title: Digital angiographic measurement of radiographic contrast material kinetics for estimation of myocardial perfusion.
abstract: We studied the use of digital angiography for the quantification of regional myocardial perfusion in the dog using selective left coronary arterial injection of radiographic contrast material as a flow dilution indicator. We developed algorithms for generating time-intensity curves from regions of interest over the proximal coronary artery and the myocardium and for densitometric error correction by subtraction of the intensity curve over a small lead blocker before logarithmic transformation. The resultant myocardial time-density curves were analyzed for time from injection to peak concentration (TPC) and for exponential washout rate (k). A linear correlation was found between absolute coronary arterial blood flow and both k (slope = 0.13, r = .85) and 1/TPC (slope = 0.18, r = .85). Reproducibility of TPC and k for repeated studies was 11% and 16%. Induced hyperemia significantly improved the sensitivity to stenosis by increasing the average difference in TPC and k between regions served by normal and stenotic coronary arteries to 65% and 80%, respectively. By combining selective coronary arterial injection with the left lateral x-ray projection it was possible to avoid most overlap of regional perfusion beds in the dog. This study suggests that contrast dilution measurements made during digital coronary angiography provide a means for assessing the hemodynamic significance of stenoses and the efficacy of therapeutic interventions.
mesh_terms: D000792:Angiography / Q000379:methods*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000378:metabolism*; D003326:Coronary Circulation; D003327:Coronary Disease / Q000503:physiopathology*; D003331:Coronary Vessels; D004176:Dipyridamole / Q000008:administration & dosage; D004285:Dogs; D006321:Heart / Q000000981:diagnostic imaging*; D006439:Hemodynamics; D007267:Injections; D007700:Kinetics; D010477:Perfusion; D012039:Regional Blood Flow
chemical_list: D003287:Contrast Media; D004176:Dipyridamole