Department of Radiology, Ajou University Medical Center, 164 Worldcup Road, Yeongtong-gu, Suwon, 16499, South Korea.
Department of Radiology, Hankook Hospital, Cheongju, South Korea.
Eur Radiol. 2019 Aug;29(8):4324-4332. doi: 10.1007/s00330-018-5883-3. Epub 2019 Jan 7.
To assess the ability of digital chest radiography (CXR) to reveal calcification in solitary pulmonary nodules (SPNs), and to examine the correlation between a visual assessment and volumetric quantification of the calcification.
This study was a retrospective review of 220 SPNs identified by both CXR and chest CT. Eleven observers did blind review of the CXR images and scored nodule calcification on a confidence scale of 1 to 5. The area under the receiver operating characteristics (ROC) curve (AUC) was obtained to analyze the diagnostic performance. The intraclass correlation coefficient (ICC) for interrater reliability was calculated. The AUC and ICC were calculated according to the following nodule diameter groups: group 1 (< 10 mm), group 2 (≥ 10 mm and < 20 mm), and group 3 (≥ 20 mm).
Of the 220 SPNs, 145 SPNs (65.6%) were identified as non-calcified and 75 (34.4%) as calcified. The average percentage of calcification volume in SPN > 160 HU (Vol160HU) among the 75 calcified nodules was 47.5%. The mean Vol160HU of the 68 SPNs classified as having definite calcification was 51.1%. The overall AUC was 0.71. The AUCs for groups 1, 2, and 3 was 0.835, 0.639, and 0.620, respectively. The ICCs for groups 1, 2, 3 was 0.65, 0.48, and 0.33, respectively.
The overall diagnostic performance of digital CXR to predict calcification in SPNs was moderately accurate and the diagnostic performance for predicting calcification in SPNs was significantly higher, and interobserver reproducibility was good when SPN < 10 mm compared with ≥ 10 mm in diameter.
• The misdiagnosis of a non-calcified nodule as a calcified one by CXR could lead to poor management choices for the SPN. • The diagnostic performance of CXR in predicting calcification was best for nodules < 10 mm in diameter. SPNs with calcification of approximately 50% of their volume tend to be considered calcified. • The diagnostic performance of CXR in identifying calcification was low for nodules ≥ 10 mm in diameter; therefore, we should carefully evaluate calcification carefully for nodules ≥ 10 mm.
评估数字胸部 X 线摄影（CXR）显示孤立性肺结节（SPN）内钙化的能力，并检查钙化的视觉评估与容积定量之间的相关性。
本研究回顾性分析了 220 个经 CXR 和胸部 CT 均证实的 SPN。11 名观察者对 CXR 图像进行了盲法评估，并对结节钙化进行了 1 至 5 分的置信度评分。获得受试者工作特征（ROC）曲线下面积（AUC）以分析诊断性能。计算了观察者间可靠性的组内相关系数（ICC）。根据以下结节直径组计算 AUC 和 ICC：组 1（<10mm）、组 2（≥10mm 且<20mm）和组 3（≥20mm）。
220 个 SPN 中，145 个 SPN（65.6%）为非钙化，75 个 SPN（34.4%）为钙化。75 个钙化结节中，平均 Vol160HU（HU 表示灰度值）的钙化体积百分比为 47.5%。68 个被归类为有明确钙化的 SPN 中，平均 Vol160HU 为 51.1%。总体 AUC 为 0.71。组 1、2 和 3 的 AUC 分别为 0.835、0.639 和 0.620。组 1、2 和 3 的 ICC 分别为 0.65、0.48 和 0.33。
数字 CXR 预测 SPN 内钙化的总体诊断性能为中度准确，预测 SPN 内钙化的诊断性能明显更高，与直径≥10mm 的 SPN 相比，直径<10mm 的 SPN 具有更好的观察者间可重复性。
CXR 误诊非钙化结节为钙化结节可能导致 SPN 管理决策不佳。
CXR 预测钙化的诊断性能在直径<10mm 的结节中最佳。Vol160HU 约为 50%的钙化结节倾向于被认为是钙化的。
CXR 识别钙化的诊断性能在直径≥10mm 的结节中较低；因此，我们应该仔细评估直径≥10mm 的结节的钙化情况。
