“Is there an alternative to a CT scan?”

There are alternatives to all imaging modalities. Each has positive and negatives for the analysis of various clinical complaints or conditions. Radiologists best practices suggest the best ways to get a diagnosis while limited radiation dosages, if any. MRI and Ultrasound
have no radiation exposure but the information obtained from them are limited to what they do best. If you have a question re: a CT exam ordered for your particular work up, discuss it with the ordering physician regarding possible alternatives and their diagnostic reliability for your particular condition or work up.

Yes. Wait and see is the alternative.