Kim Sung Mok, Chung Myung Jin, Lee Kyung Soo, Choe Yeon Hyun, Yi Chin A, Choe Bong-Keun
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Korea.
AJR Am J Roentgenol. 2008 Apr;190(4):917-22. doi: 10.2214/AJR.07.2979.
The purpose of our study was to show the usefulness of nongated low-dose chest CT for coronary screening by comparing the results of coronary artery calcium measurement with that of dedicated calcium-scoring CT.
One hundred twenty-eight consecutive participants (all men; mean age, 52 +/- 7 years) underwent low-dose chest CT and calcium-scoring CT with prospective ECG gating using 40-MDCT. Low-dose chest CT volume data were reconstructed as 25-cm field of view and three slice thicknesses: 1, 2.5, and 5 mm. For each examination, the lesion area, Agatston calcium score, and calcium mass were measured at 90- and 130-H thresholds. All measurements (130-H threshold) from the calcium-scoring CT were used as reference standards. Spearman's correlation test was used to compare the results.
Among the low-dose chest CT examinations, sensitivity was best determined with a 1-mm slice thickness at 130 H and 2.5-mm slice thickness at 90 H. Specificity was best determined with a 5-mm slice thickness at 130 H. Accuracy (90%) was best determined with a 2.5-mm slice thickness at 130 H. Of all protocols, calcium area, score, and mass from a 2.5-mm slice thickness at 130 H correlated best with the reference results (r = 0.89 for all three criteria).
Using a low radiation dose and nongated MDCT, we can detect coronary artery calcium and obtain results comparable to those obtained with dedicated calcium-scoring CT that uses a higher dose and ECG gating.
我们研究的目的是通过比较冠状动脉钙化测量结果与专用钙化积分CT的结果，来显示非门控低剂量胸部CT在冠状动脉筛查中的实用性。
128名连续的参与者（均为男性；平均年龄52±7岁）接受了低剂量胸部CT和使用40排MDCT进行的前瞻性心电图门控钙化积分CT检查。低剂量胸部CT容积数据被重建为25厘米视野和三种层厚：1毫米、2.5毫米和5毫米。对于每次检查，在90-H和130-H阈值下测量病变面积、阿加斯顿钙化积分和钙质量。来自钙化积分CT的所有测量值（130-H阈值）用作参考标准。采用Spearman相关性检验比较结果。
在低剂量胸部CT检查中，在130-H时1毫米层厚和90-H时2.5毫米层厚的敏感性最佳。在130-H时5毫米层厚的特异性最佳。在130-H时2.5毫米层厚的准确性（90%）最佳。在所有方案中，130-H时2.5毫米层厚的钙面积、积分和质量与参考结果的相关性最佳（所有三个标准的r均为0.89）。
使用低辐射剂量和非门控MDCT，我们可以检测冠状动脉钙化，并获得与使用更高剂量和心电图门控的专用钙化积分CT相当的结果。
