| ObjectiveTo investigate the accuracy and application value of main pulmonary artery (MPA)structures and measurement of hemodynamic, and the feasibility of using the formula toestimate mean pulmonary artery pressure (MPAP) with phase-contrast MRI (PC-MRI) inhealthy adult.MethodsThe diameter, area, peak flow velocity and average flow in a cardiac cycle of MPA weremeasured in20healthy volunteers with3.0T PC-MRI,MPA pulsatility, regurgitant fractionand MPAP were calculated with formula. In48hours,the diameter, peak positive velocity ofMPA were measured in same volunteer with transthoracic echocardiography (TTE), thearea,average flow in a cardiac cycle,MPA pulsatility and MPAP were calculated with formula.And the MPAP estimated with PC-MRI and TTE were compared with the MPAP reported ina systematic review of right heart catheterization, respectively.Results1.Base on measured with3.0T PC-MRI in20healthy volunteers, the maximum mainpulmonary artery diameter (26.70±2.11) mm, minimum main pulmonary artery diameterwas (21.23±3.16) mm, maximum cross-sectional area was (5.14±0.99) cm2,minimumcross-sectional area was (3.55±1.01) cm2, peak positive velocity was(72.59±11.58) cm/s,peak negative velocity (19.69±8.89) cm/s, the average flow was (61.8±13.63) ml/beat,average positive flow was (64.71±14.90) ml/beat, average negative flow was (3.07±2.32)ml/beat.Based on computation results, the MPA pulsatility was (49.08±20.55)%,regurgitant fraction was (4.54±2.98)%and MPAP was (14.08±2.95) mmHg; Base on measured withTTE in same healthy volunteers, the maximum main pulmonary artery diameter was (22.34±1.71) mm, minimum main pulmonary artery diameter was (18.61±1.67) mm, peak positivevelocity was (81.47±8.78) cm/s,.Based on computation results, maximum cross-sectionalarea was (3.94±0.62) cm2, the minimum cross-sectional area was (2.74±0.48) cm2, MPApulsatility was (45.66±19.91)%, average flow was (65.17±13.88) ml/beat, MPAP was(6.70±12.89) mmHg.2. There were significant difference between PC-MRI and TTE in the measurement ofmaximum main pulmonary artery diameter, minimum main pulmonary artery diameter was.maximum cross-sectional area, the minimum cross-sectional area,peak positive velocity,average flow MPA pulsatility (P均＜0.05)，but no significant difference in MPApulsatility(P=0.609)3.There was no significant difference between PC-MRI and the systematic review ofright heart catheterization in the measurement of MPAP from average, males, females,＜30year,30～50year and＞50year(P=0.8602，P=0.7611，P=0.7668，P=0.4460，P=0.5514，P=0.3839，respectively).4. According to a gold standard of average MPAP reported in the systematicreview,MPAP which estimate with PC-MRI in20healthy volunteers were100%in95%CI ofgold standard, and could not see negative; but MPAP which estimate with PC-MRI were only45%in95%CI of gold standard, and could see negative in6volunteers(30%).Conclusions1.The vessel size, elatic and hemodynamic parameters of MPA can be measuredaccurately by PC-MRI, and as normal reference for cardiovascular disease.2.MPAP can be estimate accurately by the formula with PC-MRI,which provides a newway for MPAP estimation with MRI.3.Because of the difference of breathing pattern, there are differences between the measurement of PC-MRI and TTE in the hemodynamic parameters, that may not be suitablefor comparative study.4.The accuracy of MPAP which estimate by PC-MRI in healthy adults significantlyoutperforme that with TTE. Forget the TTE, the PC-MRI could provide a new way ofscreening for PH. |
PDF Full Text Request