Effect of CTA Tube Current on Spot Sign Detection and Accuracy for Prediction of Intracerebral Hemorrhage Expansion.
Effect of CTA Tube Current on Spot Sign Detection and Accuracy for Prediction of Intracerebral Hemorrhage Expansion.
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DOI：
10.3174/ajnr.a4810
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发表时间：
2016-10
期刊：
影响因子：
--
通讯作者：
Goldstein JN
中科院分区：
文献类型：
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作者：
Morotti A;Romero JM;Jessel MJ;Brouwers HB;Gupta R;Schwab K;Vashkevich A;Ayres A;Anderson CD;Gurol ME;Viswanathan A;Greenberg SM;Rosand J;Goldstein JN
减小CT管电流是将辐射负荷降到最低的有效策略。然而，管电流也是图像质量的主要决定因素。我们研究了CTA管电流对脑出血扩大的斑点征象检测和诊断性能的影响。我们回顾分析了从2001年1月至2015年4月连续接受CTA检查的连续的原发性脑出血患者的队列。研究人群根据CTA管电流的中位数水平被分为两组：低电流(<；350毫安)和高电流(≥350毫安)。由两个阅读器独立分析CTA首次通过的斑点征存在的读数。通过半自动计算机辅助体积分析评估基线和随访血肿体积。计算斑点征预测血肿扩大的敏感度、特异度、阳性预测值、阴性预测值及准确性。低电流扫描发现至少一个斑点的比例较高(20.8%比14.7%，p=0.034)，但血肿扩大的频率两组相似(18.4%比16.2%，p=0.434)。敏感度、阳性预测值和阴性预测值在两组间无显著差异。相反，大电流扫描显示出更高的特异度(91%比84%，p=0.015)和总体准确性(84%比77%，p=0.038)。管内电流水平越高，CTA对斑点征预测血肿扩大的诊断准确性越高。这些发现可能会对未来临床试验中使用CTA斑点征来预测血肿扩大的研究有所启示。
Reduction of CT tube current is an effective strategy to minimize radiation load. However, tube current is also a major determinant of image quality. We investigated the impact of CTA tube current on spot sign detection and diagnostic performance for intracerebral hemorrhage expansion. We retrospectively analyzed a prospectively collected cohort of consecutive patients with primary intracerebral hemorrhage from January 2001 to April 2015 who underwent CTA.The study population was divided in two groups according to the median CTA tube current level: low current (<350 milliampere) versus high current (≥350 milliampere).CTA first pass readings for spot sign presence were independently analyzed by two readers. Baseline and follow-up hematoma volumes were assessed by semi-automated computer-assisted volumetric analysis. Sensitivity, specificity, positive and negative predictive values and accuracy of spot sign in predicting hematoma expansion were calculated. 709 subjects were included (288 and 421 in the low and high current group respectively).A higher proportion of low current scans identified at least one spot sign (20.8% versus 14.7%, p=0.034) but hematoma expansion frequency was similar in the two groups (18.4% versus 16.2%, p=0.434). Sensitivity, positive and negative predictive values were not significantly different between the two groups. Conversely, high current scans showed superior specificity (91% versus 84%, p=0.015) and overall accuracy (84% versus 77%, p=0.038). CTA obtained at high levels of tube current showed better diagnostic accuracy for prediction of hematoma expansion using spot sign. These findings may have implications for future studies using the CTA spot sign to predict hematoma expansion for clinical trials.