Neuroradiology Division, Diagnostic Centre for Imaging and Functional Medicine, Lund University, Skåne University Hospital, Malmö, 205 02, Sweden.
BMC Neurol. 2012 Sep 26;12:109. doi: 10.1186/1471-2377-12-109.
Swirl sign has previously been described in epidural hematomas as areas of low attenuation, radiolucency or irregular density. The aims of this study were to describe swirl sign in ICH, study its prevalence, study the reliability of the subjective evaluation on computed tomography (CT), and to explore its prognostic value.
CTs of 203 patients with ICH were retrospectively evaluated for the presence of swirl sign. Association between swirl sign and different clinical and radiological variables was studied.
Inter- and intraobserver agreement with regard to the occurrence of swirl sign was substantial (К 0.80) and almost perfect (К 0.87), respectively. Swirl sign was found in 30% of the study population. 61% of patients with swirl sign were dead at one month compared with 21% of those with no swirl sign (p < 0.001). Only 19% of patients with swirl sign exhibited favorable outcome at three months compared with 53% of those with no swirl sign (p < 0.001). Patients with swirl sign exhibited larger ICHs with average ICH-volume 52 ± 50 ml (median 42 ml) compared with 15 ± 25 ml (median 6) in patients whose CT did not show swirl sign (p < 0.001). Swirl sign was independent predictor of death at one month (p = 0.03; adjusted odds ratio 2.6, 95% CI 1.1 - 6), and functional outcome at three months (p = 0.045; adjusted odds ratio 2.6, 95% CI 1.02 - 6.5).
As swirl sign showed to be an ominous sign, we recommend identification of this sign in cases of ICHs.
漩涡征先前在硬膜外血肿中被描述为低衰减、透亮或不规则密度区域。本研究旨在描述 ICH 中的漩涡征，研究其发生率，研究 CT 上主观评估的可靠性，并探讨其预后价值。
回顾性评估 203 例 ICH 患者的 CT 以确定是否存在漩涡征。研究了漩涡征与不同临床和影像学变量之间的关系。
观察者间和观察者内对漩涡征发生的一致性分别为中等（Kappa 0.80）和近乎完美（Kappa 0.87）。研究人群中有 30%的患者存在漩涡征。有漩涡征的患者中有 61%在一个月时死亡，而没有漩涡征的患者中有 21%（p < 0.001）。在三个月时，有漩涡征的患者中仅有 19%表现出良好的预后，而没有漩涡征的患者中有 53%（p < 0.001）。存在漩涡征的患者 ICH 较大，平均 ICH 体积为 52 ± 50ml（中位数为 42ml），而在 CT 未显示漩涡征的患者中为 15 ± 25ml（中位数为 6ml）（p < 0.001）。漩涡征是一个月时死亡的独立预测因素（p = 0.03；调整后的优势比为 2.6，95%CI 为 1.1-6），也是三个月时功能预后的独立预测因素（p = 0.045；调整后的优势比为 2.6，95%CI 为 1.02-6.5）。
由于漩涡征显示出不祥之兆，我们建议在 ICH 病例中识别出这种征象。
