Advancements in preoperative imaging of pectus excavatum: a comprehensive review

Pectus excavatum, the most common pectus deformity, varies in severity and has been associated with cardiopulmonary impairment and psychological distress. Since its initial documentation, a multitude of imaging techniques for preoperative evaluation (i.e., diagnosis, severity classification, functional assessment, and surgical planning) have been reported. Conventional imaging techniques encompass computed tomography (CT), chest radiography, magnetic resonance imaging (MRI), echocardiography and medical photography, while three dimensional (3D) optical surface imaging is a promising emerging technique in the preoperative assessment of pectus excavatum. This narrative review explores the current insights and advancements of these imaging modalities. CT imaging allows for the calculation of pectus indices and evaluation of cardiac compression and displacement. Recent developments focus on automated calculations, minimizing radiation exposure and improving surgical planning. Chest radiography offers a radiation-reducing alternative for pectus index measurement, but is unsuitable for disproportionally asymmetric chest deformations. MRI is a radiation-free imaging method, and allows for the calculation of pectus indices as well as the assessment of cardiac function. Real-time MRI provides dynamic insights, while exercise MRI shows promise for comprehensive evaluation of cardiac function but requires additional developments. Using echocardiography, structural cardiac changes can be identified, but its use in evaluating cardiac function in pectus excavatum patients is limited. Medical photography combined with caliper measurements complements other imaging methods for qualitative and quantitative documentation of pectus excavatum. Emerging as an innovative technique, 3D optical surface imaging offers a rapid, radiation-free assessment of the deformity which correlates with conventional pectus indices. Potential applications include quantifying other morphological features and predicting cardiac compression. However, standardization and validation are needed for its widespread use. This review provides an overview of preoperative imaging of pectus excavatum, highlighting the current developments in conventional methods and the potential of the emerging 3D optical surface imaging technique. These advancements hold promise for the future of the assessment and surgical planning of pectus excavatum.