Matsumoto Hidenari, Watanabe Satoshi, Kyo Eisho, Tsuji Takafumi, Ando Yosuke, Eisenberg Evann, Otaki Yuka, Manabe Osamu, Cadet Sebastien, Slomka Piotr J, Tamarappoo Balaji K, Berman Daniel S, Dey Damini
Department of Imaging (H.M., E.E., Y.O., O.M., S.C., P.J.S., B.K.T., D.S.B.), Heart Institute (B.K.T., D.S.B.), and Biomedical Imaging Research Institute (D.D.), Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA 90048, and Department of Cardiology, Kusatsu Heart Center, Kusatsu, Shiga, Japan (S.W., E.K., T.T., Y.A.).
Radiol Cardiothorac Imaging. 2019 Dec 19;1(5):e190069. doi: 10.1148/ryct.2019190069.
To improve the evaluation of low-attenuation plaque (LAP) by using semiautomated software and to assess whether the use of a proposed automated function (LAP editor) that excludes voxels adjacent to the outer vessel wall improves the relationship between LAP and the presence and size of the lipid-rich component (LRC) verified at intravascular US. At coronary CT angiography, quantification of LAP can improve risk stratification. defined as the area between the vessel and the lumen wall, is prone to partial volume effects from the surrounding pericoronary adipose tissue.
The percentage of LAP (%LAP), defined as the percentage of noncalcified plaque with an attenuation value lower than 30 HU (LAP/total plaque volume) at greater than or equal to 0 mm (%LAP), greater than or equal to 0.1 mm (%LAP), greater than or equal to 0.3 mm (%LAP), greater than or equal to 0.5 mm (%LAP), and greater than or equal to 0.7 mm (%LAP) inward from the vessel wall boundaries, were quantified in 155 plaques in 90 patients who underwent coronary CT angiography before intravascular US. At intravascular US, the LRC was identified by using echo attenuation, and its size was measured by using the attenuation score (summed score/analysis length) based on the attenuation arc (1 = < 90°, 2 = 90° to < 180°, 3 = 180° to < 270°, 4 = 270°-360°) for every 1 mm.
Use of LAP editing improved the ability for discriminating LRC (areas under receiver operating characteristic curve: 0.667 with %LAP, 0.713 with %LAP [ < .001 for comparison with %LAP]), 0.778 with %LAP [ < .001], 0.825 with %LAP [ < .001], 0.802 with %LAP [ = .002]). %LAP had the strongest correlation ( = 0.612, < .001) with LRC size, whereas %LAP resulted in the weakest correlation ( = 0.307; < .001).
Evaluation of LAP at coronary CT angiography can be significantly improved by excluding voxels that are adjacent to the vessel wall boundaries by 0.5 mm.© RSNA, 2019.
使用半自动软件改进对低衰减斑块（LAP）的评估，并评估使用一种提议的自动功能（LAP编辑器）排除与血管外壁相邻的体素是否能改善LAP与血管内超声所证实的富含脂质成分（LRC）的存在及大小之间的关系。在冠状动脉CT血管造影中，LAP的定量分析可改善风险分层。LAP定义为血管与管腔壁之间的区域，易受周围冠状动脉周围脂肪组织的部分容积效应影响。
对90例在血管内超声检查前行冠状动脉CT血管造影的患者的155个斑块，定量分析从血管壁边界向内0毫米（%LAP）、大于或等于0.1毫米（%LAP）、大于或等于0.3毫米（%LAP）、大于或等于0.5毫米（%LAP）和大于或等于0.7毫米（%LAP）处衰减值低于30 HU的非钙化斑块的百分比（%LAP，定义为LAP/总斑块体积）。在血管内超声检查中，通过回声衰减识别LRC，并使用基于每1毫米衰减弧（1 = < 90°，2 = 90°至< 180°，3 = 180°至< 270°，4 = 270° - 360°）的衰减评分（总分/分析长度）测量其大小。
使用LAP编辑提高了区分LRC的能力（受试者操作特征曲线下面积：%LAP为0.667，%LAP为0.713 [与%LAP比较，P <.001]），%LAP为0.778 [P <.001]，%LAP为0.825 [P <.001]，%LAP为0.802 [P =.002]）。%LAP与LRC大小的相关性最强（r = 0.612，P <.001），而%LAP的相关性最弱（r = 0.307；P <.001）。
通过排除与血管壁边界相邻0.5毫米的体素，冠状动脉CT血管造影中LAP的评估可得到显著改善。©RSNA，2019年。
