Objective: The purpose of this study was to investigate the effect of the degree of sternal depression on the cardiac rotation of pectus excavatum as depicted with helical CT.
Materials and methods: Sixty-three patients (53 boys, 10 girls; mean age, 9.7 +/- 7 years) with pectus excavatum who underwent helical chest CT and surgical correction were included in this study. Depth of sternal depression, CT depression index, cardiac rotation angle, and pulmonary vein angle were measured, and the correlation of these parameters was analyzed.
Results: The mean sternal depression was 21 +/- 7 mm; CT depression index, 2.7 +/- 1.4; cardiac rotation angle, 55 degrees +/- 9 degrees ; and pulmonary vein angle, 52 degrees +/- 12 degrees . The sternal depression (18 mm) in patients with a CT depression index less than 2.4 was less than that in patients with a CT depression index of 2.4-2.9 (sternal depression, 21 mm) or greater than 2.9 (sternal depression, 28 mm) (p < 0.01). Similarly, the cardiac rotation angle (49 degrees +/- 5 degrees ) in patients with a CT depression index less than 2.4 was smaller than that in patients with a CT depression index of 2.4-2.9 (55 degrees +/- 6 degrees ) or greater than 2.9 (64 degrees +/- 12 degrees ) (p < 0.01). The pulmonary vein angle in patients with a CT depression index less than 2.4 (59 degrees +/- 11 degrees ) was larger than that in patients with a CT depression index of 2.4-2.9 (50 degrees +/- 12 degrees ) or a CT depression index greater than 2.9 (45 degrees +/- 8 degrees ) (p < 0.01). Cardiac rotation angle had a positive correlation with CT depression index (r = 0.75, p < 0.01).
Conclusion: The degree of sternal depression has a positive correlation with the degree of cardiac rotation in pectus excavatum. Helical CT is a valuable technique for evaluating the chest deformity and resultant cardiac rotation.