What does a head CT scan and neck xray rule out?

Basically what are doctors able to see and what are they looking for when trying to diagnose using these imaging machines on particular areas (Head and Neck). I came in to the ER with neck pain and dizziness and I'm still suffering from it because they were not able to make a clear diagnosis. Do these imaging tests show major problems like meningitis, or blood vessel abnormalities?

[Dr Santos]

Hi,
How are you? Do you still experience the symptoms you mentioned? Neck pain may be caused by a variety if issues such as musculoskeletal  or infectious causes. Imaging studies help determine whether anatomical issues such as blood vessel abnormalities, skeletal abnormalities  or organic causes are present.  Many conditions are diagnosed with such imaging studies. However, in some cases, additional tests may be done to correlate the imaging results and symptoms such as blood tests and spinal tap, in the case of meningitis. Take care and do keep us posted.