Development of New Cardiac Deformity Indexes for Pectus Excavatum on Computed Tomography: Feasibility for Pre- and Post-Operative Evaluation

Abstract

Purpose: The aim of this study was to evaluate new cardiac deformity indexes (CDIs) for diagnosis of pectus excavatum as well as morphological assessment of heart on computed tomography (CT). Materials and Methods: We retrospectively evaluated the CT images of the control group (n=200), and the pectus excavatum before and after correction groups (n=178), and calculated the CDIs; cardiac compression index (CCI), and cardiac asymmetry index (CAI). We also calculated chest wall compression index (CWCI) and asymmetry index (CWAI) on the axial images. We performed logistic regression analysis using each index and age as predictor variables. Results: The CDIs (CCI and CAI) were significant (p < 0.05) in the diagnosis of pectus excavatum, regardless of age (p = 0.4033, p = 0.8113). The CWCI and CWAI were significant (p < 0.05) and significantly affected by age (p < 0.05). If we selected 1.82 as the cutoff of the CCI, the sensitivity and specificity were 99.4% and 98%, respectively. The following cutoffs and the sensitivity and specificity were obtained: 1.15 for the CAI gave 94.4% and 94.5%, 3.05 for the CWCI gave 92.1% and 92%, and 1 for the CWAI gave 62.4% and 65%, respectively. The CCI after repair improved from 2.83 +/- 0.84 to 1.84 +/- 0.33, while the CWCI improved from 4.49 +/- 1.61 to 2.57 +/- 0.44. Conclusion: CDIs such as the CCI and CAI may be potentially useful to detect and estimate repair for pectus excavatum.