Pulmonary arterial hypertension: noninvasive detection with phase-contrast MR imaging.
OBJECTIVE
To retrospectively identify pulmonary arterial (PA) flow parameters measured with phase-contrast magnetic resonance (MR) imaging that allow noninvasive diagnosis of chronic PA hypertension (PAH).


METHODS
The study was HIPAA compliant and was approved by the institutional review board; a waiver of informed consent was obtained. Fifty-nine patients (49 female patients; mean age, 46 years; range, 16-85 years) known to have or suspected of having PAH underwent breath-hold phase-contrast MR imaging and right-sided heart catheterization (RHC). The presence of PAH (mean pulmonary artery pressure [mPAP], >25 mm Hg) was confirmed in 42 patients. Parameters, including PA areas, PA strain, average velocity, peak velocity, acceleration time, and ejection time, were measured in each patient by investigators blinded to RHC results. These measurements were correlated with mPAP, systolic pulmonary artery pressure (sPAP), and pulmonary vascular resistance index (PVRI). The diagnostic ability of phase-contrast MR imaging to depict PAH was quantified. Statistical tests included Spearman rho coefficients, receiver operating characteristic curve analysis, and Bland-Altman plots.


RESULTS
Results showed average velocity to have the best correlation with mPAP, sPAP, and PVRI (r = -0.73, -0.76, and -0.86, respectively; P < .001). Average velocity (cutoff value = 11.7 cm/sec) revealed PAH with a sensitivity of 92.9% (39 of 42) and a specificity of 82.4% (14 of 17). Sensitivity and specificity for the minimum PA area (cutoff value = 6.6 cm(2)) were 92.9% (39 of 42) and 88.2% (15 of 17), respectively.


CONCLUSIONS
The average blood velocity throughout the cardiac cycle is strongly correlated with pulmonary pressures and resistance.
Sanz
Javier
J
Zena and Michael A. Wiener Cardiovascular Institute, Marie-Josée and Henry R. Kravis Center for Cardiovascular Health, Mount Sinai School of Medicine, New York, NY 10029, USA. Javier.Sanz@mssm.edu
Kuschnir
Paola
P
Rius
Teresa
T
Salguero
Rafael
R
Sulica
Roxana
R
Einstein
Andrew J
AJ
Dellegrottaglie
Santo
S
Fuster
Valentin
V
Rajagopalan
Sanjay
S
Poon
Michael
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000503:physiopathology*; D012372:ROC Curve; D012189:Retrospective Studies; D018709:Statistics, Nonparametric