You can only code what is documented in the radiologist's report, so if they only documented a limited breast US, that is all the work they did and that is all they should be reimbursed for. It sounds like there needs to be a discussion between the ordering physician and the radiologist because the ordering physician obviously had a reason for requesting the complete breast US but for unknown reasons that is not was the radiologist documented as having been performed.
You cannot code a procedure as having been performed based on the order because what is ordered and what is ultimately done are often not the same services. For all we know the patient may've had a reason to stop the breast US and all the radiologist was left with to report on was the limited procedure and they did what they could based on the information available to them.