ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The use of gadolinium chelates has become an integral part of magnetic resonance imaging (MRI) of the liver and extrahepatic abdomen. Although liver specific contrast agents are now available, gadolinium chelates continue to offer significant advantages for abdominal MRI. The gadolinium chelates uniquely provide important information about tumor perfusion that is key in our assessment of liver masses. These paramagnetic contrast agents assist with liver lesion detection, characterization, and in establishing the volume of viable perfused tumor. Gadolinium chelates are equally important for MRI of the extrahepatic abdomen. The interstitial accumulation of these agents within peritoneal, omental, and gastrointestinal tumor produces marked enhancement and is key in accurate tumor staging. Depiction of lesions within solid visceral organs such as the pancreas, kidneys, and spleen is also improved following gadolinium injection. The versatility of this workhorse contrast agent assures that gadolinium chelates will continue to occupy a central role in any busy abdominal MRI practice.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Superparamagnetic nanoparticles (Feridex®) have been recently made available to the radiological community as a contrast agent for MR imaging of the liver. This article reviews the principal physicochemical characteristics of this new compound, with an emphasis on the explanation of the contrast obtained (either positive or negative enhancement) that depends on the local concentration and the sequence used. The clinical use of Feridex® is detailed, both for lesion detection and characterization. Finally, some guidelines for image optimization are given.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Because of the demand for an extension of the range of diagnostic uses for currently available extracellular magnetic resonance imaging (MRI) contrast agents, a new generation of tissue-specific (i.e., hepatobiliary) contrast agents have been successfully developed to enhance the performance of hepatic MRI. These agents include mangafodipir trisodium (formerly manganese dipyridoxal diphosphate [Mn-DPDP]), gadoxetic acid (formerly gadolinium ethoxybenzyl diethylenetriaminopentaacetic acid [Gd-EOB-DTPA]), and gadolinium butylbenzyl diethylenetriaminepentaacetic acid (MS-264). In a series of experiments in animals, the potential of these agents for noninvasive characterization of liver lesions was evaluated with the use of a comprehensive methodology. The purpose of this report was to summarize the observed imaging behaviors of these agents toward different types of cholestasis and focal liver lesions, compare the similarities or dissimilarities of these agents in their possible mechanisms of action, and discuss the clinical implications of the results of the experiments. In summary, through intravenous administration of these agents, both global and local obstructive cholestases can be identified on the postcontrast image. With certain reliability, liver tumors of different origins and grades of cellular differentiation can be detected and classified according to their contrast enhancement patterns occurring at certain postcontrast phases. The invasiveness or degree of malignancy of the liver tumor can also be suggested by the presence or absence of a peritumoral rim sign. Such diagnostic information, otherwise only invasively achievable, may prove to be invaluable in clinical decision making.

ISSN:0899-3459    

出版商:OVID    

年代:1998

数据来源: OVID