ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The current availability of liver-specific contrast media (LSCM) allows the possibility to obtain an accurate diagnosis when studying focal liver lesions (FLL). It is necessary to have an in-depth knowledge of the biologic and histologic characteristics of FLL and the enhancement mechanism of LSCM to gain significant accuracy in the differential diagnosis of FLL. It is possible to subdivide FLL into three main groups according to the kinetics of contrast enhancement: hypervascular FLL, hypovascular FLL, and FLL with delayed enhancement. Dynamic contrast-enhanced magnetic resonance imaging is an important tool in the identification and characterization of FLL. LSCM with a first phase of extracellular distribution give both dynamic (morphologic) and late phase (functional) information useful for lesion characterization. With LSCM it is possible to differentiate with high accuracy benign from malignant lesions and hepatocellular from nonhepatocellular lesions. To understand contrast behavior after injection of LSCM, it is necessary to correlate contrast enhancement with the biologic and histologic findings of FLL.

ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The intrinsic soft tissue contrast and exquisite sensitivity to contrast agents are unique attributes of magnetic resonance imaging that are beneficial when evaluating diffuse liver disease. Much like a pathologist uses different tissue or cell marker stains, the magnetic resonance imager can use a variety of imaging strategies to elucidate pathologic liver processes in vivo, including processes leading to abnormal lipid metabolization, iron deposition, perfusion abnormalities related to inflammation, fibrosis, vascular occlusion, or infarction and hemorrhage. This article reviews the most important diffuse liver diseases and the corresponding magnetic resonance imaging features.

ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Localized perfusional variations are being seen more frequently in magnetic resonance imaging (MRI) as the increased reliance of the optimized arterial-phase contrast-enhanced strategies has become more commonplace. Many of these findings are related to the various organic or functional arterioportal shunts in the liver. The associated alterations in physiologic flow, decreased or absent portal venous flow, and increased arterial flow result in a regional display of high signal intensity on arterial-phase dominant contrast-enhanced MRI. For accurate diagnosis and planning of patient management, the etiology of the shunt should be distinguished as tumor related or not, and it may need to be differentiated from a hypervascular tumor. Depending on the chronicity of diminished portal flow, substantial parenchymal changes may ensue, including focal fat sparing or the finding of functional infarct, either of which can be demonstrated on static MRI. This article reviews and illustrates the MRI findings of localized tumor-related and nontumorous arterioportal shunts in the liver.

ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Magnetic resonance imaging (MRI) provides a noninvasive technique to evaluate the hepatic vasculature. Angiographic and flow-based techniques include intrinsic properties of MRI as well as those that use contrast media. Clinical and technical perspectives of a wide range of vascular disorders affecting the liver, particularly cirrhosis and portal hypertension, portal vein obstruction, as well as imaging of the vasculature prior to and postliver transplantation are presented in this article.

ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Imaging plays a critical role in evaluating tumor response to treatment. Change in tumor size on cross-sectional imaging has been widely accepted and used to guide clinical decision making. Until recently, researchers used the World Health Organization (WHO) criteria to determine tumor response. A new set of criteria recently has been adopted by the WHO, the National Cancer Institute, and the European Organization for Research and Treatment of Cancer. These criteria, called the Response Evaluation Criteria in Solid Tumors (RECIST), attempt to unify response assessment of treated lesions. Magnetic resonance imaging plays an important role in evaluating treatment response to new therapies directed toward hepatic lesion treatment. In this article, we describe the new RECIST criteria and the role of magnetic resonance imaging in assessing tumor response. We also discuss the magnetic resonance imaging findings after surgical resection, liver transplantation, and tissue ablation techniques currently available for the management of patients with liver tumors.

ISSN:0899-3459    

出版商:OVID    

年代:2002

数据来源: OVID