Zare Tahereh, Ghorbanzadeh Mohammad, Teimourian Fard Behnoosh, Sheikhzadeh Peyman, Ghafarian Pardis, Hariri Tabrizi Sanaz, Farahani Mohammad Hossein, Reza Ay Mohammad
Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.
Research Center for Molecular and Cellular Imaging (RCMCI), Advanced Medical Technologies and Equipment (AMTEI), Tehran University of Medical Sciences (TUMS), Tehran, Iran.
J Biomed Phys Eng. 2025 Aug 1;15(4):323-332. doi: 10.31661/jbpe.v0i0.2502-1893. eCollection 2025 Aug.
Employing 2D rebinned sinograms in PET scanners has the potential to accelerate the overall reconstruction speed. Among the available rebinning techniques, Single-Slice Rebinning (SSRB) offers a computationally efficient approach.
This study aimed to evaluate the influence of varying span and Maximum Ring Difference (MRD) parameters in SSRB on the image quality of the Xtrim PET scanner.
This Monte Carlo simulation study used a GATE-simulated Xtrim-PET scanner. 3D list-mode data were histogrammed into 576 sinograms, and SSRB was applied to generate 2D sinograms. Subsequently, Maximum-Likelihood Expectation-Maximization (MLEM) reconstruction was performed on the sinograms with different MRD and span. Image quality was assessed using image quality, rod, and uniform phantoms. Furthermore, axial resolution was evaluated using point sources.
Analysis of linear profiles in uniform phantom revealed a 2.6 mm inaccuracy in axial activity estimation when comparing spans of 21 and 7. Increased span and MRD lead to artifactual data in regions of high activity gradients, as observed in both uniform and rod phantoms. However, the Recovery Coefficient (RC) and Spilled-Over Ratio (SOR) remained unaffected. Concomitantly, increasing the span improved uniformity and reduced the coefficient of variation by 1.6% and 5.9%, respectively. Axial resolution remained largely unaffected by variations in span and MRD.
The RC and SOR remain robust to variations in span and MRD. However, higher levels of axial data compression were associated with the introduction of axial artifacts. Additionally, axial resolution was unaffected by increases in span and MRD, likely due to the limited field of view of the Xtrim-PET scanner.
在正电子发射断层扫描（PET）扫描仪中使用二维重排正弦图有潜力加快整体重建速度。在现有的重排技术中，单切片重排（SSRB）提供了一种计算效率高的方法。
本研究旨在评估SSRB中不同跨度和最大环差（MRD）参数对Xtrim PET扫描仪图像质量的影响。
本蒙特卡罗模拟研究使用了GATE模拟的Xtrim-PET扫描仪。将三维列表模式数据进行直方图统计得到576个正弦图，并应用SSRB生成二维正弦图。随后，对具有不同MRD和跨度的正弦图进行最大似然期望最大化（MLEM）重建。使用图像质量、棒状和均匀体模评估图像质量。此外，使用点源评估轴向分辨率。
对均匀体模中的线性轮廓分析表明，当比较跨度为21和7时，轴向活性估计存在2.6毫米的误差。如在均匀体模和棒状体模中所观察到的，跨度和MRD的增加会导致高活性梯度区域出现伪影数据。然而，恢复系数（RC）和溢出率（SOR）不受影响。同时，增加跨度可提高均匀性，变异系数分别降低1.6%和5.9%。轴向分辨率在很大程度上不受跨度和MRD变化的影响。
RC和SOR对跨度和MRD的变化具有鲁棒性。然而，更高水平的轴向数据压缩与轴向伪影的引入有关。此外，轴向分辨率不受跨度和MRD增加的影响，这可能是由于Xtrim-PET扫描仪的视野有限。
