title: Axial movement of the intravascular ultrasound probe during the cardiac cycle: implications for three-dimensional reconstruction and measurements of coronary dimensions.
abstract: BACKGROUND
  Motion of the intravascular ultrasound (IVUS) probe within the coronary artery from cardiac contraction may result in artifacts during 3-dimensional ultrasound image reconstruction and inaccurate measurements of coronary compliance. The purpose of this study was to establish whether longitudinal movement of the IVUS transducer in the coronary artery occurs and to quantify such motion.
  
  
  METHODS
  In 31 patients we positioned IVUS transducers at 59 coronary branch points: 41 in the left anterior descending coronary artery, 11 in the left circumflex coronary artery, and 7 in the right coronary artery. In each image sequence the branching vessel oscillated in and out of the imaging plane during the cardiac cycle, confirming longitudinal transducer movement. The extent of movement was estimated by IVUS from the dimension of the branch vessel traversed. In addition, angiographic visualization and measurement of IVUS probe motion was performed at 17 branch points in 12 patients.
  
  
  RESULTS
  Average longitudinal transducer movement as measured by IVUS was 1.50 +/- 0.80 mm (n = 46, range 0.5 to 5.5 mm). Because IVUS could not account for probe motion that exceeded the vessel branch diameter, the values obtained represent minimum movement. Average probe motion as assessed by cineangiography in a subset of 12 patients was 2.43 +/- 1.42 mm (range 0.57 to 6.56 mm).
  
  
  CONCLUSIONS
  This study establishes that longitudinal movement of IVUS transducers within coronary vessels occurs during the cardiac cycle. Because documented extent of motion may be sufficient to influence analysis, IVUS images are best obtained with electrocardiographic gating.
authors.affiliation: University of California at San Diego, Division of Cardiovascular Medicine, San Diego, CA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Arbab-Zadeh
authors.forename: A N
authors.initials: AN
authors.lastname: DeMaria
authors.forename: W F
authors.initials: WF
authors.lastname: Penny
authors.forename: R J
authors.initials: RJ
authors.lastname: Russo
authors.forename: B J
authors.initials: BJ
authors.lastname: Kimura
authors.forename: V
authors.initials: V
authors.lastname: Bhargava
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001794:Blood Pressure; D006328:Cardiac Catheterization; D002932:Cineangiography; D003187:Compliance; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006339:Heart Rate; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015588:Observer Variation; D011446:Prospective Studies; D013318:Stroke Volume; D018084:Ultrasonography, Interventional