Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the last decade, i.v. contrast media use in magnetic resonance imaging (MRI) of the central nervous system has become well established. Three agents are currently available in the United States: gadopentetate dimeglumine (Magnevist), gadodiamide (Omniscan), and gadoteridol (ProHance). At a dose of 0.1 mmol/kg, for which all three agents are approved, the contrast effect is equivalent. The agents differ on the basis of stability in vivo, osmolality, and charge. A single agent (ProHance) is approved for high-dose administration (0.3 mmol/kg). The basis of this approval is due in part to the high stability of the agent and thus lower potential for toxicity from long-term heavy metal deposition. Clinical experience, combined with new developments in MR technology, continue to expand applications for these agents. Improved detection of metastatic disease to the brain has been demonstrated in multiple clinical trials with high-dose contrast administration. High dose may also play an important role in brain infection and infarction, providing improved recognition of blood-brain barrier disruption and thus disease activity. First-pass studies make possible the evaluation of regional cerebral blood volume with high intrinsic spatial resolution. The availability of new instrumentation, together with the use of high contrast dose, have improved the quality and clinical utility of these studies. Research is ongoing in the development of new agents, both with greater tissue selectivity and improved safety profile. Chelates of dysprosium, in addition to gadolinium, are receiving attention for potential clinical application in first-pass imaging.
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PMID:Update: safety, new applications, new MR agents. 765 96

The potentialities of present-day methods of imaging (computer-aided and magnetic resonance tomography) in the diagnosis of metastatic involvement of the brain are discussed. Besides routine scanning, the authors assess the efficacy of a contrast agent Gd-DTPA (Magnevist, Schering AG, Germany) used in magnetic imaging. The potentialities of reinforced-aided tomography, 0.04 and 1.0 Tesla magnetic imaging are compared on the basis of 23 cases. The results indicate that magnetic imaging at low-intensity magnetic field is approximately as effective as computer-aided tomography in the assessment of metastatic involvement of the brain; contrast reinforcement with Gd-DTPA appreciably improves the informative value of the method in comparison with reinforced computer-aided tomography. As for 1.0 Tesla magnetic imaging, it is highly informative and accurate in assessment of the type (single or multiple) of the pathologic process. Extra contrast staining with Gd-DTPA makes magnetic imaging still more reliable and superior to computer-aided tomography and 0.04 T magnetic imaging in the diagnosis of metastatic involvement of the brain. In this investigation authors performed analysis of 23 observations with metastases (22 cases were hystological verified) and estimated possibilities of modern diagnostic methods such as CT (+CM), standard MR imaging and MRI with Gd-DTPA (Magnevist, Schering AG, Germany). Authors have noticed that MR imaging with contrast enhancement is more efficient in diagnosis of brain metastases in comparison with CT. Metastases showed the signal intensity increase after Gd-DTPA injection. Small tumors and nodi situated nearly skull base and in cerebellum were more distinguished on MR imaging with contrast enhancement than before it.
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PMID:[Gd-DTPA in the diagnosis of brain metastasis]. 778 9

The purpose of this investigation was to compare the sensitivity and safety of high dose gadoteridol (Pro Hance) with routine dose gadopentetate dimeglumine (Magnevist) in the detection of intracranial metastases on magnetic resonance imaging (MRI) when a solitary intracranial lesion was detected on contrast-enhanced cranial computed tomography (CT). Four patients, each with a solitary intracranial metastasis demonstrated on contrast-enhanced CT were studied prospectively with both 0.3 mmol/kg gadoteridol and 0.1 mmol/kg gadopentetate dimeglumine. Images were acquired before and immediately following contrast administration. Both of the MR studies were performed between two and six days of each other and within 1 wk of the cranial CT. Scan parameters and injection rates were identical on both occasions. Patient monitoring for the gadoteridol study included physical examination, vital signs and laboratory tests at several pre-determined times. Eighteen total metastases were demonstrated on MRI compared to the four on CT. Seven were visualized on the unenhanced MR images, nine on the scans using gadopentetate dimeglumine, and all eighteen on the scans using gadoteridol. Additional lesions were seen on the gadoteridol images in all four patients. No adverse events attributable to contrast media occurred. No significant changes in vital signs or laboratory values occurred.
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PMID:MRI evaluation of "solitary" brain metastases with triple-dose gadoteridol: comparison with contrast-enhanced CT and conventional-dose gadopentetate dimeglumine MRI studies in the same patients. 795 17

Magnetic Resonance Imaging (MRI) with intravenous Gadolinium-DTPA (Gd-DTPA, Magnevist, Schering-AG) was performed in 44 patients, 32 with primary bladder carcinoma and 12 with suspected recurrence after treatment. Gd-DTPA often increased diagnostic confidence in the identification and staging of tumours confined to the bladder wall and was necessary to assess depth of bladder wall invasion when T2-weighted images were suboptimal. Enhancement after Gd-DTPA enabled distinction between necrotic and viable tumour and blood clot. There was little advantage in its use for tumours infiltrating perivesical fat or with metastases to lymph nodes or bone, in the absence of a fat suppression sequence. Gd-DTPA may therefore be useful in selected patients with tumours of Stage T3a or less in whom information about depth of bladder wall invasion is inadequately shown on pre-contrast sequences. Artefacts due to variable and inhomogeneous urine signal intensity, however, often degraded post-Gd-DTPA images of the bladder. Changes in the bladder due to radiotherapy were observed on MRI 3-4 months after treatment in patients referred for routine follow-up and in some patients with suspected recurrence. Mucosal hyperintensity, thickening and abnormal signal intensity of the muscular layers of the bladder wall, with enhancement after Gd-DTPA were demonstrated. Such changes obscured small volume or superficial recurrence of tumour after radiotherapy. Abnormal enhancement was also observed in pelvic organs and soft tissues irradiated several years earlier. Enhancement after Gd-DTPA does not therefore reliably distinguish between recurrent tumour and radiotherapy change.
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PMID:Magnetic resonance imaging with Gadolinium-DTPA for assessment of bladder carcinoma and its response to treatment. 850 91

The development of improvements in magnetic resonance imaging (MRI) that would enhance sensitivity, leading to earlier detection of cancer and visualization of metastatic disease, is an area of intense exploration. We have devised a tumor-targeting, liposomal nanodelivery platform for use in gene medicine. This systemically administered nanocomplex has been shown to specifically and efficiently deliver both genes and oligonucleotides to primary and metastatic tumor cells, resulting in significant tumor growth inhibition and even tumor regression. Here we examine the effect on MRI of incorporating conventional MRI contrast agent Magnevist into our anti-transferrin receptor single-chain antibody (TfRscFv) liposomal complex. Both in vitro and in an in vivo orthotopic mouse model of pancreatic cancer, we show increased resolution and image intensity with the complexed Magnevist. Using advanced microscopy techniques (scanning electron microscopy and scanning probe microscopy), we also established that the Magnevist is in fact encapsulated by the liposome in the complex and that the complex still retains its nanodimensional size. These results demonstrate that this TfRscFv-liposome-Magnevist nanocomplex has the potential to become a useful tool in early cancer detection.
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PMID:A tumor-targeted nanodelivery system to improve early MRI detection of cancer. 1677 69

In vivo knowledge of the spatial distribution of viable, necrotic, and hypoxic areas can provide prognostic information about the risk of developing metastases and regional radiation sensitivity and may be used potentially for localized dose escalation in radiation treatment. In this study, multimodality in vivo magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging using stereotactic fiduciary markers in the Dunning R3327-AT prostate tumor were performed, focusing on the relationship between dynamic contrast-enhanced (DCE) MRI using Magnevist (Gd-DTPA) and dynamic (18)F-fluoromisonidazole ((18)F-Fmiso) PET. The noninvasive measurements were verified using tumor tissue sections stained for hematoxylin/eosin and pimonidazole. To further validate the relationship between (18)F-Fmiso and pimonidazole uptake, (18)F digital autoradiography was performed on a selected tumor and compared with the corresponding pimonidazole-stained slices. The comparison of Akep values (kep = rate constant of movement of Gd-DTPA between the interstitial space and plasma and A = amplitude in the two-compartment model (Hoffmann U, Brix G, Knopp MV, Hess T and Lorenz WJ (1995). Magn Reson Med 33, 506-514) derived from DCE-MRI studies and from early (18)F-Fmiso uptake PET studies showed that tumor vasculature is a major determinant of early (18)F-Fmiso uptake. A negative correlation between the spatial map of Akep and the slope map of late (last 1 hour of the dynamic PET scan) (18)F-Fmiso uptake was observed. The relationships between DCE-MRI and hematoxylin/eosin slices and between (18)F-Fmiso PET and pimonidazole slices confirm the validity of MRI/PET measurements to image the tumor microenvironment and to identify regions of tumor necrosis, hypoxia, and well-perfused tissue.
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PMID:Noninvasive multimodality imaging of the tumor microenvironment: registered dynamic magnetic resonance imaging and positron emission tomography studies of a preclinical tumor model of tumor hypoxia. 2797 98

Three patients with known lung cancer came on different days to our department to have a bone scan to evaluate possible osseous metastatic disease. The bone scan images showed increased Tc-99m methylene diphosphonate (Tc-99m MDP) activity in the liver and to a lesser degree in the spleen, whereas bone scan images from other patients on the same days showed no abnormal activity in the liver or spleen. On the same day, shortly before the bone scan, all 3 patients had a magnetic resonance imaging scan with an intravenous injection of Magnevist (Gadolinium-DTPA), which was not previously known to cause an altered Tc-99m MDP distribution. In the follow-up bone scans performed within 1 week of the initial bone scintigraphy, images from none of these 3 patients showed abnormal liver or spleen activity. The findings indicated that the increased Tc-99m MDP activity in the liver and spleen in the early studies was indeed an effect of Gadolinium-containing magnetic resonance imaging contrast. This effect was further confirmed by an animal experiment.
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PMID:Diffuse hepatic and splenic uptake of Tc-99m methylene diphosphonate on bone scintigraphy after intravenous administration of gadolinium-containing MRI contrast. 2128 73