The value of detection of flow voids between the uterus and the leiomyoma with MRI

Flow voids are occasionally seen between the uterus and the leiomyoma, This study was performed to determine the prevalence of this sign and its relat ion to tumor size and location, internal signal intensity of the leiomyomas , and the ease of detectability using different MR sequences, Also, to unde rstand the pathologic causes for the phenomenon of now voids. The MR images of the pelvis in 92 females with 359 uterine leiomyomas were analyzed. Mow voids located between the uterus and the leiomyomas were seen in 32 lesion s on T1-weighted images and in 12 on T2-weighted images. Flow void was seen exclusively in leiomyomas of 3-cm diameter or larger. In five pedunculated subserous leiomyomas, now voids were seen within the pedicle of the tumor. Large leiomyomas and leiomyomas with irregular signal intensity on T2-weig hted images showed significantly greater frequency of signal void than othe r leiomyomas (P <.01). The sign was not seen in any other pelvic tumors. On pathologic evaluation, the now voids were found to correspond to dilated f eeding arteries located outside the capsule of the leiomyoma.