Repeatability of left ventricular dyssynchrony and function parameters in serial gated myocardial perfusion SPECT studies

Background. The purpose of this study was to establish the repeatability of left-ventricular (LV) dyssynchrony and function parameters measured from serial gated myocardial perfusion SPECT (GMPS) studies. Methods. Thirty patients, who met standard criteria for cardiac resynchronization therapy (CRT), were prospectively enrolled. One hour after resting injection, a standard GMPS was performed, and repeated 30 minutes later after repositioning the patient. The two serial studies were processed blinded from each other by an experienced operator, and processed side-by-side by another experienced operator using iterative reconstruction, Butterworth filtering, and the Emory Cardiac Toolbox with phase analysis. Phase standard deviation, phase histogram bandwidth, LV ejection fraction, end-systolic volume, and end-diastolic volume were calculated and compared. Results. All measured parameters were highly correlated (r > .90) between the serial studies without significant difference by paired t test. The variations of the parameters measured by side-by-side processing were significantly smaller than those measured by blinded processing. Conclusion. These results indicated high repeatability of LV dyssynchrony and function parameters when measured serially by GMPS, especially when the serial studies were processed side-by-side. The measured variations of these parameters can be used to evaluate changes in LV dyssynchrony and function measured by GMPS before and after CRT. (J Nucl Cardiol 2010; 17: 811-6.)