PT - JOURNAL ARTICLE AU - Matthieu BAILLY AU - Frederique THIBAULT AU - Maxime COURTEHOUX AU - Gilles METRARD AU - Maria Joao Santiago-Ribeiro TI - <strong>Impact of attenuation correction for SPECT MBF measurement with a dedicated cardiac CZT camera</strong> DP - 2019 May 01 TA - Journal of Nuclear Medicine PG - 167--167 VI - 60 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/60/supplement_1/167.short 4100 - http://jnm.snmjournals.org/content/60/supplement_1/167.full SO - J Nucl Med2019 May 01; 60 AB - 167Objectives: Dedicated cardiac cameras have been shown to provide accurate measurements of absolute myocardial blood flow (MBF) and flow reserve (MFR). Most of these SPECT myocardial perfusion imaging (MPI) procedures are reconstructed without attenuation correction (AC), whereas PET MBF studies using either Rb-82 or N-13-ammonia often apply AC correction. In this study we evaluate the impact of AC correction on SPECT regional and global MBF and MFR measurements. Methods: 26 patients referred for MPI were included (19 for coronary artery disease screening and 7 for regional stenosis evaluation). SPECT data were acquired on a CZT-based pinhole cardiac camera in listmode using a stress (256 ± 42 MBq) / rest (495 ± 52 MBq) one-day Tc-99m-tetrofosmin protocol. Low dose thoracic CT was acquired on the same day using another SPECT/CT camera in the same position. Listmode data were registered to CT by the same NM physician to generate attenuation correction maps. Kinetic analysis, AC and crosstalk corrections were done with Corridor4DM software (INVIA) and converted to MBF using a previously determined extraction fraction correction. Mean AC and non-AC regional and global MBF and MFR were compared with t-tests. Results: Stress and rest MBF were significantly lower when AC was applied (p&lt;0.001). Mean AC stress MBF were 0.96± 0.44, 0.96± 0.45, 1.00± 0.63 and 0.97± 0.48 ml/min/g for Left Anterior Descending (LAD) artery, Left Circumflex (LCx) artery, Right Coronary Artery (RCA) and global Left Ventricle (LV) respectively, whereas mean non-AC MBF were 1.65± 0.67, 1.39± 0.58, 1.25± 0.71 and 1.45± 0.62 ml/min/g for LAD, LCx, RCA and global LV respectively. The Pearson correlations between AC and non-AC stress MBF were r=0.84, 0.85, 0.90 and 0.88 for LAD, LCx, RCA and global LV respectively (p&lt;0.001). Mean AC rest MBF were 0.38± 0.08, 0.39± 0.11, 0.37± 0.08 and 0.38± 0.08 ml/min/g for LAD, LCx, RCA and global LV respectively, whereas mean non-AC MBF were 0.66± 0.26, 0.59± 0.25, 0.53± 0.21 and 0.60± 0.22 ml/min/g for LAD, LCx, RCA and global LV respectively. The Pearson correlations between AC and non-AC rest MBF were r=0.80, 0.76, 0.59 and 0.74 for LAD, LCx, RCA and global LV respectively (p&lt;0.001 except for RCA p&lt;0.01). For regional and global MFR, there was no significant difference between AC and non-AC measurements (p&gt;0.28 at least). Conclusion: AC correction does not significantly affect MFR measurement both in regional and global LV analysis. Stress and rest regional and global MBF are significantly lower when AC correction is applied. Further evaluation on a larger group of patients might be necessary.