Early detection can save life!
People refer for medical advice due to various symptoms, such as headache, dizziness, hearing loss and many other. The physician then sends them for imaging studies. Usually the cause for the symptoms is unclear; the role of imaging is to exclude conditions like cancer, infection or inflammation.
For example- let's take headache. Almost 100% of people suffering from headache will not have a brain tumor, or other serious condition, but sometimes the presenting symptom of a brain tumor is headache. Therefore, imaging studies such as CT or MR scans are performed to rule out brain tumor. If the condition is just at the beginning, it can be missed easily!
Therefore second opinion, with extra pair of eyes and more attention, can help for the early detection of conditions that needs care, and it is better to treat them early as possible. In the present situation of medicine, with shortage of radiologists, every radiologist diagnose more and more CT and MR scans a day, investing less and less time for each scan, extra attention can improve the accuracy of the diagnosis.