perfusion-weighted imaging
MRI technique that measures cerebral blood flow and volume, essential for assessing tissue viability in stroke and tumor evaluation.
Full Definition
Perfusion-weighted imaging (PWI) encompasses MRI techniques that quantify cerebral hemodynamics, including cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). The most common clinical implementation uses dynamic contrast-enhanced imaging with gadolinium-based contrast agents. PWI generates parametric maps that help differentiate salvageable tissue from irreversibly damaged tissue in acute stroke. In oncology, PWI helps distinguish tumor recurrence from radiation necrosis and assess treatment response. The technique can also be performed without contrast using arterial spin labeling methods.
Usage
Usage note: Hyphenate when used as an adjective; PWI is acceptable in technical contexts.
In Context
- "Perfusion-weighted imaging showed a large perfusion-diffusion mismatch indicating salvageable penumbra." — Stroke team consultation
- "The tumor showed increased relative cerebral blood volume on perfusion-weighted imaging, suggesting high-grade pathology." — Neuro-oncology report