Application of intravascular ultrasound to characterize @entity453 and assess the progression or regression of XXXX .

@entity1 @entity1187 @entity301 @entity5642 @entity397 @entity453 @entity1856 @entity731
Angiography has major limitations in its ability to assess @entity301 . @entity5642 ( @entity5642 ) offers unique capabilities to assess @entity453 . The tomographic orientation of ultrasound enables visualization of the full vessel wall, as opposed to the 2-dimensional projection of the lumen provided by angiography. The equipment required to perform coronary @entity5642 consists of a catheter with a miniaturized transducer and a console to reconstruct the image. High ultrasound frequencies are used, typically, 30 to 40 MHz, which provides excellent theoretical resolution. @entity5642 has been performed safely in a wide variety of clinical situations. Vessels with classic @entity731 exhibit a diversity of abnormal features that reflect the severity, composition, and distribution of the atheromata. @entity397 is sometimes evident in ultrasound examination of the culprit lesions after an @entity1187 . Most laboratories routinely perform cross-sectional area measurements of the lumen and external elastic membrane boundaries and calculate @entity1856 area. @entity5642 commonly detects @entity731 at angiographically normal sites. It has contributed substantially to our understanding of remodeling and has shown that positive remodeling is more prevalent in unstable lesions. Studies in @entity1 early after transplantation have shown the presence of advanced @entity731 in their apparently normal donors. In addition, the application of @entity5642 in detecting the rate of progression or regression of existing @entity731 is among the most dynamic areas of development. @entity5642 is likely to emerge as the "gold standard" in the study of @entity731 progression-regression over the next few years.
