点征与晕征：双能量 CT 对颅内血肿扩大的定量标志物研究
Spot and Diffuse Signs: Quantitative Markers of Intracranial Hematoma Expansion at Dual-Energy CT.
机构信息
From the Cerebrovascular Research Laboratory, Spaulding Rehabilitation Hospital, 1575 Cambridge St, Boston, MA 02138 (C.O.T.); Departments of Radiology (C.O.T., S.L., D.K., R.H.J.B., L.D.B., J.T., M.L., J.M.R., R.G.) and Emergency Medicine (J.N.G.), Massachusetts General Hospital, Boston, Mass; Departments of Physical Medicine and Rehabilitation (C.O.T.), Radiology (S.L., L.D.B., J.T., M.L., J.M.R., R.G.), and Emergency Medicine (J.N.G.), Harvard Medical School, Boston, Mass; Department of Technical Medicine, University of Twente, Enschede, the Netherlands (D.K., R.H.J.B.); Imaging Associates, Box Hill, Victoria, Australia (B.K.P.); Department of Radiology, Jewish General Hospital and McGill University, Montreal, Canada (R.F.); and Department of Radiology and Imaging Sciences, Emory University, Atlanta, Ga (R.H.).
出版信息
Radiology. 2019 Jan;290(1):179-186. doi: 10.1148/radiol.2018180322. Epub 2018 Oct 30.
Purpose To compare dual-energy CT with iodine quantification to single-energy CT for evaluation of the spot sign for intracranial hematoma expansion. Materials and Methods In this retrospective study, 42 patients (mean age, 66 years ± 15 [standard deviation]; 19 women) were referred for dual-energy CT assessment of intracranial hemorrhage from October 2014 to January 2017. A machine learning approach (naive Bayes classifier) was used to identify iodine markers of extravasation for risk of hematoma expansion. Specificity and sensitivity of these markers were then independently validated in 65 new patients from February 2017 to February 2018. Results Analysis of dual-energy CT images identified two features of iodine extravasation: total iodine concentration within the hematoma (I) and focal iodine concentration in the brightest spot in the hematoma (I) as predictors of expansion. The I2 score derived from these features provided a measure of expansion probability. Optimal classification threshold was an I2 score of 20 (95% confidence interval [CI]: 18, 23), leading to correct identification of 39 of 46 (85%; 95% CI: 71%, 94%) of the hematomas on the training set (sensitivity of 79% [11 of 14; 95% CI: 57%, 100%] and specificity of 88% [28 of 32; 95% CI: 76%, 99%]), and 62 of 70 (89%; 95% CI: 79%, 95%) of the hematomas on the validation set (sensitivity of 71% [10 of 14; 95% CI: 48%, 95%] and specificity of 93% [52 of 56; 95% CI: 86%, 100%]). Sensitivity, specificity, and accuracy of conventional spot sign were, respectively, 57% (eight of 14), 90% (29 of 32), and 80% (37 of 46) on the training set and 57% (eight of 14), 83% (47 of 56), and 75% (53 of 70) on the validation set. Conclusion This study identified two quantitative markers of intracranial hemorrhage expansion at dual-energy CT of the brain. The I2 score derived from these markers highlights the utility of dual-energy CT measurements of iodine content for high sensitivity risk assessment. © RSNA, 2018 Online supplemental material is available for this article.
目的 比较双能 CT 碘量化与单能 CT 用于评估颅内血肿扩大的斑点征。
材料与方法 本回顾性研究纳入了 2014 年 10 月至 2017 年 1 月因颅内出血行双能 CT 评估的 42 例患者（平均年龄，66 岁±15[标准差]；19 例女性）。采用机器学习方法（朴素贝叶斯分类器）识别碘外渗的碘标记物，以评估血肿扩大的风险。2017 年 2 月至 2018 年 2 月，我们对 65 例新患者的双能 CT 图像进行了这些标记物的特异性和敏感性的独立验证。
结果 对双能 CT 图像的分析确定了两种碘外渗特征：血肿内总碘浓度（I）和血肿内最亮部位的局部碘浓度（I）是预测血肿扩大的指标。源于这些特征的 I2 评分提供了一种扩展概率的度量。最佳分类阈值为 I2 评分 20（95%置信区间[CI]：18，23），可正确识别训练集 46 个血肿中的 39 个（85%；95%CI：71%，94%）（敏感性为 79%[14 个中的 11 个；95%CI：57%，100%]和特异性为 88%[32 个中的 28 个；95%CI：76%，99%]），验证集 70 个血肿中的 62 个（89%；95%CI：79%，95%）（敏感性为 71%[14 个中的 10 个；95%CI：48%，95%]和特异性为 93%[56 个中的 52 个；95%CI：86%，100%]）。传统斑点征的敏感性、特异性和准确性分别为训练集上的 57%（14 个中的 8 个）、90%（32 个中的 29 个）和 80%（46 个中的 37 个），验证集上的 57%（14 个中的 8 个）、83%（56 个中的 47 个）和 75%（70 个中的 53 个）。
结论 本研究在脑双能 CT 中发现了两个颅内出血扩展的定量标记物。源于这些标记物的 I2 评分突出了双能 CT 碘含量测量在高灵敏度风险评估中的作用。
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