title: Noninvasive prediction of pulmonary artery pressure and vascular resistance by using cardiac magnetic resonance indices.
abstract: BACKGROUND
  Cardiac magnetic resonance (CMR) has promise of being able to provide frequent cardiac morphology and function evaluations noninvasively for repeated follow-ups of pulmonary arterial hypertension (PAH) patients after the initial right heart catheterization (RHC) diagnosis. By using the noninvasive CMR indices, the present study aimed to formulate and validate a prediction model of mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR).
  
  
  METHODS
  Both Derivation Cohort (N=25) and Validation Cohort (N=25) of PAH patients underwent CMR and RHC within one week. Fast cine and phase-contrast sequences were used to calculate CMR indices, including ventricular mass index (VMI), interventricular septum curvature ratio (CR), and positive pulmonary arterial flow (QP). The gold standard mPAP (mPAPRHC) and PVR (PVRRHC) were measured from RHC. mPAP was calculated using CMR indices (mPAPCMR) from the Derivation Cohort. Multiple linear regression was applied for analysis.
  
  
  RESULTS
  The equation predicting mPAP was mPAPCMR=28.837VMI-26.479CR-0.201QP+57.021. The equation was then applied to the Validation Cohort to verify the accuracy of the prediction equation. mPAPCMRwas correlated linearly with mPAPRHCas mPAPRHC=0.8055mPAPCMR+7.9056 (r2=0.6470, p<0.001). Moreover, PVR calculated from CMR (PVRCMR) was also correlated with the PVRRHCin both the Derivation Cohort (r2=0.4092, p<0.001) and the Validation Cohort (r2=0.3480, p<0.001).
  
  
  CONCLUSIONS
  The application of the mPAPCMRand PVRCMRtechnique could potentially provide a noninvasive method to evaluate the hemodynamics for PAH patients during follow-ups as well as right ventricle function assessment.
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Zhenwen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China.
authors.forename: Tielian
authors.initials: T
authors.lastname: Yu
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052, China. Electronic address: znnn2010@sina.com.
authors.forename: Ningnannan
authors.initials: N
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014655:Vascular Resistance / Q000502:physiology*
keywords: Magnetic resonance imaging; Pulmonary arterial hypertension; Pulmonary artery pressure; Pulmonary vascular resistance