Topcuoglu Mehmet A, Arsava Ethem Murat, Akpinar Erhan
Department of Neurology and Neurological Intensive Care Unit, Hacettepe University Hospitals, Ankara, Turkey.
Department of Neurology and Neurological Intensive Care Unit, Hacettepe University Hospitals, Ankara, Turkey.
J Stroke Cerebrovasc Dis. 2015 Jun;24(6):1363-72. doi: 10.1016/j.jstrokecerebrovasdis.2015.02.017. Epub 2015 Mar 21.
Clinical and computer tomography angiography (CTA) correlates of hyperdense middle cerebral artery sign (HMCAS) and dot sign were revisited in patients treated for acute MCA stroke. Temporal evolution of these signs over 24 hours was assessed quantitatively by density (Hounsfield unit [HU]) measurements.
Maximum pixel-sized HUs throughout proximal MCA and its insular fissure branches were determined in 131 patients with acute MCA stroke treated by intravenous thrombolysis and/or interventional thrombolysis/thrombectomy; 14 patients treated for vertebrobasilar stroke (VBS) and 42 nonstroke control subjects. Utility of visually determined HMCAS and dot sign, absolute HU of proximal and distal MCA, side-to-side HU ratio and difference, and hyperdense MCA burden score for the prediction of early dramatic recovery (EDR) and third-month favorable prognosis were evaluated. The clinical value of the changes in vessel hyperdensity over 24 hours was identified in subjects who received intravenous thrombolysis (99 MCA stoke and 11 VBS). A multivariate model with adjustment for age, baseline stroke severity (National Institutes of Health Stroke Scale [NIHSS]), and CTA-based modified clot burden score (mCBS) was used to determine independent predictors of short- and long-term clinical outcome.
The presence of HMCAS and dot sign, their density indices (maximum HU, ipsilateral-to-contralateral HU ratio, and difference), and changes in quantitative attenuation over 24 hours were not significantly associated with EDR and favorable third-month outcome in the multiple regression models, whereas NIHSS and mCBS were found to be significant independent "negative predictors" of both EDR and favorable prognosis, while age was a strong "negative indicator" only for 3-month good outcome. Average HU decrease over the first day was 5.7 HU in HMCAS (+) and 2.9 HU in dot sign (+) arteries. The densities of thrombi in MCA and insular branches were not different in subjects with and without cardioembolism.
CTA provides dependable (high sensitivity and specificity) information regarding clot size and location, whereas hyperdense artery signs have low sensitivity and just acceptable specificity levels in this regard. However, the prognostic and diagnostic information generated by the presence of hyperdense artery signs and temporal change in attenuation can be useful in acute stroke settings where CTA is not readily available. Quantitative measures, rather than qualitative evaluation have a higher yield in determination of temporal change of the hyperdensity signs and its possible clinical correlates.
对接受急性大脑中动脉（MCA）卒中治疗的患者，重新探讨了大脑中动脉高密度征（HMCAS）和斑点征的临床及计算机断层血管造影（CTA）相关性。通过密度（亨氏单位[HU]）测量对这些征象在24小时内的时间演变进行了定量评估。
在131例接受静脉溶栓和/或介入溶栓/取栓治疗的急性MCA卒中患者、14例接受椎基底动脉卒中（VBS）治疗的患者以及42例非卒中对照受试者中，测定整个近端MCA及其岛叶裂分支的最大像素大小HU。评估视觉判定的HMCAS和斑点征、近端和远端MCA的绝对HU、双侧HU比值和差值以及MCA高密度负荷评分对早期显著恢复（EDR）和第三个月良好预后的预测效用。在接受静脉溶栓的受试者（99例MCA卒中患者和11例VBS患者）中确定血管高密度在24小时内变化的临床价值。使用一个对年龄、基线卒中严重程度（美国国立卫生研究院卒中量表[NIHSS]）和基于CTA的改良血栓负荷评分（mCBS）进行校正的多变量模型，以确定短期和长期临床结局的独立预测因素。
在多元回归模型中，HMCAS和斑点征的存在、它们的密度指标（最大HU、同侧与对侧HU比值和差值）以及24小时内定量衰减的变化与EDR和第三个月良好结局均无显著相关性，而NIHSS和mCBS被发现是EDR和良好预后的显著独立“负性预测因素”，而年龄仅是3个月良好结局的强“负性指标”。HMCAS（+）动脉第一天的平均HU下降为5.7 HU，斑点征（+）动脉为2.9 HU。有无心源性栓塞的受试者中，MCA和岛叶分支血栓的密度无差异。
CTA可提供关于血栓大小和位置的可靠（高敏感性和特异性）信息，而在这方面，动脉高密度征的敏感性较低，特异性仅处于可接受水平。然而，动脉高密度征的存在及衰减的时间变化所产生的预后和诊断信息，在无法轻易获得CTA的急性卒中情况下可能有用。在确定高密度征的时间变化及其可能的临床相关性方面，定量测量而非定性评估的产出更高。
