Sherif C, Bavinzski G, Dorfer C, Kanz F, Schuster E, Plenk H
Department of Neurosurgery, Medical University Vienna, Vienna, Austria.
AJNR Am J Neuroradiol. 2009 May;30(5):1046-53. doi: 10.3174/ajnr.A1463. Epub 2009 Mar 19.
Computerized methods have been introduced for more objective quantification of angiographic occlusion rate and coil density as parameters of successful embolization. This study aimed 1) to evaluate this new computerized method for angiographic occlusion rating and coil density calculations by comparison with corresponding histometric parameters from retrieved human aneurysms, and 2) to compare the new computerized method with the present standard of subjective angiographic occlusion rating.
From 14 postmortem-retrieved human aneurysms, angiographic occlusion rate was determined by contrast medium attenuation-gradient distinction on digital subtraction angiographs after Guglielmi detachable coil (GDC) embolization. Angiographic coil density was calculated, approximating aneurysms as ellipsoid and coils as cylindric volumes. On surface-stained histologic ground sections of the respective aneurysms, the occluded aneurysm area and coil area were measured. Then, we calculated and compared the histometric occlusion rates and coil densities with the corresponding angiographic parameters by using the Wilcoxon paired signed-rank test and the Spearman rank correlation.
Computerized angiographic occlusion rates (75%-100%) showed good correlation (r = 0.799; P < .01) with histometric occlusion-rates (61%-100%), resulting in no statistically significant differences (P = .2163). With 5.1% (+/-3.8), the mean difference between computerized angiographic occlusion rates and histometry was substantially lower compared with 10.7% (+/-8.7) mean difference between subjective angiographic estimations and histometry. Calculated angiographic coil density (13%-32%) significantly differed from histometric coil density (8%-35%; P < .05).
For recanalized aneurysms, computerized angiographic occlusion rating showed better correspondence with histometry compared with subjective angiographic occlusion rating. Clinical application of this new tool may lead to more objective cutoff values for re-embolization indications. The value of coil density calculations seems limited by the approximation of the aneurysms as ellipsoid volumes.
已引入计算机化方法，以更客观地量化血管造影闭塞率和弹簧圈密度，作为成功栓塞的参数。本研究旨在：1）通过与取自人类动脉瘤的相应组织计量学参数进行比较，评估这种用于血管造影闭塞分级和弹簧圈密度计算的新计算机化方法；2）将这种新计算机化方法与当前主观血管造影闭塞分级标准进行比较。
从14个尸检获得的人类动脉瘤中，在使用 Guglielmi 可脱卸弹簧圈（GDC）栓塞后，通过数字减影血管造影上的造影剂衰减梯度区分来确定血管造影闭塞率。计算血管造影弹簧圈密度，将动脉瘤近似为椭球体，将弹簧圈近似为圆柱体体积。在各个动脉瘤的表面染色组织学切片上，测量闭塞的动脉瘤面积和弹簧圈面积。然后，我们使用 Wilcoxon 配对符号秩检验和 Spearman 秩相关分析，计算并比较组织计量学闭塞率和弹簧圈密度与相应的血管造影参数。
计算机化血管造影闭塞率（75%-100%）与组织计量学闭塞率（61%-100%）显示出良好的相关性（r = 0.799；P <.01），结果无统计学显著差异（P =.2163）。计算机化血管造影闭塞率与组织计量学之间的平均差异为5.1%（±3.8%），与主观血管造影估计与组织计量学之间10.7%（±8.7%）的平均差异相比显著更低。计算得出的血管造影弹簧圈密度（13%-32%）与组织计量学弹簧圈密度（8%-35%）有显著差异（P <.05）。
对于再通的动脉瘤，与主观血管造影闭塞分级相比，计算机化血管造影闭塞分级与组织计量学显示出更好的一致性。这种新工具的临床应用可能会为再栓塞指征带来更客观的截断值。将动脉瘤近似为椭球体体积似乎限制了弹簧圈密度计算的价值。
