title: [Isotope angiocardiography: amelioration of the measurement of ejection fraction by a new treatment of the image].
abstract: Some of the limitations affecting radioisotopic images are their insufficient resolution, structure boundaries and accurate subtraction of background noise. In order to improve the signal-to-noise ratio the images of the recorded heart cycles are treated by the Karhunen-Loeve transformation. Edge detection is based on compression of the image to a bitmap at a chosen level and following of all bits set to one by a pointer. The outlines of the structures as determined by edge tracking are used to define the regions of interest within the enhanced images. Background subtraction applies the principle of interpolative background subtraction by computing an individual background for each point in an irregular region of interest. The resultant images are used to calculate an index of cardiac efficiency which shows high correlation (r = 0.92) with the ejection fraction of contrast biplane left ventricular angiography.
mesh_terms: D002302:Cardiac Output; D002951:Citrates; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D013318:Stroke Volume; D013667:Technetium
chemical_list: D002951:Citrates; D015609:Organotechnetium Compounds; D013667:Technetium; C030490:technetium Tc 99m citrate
vernacular_title: Angiocardiographie isotopique: amélioration de la mesure de la fraction d'éjection par un nouveau traitement d'image.