First, a review of the role of "diagnosis" and diagnostic tests in the basic medical process (or skip to specific details).
Over the centuries, the practice of health care and medicine has evolved into a complex system. On a basic level, if a person is sick or ill, he or she wants to become well again. At this point, people seek the help of their doctor or other certified healthcare professional.
The first step in fixing any health problem is to determine what is wrong with the person (patient) who is sick. This is called diagnosing the medical condition or illness and allows the doctor to recommend or carry out the needed healing process or course of therapy. Accurate diagnosis of disease is one of the most important aspects of medicine. Without knowing the identity of a disorder, a doctor can only relieve symptoms such as pain or fever. It was in the fifth century BC, that the Greek physician Hippocrates (c.460-377) attempted to identify and describe the course of a particular disease along with the symptoms. Prior to that, medicine consisted of a collection of various remedies for certain symptoms and injuries.
The concept of diagnosis and prognosis (an estimate of the outcome of a certain disease) led physicians to identify diseases from the medical history, which includes the patient's account of the illness. The patient history remains a fundamental element in diagnosis.
If you have a bad cold and a headache, the doctor may take your temperature and determine that you have a fever. This is one step in determining or diagnosing, for instance, that you have the flu. At this point the doctor can give you medicine to reduce your fever and help you to recover from the flu.
- your doctor observed your basic symptoms (running nose) and ran a simple diagnostic test (took your temperature to determine you had a fever)
- made a diagnosis (you have a case of the flu)
- recommended a course of therapy ("please take this medical prescription and get lots of extra rest for the next week").
During that next week, you would either get better, remain the same or possibly get sicker. If you got better, you might not see the doctor again until perhaps the next winter when you caught another flu bug. But, if you stayed sick or got sicker, you would go back to the doctor for more testing and perhaps he would make a different diagnosis. For instance, the doctor may determine that you did not get the extra rest you needed and this is why you have not recovered from the flu. Or perhaps the doctor may determine that you did not have the flu, but through running an additional diagnostic test (for example, a blood test) that you had mononucleosis. At that point he would recommend a new course of therapy ("please take this different prescription") based on the new diagnosis ("you have mononucleosis").
Diagnostic Imaging is simply another diagnostic tool like taking your pulse, measuring your blood pressure or having a blood test. But diagnostic imaging can be more powerful than these simpler tests as it may provide more information to the doctor on his or her path to diagnosing your medical problem.
Diagnostic imaging was first performed in 1895 after the discovery of the x-ray by Professor Wilhelm Conrad Roentgen at the University of Wurzburg in Germany. Over the last century it has grown to be a very powerful tool in assisting doctors and medical professionals in correctly diagnosing patient illness and recommending and completing the necessary therapy so the patient can regain good health. More on the history of medical diagnosis and diagnostic imaging
