Protocol
  1. Anatomy / LV function module (A)
  2. Phase contrast velocity encoded module (F)
  3. Sagittal oblique aorta SSFP cines (candy cane view) (B)
  4. Aortic valve cine stack (B)
  5. LGE module (E), if relevant (arteritis)
Report
  1. Dimensions: aortic root
    • Annulus, Sinuses of Valsalva, ST junction
  2. Dimensions: asc/desc Ao
    • Asc Ao at level of PA
    • Aortic arch, usually btw. left carotid and subclavian a.
    • Desc Ao at level of PA and diaphragm
  3. Aorta position (left or right) and tortuosity
  4. Atherosclerosis, aneurysm, dissection, inflammation
  5. Aortic flow
  6. Associated aortic valvular stenosis or regurgitation
Key Points
  1. Method of choice for non-acute aortic diseases
  2. Standardize protocol:
    • Measure in end-diastole from cine imaging, if possible
    • Use same slice thickness (<7mm)
    • Aortic root (from 2 orthogonal LVOT cines or AV stack)
    • Asc / desc Ao (from sagittal oblique aorta cines or alternatively from MRA, if necessary)
Tips and Tricks
  1. Always perform arterial and venous MRA
  2. Be aware of following caveats:
    • LVOT / oblique views are not planed through the centre of the aorta
    • MRA is usually ungated and averages pulsating aortic dimensions (i.e. not end-diastole)
    • Different “windowing” of MRA
    • Angled view of aorta, if taken from transaxial stack
    • Inclusion of aortic wall, if taken from BB images
Aortic diameters
1. Aortic annulus, 2. Sinuses of Valsalva, 3. Sinotubular junction, 4. Mid ascending aorta (level of the pulmonary arteries), 5. Proximal aortic arch (at the origin of the brachiocephalic trunk), 6. Mid aortic arch (btw. left common carotid and subclavian arteries), 7. Proximal descending thoracic aorta, 8. Mid descending aorta (level of the pulmonary arteries), 9. At diaphragm, 10. At the celiac axis origin, 11. Immediately proximal to aortic bifurcation.
Caveats of aortic measurements
    Transaxial
    Overestimation due to non-orthogonal plane
    Oblique sagittal
    Underestimation due to non-central or non- perpendicular plane
    Black Blood
    Overestimation possible due to inclusion of aortic wall
    MRA
    Over- / underestimation due to:
    • Lower spatial resolution
    • Motion artefacts, particular at aortic root /ascAo
    • Non-ECG triggering
    3D whole heart
    Over- / underestimation due to:
    • Lower spatial resolution
    • Motion artefacts
References
  1. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases. ESC Clinical Practice Guidelines 2014