1.5t achieva scanner

CMR was performed using a 1.5 T Achieva scanner equipped with a five-channel
cardiac phased array receiver coil (Philips Healthcare, Best, The Netherlands).
The CMR protocol included standard steady-state free-precession cine CMR in
short axis with retrospective ECG triggering and acquisition of 25 phases for LV
and RV volumetry and LV mass assessment. Native T1 mapping was performed using a
5s (3s) 3s modified look-locker inversion recovery (MOLLI) sequence three
short-axes slices (apical, mid and basal) before and 15 minutes after contrast
media administration.¹³ For T2 mapping we used a gradient (echo planar imaging) and spin-echo
multi-echo sequence in three short-axis sections corresponding to the MOLLI sections.^{14 (link)} Ten minutes after a bolus injection of 0.2 mmol/kg gadoter acid (Dotarem;
Guerbet, Sulzbach, Germany) at a rate of 2.5 ml/s end-diastolic LGE images were
acquired using end-diastolic phase-sensitive inversion recovery sequences in
short-axis orientation covering the entire heart and in two, three and
four-chamber views. More details on the magnetic resonance imaging sequences,
acquisition parameters and extracellular volume (ECV) calculation are provided
in Supplementary Appendix E1.

CMRI was performed using a 1.5‐T Achieva scanner (Philips Medical Systems) with a five‐channel coil and master gradients (maximum gradient amplitude, 33 mT/m; maximum slew rate, 100 mT/m/ms). Furthermore, CMRI was performed within 14 days from the date of right heart catheterization, during which there were no significant changes in either hemodynamic status or PH treatment. Image acquisition and analysis were performed using a previously described protocol, with high intra‐ and interobserver reproducibilities.¹⁵ Briefly, 12 axial slices were acquired using a steady‐state free‐precession pulse sequence (repetition time, 2.8 ms; echo time, 1.4 ms; flip angle, 60; acquisition matrix, 192 × 256; field of view, 380 ms; slice thickness, 10 mm; 0 mm inter‐slice gap; and 20 phases/cardiac cycle). Images were analyzed using commercially available analysis software (Extended MR Work Space ver. 2.6.3; Philips Medical Systems). In the axial datasets, the endocardial contours of the right ventricle were manually traced, and the RV and left ventricular end‐diastolic volume (EDV) and end‐systolic volume (ESV) were computed. RV and left ventricular stroke volume (SV) and EF were calculated as SV = EDV − ESV and EF = SV/EDV × 100%, respectively.