PDF(Pubmed)
Abstract：
Histogram indices (HIs) and texture features (TFs) are considered to play an important role in future oncologic PET-imaging and it is unknown how these indices are affected by changes of tracer doses. A randomized undersampling of PET list mode data enables a simulation of tracer dose reduction. We performed a phantom study to compare HIs/TFs of simulated and measured tracer dose reductions and evaluated changes of HIs/TFs in the liver of patients with PETs from simulated reduced tracer doses. Overall, 42 HIs/TFs were evaluated in a NEMA phantom at measured and simulated doses (stepwise reduction of [18 F] from 100% to 25% of the measured dose). [18 F]-FDG-PET datasets of 15 patients were simulated from 3.0 down to 0.5 MBq/kgBW in intervals of 0.25 MBq/kgBW. HIs/TFs were calculated from two VOIs placed in physiological tissue of the right and left liver lobe and linear correlations and coefficients of variation analysis were performed.
All 42 TFs did not differ significantly in measured and simulated doses (p > 0.05). Also, 40 TFs showed the same behaviour over dose reduction regarding differences in the same group (measured or simulated), and for 26 TFs a linear behaviour over dose reduction for measured and simulated doses could be validated. Out of these, 13 TFs could be identified, which showed a linear change in TF value in both the NEMA phantom and patient data and therefore should maintain the same informative value when transferred in a dose reduction setting. Out of this Homogeneity 2, Entropy and Zone size non-uniformity are of special interest because they have been described as preferentially considerable for tumour heterogeneity characterization.
We could show that there was no significant difference of measured and simulated HIs/TFs in the phantom study and most TFs reveal a linear behaviour over dose reduction, when tested in homogeneous tissue. This indicates that texture analysis in PET might be robust to dose modulations.
All 42 TFs did not differ significantly in measured and simulated doses (p > 0.05). Also, 40 TFs showed the same behaviour over dose reduction regarding differences in the same group (measured or simulated), and for 26 TFs a linear behaviour over dose reduction for measured and simulated doses could be validated. Out of these, 13 TFs could be identified, which showed a linear change in TF value in both the NEMA phantom and patient data and therefore should maintain the same informative value when transferred in a dose reduction setting. Out of this Homogeneity 2, Entropy and Zone size non-uniformity are of special interest because they have been described as preferentially considerable for tumour heterogeneity characterization.
We could show that there was no significant difference of measured and simulated HIs/TFs in the phantom study and most TFs reveal a linear behaviour over dose reduction, when tested in homogeneous tissue. This indicates that texture analysis in PET might be robust to dose modulations.
摘要：
背景：直方图指数（HI）和纹理特征（TF）被认为在未来的肿瘤PET成像中起着重要作用，并且不知道这些指数如何受到示踪剂剂量变化的影响。PET列表模式数据的随机欠采样使得能够模拟示踪剂剂量减少。我们进行了一项体模研究，以比较模拟和测量示踪剂剂量减少的HIs/TF，并评估了模拟示踪剂剂量减少的PET患者肝脏中HIs/TF的变化。总的来说,在NEMA体模中以测量剂量和模拟剂量([18F]从测量剂量的100%逐步降低至25%)评估42个HI/TF。以0.25MBq/kgBW的间隔从3.0降至0.5MBq/kgBW模拟15名患者的[18F]-FDG-PET数据集。从放置在左右肝叶的生理组织中的两个VOI计算HIs/TF，并进行线性相关性和变异系数分析。
结果：所有42种TFs在测量剂量和模拟剂量中没有显着差异（p>0.05）。此外，关于同一组（测量或模拟）的差异，40个TFs在剂量减少方面表现出相同的行为，对于26个TFs，可以验证测量和模拟剂量的剂量减少的线性行为。在这些中，可以识别13个TFs，在NEMA体模和患者数据中均显示TF值的线性变化，因此在剂量减少设置下转移时应保持相同的信息值。在该均匀性2中,熵和区域尺寸不均匀性特别令人感兴趣,因为它们已经被描述为对于肿瘤异质性表征而言优先相当大。
结论：我们可以证明，在体模研究中，测量和模拟的HIs/TFs没有显着差异，并且大多数TFs显示出剂量减少的线性行为，在均质组织中测试时。这表明PET中的纹理分析对于剂量调制可能是稳健的。
结果：所有42种TFs在测量剂量和模拟剂量中没有显着差异（p>0.05）。此外，关于同一组（测量或模拟）的差异，40个TFs在剂量减少方面表现出相同的行为，对于26个TFs，可以验证测量和模拟剂量的剂量减少的线性行为。在这些中，可以识别13个TFs，在NEMA体模和患者数据中均显示TF值的线性变化，因此在剂量减少设置下转移时应保持相同的信息值。在该均匀性2中,熵和区域尺寸不均匀性特别令人感兴趣,因为它们已经被描述为对于肿瘤异质性表征而言优先相当大。
结论：我们可以证明，在体模研究中，测量和模拟的HIs/TFs没有显着差异，并且大多数TFs显示出剂量减少的线性行为，在均质组织中测试时。这表明PET中的纹理分析对于剂量调制可能是稳健的。
