Feasibility of myocardial perfusion SPECT with prone and half-time imaging

BACKGROUND: Myocardial perfusion imaging with single-photon emission tomography (SPECT) is associated with reduced specificity due to tissue attenuation. This can be corrected by prone imaging while necessitating additional imaging time. Image processing with iterative reconstruction allows for a half-time (HT) acquisition. OBJECTIVE: To assess the feasibility of myocardial perfusion with SPECT using prone imaging with HT acquisition. METHODS: Ninety-one patients referred for SPECT myocardial perfusion imaging and weighing up to 90 kg were enrolled for HT supine and prone SPECT protocol. Patients with known myocardial infarction were excluded. HT prone imaging was performed when supine imaging was visually equivocal or abnormal. Image quality was compared for each patient between supine and prone imaging. RESULTS: Acquisition time was 17.9±2.9 min in the HT group compared with 31.8±5.8 min in patients imaged with full-time acquisition. Image quality was good or excellent in 85.7% of studies in a supine position and in 81.3% of studies in the prone position (P=0.25). No study was considered as nondiagnostic. Prone imaging reduced the rate of equivocal scans from 40.7 to 15.4% and of ischemic studies from 34.1 to 7.7%. In the study population, 80% of inferior and septal defects were corrected by the prone position. CONCLUSION: In a selected population, HT prone and supine imaging is feasible and is associated with a good image quality in most studies whereas acquisition time is reduced almost by half.