Abstract：
OBJECTIVE: CT perfusion (CTP) is a valuable tool in suspected acute ischemic stroke. A substantial variability of the delay between contrast injection and bolus arrival in the brain is conceivable. We investigated the distribution of the peak positions of the concentration time curves measured in an artery (arterial input function, AIF) and - in cases with ischemia - also measured in the penumbra.
METHODS: We report on 2624 perfusion scans (52 % female, mean age 72.2 ± 14.4 years) with stroke present in 1636 cases. From the attenuation time curves of the AIF and the penumbra, we calculated the respective bolus peak positions and investigated the distribution of the peak positions. Further, we analyzed the bolus peak positions for associations with age.
RESULTS: The bolus peaked significantly later in older patients, both in the AIF and in the penumbra (all p < 0.001). In the whole cohort, we found a significant association of age with the bolus peak position of the AIF (ρ = 0.334; p < 0.001). In patients with stroke, age was also associated to the peak position of the AIF (ρ = 0.305; p < 0.001), and the penumbra (ρ = 0.246, p < 0.001). However, a substantial range of peak positions of the AIF and penumbra was noted across all age ranges.
CONCLUSIONS: This study revealed a strong age-dependency of the contrast bolus arrival in both healthy and ischemic tissue. This variability makes non-uniform sampling schemes, which have been suggested to reduce radiation dose, problematic, as they might not always optimally capture the bolus in all cases.
METHODS: We report on 2624 perfusion scans (52 % female, mean age 72.2 ± 14.4 years) with stroke present in 1636 cases. From the attenuation time curves of the AIF and the penumbra, we calculated the respective bolus peak positions and investigated the distribution of the peak positions. Further, we analyzed the bolus peak positions for associations with age.
RESULTS: The bolus peaked significantly later in older patients, both in the AIF and in the penumbra (all p < 0.001). In the whole cohort, we found a significant association of age with the bolus peak position of the AIF (ρ = 0.334; p < 0.001). In patients with stroke, age was also associated to the peak position of the AIF (ρ = 0.305; p < 0.001), and the penumbra (ρ = 0.246, p < 0.001). However, a substantial range of peak positions of the AIF and penumbra was noted across all age ranges.
CONCLUSIONS: This study revealed a strong age-dependency of the contrast bolus arrival in both healthy and ischemic tissue. This variability makes non-uniform sampling schemes, which have been suggested to reduce radiation dose, problematic, as they might not always optimally capture the bolus in all cases.
摘要：
目的：CT灌注（CTP）是可疑急性缺血性中风的有价值的工具。可以想象造影剂注射和推注到达大脑之间的延迟的实质性变化。我们调查了在动脉中测量的浓度时间曲线的峰值位置的分布（动脉输入函数，AIF）和-在缺血的情况下-也在半影中测量。
方法：我们报告了2624次灌注扫描（52％为女性，平均年龄72.2±14.4岁），卒中1636例。从AIF和半影的衰减时间曲线来看，我们计算了各自的推注峰位置，并研究了峰位置的分布。Further,我们分析了推注峰值位置与年龄的关系.
结果：在老年患者中，大剂量的峰值明显较晚，在AIF和半影中(所有p<0.001)。在整个队列中，我们发现年龄与AIF的推注峰值位置显著相关(ρ=0.334;p<0.001)。在中风患者中，年龄也与AIF的峰值位置相关(ρ=0.305；p<0.001)，和半影(ρ=0.246，p<0.001)。然而,在所有年龄范围内都注意到AIF和半影峰位置的很大范围.
结论：这项研究揭示了健康组织和缺血组织中对比剂推注的强烈年龄依赖性。这种可变性使得采样方案不均匀，有人建议减少辐射剂量，有问题,因为它们可能并不总是在所有情况下都能最佳地捕获推注。
方法：我们报告了2624次灌注扫描（52％为女性，平均年龄72.2±14.4岁），卒中1636例。从AIF和半影的衰减时间曲线来看，我们计算了各自的推注峰位置，并研究了峰位置的分布。Further,我们分析了推注峰值位置与年龄的关系.
结果：在老年患者中，大剂量的峰值明显较晚，在AIF和半影中(所有p<0.001)。在整个队列中，我们发现年龄与AIF的推注峰值位置显著相关(ρ=0.334;p<0.001)。在中风患者中，年龄也与AIF的峰值位置相关(ρ=0.305；p<0.001)，和半影(ρ=0.246，p<0.001)。然而,在所有年龄范围内都注意到AIF和半影峰位置的很大范围.
结论：这项研究揭示了健康组织和缺血组织中对比剂推注的强烈年龄依赖性。这种可变性使得采样方案不均匀，有人建议减少辐射剂量，有问题,因为它们可能并不总是在所有情况下都能最佳地捕获推注。
