Keywords:
Cardiac, MR, Comparative studies, Hypertension
Authors:
E. A. Mershina, E. Pershina, V. Sinitsyn, T. Martyniuk; Moscow/RU
Methods and Materials
14 PAH (f/m-9/5,
mean age 47,6 years ±12) underwent both CMR and right-sided heart catheterization.
CMR was performed at 1.5T system (AVANTO,
Siemens) using velocity-encoded MR sequences (PC CMR) and SSFP-cine.
PC CMR was acquired during continuous breathing with velocity encoding perpendicular to the imaging plane and a velocity sensitivity of 120 cm/sec ( Fig. 2,
Fig. 3 ).
Slice orientation was orthogonal to the main PA,
slice thickness - 6 mm.
Aortic flow measurement was performed for calculation the ratio between pulmonary and systemic flow,
imaging plane was 2–4 cm above the aortic valve and distal to the coronary arterial ostia.
CMR-derived SV was measured by PA flow,
left (LV) and right (RV) ventricular volumes.
CMR post-processing was performed using the CVI42 software (Fig. 4)
No aliasing due to high peak systolic velocities was encountered.
The contours of the PA were automatically traced with manual correction when necessary,
simultaneously on magnitude and velocity-map images of all reconstructed phases.
This was done for every temporal phase,
resulting in blood flow as a function of time through the PA.
We measured RV and LV volumes.
The endocardial contours of the ventricles were manually traced on short-axis images in end-diastole
(Fig. 5).
Papillary muscles were excluded from manual tracing of the endocardial contours of RV and LV.
The ventricular areas were then measured and ventricular volumes (EDV and ESV) were calculated by adding the ventricular areas and multiplying by the slice distance.
EDV and ESV were used to calculate LV and RV volumes-derived SV.
These SV values were compared to the SV obtained by invasive Fick method.