Thank you for posting your query at DoctorSpring.com
I have noted your symptoms and past imaging studies.
I agree that most of the brain would be seen while doing the scan of sinuses and a large mass or tumor would have been noted.
However, I have two reservations- 1. Whether the technician was qualified/competent enough to notice and report the abnormal brain findings.
2. Small abnormalities, especially those below 5 mm in size, such as small tumor or infarct may get missed on a CT scan.
I hope it helps.
Dr. Sudhir Kumar MD (Medicine), DM (Neurology)
Senior Consultant Neurologist,