We describe a magnetic resonance (MR) imaging method that emphasizes pressu
re wave velocity to noninvasively assess pulmonary arterial hypertension. B
oth the blood flow and the corresponding vessel cross-sectional area (CSA)
were measured by MR phase mapping in the main pulmonary artery (MPA) in 15
patients. MPA pressures were also measured, in the same patients, by right-
side heart catheterization. Two significant relationships were established:
1) between the pressure wave velocity in the MPA and the mean pressure in
the MPA (Ppa) writing pressure wave velocity = 9.25 Ppa - 202.51 (r = 0.82)
and 2) between the ratio of pressure wave velocity to the systolic blood v
elocity peak in the MPA (R) and the mean pressure in the MPA writing R = 0.
68 Ppa - 4.33 (r = 0.89). Using these relationships, we estimated two press
ure values to frame the actual Ppa value in each patient from the present s
eries with a reasonable reliability percentage (87%).