Would a brain mri w/o contrast & a ct scan with and w/o contrast show a brain tumor causing symptoms? worried that it could have been missed.

MRI: A MRI with contrast is sufficient to detect evidence of a brain tumor. If there is any question as to whether a brain tumor is present or not, one can opt to repeat the MRI of the brain with contrast three months after the last MRI brain was obtained.

A brain MRI: With contrast would provide the highest sensitivity for detection of a brain tumor, but considering the negative noncontrast MRI and negative CT with/without contrast, there is a very low likelihood of a brain tumor, and a MRI with contrast would probably only be necessary if there is a high clinical suspicion.