title: Noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI: correlation with simultaneous invasive pressure recordings.
abstract: BACKGROUND
  Right heart catheterization is the gold standard for assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension. To date, MRI has not been able to produce precise measurements of mean pulmonary arterial pressure (mPAP). The purpose of the study was to create a model for estimating mPAP and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI (PC-MRI) and to correlate the results with simultaneously acquired, invasive catheter-based measurements (simultaneously measured mPAP) and with right heart catheterization measurements.
  
  
  RESULTS
  A total of 19 patients with chronic thromboembolic pulmonary hypertension underwent right heart catheterization and-after digital subtraction angiography of the pulmonary arteries-subsequent PC-MRI at 1.5 T with simultaneous recording of mPAP. Velocity- and flow-time curves of PC-MRI were used to calculate absolute acceleration time (Ata), maximum of mean velocities (MV), volume of acceleration (AV), and maximum flow acceleration (dQ/dt). On the basis of these parameters, multiple linear regression analysis revealed maximum achievable model fit (B=0.902) for the following linear combination equation to calculate mPAP (mPAP_cal): mPAP_cal=69.446-(0.521 × Ata)-(0.570 × MV)+(1.507 × AV)+(0.002 × dQ/dt). There was a statistically significant equivalence of mPAP_cal and simultaneously measured mPAP with a goodness of fit of 0.892. Pulmonary vascular resistance was overestimated by calculated pulmonary vascular resistance on the basis of PC-MRI in comparison with right heart catheterization-based measurements by a median of -112 dyn·s·cm(-5), the pairwise regression formula revealed a goodness of fit of 0.792.
  
  
  CONCLUSIONS
  PC-MRI-derived parameters enable noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Universitätsmedizin der Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Kreitner
authors.forename: Gesine Maria
authors.initials: GM
authors.lastname: Wirth
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Michael Bernhard
authors.initials: MB
authors.lastname: Pitton
authors.forename: Jens
authors.initials: J
authors.lastname: Schneider
authors.forename: Eckhard
authors.initials: E
authors.lastname: Mayer
authors.forename: Christoph
authors.initials: C
authors.lastname: Dueber
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D002908:Chronic Disease; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011652:Pulmonary Circulation; D011655:Pulmonary Embolism / Q000150:complications* / Q000503:physiopathology; D012039:Regional Blood Flow; D013997:Time Factors; D014655:Vascular Resistance; D055815:Young Adult
keywords: chronic disease; hemodynamics; magnetic resonance imaging; pulmonary embolism