Department of Medicine, Cardiovascular Imaging Center, Cardiac and Vascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
JACC Cardiovasc Imaging. 2011 Nov;4(11):1149-57. doi: 10.1016/j.jcmg.2011.09.006.
Coronary computed tomography angiography (CTA) assessment of calcified or complex coronary lesions is frequently challenging. Transluminal attenuation gradient (TAG), defined as the linear regression coefficient between luminal attenuation and axial distance, has a potential to evaluate the degree of coronary stenosis. We examined the value of TAG in determining the stenosis severity on 64-slice coronary CTA. The value of TAG of 370 major coronary arteries was measured from 7,263 intervals of 5-mm length. Compared with coronary CTA and invasive coronary angiography, TAG decreased consistently and significantly with maximum stenosis severity on a per-vessel basis, from -1.91 ± 4.25 Hounsfield units/10 mm for diameter stenosis of 0% to 49% to -13.37 ± 9.81 Hounsfield units/10 mm for diameter stenosis of 100% (p < 0.0001). Adding TAG to the interpretation of coronary CTA improved diagnostic accuracy (p = 0.001), especially in vessels with calcified lesions (N = 127; net reclassification improvement 0.095; p = 0.046). TAG appears to be able to contribute to improved classification of coronary artery stenosis severity in coronary CTA, especially in severely calcified lesions.
冠状动脉计算机断层血管造影（CTA）评估钙化或复杂的冠状动脉病变常常具有挑战性。管腔衰减梯度（TAG）定义为管腔衰减与轴向距离之间的线性回归系数，具有评估冠状动脉狭窄程度的潜力。我们检查了 TAG 在确定 64 层冠状动脉 CTA 狭窄严重程度方面的价值。从 7263 个 5mm 长度的间隔中测量了 370 条主要冠状动脉的 TAG 值。与冠状动脉 CTA 和有创性冠状动脉造影相比，TAG 值从直径狭窄 0%至 49%的 -1.91 ± 4.25 亨氏单位/10mm 到直径狭窄 100%的 -13.37 ± 9.81 亨氏单位/10mm 持续且显著降低（p<0.0001）。在冠状动脉 CTA 的解释中添加 TAG 可提高诊断准确性（p=0.001），尤其是在有钙化病变的血管中（N=127；净重新分类改善 0.095；p=0.046）。TAG 似乎能够有助于改善冠状动脉 CTA 中冠状动脉狭窄严重程度的分类，尤其是在严重钙化病变中。
