TY - JOUR T1 - Prone Versus Supine Patient Positioning During Gated <sup>99m</sup>Tc-Sestamibi SPECT: Effect on Left Ventricular Volumes, Ejection Fraction, and Heart Rate JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 2016 LP - 2020 VL - 45 IS - 12 AU - Wolfgang M. Schaefer AU - Claudia S.A. Lipke AU - Harald P. Kühl AU - Karl-Christian Koch AU - Hans-Juergen Kaiser AU - Patrick Reinartz AU - Bernd Nowak AU - Udalrich Buell Y1 - 2004/12/01 UR - http://jnm.snmjournals.org/content/45/12/2016.abstract N2 - Gated myocardial perfusion SPECT allows assessment of left ventricular end-diastolic volume (EDV), left ventricular end-systolic volume (ESV), left ventricular stroke volume (SV), and left ventricular ejection fraction (LVEF). Acquiring images with the patient both prone and supine is an approved method of identifying and reducing artifacts. Yet prone positioning alters physiologic conditions. This study investigated how prone versus supine patient positioning during gated SPECT affects EDV, ESV, SV, LVEF, and heart rate. Methods: Forty-eight patients scheduled for routine myocardial perfusion imaging were examined with gated 99mTc-sestamibi SPECT (at rest) while positioned prone and supine (consecutively, in random order). All parameters for both acquisitions were calculated using the commercially available QGS algorithm. Results: Whereas EDV and SV were significantly lower (P &lt; 0.0004) for prone acquisitions (EDV, 110.5 ± 39.1 mL; SV, 55.9 ± 13.3 mL) than for supine acquisitions (EDV, 116.9 ± 36.2 mL; SV, 61.0 ± 14.5 mL), ESV and LVEF did not differ significantly. Heart rate was significantly higher (P &lt; 0.0001) during prone acquisitions (69.1 ± 10.5 min−1) than during supine acquisitions (66.5 ± 10.0 min−1). Conclusion: The observed position-dependent effect on EDV, SV, and heart rate might be explained by decreased arterial filling and increased sympathetic nerve activity. Hence, supine reference data should not be used to classify the results of prone acquisitions. ER -