Effect of radionuclides on the left ventricular phase analysis using the gated-myocardial perfusion single photon emission computed tomography for ischemic heart disease

3080 Introduction: Phase analysis using gated-myocardial perfusion single photon emission computed tomography (MPS) provides the clinicians with significant information to evaluate left ventricular mechanical dyssynchrony. Recently, phase analysis has been reported to be a useful tool for the clinical assessment of ischemic heart disease (IHD). However, 99mTc-labeled radiopharmaceuticals are primarily recommended for gated-MPS because of the appropriate photon energy and high radioactivity administration. This study aimed to evaluate the influence of different radionuclides on the left ventricular phase analysis using the gated-MPS in patients with IHD. Materials and Methods: We retrospectively investigated 202 patients with suspected or known IHD. All the patients underwent coronary arteriography and were subsequently classified into 43 patients without any coronary lesion (0VD), 71 patients with 1 vessel disease (1VD), 59 patients with 2 vessel disease (2VD), and 29 patients with 3 vessel disease (3VD). Both stress and rest gated-MPS were performed using 99mTc-MIBI/TF in 118 patients and 201TlCl in 84 patients. Phase analysis using Heart Function View™ was performed to obtain the Peak Phase, Phase SD, and Bandwidth. Finally, we investigated potential differences between the phase analysis indices and the respective radionuclides used. Results: Peak phase did not exhibit any significant differences in the numbers of affected branches in either 99mTc-MIBI/TF or 201TlCl, even during stress MPS or rest MPS. Furthermore, both phase SD and bandwidth demonstrated a tendency to increase in patients with increased number of affected branches. Differences in phase SD were not significant in either 99mTc-MIBI/TF or 201TlCl. Although bandwidth differences pertaining 201TlCl were not significant, the use of 99mTc-MIBI/TF during stress MPS facilitated a significant bandwidth increase in patients with 3VD (P < 0.05). Conclusions: Left ventricular phase analysis using the 99mTc-MIBI/TF gated-MPS provides a bandwidth increase that cannot be obtained with 201TlCl gated-MPS.