Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd., St. Louis, MO 63110, USA.
Pediatr Radiol. 2010 Nov;40(11):1763-7. doi: 10.1007/s00247-010-1681-z. Epub 2010 May 15.
Pectus excavatum is a common chest wall anomaly in children. Pre-operative imaging for pectus excavatum is performed with CT, which is used to calculate the Haller index to determine the severity of pectus excavatum.
To determine the correlation between Haller index values calculated with two-view chest radiographs and those calculated with CT and to determine, with CT as the reference standard, the diagnostic performance of radiographic Haller index for identifying cases that meet imaging criteria for surgical correction of pectus excavatum.
For the period 2001-2009, our radiology information system was searched to identify all children who had undergone CT for Haller index calculation. Children who had also undergone two-view chest radiography (CXR) within 6 months of the CT were included in this retrospective study. Two radiologists independently calculated CT Haller index and radiographic Haller index. Data distributions were tested for normality with the Shapiro-Wilk W test. The associations between CT Haller index and radiographic Haller index were determined with the Spearman coefficient of rank correlation. Differences between CT Haller index and radiographic Haller index were tested with the Wilcoxon signed rank test. Haller index values were dichotomized into positive (>3.2) and negative (≤3.2) cases. Using CT as the reference standard, the sensitivity, specificity, and accuracy of radiographic Haller index in identifying children who meet imaging criteria for surgery were calculated.
CT and CXR for evaluation of pectus excavatum were available for 32 children (25 male; median age 14.5 years). With CT, the median Haller indices for observers 1 and 2 were 3.4 and 3.5 and with CXR 3.5 and 3.5. There were statistically significant correlations between the radiographic Haller index and CT Haller index estimated by the two observers [Spearman correlation coefficient (95% confidence interval) for observer 1 = 0.71 (0.48-0.85, P < 0.01) and for observer 2 = 0.77 (0.52-0.88, P < 0.01)]. A statistically significant correlation was found between the radiographic Haller index calculated by the two observers [Spearman correlation coefficient = 0.98 (0.95-0.99, P < 0.01)]. Using CT Haller index as the reference standard, radiographic Haller index had a sensitivity of 0.95 (0.75-0.99), specificity of 0.75 (0.43-0.94), and accuracy of 0.88 (0.72-0.95) for observer 1, and a sensitivity of 0.95 (0.75-0.99), specificity of 0.67 (0.35-0.90), and accuracy of 0.84 (0.68-0.93) for observer 2.
Radiographic Haller index correlates strongly with CT Haller index, has good interobserver correlation, and has a high diagnostic accuracy for pre-operative evaluation of pectus excavatum. We suggest that a CT of the chest is not required for pre-operative evaluation of pectus excavatum, and a two-view chest radiograph is sufficient for preoperative imaging of pectus excavatum.
漏斗胸是儿童常见的胸廓畸形。漏斗胸的术前影像学检查采用 CT，用于计算 Haller 指数以确定漏斗胸的严重程度。
确定双视图胸部 X 射线摄影计算的 Haller 指数值与 CT 计算的 Haller 指数值之间的相关性，并确定 CT 作为参考标准，用于诊断具有影像学手术矫正漏斗胸标准的放射学 Haller 指数。
在 2001 年至 2009 年期间，我们的放射学信息系统搜索了所有接受 CT 计算 Haller 指数的儿童。在此回顾性研究中，包括在 CT 检查后 6 个月内还接受过双视图胸部 X 射线摄影（CXR）的儿童。两位放射科医生独立计算 CT Haller 指数和放射学 Haller 指数。使用 Shapiro-Wilk W 检验测试数据分布的正态性。使用 Spearman 秩相关系数确定 CT Haller 指数和放射学 Haller 指数之间的相关性。使用 Wilcoxon 符号秩检验检验 CT Haller 指数和放射学 Haller 指数之间的差异。将 Haller 指数值分为阳性（>3.2）和阴性（≤3.2）病例。使用 CT 作为参考标准，计算放射学 Haller 指数在识别符合手术影像学标准的儿童方面的敏感性、特异性和准确性。
用于评估漏斗胸的 CT 和 CXR 可用于 32 名儿童（25 名男性；中位年龄 14.5 岁）。使用 CT，观察者 1 和 2 的中位数 Haller 指数分别为 3.4 和 3.5，使用 CXR 为 3.5 和 3.5。两位观察者的放射学 Haller 指数与 CT Haller 指数之间存在统计学显著相关性[观察者 1 的 Spearman 相关系数（95%置信区间）为 0.71（0.48-0.85，P<0.01）和观察者 2 的 Spearman 相关系数为 0.77（0.52-0.88，P<0.01）]。两位观察者计算的放射学 Haller 指数之间存在统计学显著相关性[Spearman 相关系数=0.98（0.95-0.99，P<0.01）]。使用 CT Haller 指数作为参考标准，放射学 Haller 指数对观察者 1 的敏感性为 0.95（0.75-0.99），特异性为 0.75（0.43-0.94），准确性为 0.88（0.72-0.95），对观察者 2 的敏感性为 0.95（0.75-0.99），特异性为 0.67（0.35-0.90），准确性为 0.84（0.68-0.93）。
放射学 Haller 指数与 CT Haller 指数密切相关，具有良好的观察者间相关性，对漏斗胸的术前评估具有较高的诊断准确性。我们建议，漏斗胸的术前评估不需要进行 CT 检查，双视图胸部 X 射线摄影足以用于漏斗胸的术前成像。
