Werncke T, Albrecht T, Wolf K-J, Meyer B C
Klinik und Hochschulambulanz für Radiologie und Nuklearmedizin, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin.
Rofo. 2010 Aug;182(8):682-9. doi: 10.1055/s-0029-1245268. Epub 2010 Mar 2.
To evaluate the accuracy of dual energy (DE)-based plaque removal in a vessel phantom.
Acrylic vessel phantoms of different diameters (3, 5, 8 mm), degrees of stenoses (25 - 100%) and plaque densities (300 - 750 HU) were filled with contrast-enhanced blood (150 - 450 HU). Dual source CT was used for simultaneous image acquisition at 80 and 140 kV. Beside a DE-based plaque-subtracted dataset (DE-PS), a virtual 120 kV non-plaque subtracted dataset (N-PS) was generated. Agreement between the known and measured luminal diameter in both datasets was determined using Lin's concordance correlation coefficient (kappaLin).
A total of 8260 measurements were taken. The correlation of measured diameter in DE-PS images was excellent (kappaLin = 0.83 - 0.96) for 5 - 8 mm vessel phantoms with high luminal enhancement (300 - 450 HU) and plaque density (500 - 750 HU), moderate (kappaLin = 0.6 - 0.67) for 5 mm vessels with lower luminal enhancement and plaque density and poor (kappaLin = 0.10 - 0.64) in the 3 mm vessels. The correlation of N-PS-based stenosis quantification was excellent (kappaLin = 0.86 - 0.99) for 5 - 8 mm vessel phantoms if the contrast between lumen and plaque was above 100 HU. The correlation decreased in 3 mm vessels (kappaLin = 0.45 - 0.93), while the lowest correlation was observed for the lowest contrast between plaque and vessel lumen.
Automatic DE-based plaque removal is highly effective for heavily calcified plaques and high luminal enhancement in larger diameter vessels > or = 5 mm). However, accuracy is limited for low density calcified plaque, lower luminal enhancement and smaller caliber vessels mainly due to poor specificity.
评估基于双能量（DE）的血管模型中斑块去除的准确性。
用不同直径（3、5、8毫米）、狭窄程度（25%-100%）和斑块密度（300-750HU）的丙烯酸血管模型填充对比增强血液（150-450HU）。采用双源CT在80kV和140kV下同时进行图像采集。除了基于双能量的斑块减除数据集（DE-PS）外，还生成了虚拟120kV非斑块减除数据集（N-PS）。使用林氏一致性相关系数（kappaLin）确定两个数据集中已知管腔直径与测量管腔直径之间的一致性。
共进行了8260次测量。对于管腔强化较高（300-450HU）且斑块密度较高（500-750HU）的5-8毫米血管模型，DE-PS图像中测量直径的相关性极佳（kappaLin = 0.83-0.96）；对于管腔强化和斑块密度较低的5毫米血管，相关性中等（kappaLin = 0.6-0.67）；对于3毫米血管，相关性较差（kappaLin = 0.10-0.64）。如果管腔与斑块之间的对比度高于100HU，基于N-PS的狭窄定量对于5-8毫米血管模型的相关性极佳（kappaLin = 0.86-0.99）。在3毫米血管中相关性降低（kappaLin = 0.45-0.93），而在斑块与血管腔之间对比度最低时观察到的相关性最低。
基于双能量的自动斑块去除对于大直径血管（≥5毫米）中重度钙化斑块和高管腔强化非常有效。然而，对于低密度钙化斑块、较低管腔强化和较小口径血管，准确性有限，主要是由于特异性较差。
