Ventriculographie isotopique : comparaison de l’acquisition sur gamma caméra CZT cardio dédiée à l’acquisition planaire

IntroductionGated equilibrium radionuclide venticulography is often used to determine left ventricule ejection fraction (LVEF), especially in case of follow up when cardio-toxic drugs are administred. During the last decade, the use of cardiac specific (CZT) gamma cameras has spread. They directly acquire 3D data. We wanted to determine the agreement between three nuclear medicine LVEF measurement techniques. We also wanted to determine the repeatability of these techniques.MethodsBetween April 16, 2016 and February 4, 2017 we consecutively included 77 patients who were adressed to the nuclear medicine department of CHU Martinique for LVEF measurement. Patients were injected with 99*Technetium labelled albumin. Usual planar scintigraphy was performed to serve as reference and 3D data was acquired with a CZT cardiac gamma camera. 3D data was analyzed directly with BPGS software, and also reprojected to planar data which was analyzed like the conventional planar acquisition.ResultsSeventy patients had acquisitions with both gamma cameras. The LVEF values from the CZT camera data were significantly higher than the reference planar LVEF measurements (+6.2 for 3D analysis, P < 0.01, concordance interval ?8.0; 20.3] and +1.7 for planar reprojection, P = 0.01, concordance interval ?8.9; 12.2]. For all three methods, the intra-method concordance intervals were within ?5; 5].ConclusionOur results indicate the same measurement method must be used in case of LVEF follow up. The variation between theses methods could lead to the false conclusion of impairment of LVEF (which is suspected in case of a 10% LVEF drop). Our secondary outcome show a good repeatability for all three techniques. Further studies should be initiated to determine which method is the most accurate and to determine the reproductibility of the CZT data acquisition process.