Purpose: To assess the role of large b-value diffusion weighted imaging (DWI) in the characterization of the physicochemical properties of the water in brain edema under experimental and clinical conditions. Materials and Methods: Vasogenic brain edema was induced in mice by means of cold injury. A total of 17 patients with extensive peritumoral brain edema were also investigated. The longitudinal relaxation time (T1) and apparent diffusion coefficient (D) were measured in the edematous area both in humans and in mice. D was calculated by using both mono- (Dmono) and biexponential (D fast and Dslow) approaches in the low and overall range of b-values, respectively. The D values were correlated with the T1 values. Results: A strong linear correlation was found between T1 and Dmono in vasogenic brain edema, both in humans and in mice. After breakdown of Dmono into fast and slow diffusing components, only Dfast exhibited a strong correlation with T1; D slow was unchanged in vasogenic brain edema. Conclusion: Large b-value DWI can furnish a detailed characterization of vasogenic brain edema, and may provide a quantitative approach for the differentiation of edema types on the basis of the physicochemical properties of the water molecules. Application of the DWI method may permit prediction and follow-up of the effects of antiedematous therapy.
- Brain edema
- Longitudinal relaxation time
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging