MRI phase contrast flow velocity imaging of main pulmonary artery.

To assess the pulmonary arterial flow parameters using phase contrast magnetic resonance imaging. To correlate the size of the main pulmonary artery as measured using spiral computerised tomography with the flow parameters as measured using phase contrast MRI and also with ECHO parameters. MATERIALS & METHODS: Studies were performed with a 1.5-T clinical magnet Magnetom symphony; Siemens Medical Solutions. Prospective study , study size - 50 subjects. After informed written consent, all subjects who had pulmonary artery size more than 2.9cm underwent phase contrast flow velocity imaging which includes in plane and through plane imaging. Mean VENC value for main pulmonary artery is kept between 75-100 cm/sec. Patients ECHO findings reviewed. Normal subjects with pulmonary artery size less 2.9cm also included in the study. RESULTS: 37 subjects who had pulmonary artery (PA) size more than 2.9cm had pulmonary artery average velocity less than 11.7cm/sec and minimum pulmonary artery area more than 10.5 cm2 , measured using phase contrast flow velocity imaging. Degree of correlation ( 86.5%) is higher between pulmonary artery(PA) size & Pulmonary artery average velocity and also between PA minimum area & PA average velocity (89.5%). CONCLUSION: The pulmonary artery size criteria for pulmonary hypertension is well correlated with PA average velocity and PA average area . MRI Phase contrast imaging is a novel non invasive imaging modality that can be used in the diagnosis of Pulmonary arterial hypertension by means of measuring flow parameters