Measurement of pulmonary circulation parameters using time-resolved MR angiography in patients after Ross procedure.

OBJECTIVE: The purposes of our study were to retrospectively evaluate the pulmonary circulation parameters of pulmonary transit time and pulmonary blood volume in patients after Ross procedures using time-resolved MR angiography and to investigate associations with right ventricular dysfunction in the same group of patients. MATERIALS AND METHODS: Sixteen patients who had undergone a Ross procedure (12 men, four women; mean age, 42.13 +/- 14.24 years; age range, 21-68 years) and 16 age- and sex-matched control patients (12 men, 4 women; mean age, 42.25 +/- 14.62 years; age range, 21-68 years) were evaluated using cardiac MRI and Argus postprocessing software. Right and left ventricular volumetric parameters, including ejection fraction, end-systolic volume, and end-diastolic volume, were measured from cine true fast imaging with steady-state precession images. Pulmonary circulation parameters, including pulmonary transit time, were measured using dynamic time-resolved MR angiography and pulmonary blood volume was calculated. Pulmonary circulation parameters were correlated with volumetric parameters. The results were statistically analyzed using the Mann-Whitney U test, paired-samples Student's t test, Pearson's correlation, and linear regression. RESULTS: Pulmonary circulation parameters were significantly prolonged in patients after the Ross procedure compared with control patients (p < 0.01). Strong correlations exist between pulmonary circulation parameters and right ventricular function, especially pulmonary transit time and right ventricular ejection fraction (R > 0.60, p < 0.001). CONCLUSION: Patients after undergoing the Ross procedure had prolonged pulmonary transit times compared with normal control patients; this and other pulmonary circulation parameters best correlate with worsened right ventricular ejection fraction and may be predictors of right ventricular dysfunction in this group of patients.