Photographic documentation and severity quantification of pectus excavatum through three-dimensional optical surface imaging

Conventional photography is commonly used to visually document pectus excavatum and objectively assess chest wall changes over time without repeated exposure to ionising radiation, as in our centre since 2008. However, as conventional photography is labour-intensive and lacks three-dimensional (3D) information that is essential in 3D deformities like pectus excavatum, we developed a novel imaging and processing protocol based on 3D optical surface imaging. The objective of this study was to report our developed protocol to visually document pectus excavatum through 3D imaging. We also investigated the absolute agreement of the 3D image- and conventional photography-derived pectus excavatum depth to investigate whether both techniques could be used interchangeably to measure pectus excavatum depth and assess its evolution. The protocol consisted of three consecutive steps: patient positioning and instructions, data acquisition, and data processing. Three-dimensional imaging through the developed protocol was feasible for all 19 participants. The 3D image- and photography-derived pectus excavatum depth demonstrated good to excellent agreement (intraclass correlation coefficient: 0.97; 95%-confidence interval: 0.88 to 0.99;p <0.001). In conclusion, 3D imaging through the developed protocol is a feasible and attractive alternative to document the surface geometry of pectus excavatum and can be used interchangeably with conventional photography to determine pectus severity.