Dynamic cardiac SPECT with Tc-99m teboroxime: compensation for rapid myocardial washout and high liver uptake

The quality of a Teboroxime single-photon emission computed tomography (SPECT) study can be degraded by Teboroxime´s rapid myocardial washout and high liver uptake. Described is the use of fast-fanning acquisition and nonlinear regression with distance penalty (NLRDP) to compensate for the two effects. Tl-201/conventional single-rotation Sestamibi (MIBI) and Tl-201/dynamic fast-fanning Teboroxime (TEBO) rest/stress acquisitions were conducted on 18 subjects. TEBO reconstructions were processed by NLRDP using group-averaged kinetics to separate images into liver, myocardium, and background. Reprojections of these compartments were registered with the measured projections. This made possible the extraction of patient-specific kinetics. NLRDP identified defects (abnormal myocardium with different kinetics from normal tissue) by differences in the kinetics of the defect pixels. Enhanced-TEBO (E-TEBO) images were produced by using the kinetic curves to calculate the Teboroxime concentration in each pixel at the time of expected peak myocardial uptake and by omitting the liver compartment. Stress and reversibility total severity scores and total impaired and reversible myocardial mass were computed for the MIBI, TEBO, and E-TEBO images using the Emory Cardiac Toolbox. Regression and correlation analyses of these quantitative indices indicate that Teboroxime SPECT can produce results similar to those of Sestamibi SPECT if E-TEBO images are generated.