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

Abstract

Because of the ultrashort tracer half-life and high positron energy of 82 Rb, 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 82 Rb for assessment of left ventricular (LV) function is not well established. To support feasibility, we compared functional parameters from gated 82 Rb PET with simultaneous high-resolution contrastenhanced 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 82 Rb perfusion studies and contrast-enhanced CT angiography, using a 64-slice scanner, for the workup of coronary artery disease. From gated PET images, LV ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) were calculated using 2 commercial products. For functional CT analysis, commercial software using endocardial contour detection was applied. Results: Inter-and intraobserver agreement was good for all methods. On CT, EF was 66% 6 13%, ESV was 41 6 29 mL, and EDV was 115 6 36 mL. On PET, EF during dipyridamole was 56% 6 15% and 52% 6 15% using the 2 commercial products (P , 0.05 vs. CT), ESV was 36 6 28 and 47 6 35 mL (P 5 not significant vs. CT), and EDV was 75 6 30 and 91 6 33 mL (P , 0.05 vs. CT). Correlations with CT were 0.85 and 0.87 for EF using commercial software, 0.76 and 0.88 for ESV, and 0.60 and 0.68 for EDV (P , 0.01 for all). Bland-Altman analysis confirmed systematic underestimation of EF and EDV by PET versus CT but did not show a significant deviation from linearity. Conclusion: Global LV function can be measured reproducibly from gated 82 Rb PET, using different available software products. However, underestimation of EF by 82 Rb PET, compared with CT ventriculography, is present, which is a result of underestimation of EDV from countpoor ED frames. This underestimation needs to be considered for clinical interpretation of 82 Rb PET.

Reference Ranges for LVEF and LV Volumes from Electrocardiographically Gated 82Rb Cardiac PET/CT Using Commercially Available Software

“…This limitation makes quantification of functional parameters a bigger challenge than when using SPECT or gated PET with other tracers. Nevertheless, reproducibility of the software algorithms was good in our analysis, and the validity of gated 82 Rb PET results was recently demonstrated by us in a comparison with contrast-enhanced CT ventriculography (11). This prior study agreed well with the reference technique but also showed a systematic underestimation of LVEF by PET.…”

Prediction of Short-Term Cardiovascular Events Using Quantification of Global Myocardial Flow Reserve in Patients Referred for Clinical 82Rb PET Perfusion Imaging

“…Endocardial contours were identified on gated PET to determine left ventricular volumes and left ventricular ejection fraction, using previously validated commercially available software (CardIQ physio; GE Healthcare) (14). Quantification of MBF and MFR.…”

Correlation of coronary artery stenosis evaluation with left heart structure and function by multi-slice computed tomography

“…This showed great advantages: the scanning speed was fast, easy, safe, noninvasive, and of low cost; synchronism was good, in which image data of the coronary artery could be obtained and cardiac function determined in one-stop access, without examination interval, where cardiac function could reflect the current vein stenosis. We also found that there were some deficiencies: the time and spatial resolutions needed to be further improved, and there were still partial motion artifacts, which could affect the precise definition of left ventricular systolic end and diastolic end; and breathing exercises, rapid heart rate, heart rate arrhythmia, and severe coronary calcification would all affect coronary stenosis assessment (Ruixing et al, 2007;Chander et al, 2008). In addition, whether the use of metoprolol and contrast agents and saline in the contrast could affect left ventricular function still remains to be further studied.…”

“…It could cause heart expansion (left atrium and left ventricle), mainly due to myocardial ischemia, myocardial cell edema, interstitial hyperplasia and left ventricular remodeling, resulting in a decrease in left ventricular compliance and cardiac function. As the degree of stenosis increases, MM will increase, suggesting that left ventricular MM could be used as an effective indicator to determine left ventricular dysfunction, especially valuable for those patients with normal early LVEF values and no effects on general activities, and in whom MM is relatively stable in a certain period, with strong repeatability (Chander et al, 2008;Wang et al, 2009a;Krim et al, 2011).…”