You could ask your doctor about it, although you should expect an answer something along the lines of comparing your symptoms isn't how diagnoses are made and can be harmful if you begin self-diagnosing. You can approach your doctor by saying you're curious whether you have it after you reviewed the symptoms listed in the DSM-IV-TR or ICD-10. If you didn't review it from these 2 sources OR your source didn't cite these, then ignore them. There aren't any specific tests for schizophrenia. Your doctor may order some MRI scans because over time it does change neuroanatomy and other neurodegenerative and neurological syndromes can resemble schizophrenic symptoms, so it's a way to rule out any TBI and monitor progress but not so much for diagnosing.