Purpose: To assess the diagnostic accuracy of different reconstruction techniques using MDCT for gastric cancer detection compared with 2D axial CT.
目的： 评估使用 MDCT 与 2D 轴向 CT 相比用于胃癌检测的不同重建技术的诊断准确性。

Materials and methods: During 7 months, we performed CT examinations of 104 consecutive patients with gastric cancer and of a control group composed of 35 patients without gastric disease. All gastric cancer was pathologically proven by endoscopy and surgery. Among 104 patients with gastric cancer, 63 patients had early gastric cancer (EGC). Two radiologists retrospectively and independently interpreted the axial CT and three different reconstruction techniques including multiplanar reformation (MPR), transparent imaging (TI), and virtual gastroscopy (VG), using a commercially available, 3D workstation. They graded the presence or absence of gastric cancer in each image sets using a five-point scale and, if present, they assessed its location. Diagnostic accuracy was compared using the area under the receiver operating characteristic curve (Az) for both gastric cancer and only EGC. Sensitivity and specificity were also calculated for each image technique. The k statistics were used to determine inter-observer agreement.
材料和方法： 在 7 个月内，我们对 104 例连续胃癌患者和由 35 例无胃病患者组成的对照组进行了 CT 检查。所有胃癌均通过内窥镜检查和手术进行病理证实。在 104 例胃癌患者中，63 例患者患有早期胃癌 （EGC）。两名放射科医生使用市售的 3D 工作站回顾性独立解释轴向 CT 和三种不同的重建技术，包括多平面改革 （MPR）、透明成像 （TI） 和虚拟胃镜检查 （VG）。他们使用五分制对每个图像集中是否存在胃癌进行分级，如果存在，则评估其位置。使用胃癌和仅 EGC 的受试者工作特征曲线下面积 （Az） 比较诊断准确性。还计算了每种图像技术的灵敏度和特异性。k 统计量用于确定观察者间一致性。

Results: The diagnostic accuracy for overall gastric cancer detection for each of the image sets was as follows: 2D axial CT (Az = 0.858); MPR (Az = 0.879); TI (Az = 0.873); and VG (Az = 0.928). VG had significantly better performance than 2D axial CT (p = 0.016). The sensitivity and specificity were as follows: 76.7% and 82.9% in axial CT; 79.6% and 85.7% in MPR; 91.3% and 80% in TI; and 95.1% and 74.3% in VG. In EGC, the diagnostic performance for its detection was as follows: axial CT (Az = 0.777); MPR (Az = 0.811); TI (Az = 0.825); and VG (Az = 0.896). VG had significantly better performance than both 2D axial CT (P = 0.006) and MRP (P = 0.038). The sensitivity and specificity were as follows: 62.9% and 82.9% in axial CT; 67.7% and 85.7% in MPR; 85.5% and 80% in TI; and 91.9% and 74.3% in VG. The inter-observer agreement showed substantial agreement (κ = 0.67-0.75).
结果： 每个图像集的总体胃癌检测诊断准确性如下：2D 轴向 CT （Az = 0.858）;MPR （Az = 0.879）;TI （Az = 0.873）;和 VG （Az = 0.928）。VG 的性能明显优于 2D 轴向 CT （p = 0.016）。敏感性和特异性如下：轴向 CT 为 76.7% 和 82.9%;MPR 为 79.6% 和 85.7%;TI 为 91.3% 和 80%;VG 为 95.1% 和 74.3%。在 EGC 中，其检测的诊断性能如下：轴向 CT （Az = 0.777）;MPR （Az = 0.811）;TI （Az = 0.825）;和 VG （Az = 0.896）。VG 的性能明显优于 2D 轴向 CT （P = 0.006） 和 MRP （P = 0.038）。敏感性和特异性如下：轴向 CT 为 62.9% 和 82.9%;MPR 为 67.7% 和 85.7%;TI 为 85.5% 和 80%;VG 为 91.9% 和 74.3%。观察者间一致性显示基本一致 （κ = 0.67-0.75）。

Conclusion: Among the different reconstruction techniques, VG accurately detects gastric cancer and is especially useful for EGC compared with 2D axial CT.
结论： 在不同的重建技术中，VG 可准确检测胃癌，与 2D 轴向 CT 相比，VG 对 EGC 特别有用。