Intravascular ultrasound imaging: A current perspective

Abstract

Catheter-based intravascular ultrasound imaging has evolved from a research tool to a device that has received Food and Drug Administration approval. Although it is currently employed as an adjunct to contrast angiography in both the peripheral and the coronary circulation, the indications for its use and its clinical utility have yet to be defined. Much of the research on the technique has explored its qualitative and quantitative capabilities to improve the assessment of atherosclerotic vascular disease. There is the hope that this imaging technique may ultimately improve the performance of endovascular interventions. This review describes the development of the technology from early in vitro validation studies to its present use in human subjects. Wherever possible, studies that validate the findings (that is, by comparison with histopathology results) of intravascular ultrasound are emphasized. Although there is great promise for this technology, limitations such as loss of image quality in severely diseased or heavily calcified vessels hinder its use. The application of imaging with endovascular intervention, imaging of intracardiac structures and the pulmonary circulation and new techniques such as computer image analysis are discussed.

Topographic Pattern of Advanced Atherosclerotic Lesions in Carotid Arteries

“…Nevertheless, angioscopy and intravascular ultrasound could play a relevant role in the assessment of ulcerated plaques located at these vascular sites. Both methods are reliably capable of detecting endovascular surface alterations [37][38][39][40][41][42][43].…”

New Techniques to Evaluate Esophageal Function

“…Swallows are classifi ed by impedance as showing: complete bolus transit if bolus entry is seen at the most proximal site (20 cm above LES) and bolus exit points are recorded in all three distal impedance-measuring sites (i.e., 15, 10, and 5 cm above the LES) and incomplete bolus transit if bolus exit is not identifi ed at any one of the three distal impedance-measuring sites [18,19] . One American study and one Netherlands-Australian cooperative study assessed the relationship of liquid and viscous bolus transit measured by impedance with esophageal contractions measured by manometry in healthy volunteers [18,19] . Subjects received 10 liquid and 10 viscous materials.…”

Feasibility for ultrasonic characterization of the surface roughness of atherosclerotic plaque

“…As well as usage in diagnosis they are often used in conjunction with atherectomy, balloon angioplasty and laser angioplasty. There are two intravascular techniques currently being developed: fiberoptic angioscopy and intravascular ultrasound (Coy et al, 1991(Coy et al, , pp. 1811(Coy et al, -1812.…”

“…This allows the presence and structure of atherosclerosis to be defined both beneath the surface and along the vessel. The limitation of the diameter of the vessel is present, but catheters as small as 1.16 millimeter are used (Coy et al, 1991(Coy et al, , p. 1812. This limitation restricts the use to lumen smaller than this diameter and means that the normal diameter of the artery will have to be greater depending on the degree of stenosis.…”