RT Journal Article SR Electronic T1 Analysis of the influence of CT attenuation correction on IQ-SPECT myocardial perfusion imaging JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1441 OP 1441 VO 60 IS supplement 1 A1 Jidi Xue A1 Sijin Li A1 Lei Zhang A1 Zhifang Wu A1 Guang Hu A1 Yuetao Wang A1 Hua Wei YR 2019 UL http://jnm.snmjournals.org/content/60/supplement_1/1441.abstract AB 1441Objectives: To evaluate the impact of CT attenuation correction (AC) on IQ-SPECT myocardial perfusion imaging (MPI). Methods: Twenty patients (15 males and 5 females) who underwent IQ-SPECT with CTAC and LEHR-SPECT with CTAC on the same day were enrolled in this study. The visual analysis, myocardial uptake value and perfusion score of 5 myocardial segment (apical, anterior, lateral, inferior and septal walls) were compared before and after AC. Results: 1) Visual analysis: In the IQ group, 13 patients’ septal wall (13/20) and 2 patients’ anterior wall (2/20) were weakened after AC. Only 4 patients’ anterior wall (4/20) were reduced in the LEHR group. The overcorrection rate of the IQ group was 75% (13+2/20), which was much higher than that of the LEHR group by 20% (4/20) (χ2=10.025, p=0.002). 2) Myocardial uptake(%): compared with the IQ-NOAC, there was a significantly decrease in the myocardial uptake among the apical (66.05±25.18 vs 59.30±19.28, p=0.005), anterior wall (208.65±43.85 vs 183.60±33.30, p<0.001) and septal wall(321.85±46.25 vs 262.90±44.86, p<0.001) after AC; While the increased myocardial uptake were observed in septal wall (320.45±43.85 vs 360.15±28.13, p<0.001) and inferior wall (183.95±32.15 vs 226.90±27.56, p<0.001) of LEHR group after AC. 3) Perfusion scores: for the IQ group, the score of septal wall (2.40±3.12 vs 6.50±4.02, p<0.001) increased after AC, but no differences were noticed in LEHR group before and after AC. Conclusions: In IQ-SPECT, misregistration between the emission and attenuation maps are more likely to appear after AC, which will lead to the overcorrection of apical, anterior wall and septal wall.