Feasibility of performing non-contrast magnetic resonance angiography in pregnant subjects with familial aortopathies.

BACKGROUND: Pregnancy is associated with an increased risk of aortic pathology. We sought to assess the feasibility of performing non-contrast 3D steady-state free-precession (SSFP) magnetic resonance angiography (MRA) in pregnant subjects with inherited aortopathy.

METHODS: Fifteen pregnant subjects (age 27±4yr) with positive genotyping for aortopathy (Marfan, Loeys-Dietz, Ehlers-Danlos) and/or a family history of aortic dissection underwent non-contrast 3D-SSFP MRA at 1.5T (Avanto, Siemens Healthcare, Erlangen, Germany) using a modified ECG-triggered orientated in a sagittal-oblique plane with a respiratory navigator at the diaphragmatic level (mean acquisition time 4.1±1.9min). Imaging was performed during the mid-trimester (21±5weeks). Image analysis was performed off-line using Cvi42 software (Circle Cardiovascular Imaging, Calgary, Canada). An assessment of image quality (score 0-3) was made before performing inner edge to inner edge measurements of the thoracic aorta at 7 levels from the multiplanar reconstructions by two independent blinded observers.

RESULTS: Non-contrast 3D-MRA was successfully acquired in all 15 subjects. Image quality was deemed excellent in 87% (13/15) of cases after a mean acquisition time of 4.1±1.9min. There was a high level of agreement for aortic measurements, with low intra- and inter-observer variability (ICC ranges; 0.95-0.99 and 0.92-0.98, respectively). All pregnancies reached term (≥37/40) with a mean gestation at delivery of 38.0±0.5weeks. The mode of delivery was vaginal in 9 out of 15 subjects (60%).

CONCLUSIONS: Non-contrast SSFP MRA imaging provides a quick and reproducible method of assessing the thoracic aorta in pregnancy.