J Comput Assist Tomogr. 2022;46(3):492-498. doi: 10.1097/RCT.0000000000001285.
The aim of the study was to compare a pediatric ultralow-dose pectus excavatum computed tomography (CT) protocol versus standard-dose pediatric thoracic CT in terms of radiation dose, subjective and objective image quality, and its ability to detect incidental nonosseous thoracic pathology compared with imaging and clinical reference.
A single institution radiology database identified a total of 104 ultralow-dose pediatric thoracic CT cases with an equal number of age-matched standard-dose chest CT cases also selected for retrospective analysis. Objective image quality (contrast-to-noise and signal-to-noise ratios) and radiation dose were assessed. Qualitative Likert scorings of the bone, lung, and soft tissues were performed by 2 expert radiologists. Electronic health records of the ultralow-dose cohort were reviewed for at least 1 year to evaluate for potentially missed thoracic pathology and symptoms. Variables were compared using parametric and nonparametric tests in R software 4.0.5.
The ultralow-dose protocol group had statistically significant reductions (P < 0.001) in the volume CT dose index (0.31 ± 0.19 vs 2.20 ± 1.64 mGy), effective radiation dose (0.14 ± 0.08 vs 1.07 ± 0.86 mSv), and size-specific dose estimates (0.50 ± 0.30 vs 3.43 ± 2.56 mGy) compared with the standard protocol, yielding an 86.51% and 85.32% reduction, respectively. The signal-to-noise ratio (20.49 ± 6.19 vs 36.48 ± 10.20), contrast-to-noise (21.65 ± 6.57 vs 38.47 ± 10.59), and subjective measures of image quality (lung parenchyma [3.07 ± 0.92 vs 4.42 ± 0.47], bony structures [3.30 ± 0.86 vs 4.52 ± 0.51], and surrounding soft tissues [2.57 ± 0.63 vs 3.89 ± 0.65]) were also significantly lower in the ultralow-dose protocol (P < 0.001). No differences were seen in the number and size of pulmonary nodules between groups. Clinical and imaging follow of all 104 patients undergoing ultralow-dose CT demonstrated no evidence of missed thoracic pathology causing symptoms.
Ultralow-dose thoracic CT is an acceptable modality for imaging pediatric patients with pectus excavatum and other conditions primarily causing osseous pathology, with effective radiation dose comparable to plain radiographs and a moderate increase in image noise that did not significantly reduce its ability to detect incidental nonosseous thoracic pathology.
本研究旨在比较小儿超低剂量漏斗胸 CT（CT）与标准剂量小儿胸部 CT 之间的辐射剂量、主观和客观图像质量，以及与影像学和临床参考相比检测偶发性非骨胸部病变的能力。
通过单机构放射学数据库共确定了 104 例超低剂量小儿胸部 CT 病例，并选择了相同数量的年龄匹配的标准剂量胸部 CT 病例进行回顾性分析。评估了客观的图像质量（对比噪声比和信噪比）和辐射剂量。由 2 名专家放射科医生对骨、肺和软组织进行定性 Likert 评分。对超低剂量组的电子健康记录进行了至少 1 年的复查，以评估潜在的漏诊胸部病变和症状。使用 R 软件 4.0.5 比较变量，使用参数和非参数检验。
超低剂量方案组的容积 CT 剂量指数（0.31 ± 0.19 与 2.20 ± 1.64 mGy）、有效辐射剂量（0.14 ± 0.08 与 1.07 ± 0.86 mSv）和大小特异性剂量估计值（0.50 ± 0.30 与 3.43 ± 2.56 mGy）均有统计学显著降低（P < 0.001），分别降低 86.51%和 85.32%。信噪比（20.49 ± 6.19 与 36.48 ± 10.20）、对比噪声（21.65 ± 6.57 与 38.47 ± 10.59）和图像质量的主观测量（肺实质[3.07 ± 0.92 与 4.42 ± 0.47]、骨结构[3.30 ± 0.86 与 4.52 ± 0.51]和周围软组织[2.57 ± 0.63 与 3.89 ± 0.65]）也明显降低（P < 0.001）。两组之间肺结节的数量和大小无差异。对所有接受超低剂量 CT 检查的 104 例患者进行临床和影像学随访，均未发现引起症状的漏诊胸部病变。
超低剂量胸部 CT 是一种可接受的成像方法，可用于成像漏斗胸和其他主要引起骨病理的小儿患者，有效辐射剂量与普通 X 线摄影相当，图像噪声适度增加，但不会显著降低其检测偶发性非骨胸部病变的能力。
