Quantification of pectus excavatum: Anatomic indices

Pectus excavatum is the most common chest wall deformity in children. The central portion of the chest is displaced posteriorly relative to the remainder of the anterior chest wall. Quantification of defect severity can be performed with multiple imaging modalities or external thoracic measures, but is most commonly quantified by the Haller Index (HI) or Pectus Correction Index (PCI). These two measures provide a measure of the chest based on cross sectional imaging, most commonly CT scans, allowing for standard comparison and definitions of pectus defects. The purpose of this article is to describe the creation, calculation, and limitations of the methods quantifying pectus defects.