Comparison of Measures of Left Ventricular Function from Electrocardiographically Gated 82Rb PET with Contrast-Enhanced CT Ventriculography: A Hybrid PET/CT Analysis

Because of the ultrashort tracer half-life and high positron energy of 82Rb, PET images acquired with this tracer are noisier and of lower resolution than those obtained with other PET tracers. The validity of electrocardiographic gating using 82Rb for assess-ment of left ventricular (LV) function is not well established. To support feasibility, we compared functional parameters from gated 82Rb PET with simultaneous high-resolution contrast-enhanced CT ventriculography, obtained as a byproduct a CT coronary angiography during hybrid cardiac PET/CT.Methods: A total of 24 patients underwent PET/CT, consisting of rest and dipyridamole 82Rb perfusion studies and contrast-enhanced CT angiography, using a 64-slice scanner, for the workup of cor-onary artery disease. From gated PET images, LV ejection frac-tion (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) were calculated using 2 commercial products. For func-tional CT analysis, commercial software using endocardial con-tour detection was applied. Results: Inter- and intraobserver agreement was good for all methods. On CT, EF was 66 %