title: Pulmonary arterial hypertension: MR imaging-derived first-pass bolus kinetic parameters are biomarkers for pulmonary hemodynamics, cardiac function, and ventricular remodeling.
abstract: OBJECTIVE
  To prospectively compare contrast material-enhanced (CE) magnetic resonance (MR) imaging-derived right-to-left ventricle pulmonary transit time (PTT), left ventricular (LV) full width at half maximum (FWHM), and LV time to peak (TTP) between patients with pulmonary arterial hypertension (PAH) and healthy volunteers and to correlate these measurements with survival markers in patients with PAH.
  
  
  METHODS
  This HIPAA-compliant study received institutional review board approval. Written informed consent was obtained from all participants. Forty-three patients (32 with PAH [29 women; median age, 55.4 years], 11 with scleroderma but not PAH [seven women; median age, 58.9 years]) underwent right-sided heart catheterization and 3-T CE cardiac MR imaging. Eighteen age- and sex-matched healthy control subjects (12 women; median age, 51.7 years) underwent only CE MR imaging. A short-axis saturation-recovery gradient-echo section was acquired in the basal third of both ventricles, and right-to-left-ventricle PTT, LV FWHM, and LV TTP were calculated. Statistical analysis included Kruskal-Wallis test, Wilcoxon rank sum test, Spearman correlation coefficient, multiple linear regression analysis, and Lin correlation coefficient analysis.
  
  
  RESULTS
  Patients had significantly longer PTT (median, 8.2 seconds; 25th-75th percentile, 6.9-9.9 seconds), FWHM (median, 8.2 seconds; 25th-75th percentile, 5.7-11.4 seconds), and TTP (median, 4.8 seconds; 25th-75th percentile, 3.9-6.5 seconds) than did control subjects (median, 6.4 seconds; 25th-75th percentile, 5.7-7.1 seconds; median, 5.2 seconds; 25th-75th percentile, 4.1-6.1 seconds; median, 3.2 seconds; 25th-75th percentile, 2.8-3.8 seconds, respectively; P < .01 for each) and subjects with scleroderma but not PAH (median, 6.5 seconds; 25th-75th percentile, 5.6-7.0 seconds; median, 5.0 seconds; 25th-75th percentile, 4.0-7.3 seconds; median, 3.6 seconds; 25th-75th percentile, 2.7-4.0 seconds, respectively; P < .02 for each). PTT, LV FWHM, and LV TTP correlated with pulmonary vascular resistance index (P < .01), right ventricular stroke volume index (P ≤ .01), and pulmonary artery capacitance (P ≤ .02). In multiple linear regression models, PTT, FWHM, and TTP were associated with mean pulmonary arterial pressure and cardiac index.
  
  
  CONCLUSIONS
  CE MR-derived PTT, LV FWHM, and LV TTP are noninvasive compound markers of pulmonary hemodynamics and cardiac function in patients with PAH. Their predictive value for patient outcome warrants further investigation.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Nelson Basement MRI 110, 600 N Wolfe St, Baltimore, MD 21287, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Skrok
authors.forename: Monda L
authors.initials: ML
authors.lastname: Shehata
authors.forename: Stephen
authors.initials: S
authors.lastname: Mathai
authors.forename: Reda E
authors.initials: RE
authors.lastname: Girgis
authors.forename: Ari
authors.initials: A
authors.lastname: Zaiman
authors.forename: James O
authors.initials: JO
authors.lastname: Mudd
authors.forename: Danielle
authors.initials: D
authors.lastname: Boyce
authors.forename: Noah
authors.initials: N
authors.lastname: Lechtzin
authors.forename: João A C
authors.initials: JA
authors.lastname: Lima
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hassoun
authors.forename: Jens
authors.initials: J
authors.lastname: Vogel-Claussen
mesh_terms: D015415:Biomarkers; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D003287:Contrast Media; D005260:Female; D006334:Heart Function Tests; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000503:physiopathology*; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012595:Scleroderma, Systemic / Q000150:complications; D018709:Statistics, Nonparametric; D020257:Ventricular Remodeling / Q000502:physiology
chemical_list: D015415:Biomarkers; D003287:Contrast Media