title: Experimental study of new diagnostic system for coronary artery disease using coronary transit index.
abstract: OBJECTIVE
  Noninvasive cardiac imaging techniques have had an increasing role in the diagnosis of coronary artery disease. However, these techniques are not widely available as a tool in the office setting. The purpose of this study was to provide an accurate assessment of coronary artery disease for screening purposes using Coronary Transit Index (CTI) assessment with small, high-resolution gamma cameras.
  
  
  METHODS
  Total coronary blood flow was measured with ultrasonic flow probes placed around the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery in a total of 33 conditions in 5 healthy mongrel dogs. The coronary blood flow was reduced stepwise with vascular occluders placed around the coronary arteries. The procedure for obtaining CTI included 4 parts: 1) The animal was injected intravenously with a bolus of a radioactive tracer (2.5-5.0 mCi of (99m)Tc-DTPA); 2) Dedicated gamma sensors monitored the passage of the injected bolus; 3) Time-activity curves were measured at the left ventricle with and without its wall; 4) The ratio of the washout rates of the 2 curves determined the CTI.
  
  
  RESULTS
  Coronary Transit Index was successfully obtained from the left ventricle. The coronary blood flows measured by flow probes were well correlated with the regional myocardial blood flow. The percentage of the baseline value of the total coronary blood flow had the highest correlation (R=0.807, p<0.0001) with the Coronary Transit Index.
  
  
  CONCLUSIONS
  These data indicated that a new diagnostic system using CTI successfully identified reduced coronary blood flow.
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ootaki
authors.forename: Keiji
authors.initials: K
authors.lastname: Kamohara
authors.forename: Soren
authors.initials: S
authors.lastname: Schenk
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kopcak
authors.forename: Raymond
authors.initials: R
authors.lastname: Dessoffy
authors.forename: Linda
authors.initials: L
authors.lastname: Graham
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
mesh_terms: D000818:Animals; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D003326:Coronary Circulation; D004285:Dogs; D015902:Gamma Cameras; D006439:Hemodynamics; D007275:Injections, Intravenous; D016014:Linear Models; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D016284:Technetium Tc 99m Pentetate / Q000008:administration & dosage; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate