DWI
Also written as: DWI — Diffusion-Weighted Imaging
Diffusion-weighted imaging technique that measures water molecule movement to detect cellular density changes.
Full Definition
Diffusion-weighted imaging (DWI) is an MRI technique that measures the random motion of water molecules within tissues. In oncology, DWI is particularly valuable for detecting areas of restricted diffusion, which often correlate with high cellular density typical of malignant tumors. The technique generates apparent diffusion coefficient (ADC) maps that quantify water mobility. DWI can detect early treatment response before morphologic changes become apparent and helps distinguish viable tumor from necrotic tissue. It is especially useful in brain, liver, and prostate cancer imaging.
Usage
Usage note: Always spell out on first use in patient reports.
In Context
- "DWI sequences revealed restricted diffusion in the left frontal lobe lesion, suggesting high-grade glioma." — MRI brain report
- "Post-treatment DWI showed increased diffusion values, indicating successful tumor necrosis." — Follow-up imaging report