Echocardiographic validation of gated SPECT ventricular function measurements
K Nichols1, D Lefkowitz, T Faber
1Department of Medicine, St Luke's-Roosevelt Hospital and Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
Summary
Gated SPECT methods for calculating left ventricular (LV) volumes show strong correlation with echocardiography. The method most similar to echocardiography provides the closest volume measurements for patients with coronary artery disease.
Area of Science:
- Cardiology
- Nuclear Medicine
- Medical Imaging
Background:
- Left ventricular (LV) volumes are crucial prognostic indicators in coronary artery disease (CAD).
- Traditional methods include x-ray contrast angiography and echocardiography.
- Scintigraphic methods offer alternative LV volume calculations based on varying modeling assumptions.
Purpose of the Study:
- To investigate discrepancies between different nuclear imaging techniques for LV volume calculation.
- To compare nuclear imaging-derived LV volumes with conventional echocardiographic measurements.
- To determine the interpretability of nuclear imaging calculations for individual patients.
Main Methods:
- Echocardiographic volumes were measured using the modified Simpson's rule in 33 CAD patients.
- Volumes were compared with three gated SPECT methods: Simpson's rule (Method 1), Gaussian fitting (Method 2), and endocardial modeling (Method 3).
- Statistical analyses included ANOVA, paired t tests, linear regression, and Bland-Altman analysis.
Main Results:
- No significant differences were found in ejection fractions (EFs) among methods.
- Significant differences existed for volumes, with Methods 2 and 3 overestimating echocardiographic and Method 1 volumes.
- Strong correlations (r=0.92) were observed between gated SPECT and echocardiographic volumes across all methods.
Conclusions:
- All gated SPECT parameters demonstrated good correlation with echocardiographic values.
- The gated SPECT method employing assumptions closest to echocardiography yielded the most agreeable mean volume values.
- Method 1 (Simpson's rule SPECT) showed the best agreement with echocardiography for LV volumes.
