Assessing variability in non-contrast CT for the evaluation of stroke: The effect of CT image reconstruction conditions on AI-based CAD measurements of ASPECTS value and hypodense volume.
Assessing variability in non-contrast CT for the evaluation of stroke: The effect of CT image reconstruction conditions on AI-based CAD measurements of ASPECTS value and hypodense volume.
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评估用于评估中风的非对比 CT 的变异性：CT 图像重建条件对基于 AI 的 ASPECTS 值和低密度体积的 CAD 测量的影响。
DOI：
10.1117/12.3006582
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
McNitt-Gray,MichaelF
中科院分区：
文献类型：
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作者：
Welland,SpencerH;Kim,GraceHyunJ;Yadav,Anil;Hoffman,JohnM;Hsu,William;Brown,MatthewS;Tavakkol,Elham;Nael,Kambiz;McNitt-Gray,MichaelF
目的：为了排除脑出血的可能性，非对比CT （NCCT）扫描可用于对疑似脑卒中患者的早期评估。最近，人工智能工具已经开发出来，通过自动测量阿尔伯塔卒中项目早期CT评分（ASPECTS）来帮助确定再灌注治疗的资格，这是一个10分制，bbb70或≤7是功能结果预测变化的阈值，症状性出血和低密度容积的可能性更高。本研究旨在探讨CT重建核和层厚对面和低密度体积的影响。方法对我院87例脑卒中CT成像患者的NCCT系列图像数据进行3个核（H40s -平滑、H40s-中等、h70h -尖锐）、2个层厚（1.5mm和5mm）重构，建立参考条件（H40s/5mm）和5个非参考条件。使用Brainomix e-Stroke软件（Brainomix, Oxford, England）对每位患者的每次重建进行分析，得出ASPECTS值并测量总低密度体积（mL）。结果87例参考条件下，74例（失败13例）返回了ASPECTS值。59例非参考条件下的指标与参考条件下相比发生了变化，其中7例高于或低于3例非参考条件下的临床阈值7。采用方差分析比较不同方案的差异，方差分析后采用Dunnett事后检验，以p < 0.05为显著性水平。果仁对其无显著影响（p = 0.91），切片厚度对其无显著影响（p < 0.01），三者间无显著交互作用（p = 0.91）。事后测试表明参考条件和任何非参考条件中估计的方面之间没有显着差异。果仁和切片厚度对低密度体积有显著影响（p < 0.01），但三者间无显著交互作用（p = 0.79）。事后检验显示，H10s/1.5mm、H40s/1.5mm、H70h/5mm低密度体积测量值差异有统计学意义（p = 0.03）。H10s/5mm条件下的低密度体积无显著差异（p = 0.96）。结论重建核和切片厚度对自动化方面和低密度体积测量有显著影响。
PurposeTo rule out hemorrhage, non-contrast CT (NCCT) scans are used for early evaluation of patients with suspected stroke. Recently, artificial intelligence tools have been developed to assist with determining eligibility for reperfusion therapies by automating measurement of the Alberta Stroke Program Early CT Score (ASPECTS), a 10-point scale with > 7 or ≤ 7 being a threshold for change in functional outcome prediction and higher chance of symptomatic hemorrhage, and hypodense volume. The purpose of this work was to investigate the effects of CT reconstruction kernel and slice thickness on ASPECTS and hypodense volume.MethodsThe NCCT series image data of 87 patients imaged with a CT stroke protocol at our institution were reconstructed with 3 kernels (H10s-smooth, H40s-medium, H70h-sharp) and 2 slice thicknesses (1.5mm and 5mm) to create a reference condition (H40s/5mm) and 5 non-reference conditions. Each reconstruction for each patient was analyzed with the Brainomix e-Stroke software (Brainomix, Oxford, England) which yields an ASPECTS value and measure of total hypodense volume (mL).ResultsAn ASPECTS value was returned for 74 of 87 cases in the reference condition (13 failures). ASPECTS in non-reference conditions changed from that measured in the reference condition for 59 cases, 7 of which changed above or below the clinical threshold of 7 for 3 non-reference conditions. ANOVA tests were performed to compare the differences in protocols, Dunnett’s post-hoc tests were performed after ANOVA, and a significance level of p < 0.05 was defined. There was no significant effect of kernel (p = 0.91), a significant effect of slice thickness (p < 0.01) and no significant interaction between these factors (p = 0.91). Post-hoc tests indicated no significant difference between ASPECTS estimated in the reference and any non-reference conditions. There was a significant effect of kernel (p < 0.01) and slice thickness (p < 0.01) on hypodense volume, however there was no significant interaction between these factors (p = 0.79). Post-hoc tests indicated significantly different hypodense volume measurements for H10s/1.5mm (p = 0.03), H40s/1.5mm (p < 0.01), H70h/5mm (p < 0.01). No significant difference was found in hypodense volume measured in the H10s/5mm condition (p = 0.96).ConclusionAutomated ASPECTS and hypodense volume measurements can be significantly impacted by reconstruction kernel and slice thickness.