Abstract 19973: Dynamic Thallium-201 SPECT/CT Provides Quantitative Index of Myocardial Flow and Viability: Validation in Porcine Post-Myocardial Infarction Model
Introduction: Thallium-201 (Tl-201) SPECT imaging is routinely used to evaluate relative myocardial perfusion and/or viability. In this study, we have evaluated Tl-201 kinetics in a porcine model of myocardial infarction (MI) with dynamic imaging on a hybrid SPECT/CT system.
Methods: Tl-201 SPECT and contrast CT imaging were performed on hybrid SPECT/64-slice CT (GE Discovery NM/CT 570c) in Yorkshire pigs (n=5) one week following a 90 min balloon occlusion of the LAD below the first diagonal branch. Tl-201 (83-158 MBq) was injected after the initiation of a 900s list-mode acquisition. The list-mode data was reconstructed with MLEM using 30 iterations creating 23 frames (12 x 10s; 6 x 30s; 5 x 120s). Reconstructed dynamic SPECT data was analyzed using FlowquantTM semi-automated analysis software with a 1-compartment model. K1 (index of flow) and k2 (index of viability) were assessed within a 17-segment model of the left ventricle. Four segments within the central infarcted LAD territory were compared to six segments of the contralateral inferolateral wall. The same segments were analyzed for wall thickening from ECG-gated contrast CT scans using centerline approach (GE AW Cardiac Function Xpress).
Results: K1 was significantly decreased in the MI vs contralateral normal regions (0.52 ± 0.17 vs 0.61 ± 0.16 ml/min/g, p<0.02). K2 an index of tissue viability was significantly increased in the MI region (0.42 ± 0.19 vs 0.32 ± 0.12 /min, p<0.04), reflecting accelerated Tl-201 washout in MI. Wall thickening in the same MI region was significantly decreased (0.33 ± 1.5 mm vs 3.3 ± 1.9 mm, p<0.005).
Conclusions: Dynamic Tl-201 SPECT/CT imaging provides a quantitative index of both myocardial flow and viability using a 1-compartment model. This preliminary pre-clinical demonstrates the potential for dynamic Tl-201 SPECT imaging to quantify myocardial viability early post-MI.
Author Disclosures: S.L. Thorn: None. M.R. Stacy: None. A. Bregasi: None. J.C. Paeng: None. V.A. Tavakoli: None. J.O. Winters: None. C. Hawley: None. Y. Tang: None. J. Bennett: None. R.G. Wells: None. C. Liu: None. R. Klein: Other; Modest; Revenues from Flowquant sales. A.J. Sinusas: None.
- © 2014 by American Heart Association, Inc.