부산대학교 도서관

Introduction: Coronary PET has shown promise in the detection of high-risk plaques; however, there is a need to optimize imaging techniques to improve quantitation and overcome challenges faced by motion. We investigated the impact of different reconstructions and motion correction (MC) techniques on F-NaF PET quantification in patients with ACS.Methods: Twenty patients underwent PET-CT and CTA following injection of 250 MBq F-NaF within 21 days of ACS. Time-of-flight and resolution recovery (Sharp IR) were used with iterative reconstruction. The optimal number of iterations and post-filtering were determined in a subgroup of 6 patients. Subsequently, MC by diffeomorphic mass-preserving anatomy-guided registration within vessels automatically defined by CTA was performed on ECG-gated data (10-bins) of all patients forming motion frozen images from all cardiac gates. Tracer uptake was quantified in culprit (identified on invasive angiography) and reference lesions by computing signal-to-noise ratio (SNR) in diastolic, summed and MC images. SNR was calculated as plaque SUVmax divided by mean standard deviation of blood pool activity.Results: PET reconstruction using 24 subsets, 4 iterations and 5mm filter provided the highest SNR (31.5) compared to 4 iterations 0mm (22.5), 8 iterations 0mm (21.1) and 8 iterations 5mm (25.6) [median; p<0.05 for all). In all subjects, MC improved SNR of culprit lesions (n=30) (24.4 [19.9-32.3]) when compared to diastolic (15.8 [12.0-18.2]; p<0.001) and summed (22.2 [18.1-29.4]; p=0.002). Further, MC led to a greater SNR difference between culprit and reference lesions (11.1 [6.3-12.7]) compared to diastolic (7.0 [4.1-10.9] p=0.002) and summed data (7.3 [5.2-11.7] p=0.001).Conclusion: The number of iterations and extent of post-filtering in F-NaF PET reconstruction has marked effects on quantification and should be considered when using coronary PET. MC improves discrimination between culprit and reference lesions.