The relationship of T2 hypointensity and diffusion restriction of brain metastases with the presence and amount of vasogenic edema in MRI.

Aim: Brain metastases are seen in 15-40% of patients diagnosed with cancer. We aimed to search the relationship between the T2 hypointensity, diffusion-weighted imaging characteristics, and the presence and amount of vasogenic edema of brain metastasis in magnetic resonance imaging (MRI).

Methods: A total of 292 patients with brain metastasis were included in the study. T2 signals of metastatic lesions, accompanying diffusion restriction and perilesional vasogenic edema findings, were investigated. In metastases accompanied by vasogenic edema, the largest dimension of the vasogenic edema-mass complex on T2-weighted sequences and the largest dimension of the mass in contrast-enhanced T1-weighted series were measured and the edema-mass ratio (EMR) was calculated by comparing these two values.

Results: The frequency of vasogenic edema was statistically significantly higher in T2 hypointense metastases (89.1% vs 58.8%, χ2 = 18.949, p = <.001) and metastases accompanied by diffusion restriction(81% vs 61.5%, χ2 = 6.971, = .008). EMR values were found to be statistically significantly higher in T2 hypointense metastases (EMR→ Z = -4.507, = <.001) and metastases with diffusion restriction(EMR→ Z = -3.819, = .001).

Conclusions: The frequency of vasogenic edema and EMR rates were higher in patients in T2 hypointense metastases and metastases accompanied by diffusion restriction in MRI.