Dark spots on c scans and MRI's = dead brain cells, tumors aneurysms, blocked arteries. a normal brain scan Also shows a dark middle area - a type of hollow shaped sort of like a butterfly. Sometimes when they do various scans they inject radioactive isotopes into the blood stream to detect aneurisms and blockages in the blood stream. Scans are like X rays. They can detect normal size vs abnormal size, shape of the main hollow area in the middle and physical problems like blood flow, Aneurysms, tumors, epilepsy but cannnot test for the various chemicals in the brains synapses such as dopamine, lithium. Only by drawing blood and sending that blood to a lab can the chemicals of the body - lithium, dopamine, potasium, iron, calcium, phosphorus, sodium and so on.

Mental health disorders are detected through a psychiatrist, psychologist giving a Comprehensive Psychological Evaluation. You can find details of what that test includes for the diagnosis of mental disorders in my blog. Tests for Schzophrenia are - in part the MMPI (Minnesota Multiphasic Personality Inventory and tests for Narcessistic, Schizophrenia, Borderline Personality Disorder, Schto-affective, paranoia, depression and a few others that I cant remember at the moment.)and the MCMI (Millon Clinical Multiaxial Inventory), an interview an hour or more in length with a psychiatrist or psychologist, an IQ test called Wechsler Adult Intelligence Scale, TAT, Rorshacks (Spelling wrong but its the ink blots test) Once all these are scored the person has their diagnosis (disorders listed in the DSM) on the Axis I,II, III, IV, and V. Your therapist can explain the procedures for and content of psychological testing in more detail.