Abstract 14048: Diagnostic MRI Criteria for Identification of Intra-Mural Hematoma and Prediction of High Likelihood of Aortic Healing After Type B Acute Aortic Syndromes
Introduction: Type B acute aortic syndromes (AAS) encompasses aortic dissection (AD) and intramural hematoma (IMH), whose diagnostic, evolution and treatment are subject to many controversies among cardio-vascular specialists. The aim of our study was to assess the ability of specific diagnostic MRI criteria to differentiate AD from IMH and predict optimal aortic remodeling following AAS.
Methods: In this retrospective study, we included all patients presenting at our institution between 2008 and 2015 with type B AAS and who had a diagnostic MRI following their admission. Four diagnostic MRI criteria were established to identify IMH, which was hypothesized to predict high likelihood of aortic healing, defined as false lumen (FL)/mural hematoma (MH) shrinking and true lumen expansion over time: - No visualized entry tear - No contrast uptake in the FL/MH on first pass angiographic run - No contrast uptake in the FL/MH on equilibrium phase T1 weighted sequence - Less than 2.5 mm of maximal septal mobility on a cine acquisition. On each patient’s diagnostic MRI and last follow-up imaging study, we computed the volume of: 1) FL/MH, 2) total aorta, and 3) true lumen. Using paired t-test analysis, we compared the evolution of these volumes according to the presence or absence of the afore-mentioned MRI criteria.
Results: Thirty seven patients were included in our study. Seven patients had all MRI criteria positive (IMH group), 30 had one or more negative criteria (AD group). There was no difference between both groups concerning patient gender, age or delay between onset of symptoms, diagnostic and follow up imaging study. 17 patients had a follow up imaging study (MRI or CT) after a mean (±SD) follow up of 14.2 ± 4 months: 6 patients in IMH group and 11 in AD group. FL/MH volume decrease and true lumen volume increase were statistically significant over time in IMH group (p = 0.043 and p = 0.029 respectively) In AD group, follow-up imaging study showed a significant increase of FL/MH volume (p = 0.016), without significant increase of true lumen.
Conclusion: We established 4 diagnostic MRI criteria that aid in identification of IMH and are associated with high likelihood of aortic healing after type B AAS. This may have an impact on therapeutic decisions and imaging follow-up protocols.
Author Disclosures: A. Schwein: None. M. Bennett: None. M.A. Khan: None. F. Nabi: None. D.J. Shah: None. J. Bismuth: None.
- © 2016 by American Heart Association, Inc.