Systematic studies of intravascular ultrasound imaging of in vitro balloon angioplasty on coronary arteries with a greater than 50% diameter stenosis on angiogram have not been performed. We used 23 plasma-perfused postmortem human coronary arteries with an angiographic diameter stenosis of > or = 50%. After balloon dilation the vessels were examined by 30-MHz intravascular ultrasound imaging (IVUS) and the presence of ruptures and dissections was noted. Ruptures were defined as disruptions of the vessel wall in a radial direction, and dissections were defined as disruptions in a circumferential direction. After pressure fixation they were studied by histology. On IVUS, 24 vessel wall disruptions were diagnosed in 14 arteries. On histology, 29 disruptions were diagnosed in 19 arteries. The sensitivity of IVUS for the detection of disruptions was 79%, the specificity was 75%. Total agreement was 79%. Accuracy was better for dissections (total agreement 96%) than for ruptures (total agreement 74%). Shadowing behind calcium and close contact of the catheter to the arterial wall were important sources of error in the IVUS analysis. We conclude that intravascular ultrasound imaging is accurate for the detection of disruptions after balloon angioplasty of angiographically significant coronary artery stenoses.