Measurement of Pulmonary Circulation Parameters Using Time-Resolved MR Angiography in Patients After Ross Procedure

Abstract

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. 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. 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). 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.