ObjectiveTo investigate the changes and clinical significance of cardiac structure and function evaluation by cardiac magnetic resonance imaging (CMR) for patients with pectus excavatum deformity at preoperation. MethodsWe retrospectively analyzed 54 patients (24 children and 30 adults) who underwent pectus excavatum surgery from June 2012 to June 2014. There were 48 males and 6 females at age of 7-33 (19.08±5.17) years. All the patients underwent CMR using 1.5 Tesla scanner for evaluation of compressing and displacement of the heart. The major and minor dimensions of right ventricle were measured. The right ventricle end-diastole volume (RVEDV), right ventricle end-systolic volume (RVESV), and right ventricle ejection fraction (RVEF) were also recorded and analyzed. ResultsThe heart compression and displacement occurred in 83.3% of the children group and 90.0% of the adults group. The extent of heart displacement in the adults was more serious than that in the children (76.86%±13.30% vs. 67.99%±8.15%, P<0.05). The structure of right ventricle were striking distorted because right atrum or right ventricule below valve ring was compressed locally, with the major dimension of right ventricle obviously increased, and the minor dimension of right ventricle obviously decreased. The indices of right ventricle major dimension and right ventricle minor dimension were 61.14±0.44 mm/m2 and 14.82±2.52 mm/m2 in the children, 49.54±15.40 mm/m2 and 18.90 ±3.14 mm/m2 in the adults. The RVEDV and RVESV were significantly higher in the adults than those in the children (139.09±29.08 ml vs. 121.50±31.27 ml; 73.61±16.05 ml vs. 64.92±19.28 ml; P<0.05). RVEF was similar between the children and the adults (45.29%±4.14% vs. 46.30±6.09%). The patients' symptoms disappeared after correction of pectus excavatum. ConclusionCMR is an useful method for evaluating right ventricular structure and functions in patients with cardiac compression and distortion by pectus excavatum before operation, which can bring strong indications for pectus excavatum repair surgery.