Calculation of shear stiffness in noise dominated magnetic resonance elastography data based on principal frequency estimation

Kiaran Patrick McGee, D. Lake, Y. Mariappan, R. D. Hubmayr, Armando Manduca, K. Ansell, Richard Lorne Ehman

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Magnetic resonance elastography (MRE) is a non-invasive phase-contrast-based method for quantifying the shear stiffness of biological tissues. Synchronous application of a shear wave source and motion encoding gradient waveforms within the MRE pulse sequence enable visualization of the propagating shear wave throughout the medium under investigation. Encoded shear wave-induced displacements are then processed to calculate the local shear stiffness of each voxel. An important consideration in local shear stiffness estimates is that the algorithms employed typically calculate shear stiffness using relatively high signal-to-noise ratio (SNR) MRE images and have difficulties at an extremely low SNR. A new method of estimating shear stiffness based on the principal spatial frequency of the shear wave displacement map is presented. Finite element simulations were performed to assess the relative insensitivity of this approach to decreases in SNR. Additionally, ex vivo experiments were conducted on normal rat lungs to assess the robustness of this approach in low SNR biological tissue. Simulation and experimental results indicate that calculation of shear stiffness by the principal frequency method is less sensitive to extremely low SNR than previously reported MRE inversion methods but at the expense of loss of spatial information within the region of interest from which the principal frequency estimate is derived.

Original languageEnglish (US)
Pages (from-to)4291-4309
Number of pages19
JournalPhysics in Medicine and Biology
Volume56
Issue number14
DOIs
StatePublished - Jul 21 2011

Fingerprint

Elasticity Imaging Techniques
Signal-To-Noise Ratio
Noise
Lung

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Calculation of shear stiffness in noise dominated magnetic resonance elastography data based on principal frequency estimation. / McGee, Kiaran Patrick; Lake, D.; Mariappan, Y.; Hubmayr, R. D.; Manduca, Armando; Ansell, K.; Ehman, Richard Lorne.

In: Physics in Medicine and Biology, Vol. 56, No. 14, 21.07.2011, p. 4291-4309.

Research output: Contribution to journalArticle

@article{66dfbd4970944304a875a4cf6cb9b50b,
title = "Calculation of shear stiffness in noise dominated magnetic resonance elastography data based on principal frequency estimation",
abstract = "Magnetic resonance elastography (MRE) is a non-invasive phase-contrast-based method for quantifying the shear stiffness of biological tissues. Synchronous application of a shear wave source and motion encoding gradient waveforms within the MRE pulse sequence enable visualization of the propagating shear wave throughout the medium under investigation. Encoded shear wave-induced displacements are then processed to calculate the local shear stiffness of each voxel. An important consideration in local shear stiffness estimates is that the algorithms employed typically calculate shear stiffness using relatively high signal-to-noise ratio (SNR) MRE images and have difficulties at an extremely low SNR. A new method of estimating shear stiffness based on the principal spatial frequency of the shear wave displacement map is presented. Finite element simulations were performed to assess the relative insensitivity of this approach to decreases in SNR. Additionally, ex vivo experiments were conducted on normal rat lungs to assess the robustness of this approach in low SNR biological tissue. Simulation and experimental results indicate that calculation of shear stiffness by the principal frequency method is less sensitive to extremely low SNR than previously reported MRE inversion methods but at the expense of loss of spatial information within the region of interest from which the principal frequency estimate is derived.",
author = "McGee, {Kiaran Patrick} and D. Lake and Y. Mariappan and Hubmayr, {R. D.} and Armando Manduca and K. Ansell and Ehman, {Richard Lorne}",
year = "2011",
month = "7",
day = "21",
doi = "10.1088/0031-9155/56/14/006",
language = "English (US)",
volume = "56",
pages = "4291--4309",
journal = "Physics in Medicine and Biology",
issn = "0031-9155",
publisher = "IOP Publishing Ltd.",
number = "14",

}

TY - JOUR

T1 - Calculation of shear stiffness in noise dominated magnetic resonance elastography data based on principal frequency estimation

AU - McGee, Kiaran Patrick

AU - Lake, D.

AU - Mariappan, Y.

AU - Hubmayr, R. D.

AU - Manduca, Armando

AU - Ansell, K.

AU - Ehman, Richard Lorne

PY - 2011/7/21

Y1 - 2011/7/21

N2 - Magnetic resonance elastography (MRE) is a non-invasive phase-contrast-based method for quantifying the shear stiffness of biological tissues. Synchronous application of a shear wave source and motion encoding gradient waveforms within the MRE pulse sequence enable visualization of the propagating shear wave throughout the medium under investigation. Encoded shear wave-induced displacements are then processed to calculate the local shear stiffness of each voxel. An important consideration in local shear stiffness estimates is that the algorithms employed typically calculate shear stiffness using relatively high signal-to-noise ratio (SNR) MRE images and have difficulties at an extremely low SNR. A new method of estimating shear stiffness based on the principal spatial frequency of the shear wave displacement map is presented. Finite element simulations were performed to assess the relative insensitivity of this approach to decreases in SNR. Additionally, ex vivo experiments were conducted on normal rat lungs to assess the robustness of this approach in low SNR biological tissue. Simulation and experimental results indicate that calculation of shear stiffness by the principal frequency method is less sensitive to extremely low SNR than previously reported MRE inversion methods but at the expense of loss of spatial information within the region of interest from which the principal frequency estimate is derived.

AB - Magnetic resonance elastography (MRE) is a non-invasive phase-contrast-based method for quantifying the shear stiffness of biological tissues. Synchronous application of a shear wave source and motion encoding gradient waveforms within the MRE pulse sequence enable visualization of the propagating shear wave throughout the medium under investigation. Encoded shear wave-induced displacements are then processed to calculate the local shear stiffness of each voxel. An important consideration in local shear stiffness estimates is that the algorithms employed typically calculate shear stiffness using relatively high signal-to-noise ratio (SNR) MRE images and have difficulties at an extremely low SNR. A new method of estimating shear stiffness based on the principal spatial frequency of the shear wave displacement map is presented. Finite element simulations were performed to assess the relative insensitivity of this approach to decreases in SNR. Additionally, ex vivo experiments were conducted on normal rat lungs to assess the robustness of this approach in low SNR biological tissue. Simulation and experimental results indicate that calculation of shear stiffness by the principal frequency method is less sensitive to extremely low SNR than previously reported MRE inversion methods but at the expense of loss of spatial information within the region of interest from which the principal frequency estimate is derived.

UR - http://www.scopus.com/inward/record.url?scp=79960366559&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79960366559&partnerID=8YFLogxK

U2 - 10.1088/0031-9155/56/14/006

DO - 10.1088/0031-9155/56/14/006

M3 - Article

VL - 56

SP - 4291

EP - 4309

JO - Physics in Medicine and Biology

JF - Physics in Medicine and Biology

SN - 0031-9155

IS - 14

ER -