请问：关于mammogram report 上写的 : your breast tissue is dense

去年的报告上没有写这一条，是不是有什么不同了？报告上写着dense breast tissue is common and not abnormal. However, dense tissue can make it harder to evaluate the results of your mammogram and may also be associated with an increased risk of breast cancer. 需要再做MRI 或者ultrasound 吗？收到今天的报告前，医生办公室上周给我打过电话跟我说一切正常。不知道为什么这么说？谢谢大家答疑！