Q.Clear reconstruction shortening the scanning time for 11C-CFT brain PET/MR imaging

As a tracer in brain PET imaging for diagnosis of Parkinson’s disease (PD), the application of 11C-methyl-N-2β-carbomethoxy-3β-(4-fluorophenyl)-tropane (11C-CFT) is limited due to its short half-life. This study aims to explore the feasibility of using Q.Clear reconstruction to reduce the scanning time of 11C-CFT brain PET imaging. We retrospectively enrolled 43 patients who underwent 11C-CFT PET/MRI examination. Their image data was reconstructed using classical ordered subset expectation maximization (OSEM) with 20 min and Q.Clear with 5, 10, 15, 20 min of scanning time (QC05, QC10, QC15, QC20). Subsequently, subjective quality assessment and semi-quantitative assessment were employed across the five reconstruction groups. Subjective image assessment included overall image quality, image noise and lesion depiction. Signal-to-noise ratio (SNR), signal-to-background ratio (SBR) and dopamine transporters (DAT) binding rate were measured in semi-quantitative assessment. In subjective assessment, all Q.Clear groups showed image quality and noise comparable or superior to OSEM. However, QC05 group received significantly lower overall image quality scores than QC10, QC15, QC20 (all P < 0.05). In several QC05 cases, both readers noted conspicuous signal absence with locational and uptake inconsistencies versus OSEM, leading to diagnostic discrepancy. By contrast, QC10, QC15, QC20 provided lesion visibility equivalent to the OSEM reference. Semi‑quantitative analysis indicated no significant differences among all groups in SNR, SBR, or DAT binding rate (all P > 0.05). The Q.Clear reconstruction demonstrates reliable performance in the quantitative assessment of 11C-CFT brain PET imaging, therefore can shorten scanning time to at least 10 min under the premise of meeting clinical diagnostic requirements.