Intravascular ultrasound imaging of human coronary arteries after percutaneous transluminal angioplasty: morphologic and quantitative assessment.

An intravascular ultrasound catheter system was used in patients to assess the effect of percutaneous transluminal coronary angioplasty. In 14 out of 16 patients, the intravascular ultrasound catheter could be successfully advanced to the site of a previous dilatation. Qualitative assessment of the cross-sectional images revealed intimal thickening and an increase of ultrasound reflectance and calcification at atherosclerotic coronary arteries. A disruption of the obstructing plaque and evidence for local dissections (11 of 14 cases) were observed after angioplasty. The quantitative comparison between angiography and the ultrasound measurement showed a close correlation for vessel sites distant to the dilatation (r = 0.91 for vessel diameter; r = 0.86 for luminal area; p less than 0.001). After angioplasty, the quantitative evaluation of the dilated area was possible in 11 cases. The correlation of angiographic and sonographic measurements of these segments was good for the assessment of the vessel diameter (r = 0.82, p less than 0.001), but poor for the determination of the luminal area (r = 0.48, p = 0.10). This difference reflected the complex morphology of the vessel lumen after angioplasty, which would be better assessed by the cross-sectional sonographic technique than by contrast angiography. The intravascular imaging of coronary arteries provides a new and unique method to obtain information on the plaque morphology and composition, and to assess the local effects of interventional procedures and their complications.