Bartlett E S, Symons S P, Fox A J
Department of Neuroradiology, Northwestern University, Chicago, Ill, USA.
AJNR Am J Neuroradiol. 2006 Mar;27(3):638-42.
Carotid stenosis quantification traditionally uses measurements of narrowest stenosis diameter. The stenotic carotid lumen, however, is often irregularly shaped. New PACS workstation tools allow for more precise calculation of carotid geometry. We compare the narrowest stenosis diameter with 2D area stenosis measurements, with the hypothesis that the narrowest diameter is a good predictor of the more precise area measurement.
Two neuroradiologists evaluated 178 stenosed carotids in a blinded protocol. Carotid artery bulb stenosis was identified on axial CT angiography and measured in millimeters at its narrowest diameter. An AGFA Impax 4.5 Volume Tool (VT) using Hounsfield units was used to estimate the cross-sectional area of the contrast luminogram. Pearson correlation coefficients were calculated between the millimeter stenosis and the VT area, as well as between the VT area and the calculated area (radius based on narrowest diameter). Regression analysis was performed with the VT area and narrowest diameter datasets.
Excellent interobserver correlation (correlation coefficients, 0.71-0.85; 2-tailed significance = .01) permitted averaging of measurement data. There is excellent correlation between the VT area and the narrowest diameter (correlation coefficient, 0.88; n = 176). The VT area was generally greater than the calculated area by an average of 2.77 mm2. There was excellent correlation between the VT area and the calculated area (correlation coefficient, 0.87; n = 176). Regression analysis shows the ability of the diameter measurements to predict corresponding area stenosis.
Although some carotid stenoses are irregularly shaped and noncircular, measurement of the narrowest stenosis is a reasonably reliable predictor of the cross-sectional area.
传统上，颈动脉狭窄的量化采用最窄狭窄直径的测量方法。然而，狭窄的颈动脉管腔通常形状不规则。新型PACS工作站工具可更精确地计算颈动脉几何形状。我们将最窄狭窄直径与二维面积狭窄测量值进行比较，假设最窄直径是更精确面积测量值的良好预测指标。
两名神经放射科医生按照盲法方案评估了178例狭窄的颈动脉。在轴向CT血管造影上识别颈动脉球部狭窄，并测量其最窄直径（以毫米为单位）。使用基于亨氏单位的AGFA Impax 4.5容积工具（VT）来估计对比剂造影剂的横截面积。计算毫米级狭窄与VT面积之间、VT面积与计算面积（基于最窄直径的半径）之间的Pearson相关系数。对VT面积和最窄直径数据集进行回归分析。
观察者间相关性极佳（相关系数为0.71 - 0.85；双侧显著性 = 0.01），允许对测量数据进行平均。VT面积与最窄直径之间存在极佳的相关性（相关系数为0.88；n = 176）。VT面积通常比计算面积大，平均大2.77平方毫米。VT面积与计算面积之间存在极佳的相关性（相关系数为0.87；n = 176）。回归分析显示了直径测量预测相应面积狭窄的能力。
尽管一些颈动脉狭窄形状不规则且非圆形，但最窄狭窄的测量是横截面积的合理可靠预测指标。
