title: Enhancement of spatial orientation of intravascular ultrasound images with side holes in guiding catheters.
abstract: BACKGROUND
  Intravascular ultrasound (IVUS) images are typically viewed and recorded in an arbitrary rotational orientation. This study was performed to validate a new method for improved orientation of sonographic vascular cross-sections.
  
  
  RESULTS
  We have tested a simple technique for rotational indexing of IVUS in cases in which guiding catheters with side holes are used. Although guiding catheters are opaque to ultrasonography, the side holes transmit the beam and therefore can be easily identified. The orientation of the side holes, which is characteristic for each make of guiding catheter, can be used to determine 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 the side holes and to characterize their orientation for purposes of rotational orientation of images. Feasibility tests of rotational orientation based on side holes were then performed in canine coronary arteries (n = 3) and in six human coronary arteries. Three serial imaging runs in each clinical case yielded a mean variability in rotational orientation of 7.5 +/- 1.5 degrees.
  
  
  CONCLUSIONS
  Validation testing of the side-hole technique demonstrates the potential for consistent and anatomically appropriate orientation of intravascular ultrasound images.
authors.affiliation: Division of Cardiology, Center for Research in Cardiovascular Interventions, Stanford University School of Medicine, Calif, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Schwarzacher
authors.forename: P J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: J A
authors.initials: JA
authors.lastname: Metz
authors.forename: A C
authors.initials: AC
authors.lastname: Yeung
authors.forename: S N
authors.initials: SN
authors.lastname: Oesterle
authors.forename: M
authors.initials: M
authors.lastname: Belef
authors.forename: R S
authors.initials: RS
authors.lastname: Kernoff
authors.forename: P G
authors.initials: PG
authors.lastname: Yock
mesh_terms: D000818:Animals; D002404:Catheterization; D004285:Dogs; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D012399:Rotation; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods*