Assessing Tumor Mechanics by MR Elastography at Different Strain Levels
Gwenaël Pagé1, Marion Tardieu1, Laurent Besret2
1Laboratory of Imaging Biomarkers, UMR1149, INSERM-University Paris Diderot, Paris, France.
Journal of Magnetic Resonance Imaging : JMRI
|May 16, 2019
Summary
This study demonstrates that malignant tumor stiffness increases under mechanical compression, a change effectively monitored using a novel MR elastography (MRE) setup in vivo. This finding advances the understanding of tumor mechanics and progression.
Area of Science:
- Biophysics
- Medical Imaging
- Oncology
Background:
- Malignant tumors exhibit increased tissue rigidity, indicating potential tumor progression.
- Magnetic Resonance Elastography (MRE) can assess mechanical properties, but in vivo studies are limited.
- Previous ex vivo studies confirmed MRE's ability to detect increased mechanical properties.
Purpose of the Study:
- To develop and validate an in vivo method for assessing tumor mechanical property changes under static external compression using MRE.
- To investigate the relationship between tumor stiffness and deformation in response to applied loads.
Main Methods:
- A prospective experimental study was conducted on 46 SCID mice with subcutaneous hepatocellular carcinoma xenografts.
- A 7.0T MRI scanner with a modified spin echo sequence for MRE (600 Hz vibration) was used.
- External abdominal compression was applied via an inflatable balloon, with MRE acquired at varying load levels.
Main Results:
- The proposed MRE method demonstrated good repeatability for assessing tumor stiffness (G*).
- A significant positive correlation was found between tumor stiffness and deformation across both tumor models (Model 1: r=0.57, P<0.0001; Model 2: r=0.31, P<0.0001).
Conclusions:
- Tumor mechanical properties demonstrably increase under external mechanical compression.
- The developed MRE setup is effective for monitoring these in vivo changes in tumor stiffness.
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