In vitro assessment of luminal dimensions of coronary arteries by intravascular ultrasound with and without application of echogenic contrast dye.

To evaluate the impact and limitations of intracoronary ultrasound in the assessment of lumen, we examined 80 segments of 20 isolated coronary arteries with a mechanical ultrasound device (CVIS) comparing the results of ultrasound with the corresponding histological specimens. Ultrasound was performed with and without echogenic contrast dye (Laevovist, Schering AG, FRG). After application of contrast dye, correlation of luminal area between histology and ultrasound was improved from r = 0.85 to r = 0.89 (p = ns). Accuracy of lumen measurements was low in segments < 2.5 mm; only after application of contrast dye a relationship between ultrasound and histological measurements was found. In all cases in which a deviation of more than 20% between ultrasound and histology was observed, this deviation could be reduced by the application of contrast dye. There are considerable limitations in the accuracy of ultrasound measurements in the near field. Thus, further improvement of intracoronary ultrasound devices is mandatory. However, with the use of the currently available systems, additional application of echogenic contrast dye can improve accuracy of luminal measurements, especially in smaller size vessels.