Abstract
The goal of this study was to validate the accuracy of the Emory Cardiac Tool Box (ECTB) in assessing left ventricular end-diastolic or end-systolic volume (EDV, ESV) and ejection fraction (LVEF) from gated 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SPECT using cardiac MRI (cMRI) as a reference. Furthermore, software-specific characteristics of ECTB were analyzed in comparison with 4D-MSPECT and Quantitative Gated SPECT (QGS) results (all relative to cMRI). Methods: Seventy patients with suspected or known coronary artery disease were examined using gated 99mTc-MIBI SPECT (8 gates/cardiac cycle) 60 min after tracer injection at rest. EDV, ESV, and LVEF were calculated from gated 99mTc-MIBI SPECT using ECTB, 4D-MSPECT, and QGS. Directly before or after gated SPECT, cMRI (20 gates/cardiac cycle) was performed as a reference. EDV, ESV, and LVEF were calculated using Simpson’s rule. Results: Correlation between results of gated 99mTc-MIBI SPECT and cMRI was high for EDV (R = 0.90 [ECTB], R = 0.88 [4D-MSPECT], R = 0.92 [QGS]), ESV (R = 0.94 [ECTB], R = 0.96 [4D-MSPECT], R = 0.96 [QGS]), and LVEF (R = 0.85 [ECTB], R = 0.87 [4D-MSPECT], R = 0.89 [QGS]). EDV (ECTB) did not differ significantly from cMRI, whereas 4D-MSPECT and QGS underestimated EDV significantly compared with cMRI (mean ± SD: 131 ± 43 mL [ECTB], 127 ± 42 mL [4D-MSPECT], 120 ± 38 mL [QGS], 137 ± 36 mL [cMRI]). For ESV, only ECTB yielded values that were significantly lower than cMRI. For LVEF, ECTB and 4D-MSPECT values did not differ significantly from cMRI, whereas QGS values were significantly lower than cMRI (mean ± SD: 62.7% ± 13.7% [ECTB], 59.0% ± 12.7% [4DM-SPECT], 53.2% ± 11.5% [QGS], 60.6% ± 13.9% [cMRI]). Conclusion: EDV, ESV, and LVEF as determined by ECTB, 4D-MSPECT, and QGS from gated 99mTc-MIBI SPECT agree over a wide range of clinically relevant values with cMRI. Nevertheless, any algorithm-inherent over- or underestimation of volumes and LVEF should be accounted for and an interchangeable use of different software packages should be avoided.
- gated 99mTc-MIBI SPECT
- Emory Cardiac Tool Box
- 4D-MSPECT
- Quantitative Gated SPECT
- cardiovascular MRI
- left ventricular volumes
- ejection fraction
Footnotes
Received Aug. 13, 2004; revision accepted Jan. 5, 2005.
For correspondence or reprints contact: Wolfgang M. Schaefer, MD, PhD, Department of Nuclear Medicine, University Hospital, Aachen University of Technology, Pauwelsstrasse 30, 52074 Aachen, Germany.
E-mail: wschaefer{at}ukaachen.de