The MR imaging features and the analyses of quantitative parameters in cases with surgically repaired tetralogy of Fallot

To present postoperative cardiac magnetic resonance (CMR) imaging features of cases of surgically repaired tetralogy of Fallot (TOF) and to evaluate the relationship among data used in follow-up procedures, such as right ventricular ejection fraction (RV-EF), pulmonary regurgitation fraction (PRF), and the degree of right ventricular (RV) dysfunction. Materials and methods: Fourteen patients (9 males and 5 females; mean age 11.9 ± 3.6 years) with surgically repaired TOF who were admitted to our clinic for follow-up CMR imaging between July 2008 and September 2011 were included in the study. A protocol that consisted of cine steady-state free precession (SSFP) and velocity-encoding phase-contrast and contrast-enhanced MR angiography techniques was performed for every patient with 1.5-T equipment. PRF, RV function, and vascular pathologies were evaluated with phase-contrast velocity-encoding MR technique, cine SSFP sequence, and contrast-enhanced MR angiography, respectively. The relationship among RV-EF, PRF, and the degree of RV dysfunction were evaluated by using chi-square and Mann–Whitney U tests. Results: Various findings such as pulmonary regurgitation, decreased RV-EF, RV enlargement, increased trabeculation of RV wall, deterioration of the RV function, RV outflow tract dilatation, dyskinesia of the interventricular septum, and tricuspid regurgitation were observed. Mean PRF was 41.4 ± 5.4% (range: 29% to 48%), while mean RV-EF was 42.3 ± 9.2% (range: 29.3% to 58.5%). There was no statistically significant relationship between the degree of PRF and the degree of RV dysfunction (P = 0.147, chi-square test, Spearman's rho= -0.158). Conclusion: CMR imaging is an adequate method in follow-up of quantitative measurements of parameters such as PRF and RV dysfunction in addition to morphological features, and in determination of the possible complications in patients with surgically repaired TOF. In these patients, the degree of PRF does not correlate with the degree of RV dysfunction.