Age-related normal ranges for the Haller index in children.

PURPOSE: The Haller index is an accepted CT method for evaluating thoracic dimensions in patients with pectus excavatum. The purpose of this study is to establish age- and gender-related norms for the Haller index in childhood. MATERIALS AND METHODS: We retrospectively reviewed 574 consecutive chest CT examinations (M=285, F=289) performed at our institution from August 2001 through March 2002. Seventeen patients with a history of chest-wall deformity, trauma, or syndrome were excluded, for a total sample size of 557 patients. The Haller index was calculated for each patient, using electronic calipers. The sample population was then separated by gender and placed into 2-year age groupings. Two-way analysis of variance and Tukey's multiple comparisons were performed to determine significance at a=0.05. The least-square mean Haller index values for each age group and gender were calculated with 95% confidence intervals. RESULTS: In both males and females, the 0- to 2-year age group showed a significantly smaller mean Haller index than older children. In addition, females had significantly greater Haller index values than males in the 0- to 6- and 12- to 18-year age groups. CONCLUSION: The Haller index, a quantitative measurement of chest-wall configuration, demonstrates significant age- and gender-related variability. This should be considered when evaluating the patient with suspected chest-wall deformity.