Department of Radiology, University of Trieste, Trieste, Italy.
Department of Medicine, Surgery and Health Science, University of Trieste, Trieste, Italy.
Radiography (Lond). 2021 May;27(2):574-580. doi: 10.1016/j.radi.2020.11.019. Epub 2020 Dec 16.
Ground-glass nodules may be the expression of benign conditions, pre-invasive lesions or malignancies. The aim of our study was to evaluate the capability of chest digital tomosynthesis (DTS) in detecting pulmonary ground-glass opacities (GGOs).
An anthropomorphic chest phantom and synthetic nodules were used to simulate pulmonary ground-glass nodules. The nodules were positioned in 3 different regions (apex, hilum and basal); then the phantom was scanned by multi-detector CT (MDCT) and DTS. For each set (nodule-free phantom, nodule in apical zone, nodule in hilar zone, nodule in basal zone) seven different scans (n = 28) were performed varying the following technical parameters: Cu-filter (0.1-0.3 mm), dose rateo (10-25) and X-ray tube voltage (105-125 kVp). Two radiologists in consensus evaluated the DTS images and provided in agreement a visual score: 1 for unidentifiable nodules, 2 for poorly identifiable nodules, 3 for nodules identifiable with fair certainty, 4 for nodules identifiable with absolute certainty.
Increasing the dose rateo from 10 to 15, GGOs located in the apex and in the basal zone were better identified (from a score = 2 to a score = 3). GGOs located in the hilar zone were not visible even with a higher dose rate. Intermediate density GGOs had a good visibility score (score = 3) and it did not improve by varying technical parameters. A progressive increase of voltage (from 105 kVp to 125 kVp) did not provide a better nodule visibility.
DTS with optimized technical parameters can identify GGOs, in particular those with a diameter greater than 10 mm.
DTS could have a role in the follow-up of patients with known GGOs identified in lung apex or base region.
磨玻璃结节可能是良性病变、癌前病变或恶性肿瘤的表现。本研究旨在评估胸部数字断层合成摄影术（DTS）检测肺部磨玻璃密度（GGO）的能力。
使用人工胸部体模和合成结节来模拟肺部磨玻璃结节。将结节放置在 3 个不同区域（肺尖、肺门和基底）；然后使用多探测器 CT（MDCT）和 DTS 对体模进行扫描。对于每个组（无结节体模、肺尖区结节、肺门区结节、基底区结节），改变以下技术参数进行了 7 次不同的扫描（n=28）：Cu 滤器（0.1-0.3mm）、剂量率（10-25）和 X 射线管电压（105-125kVp）。两位放射科医生一致评估了 DTS 图像，并一致提供了一个视觉评分：1 为无法识别的结节，2 为难以识别的结节，3 为可识别的结节，4 为可明确识别的结节。
随着剂量率从 10 增加到 15，位于肺尖和基底区的 GGO 更容易被识别（从评分=2 变为评分=3）。位于肺门区的 GGO 即使使用更高的剂量率也无法被识别。中等密度的 GGO 具有良好的可视性评分（评分=3），并且通过改变技术参数无法提高。电压的逐渐增加（从 105kVp 增加到 125kVp）并不能提高结节的可视性。
优化后的 DTS 技术参数可识别 GGO，特别是直径大于 10mm 的 GGO。
DTS 可在已知肺尖或基底区 GGO 患者的随访中发挥作用。
