Tv ultrasound showed 6cm solid adnexal mass but ct did not show it? only ct findings - fluid and/or endometrial thickening in uterus. any explination?

Possible resolution: if there was a few days or more between tests, it is possible that whatever lesion that was seen on ultrasound resolved on its own. Ultrasound uterus and ovaries is sometimes a challenge based on intestinal issues and potentially what was seen on ultrasound could have been shadows of bowel. If you continue to have symptoms, repeat imaging in 4-6 weeks could be considered.