Wan Yung-Liang, Tsay Pei-Kwei, Wu Patricia Wanping, Juan Yu-Hsiang, Tsai Hui-Yu, Lin Chung-Yin, Yeh Chih-Sheng, Wang Chun-Hua, Chen Chun-Chi
Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Institute for Radiological Research, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
Department of Public Health and Center of Biostatistics, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.
Int J Cardiol. 2017 Jun 1;236:451-457. doi: 10.1016/j.ijcard.2017.02.124. Epub 2017 Feb 27.
Coronary artery calcification (CAC) may be quantified on low-dose computed tomography (CT) of the lung (LDCT). This study aims to evaluate the effects of filter convolution (FC) and displayed field of view (dFOV) in a Toshiba 320-row CT scanner in quantifying CAC, and to compare the CAC scores obtained by LDCT with standard cardiac CT.
Fifty subjects (52 to 85years, mean 68.5, 36 males) with visible CAC underwent both standard cardiac CT and LDCT. CAC scores were obtained from standard cardiac CT using conventional FC12(22) (FC12 with 22-cm dFOV) and four different LDCT protocols: FC02(22), FC02(40), FC08(22), and FC08(40). CAC scores obtained by each LDCT protocol were compared with those obtained by standard cardiac CT.
CAC scores obtained by all four LDCT protocols were well correlated with those by standard protocol (Pearson's coefficient=0.978 to 0.987, p<0.001; kappa=0.731 to 0.836, p<0.001). CAC scores obtained by FC08(22) showed the best agreement with standard cardiac CT (kappa=0.836, p<0.001). Under fixed dFOV, CAC scores in FC08 were significantly higher than in FC02 (p<0.001). Under fixed FC, CAC scores were significantly higher in 22-cm dFOV than in 40-cm dFOV (p≤0.006).
Both FC and dFOV have significant impact on CAC scoring. To obtain reliable data, consistent parameters should be employed when quantifying CAC using LDCT. In a Toshiba 320-row CT scanner, CAC scores obtained by FC08(22) agree well with standard cardiac CT.
冠状动脉钙化（CAC）可通过肺部低剂量计算机断层扫描（CT）（LDCT）进行量化。本研究旨在评估东芝320排CT扫描仪中滤波卷积（FC）和显示视野（dFOV）在量化CAC方面的效果，并比较LDCT获得的CAC评分与标准心脏CT获得的评分。
50名（年龄52至85岁，平均68.5岁，男性36名）可见CAC的受试者接受了标准心脏CT和LDCT检查。使用传统的FC12(22)（22厘米dFOV的FC12）从标准心脏CT获得CAC评分，并采用四种不同的LDCT方案：FC02(22)、FC02(40)、FC08(22)和FC08(40)。将每种LDCT方案获得的CAC评分与标准心脏CT获得的评分进行比较。
所有四种LDCT方案获得的CAC评分与标准方案获得的评分高度相关（Pearson系数=0.978至0.987，p<0.001；kappa=0.731至0.836，p<0.001）。FC08(22)获得的CAC评分与标准心脏CT显示出最佳一致性（kappa=0.836，p<0.001）。在固定dFOV下，FC08的CAC评分显著高于FC02（p<0.001）。在固定FC下，22厘米dFOV的CAC评分显著高于40厘米dFOV（p≤0.006）。
FC和dFOV对CAC评分均有显著影响。为获得可靠数据，使用LDCT量化CAC时应采用一致的参数。在东芝320排CT扫描仪中，FC08(22)获得的CAC评分与标准心脏CT吻合良好。
