Lefcoe M S, Cunningham I A, Vanderburgh L C, Sparrow R K
Department of Diagnostic Radiology, Victoria Hospital, London, Ontario.
Can Assoc Radiol J. 1996 Jun;47(3):213-9.
To compare conventional and asymmetric film-screen chest radiography systems in a prospective, randomized trial.
Posteroanterior and lateral films were obtained with each system for one healthy volunteer and 49 consenting patients referred from pulmonary clinics and wards (for a total of 27 male and 23 female subjects ranging in age from 16 to 82 [mean 58] years). The radiographs, obtained and presented in random order, were reviewed and rated independently by two experienced radiologists and one resident in radiology; all observers were blinded to patient identification and film type. The Wilcoxon signed rank sum nonparametric test for paired samples was used to test for significant differences between the two film-screen systems. A second evaluation involving direct (blinded) comparison of the two types of films was then performed for each of the 25 patients in whom abnormality was noted during the first evaluation.
For the posteroanterior radiographs, the asymmetric film-screen system was significantly better for assessing the trachea and mainstem bronchi, the descending thoracic-aortic edge, the left paraspinal line, the thoracic vertebral body interspace and the azygo-esophageal line (p < 0.05), whereas the conventional system had superior conspicuity in the lateral subpleural zones (p < 0.05). For the lateral radiographs, the asymmetric system was superior for assessing retrosternal lung markings (p < 0.05) but inferior for assessing fissures (p < 0.05).
In general, the asymmetric system was superior for assessing mediastinal features and inferior for assessing the lateral subpleural zones in the posteroanterior radiographs. The asymmetric system was superior for assessing retrosternal lung markings and inferior for assessing fissures in the lateral radiographs. The results for the posteroanterior radiographs were consistent with the results of nonblinded studies reported elsewhere.
在一项前瞻性随机试验中比较传统型和非对称型屏-片胸部摄影系统。
使用每种系统为一名健康志愿者以及49名来自肺科门诊和病房的同意参与的患者拍摄后前位和侧位胸片（共27名男性和23名女性受试者，年龄范围为16至82岁[平均58岁]）。以随机顺序获取并展示的X线片由两名经验丰富的放射科医生和一名放射科住院医师独立进行审阅和评级；所有观察者均不知道患者身份和胶片类型。采用配对样本的Wilcoxon符号秩和非参数检验来检测两种屏-片系统之间的显著差异。然后，对在首次评估中发现异常的25名患者中的每一位进行第二次评估，直接（盲法）比较两种类型的胶片。
在后前位X线片中，非对称型屏-片系统在评估气管和主支气管、降主动脉边缘、左侧脊柱旁线、胸椎椎体间隙和奇静脉-食管线方面明显更好（p<0.05），而传统系统在外侧胸膜下区域的显示效果更佳（p<0.05）。在侧位X线片中，非对称系统在评估胸骨后肺纹理方面更具优势（p<0.05），但在评估肺裂方面则较差（p<0.05）。
总体而言，非对称系统在评估后前位X线片中的纵隔特征方面更具优势，而在评估外侧胸膜下区域方面则较差。非对称系统在评估侧位X线片中的胸骨后肺纹理方面更具优势，而在评估肺裂方面则较差。后前位X线片的结果与其他地方报道的非盲法研究结果一致。
