Farb R I, Forghani R, Lee S K, Mikulis D J, Agid R
Department of Medical Imaging, Division of Neuroradiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
AJNR Am J Neuroradiol. 2007 Sep;28(8):1489-93. doi: 10.3174/ajnr.A0621.
Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This sign is introduced, and its performance as a test for the presence of this disease is evaluated.
The transverse sinuses on T1-weighted sagittal imaging of 15 patients with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a consensus result for each patient was determined by unanimity or majority rule.
Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers for the interpretation of the VDS (multirater kappa = 0.82). The overall sensitivity of the VDS for the diagnosis of intracranial hypotension was 94%. Specificity was also 94%.
The VDS appears to be an accurate test for the presence or absence of IH and may be helpful in the evaluation of these patients.
颅内低压（IH）患者在常规T1加权矢状位成像上显示颅内静脉扩张，横窦轮廓有特征性改变。在颅内低压中，优势横窦中部的下缘呈现扩张的凸面外观；我们将此称为静脉扩张征（VDS）。这与该节段的正常外观不同，正常情况下其下缘通常略呈凹形或直线形。本文介绍了该征象，并评估了其作为该病存在与否的检测指标的性能。
3名阅片者以盲法独立评估15例颅内低压患者和15例对照患者的T1加权矢状位成像上的横窦，判断是否存在静脉扩张征。每位阅片者确定每位患者是否存在静脉扩张征，每位患者的一致结果通过一致同意或多数决规则确定。
利用静脉扩张征，阅片者正确识别出93%（15例中的14例）的颅内低压患者，对照患者的识别率同样为93%（15例中的14例）。阅片者对静脉扩张征的解读一致性很高（多评分者kappa值=0.82）。静脉扩张征诊断颅内低压的总体敏感性为94%，特异性也为94%。
静脉扩张征似乎是判断颅内低压是否存在的准确检测指标，可能有助于对这些患者的评估。
