Dear Tp136, It is not unusual for a person to be asked to return for a more precise mammogram after a screening mammogram if there are any areas that may be of concern. In general when a mammogram is read it is compared to the results of prior mammograms, which would help in the interpretation as to whether something seen in the current mammogram that had been evaluated and documented previously and is now unchanged. A significant change in weight could make a difference in what is seen in a mammogram.