Detecting Regional Stiffness Changes in Aortic Aneurysmal Geometries Using Pressure-Normalized Strain

Doran S Mix; Ling Yang; Camille C Johnson; Nathan Couper; Ben Zarras; Isaac Arabadjis; Lauren E Trakimas; Michael C Stoner; Steven W Day; Michael S Richards

doi:10.1016/j.ultrasmedbio.2017.06.002

Detecting Regional Stiffness Changes in Aortic Aneurysmal Geometries Using Pressure-Normalized Strain

Ultrasound Med Biol. 2017 Oct;43(10):2372-2394. doi: 10.1016/j.ultrasmedbio.2017.06.002. Epub 2017 Jul 17.

Authors

Affiliations

¹ Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA; Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA. Electronic address: [email protected].
² Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
³ Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA.
⁴ Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA; Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
⁵ Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA.
⁶ Division of Vascular Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA; Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, New York, USA.

Abstract

Transabdominal ultrasound elasticity imaging could improve the assessment of rupture risk for abdominal aortic aneurysms by providing information on the mechanical properties and stress or strain states of vessel walls. We implemented a non-rigid image registration method to visualize the pressure-normalized strain within vascular tissues and adapted it to measure total strain over an entire cardiac cycle. We validated the algorithm's performance with both simulated ultrasound images with known principal strains and anatomically accurate heterogeneous polyvinyl alcohol cryogel vessel phantoms. Patient images of abdominal aortic aneurysm were also used to illustrate the clinical feasibility of our imaging algorithm and the potential value of pressure-normalized strain as a clinical metric. Our results indicated that pressure-normalized strain could be used to identify spatial variations in vessel tissue stiffness. The results of this investigation were sufficiently encouraging to warrant a clinical study measuring abdominal aortic pressure-normalized strain in a patient population with aneurysmal disease.

Keywords: 3-D printing; Aneurysm; Elasticity imaging; Elastography; Registration; Strain; Tissue-mimicking phantoms; Ultrasound.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Algorithms
Aorta, Abdominal / diagnostic imaging
Aortic Aneurysm, Abdominal / diagnostic imaging*
Aortic Aneurysm, Abdominal / physiopathology*
Elasticity Imaging Techniques / methods*
Feasibility Studies
Phantoms, Imaging*
Risk Assessment
Risk Factors
Vascular Stiffness / physiology*

Abstract

Publication types

MeSH terms

Grants and funding