Abdominal aortic aneurysm (AAA) monitoring and risk of rupture is currently assumed to be correlated with the aneurysm diameter. Aneurysm growth, however, has been demonstrated to be unpredictable. Using PET to measure uptake of [¹⁸F]-NaF in calcified lesions of the abdominal aorta has been shown to be useful for identifying AAA and to predict its growth. The PET low spatial resolution, however, can affect the accuracy of the diagnosis. Advanced edge-preserving reconstruction algorithms can overcome this issue. The kernel method has been demonstrated to provide noise suppression while retaining emission and edge information. Nevertheless, these findings were obtained using simulations, phantoms and a limited amount of patient data. In this study, the authors aim to investigate the usefulness of the anatomically guided kernelized expectation maximization (KEM) and the hybrid KEM (HKEM) methods and to judge the statistical significance of the related improvements. Sixty-one datasets of patients with AAA and 11 from control patients were reconstructed with ordered subsets expectation maximization (OSEM), HKEM and KEM and the analysis was carried out using the target-to-blood-pool ratio, and a series of statistical tests. The results show that all algorithms have similar diagnostic power, but HKEM and KEM can significantly recover uptake of lesions and improve the accuracy of the diagnosis by up to 22% compared to OSEM. The same improvements are likely to be obtained in clinical applications based on the quantification of small lesions, like for example cancer.

This article is part of the theme issue ‘Synergistic tomographic image reconstruction: part 1’.

目前假设腹主动脉瘤 (AAA) 监测和破裂风险与动脉瘤直径相关。然而，动脉瘤的生长已被证明是不可预测的。使用 PET 测量 [ ¹⁸腹主动脉钙化病变中的 F]-NaF 已被证明可用于识别 AAA 并预测其生长。然而，PET的低空间分辨率会影响诊断的准确性。先进的边缘保留重建算法可以克服这个问题。核方法已被证明可以在保留发射和边缘信息的同时提供噪声抑制。然而，这些发现是使用模拟、体模和有限数量的患者数据获得的。在这项研究中，作者旨在研究解剖引导核化期望最大化 (KEM) 和混合 KEM (HKEM) 方法的有用性，并判断相关改进的统计意义。使用有序子集期望最大化 (OSEM)、HKEM 和 KEM 重建了 61 个 AAA 患者和 11 个对照患者的数据集，并使用目标与血池比率和一系列统计检验进行了分析. 结果表明，所有算法都具有相似的诊断能力，但与 OSEM 相比，HKEM 和 KEM 可以显着恢复病灶的摄取，并提高诊断准确率高达 22%。基于对小病变（例如癌症）的量化，在临床应用中可能会获得相同的改进。但与 OSEM 相比，HKEM 和 KEM 可以显着恢复病灶的摄取，并提高诊断的准确性高达 22%。基于对小病变（例如癌症）的量化，在临床应用中可能会获得相同的改进。但与 OSEM 相比，HKEM 和 KEM 可以显着恢复病灶的摄取，并提高诊断的准确性高达 22%。基于对小病变（例如癌症）的量化，在临床应用中可能会获得相同的改进。

本文是主题问题“协同断层图像重建：第 1 部分”的一部分。