²⁰¹Tl 게이트 심근관류 스펙트에서의 휴식기와 부하기 좌심실 구혈률 상관관계 분석

The Correlation Analysis of Stress/Rest Ejection Fraction of ²⁰¹Tl Gated Myocardial Perfusion SPECT

Purpose: It is well-known that stress-induced stunning and reversible perfusion defect have impact on ejection fraction (EF) when performing myocardial perfusion SPECT. Due to these reasons, gated SPECT is recommended at stress and rest studies. And there was many experiments to analyze between Stress and Rest EF by using ⁹⁹ᵐTc-MIBI. The aim of this study is to analyze between stress EF and rest EF at myocardial perfusion SPECT by using ²⁰¹Tl and define possible predictors of EF variability. Materials and Methods: From 2008 June to 2009 February, we analyzed 144 patients undergoing ²⁰¹Tl gated myocardial perfusion SPECT in ASAN medical center. To analyze the data, we use QGS (Quantitative gated SPECT) software, and derived End-systolic volume (ESV), End-diastolic volume (EDV), EF from the result. In this study, we comparatively analyzed stress/rest EF correlation based on stress/rest EF, EDV, ESV and reversibility of myocardial perfusion defect by using paired t-test, Bland-Altman analysis. Results: Mached pairs of stress EF and rest EF demonstrated excellent correlation (r=0.92) with no statistically significant difference (p=0.11). Bland-Altman analysis demonstrated a mean ΔEF was 0.52% (95% confidential interval[CI], -1.17~0.12%). No statistically significant difference between a mean ΔEF and hypothetic mean of 0 (ΔEF=0) (p=0.10). In the correlation of ΔEF according to stress/rest EDV and ESV, except rest ESV of <28mL (p<0.05), there was no statistically significant difference. In the correlation of ΔEF according to reversibility of perfusion defect, patients with reversible perfusion defect has statistically significant difference of ΔEF (p<0.05). ΔEF of stress/rest EF showed no statistically significant difference except 55% of rest EF (p<0.05). Conclusion: Like studies with ⁹⁹ᵐTc-MIBI, there was generally no statistically significant difference between stress and rest EF in this study results. However a stress EF of <55%, a rest ESV of <28mL and patients with reversible perfusion defect showed statistically significant difference in ΔEF. If performing ²⁰¹T myocardial perfusion SPECT to patients with abnormal cardiac function or reversible perfusion defect, consider this study results and apply it. We expect this study results could be useful predictors of ΔEF variability.