Assessment of the vasomotility of epicardial coronary arteries with quantitative coronary angiography.
Quantitative in vivo analysis of the vasomotility of epicardial coronary arteries is based on the measurement of changes of the vessel diameters. Vessel contours can be determined with the help of a precision caliper by the investigator or with computer-assisted geometrical analysis systems applying a contour detection algorithm; the variability of the results from repeated coronary diameter measurements in the identical film frame is comparably low with all systems (less than or equal to 0.12 mm standard deviation). When investigating the influence of an intervention on coronary vasomotility the variability of the measurements can only be kept low by careful standardization of the entire method. Repeated coronary angiograms are performed in identical angiographic projections (mono- or biplane) with standardization of the inspiratory status of the patient and of the rate of contrast material injection (automatic injection pump). For quantitative analysis all coronary segments with a diameter greater than 1 mm which are clearly outlined, free from overlaps, and mainly run parallel to the image plane, are selected by the investigator in preferably end-diastolic cineframes. Whereas with a caliper and with most of the semi-automatic edge detection systems the segment diameter can only be measured at particular sites defined by the investigator, few systems are able to analyze and average the diameter over the entire segment length. The variability of measurements of the minimal diameters of coronary stenoses in different cine frames is particularly high; therefore, only distinct changes of this parameter (e.g. with the CAAS-system greater than 0.24 mm) may be considered significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Jost
S
S
Abteilung für Kardiologie, Medizinische Hochschule Hannover, FRG.
Rafflenbeul
W
W
Lichtlen
P
P
D002932:Cineangiography; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D003329:Coronary Vasospasm / Q000000981:diagnostic imaging*; D006801:Humans; D014655:Vascular Resistance / Q000502:physiology*