title: Technetium-99m teboroxime regional myocardial washout in subjects with and without coronary artery disease.
abstract: The aim of this study was to test the hypothesis that regional myocardial washout of technetium-99m teboroxime is slowed in the presence of coronary stenosis. Washout was assessed in 33 catheterized patients and in 13 with a low likelihood of coronary artery disease, using a triple detector camera and dynamic single-photon emission computed tomography, with serial 1-minute acquisitions after injection of 20 to 25 mCi of teboroxime at the third minute of adenosine-induced hyperemia. Washout was measured as the percent change in counts between the first, second and third minutes after injection, as measured in 6 short-axis myocardial regions of interest. Myocardial regions were classified as ischemic (> or = 50% diameter stenosis and no prior myocardial infarct), infarcted, normal (no significant coronary stenosis) or "low likelihood" (from the 13 patients with a low likelihood of coronary artery disease). Teboroxime washout was significantly (p < 0.001) slowed in the ischemic myocardium (12.7 +/- 8.3%) compared with the normal (18.5 +/- 5.7%), low-likelihood (17.8 +/- 6.1%) and infarcted (17.8 +/- 4.4%) zones. There was regional variability in washout rates (% washout/min), with the anterior wall having the lowest (13.8 +/- 3.4%/min) and the inferior wall the highest (20.7 +/- 7.9%/min) values. In regard to individual coronary territories, 21 of 41 ischemic, noninfarcted territories (51%) had abnormal washout compared with 3 of 43 normal territories (7%) (p = 0.001). In conclusion, regional washout of teboroxime is detectably slowed in ischemic, noninfarcted myocardium. The clinical value of washout analysis in teboroxime single-photon emission computed tomography warrants further investigation.
authors.affiliation: Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048.
authors.forename: T
authors.initials: T
authors.lastname: Chua
authors.forename: H
authors.initials: H
authors.lastname: Kiat
authors.forename: G
authors.initials: G
authors.lastname: Germano
authors.forename: W
authors.initials: W
authors.lastname: Palmas
authors.forename: K
authors.initials: K
authors.lastname: Takemoto
authors.forename: J
authors.initials: J
authors.lastname: Friedman
authors.forename: D S
authors.initials: DS
authors.lastname: Berman
mesh_terms: D015331:Cohort Studies; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000378:metabolism; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000378:metabolism; D004058:Diffusion; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D010091:Oximes / Q000493:pharmacokinetics*; D012680:Sensitivity and Specificity; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; C060156:technetium Tc 99m teboroxime