title: Quantification of abdominal aortic aneurysm stiffness using magnetic resonance elastography and its comparison to aneurysm diameter.
abstract: OBJECTIVE
  Abdominal aortic aneurysm (AAA) wall stiffness has been suggested to be an important factor in the overall rupture risk assessment compared with anatomic measure. We hypothesize that AAA diameter will have no correlation to AAA wall stiffness. The aim of this study is to (1) determine magnetic resonance elastography (MRE)-derived aortic wall stiffness in AAA patients and its correlation to AAA diameter; (2) determine the correlation between AAA stiffness and amount of thrombus and calcium; and (3) compare the AAA stiffness measurements against age-matched healthy individuals.
  
  
  METHODS
  In vivo abdominal aortic MRE was performed on 36 individuals (24 patients with AAA measuring 3-10 cm and 12 healthy volunteers), aged 36 to 78 years, after obtaining written informed consent under the approval of the Institutional Review Board. MRE images were processed to obtain spatial stiffness maps of the aorta. AAA diameter, amount of thrombus, and calcium score were reported by experienced interventional radiologists. Spearman correlation, Wilcoxon signed rank test, and Mann-Whitney test were performed to determine the correlation between AAA stiffness and diameter and to determine the significant difference in stiffness measurements between AAA patients and healthy individuals.
  
  
  RESULTS
  No significant correlation (P > .1) was found between AAA stiffness and diameter or amount of thrombus or calcium score. AAA stiffness (mean 13.97 ± 4.2 kPa) is significantly (P ≤ .02) higher than remote normal aorta in AAA (mean 8.87 ± 2.2 kPa) patients and in normal individuals (mean 7.1 ± 1.9 kPa).
  
  
  CONCLUSIONS
  Our results suggest that AAA wall stiffness may provide additional information independent of AAA diameter, which may contribute to our understanding of AAA pathophysiology, biomechanics, and risk for rupture.
authors.affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, The Ohio State University Wexner Medical Center, Columbus, Ohio. Electronic address: arunark.kolipaka@osumc.edu.
authors.forename: Arunark
authors.initials: A
authors.lastname: Kolipaka
authors.affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Venkata Sita Priyanka
authors.initials: VS
authors.lastname: Illapani
authors.affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: William
authors.initials: W
authors.lastname: Kenyhercz
authors.affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Dowell
authors.affiliation: Division of Vascular Diseases and Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Go
authors.affiliation: Division of Vascular Diseases and Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Jean E
authors.initials: JE
authors.lastname: Starr
authors.affiliation: Division of Vascular Diseases and Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Vaccaro
authors.affiliation: Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio.
authors.forename: Richard D
authors.initials: RD
authors.lastname: White
mesh_terms: D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001019:Aortic Rupture / Q000209:etiology; D001027:Aortography / Q000379:methods; D016022:Case-Control Studies; D000072226:Computed Tomography Angiography; D004108:Dilatation, Pathologic; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D018709:Statistics, Nonparametric; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000503:physiopathology; D059289:Vascular Stiffness