title: Temporal Fourier transform of digital angiograms for left ventricular regional wall motion analysis.
abstract: To determine whether or not the first harmonic of a temporal Fourier transform, applied pixel-by-pixel on time-intensity curves, can detect the subtle wall motion abnormalities due to ischemia, 6 dogs were instrumented with a micromanometer in the left ventricles, a hydraulic cuff occluder around the circumflex coronary artery, and sonomicrometers on the inferior (ischemic) and anterior (non-ischemic) walls. Left ventricular images, obtained after contrast injection via the pulmonary artery, were compared with dimension signals in control and 3 progressive levels of coronary stenosis (Stenosis I, II and III). Normalized, digital functional images (512 x 512 matrix, 256 shades of gray/pixel) were divided into anterior, apical, and inferior areas to acquire regional mean phase (degrees) and amplitude (intensity units) values. After inducing stenosis, phase in ischemic region significantly increased at all 3 levels of stenosis, whereas amplitude significantly decreased at Stenosis II and III. However, amplitude images showed clearly the topographic site of ischemia. There was a progressive increase in phase and decrease in amplitude in ischemic areas as the percent wall thickening (%WTh) fell (phase vs. %WTh: r = -0.55, p less than 0.005; amplitude vs. %WTh: r = 0.71, p less than 0.001). Heart rate and peak systolic pressure showed no significant changes during stenosis. We conclude that quantitative functional images, generated from a temporal Fourier transform, are sensitive to the detection of left ventricular regional wall motion abnormalities during mild, moderate, and severe degrees of ischemia.
authors.affiliation: Department of Medicine, School of Medicine, University of California, San Diego, La Jolla.
authors.forename: K
authors.initials: K
authors.lastname: Katayama
authors.forename: B D
authors.initials: BD
authors.lastname: Guth
authors.forename: T F
authors.initials: TF
authors.lastname: Widmann
authors.forename: J D
authors.initials: JD
authors.lastname: Lee
authors.forename: R
authors.initials: R
authors.lastname: Seitelberger
authors.forename: K L
authors.initials: KL
authors.lastname: Peterson
mesh_terms: D000818:Animals; D003327:Coronary Disease / Q000000981:diagnostic imaging; D004285:Dogs; D005583:Fourier Analysis; D006439:Hemodynamics; D009200:Myocardial Contraction; D011875:Radionuclide Angiography