The detection rate of DWI hyperintense lesions varies widely in patients with TGA. The aim was to examine the association of hyperintense lesions on DWI MRI with patient characteristics, precipitating factors, clinical presentation, and MRI settings in patients with TGA.

In this observational study, using the standardized diagnosis entry system of electronic health records of four tertiary medical centers, TGA patients total of 261 who underwent brain MRI within 28 days of onset were examined. When the onset time was unavailable, the discovery time was used.

Diffusion‐weighted hyperintense lesions were observed in 79 patients. There were no significant differences in age, sex, vascular risk factors, precipitating factors, or clinical presentation between patients with and without DWI lesions. The detection rate increased linearly 24 h after onset and then reached a plateau by 84 h. After 84 h, the detection rate decreased rapidly. In a multivariate logistic regression model, MRI examination 24–84 h after onset and a thin‐slice DWI sequence were independent predictors of DWI lesions.

This study concluded on the basis of its findings that DWI hyperintense lesions in TGA are not associated with patient characteristics and clinical presentation. Brain MRI examination 24–84 h after onset and thin‐slice DWI sequences enhance the detection of DWI lesions in TGA patients.