Schwamm Lee H, Rosenthal Eric S, Swap Clifford J, Rosand Jonathan, Rordorf Guy, Buonanno Ferdinando S, Vangel Mark G, Koroshetz Walter J, Lev Michael H
Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.
AJNR Am J Neuroradiol. 2005 Aug;26(7):1798-803.
Symptomatic hemorrhagic transformation (HT) is a significant complication of intravenous and catheter-based reperfusion. We hypothesized that the degree of vascular insufficiency, reflected as hypoattenuation on initial CT angiography (CTA) axial source images, is predictive of HT risk in stroke patients receiving intra-arterial reperfusion therapy.
We examined initial CTA source images and follow-up CT scans in 32 consecutive patients. Regions of interest were semiautomatically segmented and reviewed. Mean intensity was determined in the region of maximal hypoattenuation and in normal contralateral tissue, and the arithmetic difference (deltaHU) calculated. Receiver operator characteristic (ROC) curves and cross-validation were used to identify threshold deltaHU values.
Thirteen patients had HT on follow-up CT (seven with parenchymal hematoma, six with hemorrhagic infarction). Patients with and those without HT did not differ in age, blood glucose level, lesion volume, or time to treatment or recanalization, though the former had a greater mean deltaHU (9.0 vs 6.3, P = .006). The ROC threshold at deltaHU > or = 8.1 was 69% sensitive and 90% specific for patients who developed HT (odds ratio = 19.1; 95% confidence interval: 2.9, 125; P = .002) and was predictive of poor clinical outcome (modified Rankin scale score > 2, P = .03). Neither HT in general nor parenchymal hematoma subtype was associated with poor outcome.
The degree of hypoattenuation on initial CTA source images is a risk factor for HT and poor clinical outcome after intra-arterial reperfusion therapy. Prospective validation of this relationship in large populations may permit feasible real-time risk stratification.
症状性出血转化（HT）是静脉和基于导管的再灌注治疗的一种重要并发症。我们假设，在初次CT血管造影（CTA）轴位源图像上表现为低密度的血管供血不足程度，可预测接受动脉内再灌注治疗的卒中患者发生HT的风险。
我们检查了32例连续患者的初次CTA源图像和后续CT扫描。感兴趣区域进行半自动分割并复查。在最大低密度区域和对侧正常组织中确定平均强度，并计算算术差值（deltaHU）。采用受试者操作特征（ROC）曲线和交叉验证来确定阈值deltaHU值。
13例患者在后续CT上出现HT（7例为实质内血肿，6例为出血性梗死）。发生HT和未发生HT的患者在年龄、血糖水平、病变体积、治疗或再通时间方面无差异，不过前者的平均deltaHU更大（9.0对6.3，P = 0.006）。对于发生HT的患者，deltaHU>或 = 8.1时的ROC阈值敏感性为69%，特异性为90%（优势比 = 19.1；95%置信区间：2.9，125；P = 0.002），并且可预测不良临床结局（改良Rankin量表评分>2，P = 0.03）。总体HT和实质内血肿亚型均与不良结局无关。
初次CTA源图像上的低密度程度是动脉内再灌注治疗后发生HT和不良临床结局的一个危险因素。在大量人群中对这种关系进行前瞻性验证可能有助于实现可行的实时风险分层。
