A7, a monoclonal antibody (MoAb) against a human colorectal cancer, was performed in nude mice bearing a human colon cancer, HCT-15. MoAb-A7 was labeled with 99mTc in the presence of methylene diphosphate (MDP). At 24 h post-injection of 99mTc-MDP-A7, colon cancer was clearly visualized, and the tumor-to-tissue ratio of 99mTc-MDP-A7 was higher than the ratio of 111In-DTPA-A7 which was described previously. These results suggest the possibility of the clinical application of 99mTc-MDP-A7 for RIS of a human colon cancer.
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PMID:Radioimmunodetection of human colon cancer using 99mTc-MDP-MoAb-A7 in mice. 157 9

To reduce the high background liver radioactivity in immunoscintigraphy using 111In-labeled monoclonal antibody (In-MoAb), we investigated the effect of diethylenetriaminepentaacetic acid (DPTA) on the in vitro stability of In-MoAb in human serum and the biodistribution of In-MoAb in tumor-bearing mice. In-MoAb was incubated for four days in human serum at 37 degrees C (pH 7.4) in a humidified atmosphere at 5% CO2. The serum sample was analyzed by high performance liquid chromatography every day. Indium-111 gradually transferred from the conjugate to the fraction of transferrin. When DTPA was added to the serum, radioactivity in this fraction disappeared completely and moved to the fraction of DTPA. The daily administration of DTPA to the mice after injection of In-MoAb reduced radioactivity in the normal tissues, especially in the liver after the second day, and improved tumor to normal tissue ratios. Scintigraphic examination also revealed apparent decrease of the liver radioactivity in the mice administered DTPA. These results indicate that 111In dissociated from the conjugate is one of the causes of nonspecific accumulation in the liver and it is possible to decrease this accumulation by the daily administration of DTPA.
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PMID:[Effect of DTPA on biodistribution of 111In-labeled monoclonal antibody in tumor-bearing mice]. 157 30

Magnetic resonance imaging with fat saturation after the administration of gadolinium-DTPA can detect and demarcate meningioma of the optic nerve sheath with a precision not attainable with any other current imaging technique. This article describes some of the clinical implications of this technique and illustrates the appearance of this tumor on magnetic resonance images.
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PMID:Optic nerve sheath meningioma. Definition of intraorbital, intracanalicular, and intracranial components with magnetic resonance imaging. 158 75

Intramedullary spinal cord tuberculoma in a young, homosexual man with AIDS was detected with the use of MR and confirmed pathologically. MR findings were similar to those seen in other intramedullary lesions, eg, astrocytoma, ependymoma, hemangioblastoma, metastasis, lymphoma, and opportunistic infections. Delineation of the lesion improved with administration of Gd-DTPA; enhancement of the lesion, however, does not always correlate with true tumor margins at pathologic examination.
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PMID:Intramedullary spinal cord tuberculoma in a patient with AIDS. 159 Feb 2


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