Myocardial perfusion results

I recently had 2 treadmill test and both were normal.  I then had myocardial perfusion scan which showed some blood perfusion deficit in the posterior heart wall. My doc upped by daily aspirin from 81mg to 325 mg. I have a appointment with a cardiologist .  I am curious as to how significant this can be.  I realize this is limited info but any help would be appreciated.

[Cleveland Clinic]

This probably represents a false positive due to an attenuation artifact created by the diaphragm.  Depending on your symptoms, your cardiologist may recommend a catheteriation to be completely certain.