Assessing Tumor Microstructure with Time-Dependent Diffusion Imaging
Author Information
Author(s): Minea Jokivuolle, Faisal Mahmood, Kristoffer Hougaard Madsen, Frederik Severin Gråe Harbo, Lars Johnsen, Henrik Lundell
Primary Institution: Odense University Hospital, University of Southern Denmark, and Copenhagen University Hospital
Hypothesis
The study investigates the feasibility of a simple analysis framework for detecting restricted diffusion and diffusional exchange effects in tumor microstructure using time-dependent diffusion MRI.
Conclusion
The TDD contrast maps showed consistent tumor sub-regions indicating different dominating TDD effects, potentially providing information on spatial tumor heterogeneity.
Supporting Evidence
- Simulations showed that TDD contrast could differentiate between restricted diffusion and diffusional exchange effects.
- Measurements in asparagus indicated dominating restricted diffusion compared to water.
- TDD contrast maps in patients showed consistent regions indicating different TDD effects.
- The study supports the hypothesis that larger tumor cell sizes can help detect TDD effects with moderate gradient strengths.
- Thermal noise levels were estimated to be lower in tumor regions compared to white matter.
- TDD contrast maps could distinguish between vasogenic edema and infiltrative edema.
- Results suggest that diffusional exchange should be considered in tumor microstructure modeling.
- The TDD contrast framework could complement existing imaging techniques for tumor characterization.
Takeaway
This study looks at how to better see the differences in tumors using special MRI techniques that can show how water moves in and out of cells.
Methodology
The study used simulations and experiments on a conventional 1.5 T MRI system and a 1.5 T MRI-Linac system to evaluate time-dependent diffusion effects in tumor microstructure.
Potential Biases
The study may have risks of bias due to the complexity of modeling and potential misregistration of images.
Limitations
The measured TDD contrast was low in patient experiments, and the study had a limited and heterogeneous sample size.
Participant Demographics
The study included 10 patients with brain lesions, aged 36 to 72 years, with a mix of male and female participants.
Digital Object Identifier (DOI)
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