Quantitative effects of off‐resonance related distortion on brain mechanical property estimation with magnetic resonance elastography

2021 ◽  
Author(s):  
Grace McIlvain ◽  
Matthew D. J. McGarry ◽  
Curtis L. Johnson
Keyword(s):  
Mechanical Property ◽  
Magnetic Resonance ◽  
Magnetic Resonance Elastography ◽  
Property Estimation

scholarly journals Lorentz force induced shear waves for magnetic resonance elastography applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillaume Flé ◽  
Guillaume Gilbert ◽  
Pol Grasland-Mongrain ◽  
Guy Cloutier
Keyword(s):  
Magnetic Resonance ◽  
Shear Wave ◽  
Lorentz Force ◽  
Wave Attenuation ◽  
Shear Waves ◽  
Estimation Method ◽  
Biological Tissues ◽  
Magnetic Resonance Elastography ◽  
Motion Generation ◽  
Wave Source

AbstractQuantitative mechanical properties of biological tissues can be mapped using the shear wave elastography technique. This technology has demonstrated a great potential in various organs but shows a limit due to wave attenuation in biological tissues. An option to overcome the inherent loss in shear wave magnitude along the propagation pathway may be to stimulate tissues closer to regions of interest using alternative motion generation techniques. The present study investigated the feasibility of generating shear waves by applying a Lorentz force directly to tissue mimicking samples for magnetic resonance elastography applications. This was done by combining an electrical current with the strong magnetic field of a clinical MRI scanner. The Local Frequency Estimation method was used to assess the real value of the shear modulus of tested phantoms from Lorentz force induced motion. Finite elements modeling of reported experiments showed a consistent behavior but featured wavelengths larger than measured ones. Results suggest the feasibility of a magnetic resonance elastography technique based on the Lorentz force to produce an shear wave source.

Stiffness change of the supraspinatus muscle can be detected by magnetic resonance elastography

2021 ◽  
Author(s):  
Akihisa Koga ◽  
Yoshiaki Itoigawa ◽  
Mikio Suga ◽  
Daichi Morikawa ◽  
Hirohisa Uehara ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Elastography ◽  
Supraspinatus Muscle

scholarly journals NI-01 Usefulness of preoperative evaluation of glioma elasticity by the magnetic resonance elastography

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii12-ii13
Author(s):  
Shinichiro Koizumi ◽  
Kazuhiko Kurozumi
Keyword(s):  
Elastic Modulus ◽  
Magnetic Resonance ◽  
Preoperative Evaluation ◽  
Tumor Resection ◽  
High Grade Glioma ◽  
Magnetic Resonance Elastography ◽  
Low Grade ◽  
Intracranial Tumors ◽  
Grade 3 ◽  
Malignant Grade

Abstract Introduction: The elasticity of intracranial tumors is difficult to assess non-invasively because the lesion is surrounded by the skull. Therefore, intracranial tumors have not been verified before surgery in terms of elastic modulus. Magnetic resonance elastography (MRE) is an epoch-making method capable of non-invasively imaging the elasticity of internal organs. We have examined the elasticity of meningiomas and pituitary adenomas and reported their usefulness. This time, we measured the glioma elasticity and verified usefulness of MRE. Method: Twenty-four gliomas (mean age 51.8±15.7 years, male: female = 17: 7) who underwent tumor resection after MRE imaging from July 2017 to May 2020 were targeted. The average elasticity was measured as an evaluation of tumor elastic modulus by MRE. Gliomas were divided into a low-grade glioma group (LGG: Grade 1, 2) and a high-grade glioma group (HGG: Grade 3, 4). Then, a comparative statistical study was conducted. Results: The average values of the average elasticity of LGG group (9 cases) and HGG group (15 cases) were 1.8±0.8 kPa and 2.5±0.8 kPa, respectively. The average elasticity was significantly higher in the HGG group (p=0.023). In the ROC analysis, the cutoff value was 2.1 kPa (sensitivity 70%, specificity 70%). Therefore, it was suggested that the tumor is likely to be HGG when the average elasticity is 2.1 kPa or more. Discussion: The glioma elasticity by preoperative MRE was significantly higher in the HGG group. Based on actual surgical experience, the tumor seems to be hard in the HGG group, and it was judged to be consistent with this our MRE research. The preoperative evaluation of glioma elasticity by MRE was considered useful, and it might help in planning a surgical strategy considering malignant grade.

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