Intra-tumoral hemorrhagic necrosis is one of the characteristic pathological finding of uterine sarcomas. High intensity hemorrhagic foci on T1WI may be suggestive finding, however, the prevalence is not high possibly because only methemoglobin could be detected. Signal voids on SWAN may reflect all phases of hemorrhage, especially both deoxyhemoglobin and hemosiderin and could be useful for the diagnosis. Surgically proven ten sarcomas and 22 benign leiomyomas were retrospectively evaluated. High intensity foci on T1WI were detected in four sarcomas (40%) and in none of leiomyomas, whereas signal voids on SWAN were detected in all sarcomas and in one leiomyoma (5%).