In vitro and in vivo comparison of three different intravascular ultrasound catheter designs

Intravascular ultrasound (IVUS) is an invasive imaging modality which provi des detailed two-dimensional images of blood vessels. There are currently t wo different types of IVUS catheters available, namely, the phased-array an d the mechanical designs. The operating ultrasound frequency of these cathe ters ranges from 20 to 40 MHz. This study sought to evaluate the image qual ity, accuracy of diameter and pullback length measurements, and catheter ha ndling characteristics of three different IVUS catheters currently availabl e for clinical use using both in vitro phantom models and in patients under going percutaneous coronary intervention (PCI). in gelatin phantom models, image quality assessed on a semiquantitative scale was significantly differ ent between the three IVUS catheters (P = 0.01) with the 40-MHz catheter pr oviding the best images. Accuracy of lumen diameter measurements, when comp ared to optical microscopy, were similar between the three IVUS catheter de signs (all R-2 = 0.99). There were no significant differences in accuracy o f pullback length measurements in vitro between the three designs. However, there were differences in the performance of the three IVUS catheters when used for preinterventional imaging in patients undergoing PCI. Both mechan ical IVUS catheters were associated with lower procedural, fluoroscopy, and lesion crossing times compared to the phased-array catheter (all P < 0.05) . There were no significant differences between the catheters during postin terventional IVUS imaging. There were also small but potentially important differences with regards to clinical events and complications associated wi th the use of the different IVUS catheters during the PCI procedures, refle cting differences in catheter design. (C) 2001 Wiley-Liss, Inc.