RESEARCH Open Access Altered aortic 3D hemodynamics and geometry in pediatric Marfan syndrome patients Roel L. F. van der Palen 1,2* , Alex J. Barker 1 , Emilie Bollache 1 , Julio Garcia 1,3 , Michael J. Rose 4 , Pim van Ooij 1,5 , Luciana T. Young 7 , Arno A. W. Roest 2 , Michael Markl 1,6 , Joshua D. Robinson 1,7,8 and Cynthia K. Rigsby 1,4,8 Abstract Background: Blood flow dynamics make it possible to better understand the development of aortopathy and cardiovascular events in patients with Marfan syndrome (MFS). Aortic 3D blood flow characteristics were investigated in relation to aortic geometry in children and adolescents with MFS. Methods: Twenty-five MFS patients (age 15.6 ± 4.0 years; 11 females) and 21 healthy controls (age 16.0 ± 2.6 years; 12 females) underwent magnetic resonance angiography and 4D flow CMR for assessment of thoracic aortic size and 3D blood flow velocities. Data analysis included calculation of aortic diameter and BSA-indexed aortic dimensions (Z-score) along the thoracic aorta, 3D mean systolic wall shear stress (WSS mean ) in ten aortic segments and assessment of aortic blood flow patterns. Results: Aortic root (root), ascending (AAo) and descending (DAo) aortic size was significantly larger in MFS patients than healthy controls (Root Z-score: 3.56 ± 1.45 vs 0.49 ± 0.78, p < 0.001; AAo Z-score 0.21 ± 0.95 vs -0.54 ± 0.64, p = 0. 004; proximal DAo Z-score 2.02 ± 1.60 vs 0.56 ± 0.66, p < 0.001). A regional variation in prevalence and severity of flow patterns (vortex and helix flow patterns) was observed, with the aortic root and the proximal DAo (pDAo) being more frequently affected in MFS. MFS patients had significantly reduced WSS mean in the proximal AAo (pAAo) outer segment (0.65 ± 0.12 vs. 0.73 ± 0.14 Pa, p = 0.029) and pDAo inner segment (0.74 ± 0.17 vs. 0.87 ± 0.21 Pa, p = 0.021), as well as higher WSS mean in the inner segment of the distal AAo (0.94 ± 0.14 vs. 0.84 ± 0.15 Pa, p = 0.036) compared to healthy subjects. An inverse relationship existed between pDAo WSS mean and both pDAo diameter (R = -0.53, p < 0.001) and % diameter change along the pDAo segment (R = -0.64, p < 0.001). Conclusions: MFS children and young adults have altered aortic flow patterns and differences in aortic WSS that were most pronounced in the pAAo and pDAo, segments where aortic dissection or rupture often originate. The presence of vortex flow patterns and abnormal WSS correlated with regional size of the pDAo and are potentially valuable additional markers of disease severity. Keywords: Marfan syndrome, Aorta hemodynamics, Aortic geometry, 4D flow, Children * Correspondence: r.vanderpalen@lumc.nl 1 Department of Radiology, Feinberg School of Medicine, Northwestern University , Chicago, IL, USA 2 Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Albinusdreef 2, 2333, ZA, Leiden, The Netherlands Full list of author information is available at the end of the article © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. van der Palen et al. Journal of Cardiovascular Magnetic Resonance (2017) 19:30 DOI 10.1186/s12968-017-0345-7