Thallium-201 gated single-photon emission tomography for the assessment of left ventricular ejection fraction and regional wall motion abnormalities in comparison with two-dimensional echocardiography

Abstract

Simultaneous assessment of myocardial perfusion and function by gated single-photon emission tomography (GS) after a single tracer injection provides incremental information and is feasible with technetium-99m sestamibi. The present study validated the use of GS with thallium-201 for the assessment of left ventricular ejection fraction (LVEF) and regional wall motion by comparison with two-dimensional (2D) echocardiography (echo), which has not been done before. After injection of 111 MBq 201Tl at peak bicycle exercise (n = 55) or pharmacological stress (n = 17), GS was acquired 15 (post stress) and 120 min post injection (rest) on a double-head camera. An automatic algorithm (QGS) was used for processing. Echo (Acuson Sequoia C256) was performed immediately after rest GS. LVEFs assessed by GS and echo were correlated. The overall and segmental sensitivity and specificity of GS for the detection of regional wall motion abnormalities (WMAs) were calculated, echo serving as the gold standard. Perfusion abnormalities were scored. The success rate of the automatic algorithm was 100%, and visually assessed image quality was good to excellent in 88% of cases. Post-stress and rest LVEF as assessed by GS were highly correlated (r = 0.91). Good correlations were obtained between post-stress LVEF (GS) and rest LVEF (echo) and between rest LVEF (GS) and rest LVEF (echo) (r = 0.76 and 0.86 respectively). In patients with a reduced LVEF of less than 50% (n = 23), these correlations were even better (r = 0.84 and 0.89 respectively). Regional wall motion abnormalities (WMAs) were identified by GS with high sensitivity and specificity (88%-100% and 82%-98% respectively) and were directly related to the extent and severity of stress as well as of resting perfusion defects. It is concluded that GS with 201Tl is a feasible and reliable tool for the evaluation of patients with compromised left ventricular function in the context of coronary artery disease, and thus improves diagnosis and prognostic stratification. Regional WMAs were identified with high diagnostic accuracy and the method may prove helpful for the detection of myocardial viability.

Transient ischemic stunning of the myocardium in stress thallium-201 gated SPET myocardial perfusion imaging: segmental analysis of myocardial perfusion, wall motion and wall thickening changes

“…The early start of imaging and the different mode of stress used in our study are possible reasons for the higher incidence of transient stunning among segments with poststress abnormal contractility as compared with the study of Lee et al We additionally demonstrated that the transient stunning in ischemic myocardium assessed by either WM or WT is related to the severity of myocardial ischemia in those segments. In a study by Bacher-Stier et al [15], assessment of WT using echocardiography was compared with 201 Tl perfusion imaging. A good correlation was shown between the 201 Tl myocardial perfusion and abnormalities in regional contractility as assessed by echocardiography.…”

Evaluation of the Quantitative Gated SPECT (QGS) software program in the presence of large perfusion defects

“…Several groups have compared the quantitative results from the QGS software with similar results from other modalities. Generally in mixed datasets, the concordance with regard to the LVEF is good for contrast ventriculography and ultrasound techniques [6][7][8][9]. Similarly, the concordance with regard to wall thickening is quite good [12].…”

“…In which quantitative assessment of end-diastolic and end-systolic perfusion, wall motion and wall thickening using the 20-segment bull's eye representation of the QGS model [ figure 2], as well as estimates for end-diastolic (EDV) and end-systolic (ESV) ventricular volume and derived stroke volume and LVEF is incorporated. The underlying algorithms have been reviewed in literature [2][3][4][5][6][7][8][9][10][11][12][13]17]. The software algorithm implementation is the same in the different camera systems.…”

“…With regard to the validation of the Cedars-Sinai's Quantitative SPECT (QGS) software, several requirements have already been met. The algorithm and its basic validation have already been described [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. However, one particular issue is still not fully solved: reproducibility of the quantitative assessment of regional functional parameters in the presence of severe major defects or artifacts.…”

Detection of residual wall motion after myocardial infarction by gated technetium-99m tetrofosmin SPET: a comparison with contrast ventriculography

“…Germano et al [5] developed a fully automatic quantitative technique (QGS) to measure left ventricular functional data. Gated SPET has been validated against a variety of techniques, such as equilibrium blood pool studies [6], contrast ventriculography [7,8,9], first-pass ventriculography [8,9,10], magnetic resonance imaging [11,12,13,14] and two-dimensional echocardiography [15,16,17]. Because the tracer distribution in the myocardium is stable, spatial and temporal changes in myocardial tracer activity during the cardiac cycle reflect regional myocardial wall motion and wall thickening [4].…”