ISSN:0899-3459    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Abdominal magnetic resonance (MR) angiography has become a robust technique for evaluation of the aorta and its major branch vessels. Its safety and accuracy make MR angiography an ideal choice for screening and diagnostic angiography of the abdominal aorta and renal and visceral arteries; however, interventional procedures (i.e., angioplasty and stenting) still require conventional digital subtraction angiography. This article focuses on practical applications of abdominal MR angiography that have been made possible by recent technological advances in MR hardware and software.

ISSN:0899-3459    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Peripheral vascular disease (PVD) is a common disorder in western society. Reflecting on the risks and costs of contrast arteriography, magnetic resonance angiography is a powerful noninvasive imaging modality for the diagnostic workup of patients with peripheral vascular disease. This article reviews the current state of the art of magnetic resonance angiography of the peripheral vasculature.

ISSN:0899-3459    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Conventional x-ray angiography is presently the gold standard for detecting coronary artery disease. This is a highly invasive procedure with a risk of developing potentially serious complications in addition to its drawback of exposure to ionizing radiation. Magnetic resonance imaging (MRI), a noninvasive method with no known adverse effects, offers exciting possibilities with its ability to acquire true three-dimensional (3D) volume information, image double oblique tomographic planes in the body, and generate excellent soft tissue contrast. These advantages have led to the emergence of MRI as one of the important tools for cardiac imaging. There have been significant improvements in MR systems in recent years that allow for higher gradient subsystems and higher slew rates. This has enabled the realization of magnetic resonance (MR) angiography, which now is consistently used for imaging the head, neck, and body vasculature. Despite all these advances, coronary MR angiography remains a challenge due to the small size of the coronary vessels, their tortuous nature, and the sensitivity of MRI to motion. Different methods, such as electrocardiographic gating and breath-holding or free-breathing approaches using navigators, have been investigated to overcome the cardiac and respiratory motion in coronary MR angiography, respectively. Various pulse sequences have been used in conjunction with these strategies. Injection of extravascular contrast agents led to the improvement of angiographic techniques in terms of higher signal-to-noise and contrast-to-noise ratios. The advent of intravascular agents may improve further the quality and reliability of coronary MR angiography. Recently, true fast imaging with steady-state precession (FISP), an imaging technique with an inherently high imaging efficiency, has emerged as a new angiographic technique. Although coronary MR angiography is still not proven clinically, it is a promising modality for detecting coronary artery disease.

ISSN:0899-3459    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Contrast-enhanced MR angiography (CE MR angiography) is rapidly becoming the investigation of first choice for evaluating disease of the vascular system. It is particularly applicable to the carotid circulation and has replaced more traditional time-of-flight imaging because of shorter acquisition times and fewer artifacts. With recent advances in gradient hardware, shorter repetition times allow high spatial resolution imaging of the entire carotid circulation form the aortic arch to the circle of Willis in less than 20 seconds. Additional acquisitions can be utilized as part of the same study to accurately time the arrival of contrast in the arterial system and overcome the problem of early venous enhancement. A number of techniques have been developed recently that allow CE MR angiography to be implemented with high temporal resolution. Both atherosclerotic and nonatherosclerotic carotid artery disease can be comprehensively assessed with CE MR angiography, preventing the need for conventional diagnostic angiography.

ISSN:0899-3459    

出版商:OVID    

年代:2001

数据来源: OVID