MRI Acquisition recommended

MRI protocol completed in less than 5 minutes, non-invasive, with no radiation, and without the use of contrast agents.

Steady-State Free Procession Cine 2D+t Acquisitions

ArtFun+ uses Cine Steady-State Free Procession (SSFP) sequences to perform anatomical measurements for its biomarkers. Specifically, SSFP sequences enable the precise measurement of strain, diameters, and distensibility.

  • Positioning : Acquisition ( >40 phases ) perpendicular to the vessel at the height of the pulmonary artery – localisation of the ascending aorta.
  • Acquisition matrix scale range : 192×192 – 256×256
  • Adjust field of view (FOV) : use small FOV centered on the aorta.
  • Target temporal resolution : ≤30 ms ; ideally <20ms . Adjust the number of views per segment according to heart rate, to be compatible with the individual breathhold capability.
  • Corresponding real phases :Corresponding to ≥ 40 real phases for a typical cardiac cycle (average heart rate)
  • Slice thickness range : 5-8 mm.

Phase-Contrast Cine 2D+t Acquisitions

ArtFun+ uses Phase Contrast (PC) sequences to perform flow measurements for its biomarkers. Specifically, PC sequences enable the measurement of the net flow and the transit time, which are relevant for the calculation of Pulse Wave Velocity and regurgitation biomarkers.

  • Positioning : Acquisition ( >40 phases ) perpendicular to the vessel at the height of the pulmonary artery – localisation of the ascending aorta.
  • Acquisition matrix scale range : 192×192 – 256×256.
  • Adjust field of view (FOV) : use small FOV centered on the aorta.
  • Acquisition matrix scale range : 192×192 – 256×256.
  • Adjust field of view (FOV) : use small FOV centered on the aorta.
  • Target temporal resolution : ≤30 ms ; ideally <20ms Adjust the number of views per segment according to heart rate, to be compatible with the individual breathhold capability.
  • Corresponding real phases : Corresponding to ≥ 40 real phases for a typical cardiac cycle (average heart rate)
  • Slice thickness range : 5-8 mm
  • Encoding velocity : Adjusted to the maximal velocity to avoid aliasing; By default ~150 cm/s.

Thoracic 3D Steady-State Free Procession acquisitions

ArtFun+ uses Thoracic 3D Steady-State Free Procession (SSFP) sequences to perform anatomical measurements for its biomarkers. Specifically, Thoracic 3D SSFP enable the precise measurement of arterial length . which is relevant for the calculation of Pulse Wave Velocity biomarkers.

important additional measurements

Systolic and diastolic Pressures measurments

ArtFun+ uses Systolic and diastolic Pressures to measure the pulse pressure which is relevant for the calculation of distensibility biomarkers

Measure blood pressure ideally at the beginning, during and at the end of the MRI scan and if possible, during the cine sequence.

Blood pressure measurement can be done:

  • By central pressure measurements (preferably in subjects <50years).
  • By brachial cuff measurement of SBP and DBP.

Measure central pressure:

  • Inside the magnet : Aortic pressure waveform (e.g. SphygmoCor® CVMS).
  • Outside the magnet : Carotid tonometry.