DWI
Diffusion-Weighted Imaging — MR sequence sensitive to the random Brownian motion of water molecules. Areas of restricted diffusion (acute stroke, abscess, hypercellular tumor) appear bright on DWI and dark on the corresponding ADC (apparent diffusion coefficient) map. Detects acute stroke within minutes of onset — DWI is the load-bearing sequence in the ED neuro workflow.
Why it matters to buyers: Stroke-protocol core. DWI + FLAIR + susceptibility-weighted imaging (SWI / SWAN) is the ED neuro essentials package. Every modern brain MRI protocol includes DWI; advanced applications (DTI, IVIM, neuro tractography) build on the same physics.
Why it matters to engineers: Requires high gradient performance — both peak amplitude and slew rate. Underperforming gradient amplifiers (GPAs) produce distorted DWI with B0-inhomogeneity artifacts and reduced quantitative accuracy. Gradient cooling is the most common service event affecting DWI quality; flow alarms = stop scanning.