Different acquisition arcs for better imaging left ventricular wall in myocardial perfusion single photon emission tomography.

OBJECTIVE: Conventional Single-photon emission tomography (SPET) myocardial perfusion imaging (MPI) is performed in the supine position range RAO 45o -LPO 45o , but the effect of other acquisition arcs on imaging quality have not been well described. In this study, we compared the radioactivity over left ventricle walls as measured by different acquisition arcs to identify the best specific applications.

SUBJECTS AND METHODS: A total of 125 low-risk coronary heart disease patients underwent technetium-99m methoxy isobutyl isonitrile (99m Tc-MIBI) stress MPI, of which 52 received 360o acquisition with reconstruction using different 180o projections and the remaining 73 received conventional 180o (LPO 45o -RAO 45o ) and left-side 180o (POST 180o -ANT 0o ) acquisition consecutively. We statistically compared the radioactivity and defect score of each left ventricular wall from different acquisition arcs.

RESULTS: Myocardial slices reconstructed from POST 180o -ANT 0o yielded highest radioactivity uptake for lateral, inferior and septal walls, LPO 45 -RAO 45 for the anterior wall and LPO 35o -RAO 55o for the apical region. Compared to conventional 180o acquisition, the segments with decreased defect scores were observed in 27.67% using left-side 180o acquisition. The proportion was significantly higher for males (P=0.035) and patients with high body mass index (BMI) (P=0.036). Segments with decreased defect scores were mainly in the inferior, septal and lateral walls and more in males than in females in the inferior wall (P=0.004).

CONCLUSION: The different arc of data acquisition could significantly affect the appearance of each wall of the left ventricle, POST 180o -ANT 0o acquisition arc represented a significantly enhanced imaging quality of inferior walls as compared to the conventional acquisition arc LPO 45 -RAO 45 in 180 protocol, especially in males.