perfusion-weighted imaging
Also written as: PWI — Perfusion-Weighted Imaging
MRI technique that measures blood flow and vascular characteristics within brain tissue to assess tumor vascularity.
Full Definition
Perfusion-weighted imaging (PWI) is an advanced MRI technique that evaluates cerebral blood flow, blood volume, and vascular permeability within brain tissue. In neuro-oncology, PWI is particularly valuable for distinguishing between tumor recurrence and treatment-related changes like radiation necrosis, as these conditions have different vascular characteristics. The technique can also help grade tumors, as higher-grade malignancies typically demonstrate increased blood volume and abnormal vascular permeability. PWI parameters such as relative cerebral blood volume (rCBV) and transfer coefficient (Ktrans) provide quantitative measures that support clinical decision-making in tumor surveillance and treatment response assessment.
Usage
Usage note: Can be abbreviated as PWI in clinical contexts. Hyphenate when used as a compound modifier.
In Context
- "Perfusion-weighted imaging showed elevated relative cerebral blood volume in the enhancing lesion." — Radiology report
- "PWI parameters suggested tumor progression rather than pseudoprogression." — Multidisciplinary team meeting