title: The paradox image: a noninvasive index of regional left-ventricular dyskinesis.
abstract: The paradox image, a functional image of regional dyskinesis derived from the equilibrium (gated) radionuclide ventriculogram, was constructed by subtracting the background-corrected end-diastolic frame from the background-corrected end-systolic frame. In 11 patients showing dyskinesis by contract ventriculography, the percentage of left-ventricular picture elements containing paradox ranged from 3.6 to 55.6% (21.44% +/- 4.45 s.e.m.). In 11 patients with normokinesis and in eight patients with hypokinesis by contract ventriculography, the left-ventricular picture elements demonstrating paradox were less than 1.1% in all cases. In nine patients with akinesis, the percentage of left-ventricular picture elements containing paradox was 2.05% +/- 0.96 s.e.m. and was less tha 2% in seven patients. There was also an excellent agreement between the location of dyskinesis on the paradox image and that by contrast ventriculography. The paradox image is a sensitive indicator of left-ventricular dyskinesis and should be useful in the evaluation of patients with suspected left-ventricular asynergy.
mesh_terms: D002302:Cardiac Output; D003971:Diastole; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007089:Image Enhancement; D009200:Myocardial Contraction; D011859:Radiography; D011877:Radionuclide Imaging; D013382:Subtraction Technique; D013599:Systole; D013667:Technetium; D014003:Tin Polyphosphates
chemical_list: D014003:Tin Polyphosphates; D013667:Technetium