PT - JOURNAL ARTICLE AU - Matthieu Bailly AU - Frédérique Thibault AU - Gilles Metrard AU - Maxime Courtehoux AU - Denis Angoulvant AU - Maria-João Ribeiro TI - Precision of Myocardial Blood Flow and Flow Reserve measurement during CZT-SPECT perfusion imaging processing: intra- and inter-observer variability AID - 10.2967/jnumed.122.264454 DP - 2022 Sep 01 TA - Journal of Nuclear Medicine PG - jnumed.122.264454 4099 - http://jnm.snmjournals.org/content/early/2022/09/15/jnumed.122.264454.short 4100 - http://jnm.snmjournals.org/content/early/2022/09/15/jnumed.122.264454.full AB - The aim of this study was to evaluate the reproducibility of myocardial blood flow (MBF) and flow reserve (MFR) measurement in patients referred for dynamic SPECT. Methods: We retrospectively analyzed patients referred for Myocardial Perfusion Imaging (MPI). SPECT data were acquired on a CZT-based pinhole cardiac camera (Discovery NM530c, GE Healthcare, Haïfa, Israël) in listmode using a stress (251 ± 15 MBq) / rest (512 ± 26 MBq) one-day Tc-99m-tetrofosmin protocol. Kinetic analyses were done with Corridor4DMTM software using a 1-tissue-compartment model and converted to MBF using a previously determined extraction fraction correction. MFR was analyzed and compared globally and regionally. Motion detection was applied, but no attenuation correction. Results: 124 patients (64 male, 60 female) were included, and SPECT acquisitions were twice reconstructed by the same nuclear medicine board certified physician for 50 patients and by two different physicians for 74. Both intra- and inter-observer measurements of global MFR had no significant bias (-0.01 (P = 0.94) and 0.01 (P = 0.67) respectively). However, rMBF and sMBF were significantly different on global LV evaluation (P = 0.001 and P = 0.002 respectively) and on the anterior territory (p<0.0001) on the inter-user analysis. The average coefficient of variation was between 15% and 30% of the mean sMBF if the analysis is performed by the same or by two different nuclear medicine physicians, and around 20% of the mean MFR independently of the processing physician. Using the MFR threshold of 2, we noticed a good intra-user agreement, whereas it was moderate when the observers were different (kappa of 0.75, 95%IC: 0.56-0.94 vs 0.56, 95%IC:0.36-0.75 respectively). Conclusion: Repeated measurements of global MFR by the same or two different physicians are similar with an average coefficient of variation of 20%. Better reproducibility is achieved for intra-user MBF evaluation. An automatization of the processing is needed to improve the reproducibility.