Validation of Gated Blood-Pool SPECT Regional Left Ventricular Function Measurements

Blood-pool (BP)–gated SPECT should be able to detect re-gional left ventricular (LV) dysfunction, as the modality is fully 3-dimensional and capable of resolving all cardiac chambers. This study investigates the hypothesis that LV segments that have abnormal regional wall motion (WM) on a cardiac MRI scan also have abnormal BP regional ejection fraction (EF) as computed by fully automated quantitation (AQ) of BP data. Methods:A total of 34 patients evaluated for coronary artery dis-ease who underwent visual assessment of WM by review of BP cines and cardiac MRI evaluations were included in this retro-spective investigation. Cardiac MRI values for these patients were compared with an institutional database of cardiac MRI values for an age-matched cohort of 10 healthy volunteers. An AQ algorithm segmented the LV BPs on the BP tomograms and subdivided volumes into 17 subregions. Count-versus-time curves were fit to third-order Fourier series for each LV subvo-lume to compute regional EFs. For cardiac MRI data, endocardial and epicardial drawings were performed manually for 60 sam-ples of 11–13 short-axis tomograms spanning the entire heart, from which regional WM values were computed and rebinned into 17 conventional LV segments. Results: Global EF range