VALIDATION OF CADNIUM-ZINC-TELLURIDE CAMERA FOR MEASUREMENT OF LEFT VENTRICULAR SYSTOLIC PERFORMANCE E.Coupez (corresponding author), C.merlin, L.sarry, B.pereira, JR Lusson, L.Boyer, L.Cassagnes

Context After have been mainly carried out with the Anger camera, validated against CMR for measuring LVEF, myocardial perfusion scintigraphy is now available on new cadmium zinc telluride (CZT ) semiconductor camera Two papers have reported on a comparison of LVEF measurements made by the Discovery® camera (GE Healthcare) The goal of our study was the validation of the D-SPECT® (Spectrum Dynamics) camera for measurement of left ventricular ejection fraction (LVEF) Methods measurements of LVEF at rest taking as references CMR and echocardiography in a population of patients with proven coronary heart disease post-infarct

Agreement between CZT-SPECT, CMR and echo for LVEF measurment Agreement between CZT-SPECT, CMR and echo for SWM and thickenig   Echo CZT CMR Mean LVEF 51.3 55.6 50.5 Standard deviation 11.8 14.0 15.8 Minimum value 13 23 14 Maximum value 66 76 Lin’s coefficient (ref : CMR) Kappa agreement (ref : CMR) 0.79 0.65 0.84 0.59 - Concordance on the measurement of LVEF was satisfactory for all three techniques Agreement between CZT-SPECT, CMR and echo for EDV and ESV measurment CZT-SPECT/echocadiography comparison for SWM showed a better concordance for all segments than CZT-SPECT/CMR and echocardiography/CMR. For segmental wall thickening assesment, agreement levels were better for CZT-SPECT/CMR and CZT-SPECT/echocardiography than echocardiography/CMR   Echo CZT-SPECT CMR Mean EDV 106.86 124.32 148.88 Standard deviation 41.11 49.04 41.94 Minimum value 50 41 91 Maximum value 273 272 309 Pearson coeff. (ref = CMR) Bradley-Blackwood F (ref = CMR) 0.37* 34,53* 0.65* 16,67* 1 Mean ESV 54.72 62.32 75.97 38.03 45.72 45.50 Minimal value 22 16 30 Maximal value 238 264 (ref =CMR) Bradley-Blackwood P (ref = CMR) 0.72* 23,02* 0.87* 12,62* CZT-SPECT : myocardial scintigraphy CMR : cardiac magnetic resonance imaging Echo : echocardiography LVEF : left ventricular ejection fraction ESV : end systolic volume EDV : end diastolic volume SWM : segmental wall motion Both ESV and EDV were underestimated by CZT-SPECT and echocardiography compared with the reference CMR technique

For three patients, we found differences in automated measurement of LVEF between fully-automated scintigraphy and CMR above 15%, respectively 26% (63 vs. 37%), 20% (70 vs. 50%), and 15% (63 vs. 48%). These examinations were re-read and corrected for myocardial contouring in the basal segments carried out automatically by the CZT-SPECT. After correcting this imprecision, these gaps in measurement differences between CZT-SPECT and CMR were reduced from 26% to 20% (57% vs. 37%) 20 to 10% (60 vs. 70%), and 15% to 8% (55% vs. 48%), respectively. Manual adjustment of the automatic contouring in patients whose LVEF measurements happened to be close to those of CMR never gave a correction of more than 2%.

Conclusion CZT-SPECT is reliable for LVEF measurment Reliability hinges on systematically running strict quality control on the automatic contouring of the left ventricular bases.