Intravascular ultrasound imaging: development and clinical applications

Intravascular ultrasound is an exciting, new catheter based technique for imaging blood vessels. It provides accurate, real-time information about the types and distribution of vascular disease and displays both the macro- and micro-structure of blood vessels utilizating transducer frequencies of 10 MHz to 50 MHz. This paper discusses the development and current clinical applications of intravascular ultrasound technology, based on early intracardiac devices in the 1950s and resulting in very small diameter (1.3 mm), flexible probes in the 1990s for use in coronary and small peripheral vessels. Preliminary studies have established the dimensional accuracy of intravascular ultrasound, and more recent techniques such as three-dimensional image reconstruction have produced a very powerful research and clinical tool. The value of intravascular ultrasound in the diagnosis and therapy of vascular disease is based on its ability to define the transmural distribution of disease within the vessel, characterize plaque and intimal lesions, and provide accurate cross-sectional information regarding luminal and vessel wall morphology before and after intervention. Major priorities in the ongoing development of intravascular ultrasound are the need for further miniaturization and cost-effective manufacturing. Future angioplasty guidance devices may combine the benefits of angioscopy and intravascular ultrasound in a single delivery system suitable for incorporation into any ablative (mechanical or laser) catheter.