Hi i have been having a headache that hurts so bad its been disabling went to the er twice and the 2nd time they did a ct scan of head which showed sinusitis rest was normal the hospital said that the insurance would not approve a mri because its so expensive and said i would have to go to the dr. or a neurologist and get a order for a mri this was thursday i called my doctors office the next morning and they said that since i just had the ct scan of head that there is no use in following up right now but im in severe pain and dunno what to do i do have a bad tooth on left side bottom of my mouth very last tooth not sure what is causing my severe head pain? could the ct scan have missed something? thanks