ENHANCEMENT OF SPATIAL ORIENTATION OF INTRAVASCULAR ULTRASOUND IMAGESWITH SIDE HOLES IN GUIDING CATHETERS

Background intravascular ultrasound (IVUS) images are typically viewed and recorded in an arbitrary rotational orientation. This study was p erformed to validate a new method for improved orientation of sonograp hic vascular cross-sections. Methods and Results We have tested a simp le technique for rotational indexing of IVUS in cases in which guiding catheters with side holes are used. Although guiding catheters are op aque to ultrasonography, the side holes transmit the beam and therefor e can be easily identified. The orientation of the side holes, which i s characteristic for each make of guiding catheter, con be used to det ermine the anatomically appropriate rotational orientation of the IVUS image. In this study images of four commercially available side-hole guiding catheters were viewed in vitro to confirm the visibility of th e side holes and to characterize their orientation for purposes of rot ational orientation of images. Feasibility tests of rotational orienta tion based on side holes were then performed in canine coronary arteri es (n = 3) and in six human coronary arteries. Three serial imaging ru ns in each clinical case yielded a mean variability in rotational orie ntation of 7.5 +/- 1.5 degrees. Conclusion Validation resting of the s ide-hole technique demonstrates the potential for consistent and anato mically appropriate orientation of intravascular ultrasound images.