[Intravascular ultrasound: a new dimension of invasive vascular diagnosis]

Intravascular ultrasound is a new imaging modality which allows the visualization of the vessel wall in vivo and could thus become an important adjunct to conventional angiography. Using miniature high-frequency transducers mounted at the tip of flexible catheters, high-resolution cross-sectional images are created and displayed in real-time. Several investigations have shown good correlations between ultrasound and histologic or angiographic techniques for the measurement of cross-sectional dimensions. Atherosclerotic lesions can be characterized by their differences in echo-density as calcified, fibrous or lipoid. Initial clinical studies have demonstrated the possibility to detect acute changes, such as dissections, following PTCA and other interventions. Several potential clinical applications are being discussed, where intravascular ultrasound may yield valuable information in addition to that provided by angiography. If some important current limitations can be overcome, this method may add a new dimension to invasive vascular diagnostics.