Improved characterization of lesions using a novel DW-MRI analysis method
Inventors: Simon Warfield
Invention Types: Information Technology/Software, Diagnostic/Prognostic
Research Areas: Gastrointestinal/Nutrition, Musculoskeletal
Keywords: Software, ImagingFor More Information Contact: Yen, Alan
Diffusion-weighted MRI (DW-MRI) is a non-invasive imaging technique that has the potential to provide important new insights into physiological and microstructural properties of the body. DW-MRI is sensitive to the incoherent motion (IM) of water molecules inside an area of interest. Motion of water molecules is known to be a combination of a slow diffusion component associated with the Brownian motion of water molecules, and a fast diffusion component associated with the bulk motion of intravascular molecules, for example, in the micro-capillaries of tissue vasculature. These phenomena may be characterized via a model referred to herein as the intra-voxel incoherent motion (IVIM) model having a slow diffusion decay parameter, a fast diffusion decay parameter and a fractional contribution of the above two motion components of the DW-MRI signal decay.
The technique has been used to image biomarkers in various clinical applications. However, conventional implementations of the IVIM model have substantial drawbacks due to the difficulty in determining reliable estimates of the IVIM model parameters from the DW-MRI signal/data, and suffers from a key limitation in that only part of the information from the magnetic signal is modeled. In particular, reliable estimates of IVIM model parameters are difficult to obtain for a number of factors including the non-linearity of the DW-MRI signal decay; the limited number of DW-MRI images as compared to the number of the IVIM model parameters and the low signal-to-noise ratio (SNR) observed in DW-MRI signals obtained from the body. Therefore, conventional techniques frequently lead to imprecise parameter estimates, which have hampered the practical usage of DW-MRI.
Simon Warfield, PhD, director of the Computational Radiology Laboratory, and his group at Boston Children’s have developed a new model of DW-MRI, known as IM-FBM (incoherent motion fusion bootstrap moves) that addresses the key limitation. This technique models the entire magnetic signal, thus increasing the reliability of the information without the acquisition of more data. The inventors have developed an IM model and techniques for estimating the model parameters that accounts for both intra-voxel and inter-voxel interactions. Additionally, the inventors have developed techniques that facilitate improving the accuracy and precision of estimating model parameters for the IM model.
IM-FBM was used to analyze MRI data from 30 abdominal patients and 3 patients with musculoskeletal lesions. When compared to IVIM, IM-FBM increased the contrast-to-noise ratio significantly.
• Quantitative non-invasive imaging biomarker used in various clinical applications including: analysis of tumors, assessment of liver damage from cirrhosis, and Crohn’s disease.
• DW-MRI data is limited because only part of the information from the magnetic signal is modeled.
• Vastly improves visual quality and precision over DW-MRI images
• Does not increase acquisition times of MRI
• Improves the ability to distinguish lesions and tumors from other tissue using MRI
Freiman M, et al., Reliable estimation of incoherent motion parametric maps from diffusion-weighted MRI using fusion bootstrap moves. Med Image Anal. 2013 Apr;17(3):325-36.
Taimouri V, et al., Spatially constrained incoherent motion method improves diffusion-weighted MRI signal decay analysis in the liver and spleen. Med Phys. 2015 Apr;1895-903.
Kurugol S, et al., Spatially-constrained probability distribution model of incoherent motion (SPIM) for abdominal diffusion-weighted MRI. Med Image Anal. 2016 Aug;32:173-83.