First human validation of rapid myocardial perfusion imaging and quantification using 99m Tc-Teboroxime CZT-SPECT: A feasibility study

Background: Myocardial perfusion imaging (MPI) is essential for diagnosing and managing coronary artery disease (CAD). Traditional MPI agents like 99m Tc-methoxyisobutylisonitrile ( 99m Tc-MIBI) have limitations, including long acquisition times and non-linear myocardial uptake. 99m Tc-Teboroxime, known for its rapid myocardial uptake and washout, has been underutilized due to challenges with conventional NaI SPECT cameras. The advent of cadmium-zinc-telluride (CZT) SPECT cameras, with higher detection efficiency, has renewed interest in 99m Tc-Teboroxime for rapid MPI and myocardial blood flow (MBF) quantification. Methods: This study included 45 patients with known or suspected CAD who underwent rest and stress 99m Tc-Teboroxime dynamic scintigraphy using a CZT-SPECT camera. Dynamic 99m Tc-Teboroxime images were rebinned and analyzed to get time-activity curves (TACs) of the heart, liver, and blood pool, as well as heart-to-liver and heart-to-blood pool ratios. MPI semi-quantitative analysis was conducted using the standard American Heart Association (AHA) 17-segment model and 5-grade scoring system, and the results were compared with those of 99m Tc-MIBI. A one-tissue compartment model was implemented to obtain K 1 , K 2 , and myocardial perfusion reserve (MPR) values. Results: CZT acquisition presented rapid myocardial uptake of 99m Tc-Teboroxime, which washed out quickly after 5 min post-injection (p.i.). 99m Tc-Teboroxime MPI showed excellent agreement with 99m Tc-MIBI MPI in detecting perfusion abnormalities ( Kappa value = 0.75), with no statistically significant differences in segmental analysis. 99m Tc-Teboroxime tended to reveal higher summed stress score (SSS), summed rest score (SRS), and summed defect score (SDS), suggesting a potential for detecting more pronounced ischemic segments. The stress K 1 value was significantly higher in the normal group than in the MPI abnormal group (1.65 ± 0.57 mL·min –1 ·g –1 vs. 1.20 ± 0.35 mL·min –1 ·g –1 , P = 0.027), as well as the result of MPR index in the two groups (2.03 ± 0.54 vs. 1.51 ± 0.35, P <0.001). Conclusion: This study demonstrates the feasibility of using 99m Tc-Teboroxime with CZT-SPECT for rapid MPI and quantitative analysis in CAD patients. The high sensitivity of CZT-SPECT overcomes the rapid washout limitation of 99m Tc-Teboroxime, making it a promising agent for clinical MPI and MBF quantification.