Woodcock R J, Goldstein J H, Kallmes D F, Cloft H J, Phillips C D
Department of Radiology, University of Virginia Charlottesville 22908, USA.
AJNR Am J Neuroradiol. 1999 Mar;20(3):495-9.
Calcification in the coronary arteries has been correlated with significant vessel stenosis. The predictive value of calcification within the carotid siphon has not been characterized; however, stenosis in the carotid siphon is potentially important in determining management of patients with ipsilateral carotid bifurcation stenosis. The purpose of this study was to determine optimal parameters for assessing carotid siphon calcification on head CT scans and to compare the CT findings with angiographic results.
We performed a retrospective review of patients referred for diagnostic carotid arteriography. Those patients who also had undergone a head CT study at our institution were selected. The CT scans and angiograms of 64 patients (128 vessels) were reviewed. Carotid siphon calcification on CT scans was characterized on brain and bone windows as mild, moderate, or severe. Comparison was then made with angiographic findings.
The sensitivity and specificity of CT for depicting greater than 50% angiographic stenosis in the carotid siphon were 86% and 98%, respectively, for bone windows and 100% and 0%, respectively, for brain windows. The positive predictive value (PPV) for a stenosis of greater than 50% as evidenced by severe calcification was 86% on bone windows and 11% on brain windows. The PPV for mild and moderate calcification on bone windows was 2.5% and 0%, respectively.
Severe CT calcification in the carotid siphon as characterized on bone windows correlates with a carotid siphon stenosis of greater than 50% as determined angiographically. Therefore, the identification of severe calcification offers a potential noninvasive method for identifying stenosis of the carotid siphon. This information may be essential in determining management and prognosis for patients with carotid bifurcation stenosis.
冠状动脉钙化与显著的血管狭窄相关。颈动脉虹吸部钙化的预测价值尚未明确；然而，颈动脉虹吸部狭窄在同侧颈动脉分叉狭窄患者的治疗决策中可能具有重要意义。本研究的目的是确定在头部CT扫描上评估颈动脉虹吸部钙化的最佳参数，并将CT结果与血管造影结果进行比较。
我们对因诊断性颈动脉血管造影而转诊的患者进行了回顾性研究。选择在我们机构同时接受过头部CT检查的患者。对64例患者（128条血管）的CT扫描和血管造影进行了回顾。CT扫描上颈动脉虹吸部钙化在脑窗和骨窗上分为轻度、中度或重度。然后与血管造影结果进行比较。
对于颈动脉虹吸部血管造影狭窄大于50%的情况，骨窗CT的敏感性和特异性分别为86%和98%，脑窗CT的敏感性和特异性分别为100%和0%。重度钙化所证实的大于50%狭窄的阳性预测值（PPV）在骨窗上为86%，在脑窗上为11%。骨窗上轻度和中度钙化的PPV分别为2.5%和0%。
骨窗上表现为重度CT钙化的颈动脉虹吸部与血管造影确定的大于50%的颈动脉虹吸部狭窄相关。因此，识别重度钙化提供了一种潜在的非侵入性方法来识别颈动脉虹吸部狭窄。这些信息对于确定颈动脉分叉狭窄患者的治疗和预后可能至关重要。
