title: Quantification of regional aortic stiffness using MR elastography: A phantom and ex-vivo porcine aorta study.
abstract: MR Elastography (MRE) is a noninvasive technique for measuring tissue stiffness that has been used to assess the average stiffness of the abdominal aorta. The utility of aortic MRE would be improved if it could provide information about local variations in aortic stiffness. We hypothesize that regional variations in aortic stiffness can also be measured with MRE and the purpose of this work was to demonstrate that MRE can measure regional stiffness variations in a vascular phantom and in ex vivo porcine aortas. A vascular phantom was fabricated, containing two silicone tubes embedded in gel. A segment of one of the tubes was modified to increase its stiffness. MRE was performed on the phantom with a continuous flow of water through the tubes. The stiffness distribution along the modified tube was measured and compared to the reference tube. MRE was also performed in porcine aortas embedded in gel with segments treated with saline or formalin for 4 days. The stiffness difference between saline- and formalin-treated aortic segments was measured by MRE and mechanical tests. A positive correlation was found between the regional stiffnesses measured by MRE and mechanical tests. The results indicate that MRE can be used to evaluate the local stiffness distribution in silicone tubes and ex vivo porcine aortas. It may therefore be possible to apply MRE to measure regional stiffness variations of the aorta in vivo.
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester 55905, MN, USA; Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Chaoyang District Anzhen Road 2nd, Beijing 100029, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester 55905, MN, USA. Electronic address: Chen.Jun@mayo.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester 55905, MN, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Yin
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester 55905, MN, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.affiliation: Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Chaoyang District Anzhen Road 2nd, Beijing 100029, China. Electronic address: leixu2001@hotmail.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester 55905, MN, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
mesh_terms: D000465:Algorithms; D000818:Animals; D001011:Aorta / Q000033:anatomy & histology* / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology*; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D008297:Male; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013552:Swine
keywords: Aorta; MR elastography; Regional arterial stiffness; Stiffness