Detection of Nodules Showing Ground-Glass Opacity in the Lungs at Low-Dose Multidetector Computed Tomography: Phantom and Clinical Study
Detection of Nodules Showing Ground-Glass Opacity in the Lungs at Low-Dose Multidetector Computed Tomography: Phantom and Clinical Study
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DOI：
10.1097/rct.0b013e31815e6291
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发表时间：
2009-01-01
影响因子：
1.3
通讯作者：
Yamashita, Yasuyuki
中科院分区：
文献类型：
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作者：
Funama, Yoshinori;Awai, Kazuo;Yamashita, Yasuyuki
目的：研究辐射剂量（管电流第二产品）和磨玻璃样结节（GGO）的衰减值对其在多排计算机断层扫描（MDCT）中的可检测性的影响。方法：我们使用 MDCT 扫描仪扫描包含模拟 GGO 结节的胸部 CT 模型。模拟肺实质的衰减值为-900 Hounsfield 单位（HU）；模拟 GGO 结节的值是 -800 和 -650 HU。我们使用180 mA的管电流第二产品作为标准，21、45、60和90 mA作为低剂量，并进行接收器操作特性分析，以比较5名放射科医生在每毫安检测GGO结节的性能。为了评估 GGO 结节在人类肺部图像上的可检测性，观察者获得了来自 15 名患者的 38 个 GGO 结节。 5 名放射科医生独立审查了 21 和 45 mAs 时的胸部 CT 图像。结果：在体模研究中，CT 数为 -800 HU 的 GGO 结节的 Az 值在 21 时显着低于 180 mAs（0.86 vs. 0.96；P < 0.01）。无论使用何种毫安电流，CT 数为 -650 HU 的 GGO 结节的 Az 值均无统计学显着差异（P = 0.165）。在临床研究中，在 21 和 45 mAs 时分别有 39.5% 和 25.8% 的 GGO 被漏诊。结论：在 MDCT 中，在较低毫安设置（21 和 45 mAs）下很难检测到 CT 数为 -650 HU 或更少的 GGO 结节。
Objective: To investigate the effect of the radiation dose (tube current second product) and the attenuation value of nodules with ground-glass opacity (GGO) on their detectability at multidetector computed tomography (MDCT).Methods: We scanned a chest CT phantom that included simulated GGO nodules with an MDCT scanner. The attenuation value of the simulated lung parenchyma was -900 Hounsfield units (HU); it was -800 and -650 HU for the simulated GGO nodules. We used a tube current second product of 180 mA as the standard and 21, 45, 60, and 90 mAs as the low-dose and performed receiver operating characteristic analysis to compare the performance of 5 radiologists in detecting GGO nodules at each milliampere. To assess the detectability of GGO nodules on human lung images, the observers were presented with 38 GGO nodules from 15 patients. The 5 radiologists independently reviewed chest CT images at 21 and 45 mAs.Results: In the phantom study, the Az value for GGO nodules with a CT number of -800 HU was significantly lower at 21 than 180 effective mA (0.86 vs. 0.96; P < 0.01). There was no statistically significant difference in the Az value of GGO nodules with a CT number of -650 HU, irrespective of milliamperes used (P = 0.165). In the clinical study, 39.5% and 25.8% of GGO were missed at 21 and 45 mAs, respectively.Conclusions: At MDCT, GGO nodules with a CT number of -650 HU or less were difficult to detect at the lower milliampere settings (21 and 45 mAs).