Ultra-fast [18F]florbetapir PET imaging using the uMI Panorama PET/CT system

Background There is a need for faster amyloid PET scans to reduce patients' discomfort, minimize movement artifacts, and increase throughput. The recently introduced uMI Panorama PET/CT system featuring enhanced spatial resolution and sub-200ps TOF offers the potential for shorter scan duration without sacrificing image quality or efficacy to detect A beta deposition. The study aims to establish a faster acquisition protocol for [F-18]florbetapir PET imaging using digital PET/CT scanner uMI Panorama, while ensuring adequate image quality and amyloid-beta (A beta) detectability comparable to the standard 10-minute scan. Methods Thirty-eight participants (29 A beta positive and 9 A beta negative) from a prospective dementia cohort at Peking Union Medical University Hospital underwent routine [F-18]florbetapir PET scans using the uMI Panorama PET/CT scanner and a T1-weighted brain MRI scan. List-mode PET data were reconstructed into durations of 10 min, 2 min, 1 min, 45 s, and 30 s (G10min, G2min, G1min, G45s, G30s). Two trained nuclear medicine physicians independently evaluated the image quality using a 5-point scale and provided binary diagnosis. Standardized uptake value ratios (SUVr) of the composite cortex (frontal, lateral parietal, lateral temporal, and cingulate cortices) were calculated to discriminate A beta status and coefficient of variation assessed objective image quality. Comparisons of image quality and A beta detectability between various fast scan groups and G10min group were conducted. Results The subjective image quality evaluation and A beta detectability results from the two physicians showed both good intra-reader and inter-reader agreements (Cohen's kappa coefficient: 0.759-1.000). The subjective and objective image qualities of the G2min scans were comparable to the G10min scans, whereas adequate image quality was achieved with the G1min and G45s scans (5-point score >= 3). Subjective visual diagnosis by two physicians yielded consistent accuracy for G10min, G2min, and G1min groups, but lower specificity for G45s and G30s groups. The objective detection of A beta status by cortex SUVr across all scan durations maintained perfect discriminatory efficiency and relatively high effect size (Hedge's G: 2.48-2.54). Conclusions A 1-min ultra-fast scan is feasible for [F-18]florbetapir PET imaging using uMI Panorama PET/CT, while maintaining adequate image quality and A beta diagnostic efficiency.