Abdominal aortic aneurysm (AAA) wall stress is a candidate rupture risk marker but is typically computed from single-phase images without known cardiac phase. Linear stress recovery methods, which solve a single geometrically linear equilibrium problem on the imaged, already-loaded geometry, have been validated for static stress estimation, but their robustness to unknown imaging phase remains unexplored. We investigated whether imaging phase materially biases 99th percentile stress recovered linearly, and whether linear recovery agrees with non-linear analysis under matched loads. Two patient-specific AAAs from a public 4D-CTA cohort (Case 1: 5.5% strain; Case 2: 4.5% strain) were analyzed. For each, we analyzed diastolic and synthetic systolic geometry, the latter generated by warping the diastolic mesh via displacements from non-linear hyperelastic analysis. Linear stresses were recovered on both geometries under systolic pressure and compared via 99th-percentile maximum principal stress, stress distributions, and 3D stress differential contours. Linear stresses under pulse pressure were compared against non-linear stresses. 99th-percentile stresses from linear recovery on diastolic vs synthetic systolic geometries under systolic pressure differed by 8.6% (Case 1) and 3.5% (Case 2), within segmentation uncertainty. 99th-percentile stresses from linear recovery and non-linear analysis under pulse pressure agreed closely: 0% difference (Case 1) and 1.1% (Case 2), with nearly identical distributions. These findings support linear stress recovery for patient-specific AAA analysis in clinical settings with static single-phase imaging, offering a computationally efficient alternative without compromising accuracy or requiring patient-specific wall properties.

翻译：腹主动脉瘤（AAA）壁应力是潜在的破裂风险标志物，但通常基于未知心动周期的单时相影像计算。线性应力恢复方法通过在已加载的成像几何体上求解单一几何线性平衡问题，已被验证可用于静态应力估计，但其对未知成像时相的鲁棒性尚未得到研究。我们探究了成像时相是否显著影响线性恢复的第99百分位应力，以及在线性恢复与非线性分析在相同载荷下是否一致。我们分析了来自公开4D-CTA队列的两例患者特异性AAA（病例1：应变5.5%；病例2：应变4.5%）。对每例病例，我们分析了舒张期几何形态及合成的收缩期几何形态，后者通过将舒张期网格基于非线性超弹性分析的位移进行形变而生成。在收缩压载荷下对两种几何形态进行线性应力恢复，并通过第99百分位最大主应力、应力分布及三维应力差异等值线进行比较。脉压载荷下的线性应力与非线性应力进行了对比。在收缩压载荷下，基于舒张期与合成收缩期几何形态的线性恢复所得第99百分位应力差异分别为8.6%（病例1）和3.5%（病例2），处于分割不确定性范围内。脉压载荷下线性恢复与非线性分析所得第99百分位应力高度一致：差异为0%（病例1）和1.1%（病例2），且分布几乎相同。这些发现支持在临床静态单时相成像场景中采用线性应力恢复进行患者特异性AAA分析，该方法在保证精度且无需患者特异性壁属性的前提下，提供了计算高效的替代方案。