Headaches occur in approximately 50 percent of people who have brain tumors, although it's a most common brain tumor symptom.
It's possible for patient to has a negative CT scan, but if there is a strong clinical suspicion of a brain tumor, MRI is always performed.
MR is more sensitive than CT for detecting intracranial masses and determining the anatomic site of tumor and its extension.
CT scan And MRI are very helpful examinations, but the definitive diagnosis of brain tumor can only be confirmed by histological examination of tumor tissue samples obtained either by brain biopsy or open surgery.

What kind of symptoms you are experiencing and since when?

I was told i had a philocytic astrocytoma after a CT scan but when i went for an MRI scan they told me i had been mis diagnosed and there was nothing to worry about! What could it have been that caused the concern in the first place?