Introduction
Diffusion MRI provides information about tissue microstructure and water mobility that is useful in stroke tumor and neurodegenerative disease. Diffusion weighted imaging and diffusion tensor imaging are standard clinical tools. Quantitative diffusion metrics support diagnosis and treatment planning.
Acute Stroke
Diffusion imaging identifies ischemic core within minutes of symptom onset and guides reperfusion decisions. Apparent diffusion coefficient maps help distinguish acute from chronic lesions. Perfusion diffusion mismatch assessment supports selection for thrombectomy in extended time windows.
Oncology and White Matter
Diffusion metrics assist in tumor grading treatment response and detection of tumor infiltration beyond contrast enhancement. Diffusion tensor imaging maps white matter tracts for surgical planning and radiation avoidance. Advanced models such as diffusion kurtosis and neurite orientation dispersion provide additional microstructural detail.
Technical Considerations
Susceptibility artifacts and motion can degrade diffusion images especially near air bone interfaces. Protocol harmonization and b value selection affect quantitative comparability across scanners. Quality assurance and standardized postprocessing are essential for reliable clinical use.