Exploring IVIM-DKI and DKI for Assessing Microvascular and Microstructural Changes After Traumatic Brain Injury
Tobias Harritz1,2,3, Brian Hansen4, Baogui Zhang1,5
1State Key Laboratory of Cognitive Science and Mental Health, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
NMR in Biomedicine
|August 2, 2025
Summary
Diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM)-DKI analysis show promise for detecting brain injury markers after traumatic brain injury (TBI). These advanced MRI techniques offer greater sensitivity to microstructural and microvascular changes than standard diffusion tensor imaging (DTI) and IVIM.
Area of Science:
- Neuroimaging
- Biomedical Engineering
- Radiology
Background:
- Traumatic brain injury (TBI) presents a significant public health challenge with a lack of reliable diagnostic markers.
- Microstructural alterations, including axonal and microvascular damage, are hallmarks of TBI.
- Diffusion MRI techniques, such as diffusion tensor imaging (DTI), are sensitive to tissue microstructure, but advanced methods may offer improved detection capabilities.
Purpose of the Study:
- To evaluate the efficacy of Diffusion Kurtosis Imaging (DKI) and combined Intravoxel Incoherent Motion (IVIM)-DKI in detecting microstructural and microvascular changes following TBI.
- To compare the sensitivity of DKI and IVIM-DKI against standard DTI and IVIM models in a mouse model of TBI.
- To investigate longitudinal changes in DKI and IVIM-DKI parameters at multiple time points post-TBI.
Main Methods:
- Controlled cortical impact (CCI) was used to induce TBI in mice.
- Longitudinal diffusion MRI scans were acquired at 3, 10, and 22 days post-injury.
- Parametric maps were generated for DKI (FA, AD, RD, MD, AK, RK, MK) and IVIM-DKI (f, D*, D, K̇), and compared with standard DTI and IVIM metrics.
Main Results:
- DKI revealed widespread increases in diffusivity (MD, AD, RD) by Day 3, followed by focal decreases in FA and AD in white matter and increased perfusion fraction (f) in gray matter by Day 10.
- By Day 22, widespread white matter alterations were observed with decreased FA, AD, MD, MK, AK, and RK.
- Standard DTI showed less extensive changes, and standard IVIM failed to detect significant alterations in f, highlighting the superior sensitivity of DKI and IVIM-DKI.
Conclusions:
- DKI and IVIM-DKI are promising advanced MRI techniques for assessing microstructural and microvascular damage after TBI.
- DKI effectively captures widespread white matter and early gray matter changes, while IVIM-DKI detects intermediate gray matter microvascular alterations.
- These advanced methods provide more comprehensive insights into TBI-related pathology compared to conventional DTI and IVIM.
